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  <TITLE>S-8</TITLE>
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   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>As filed with the Securities and Exchange Commission on August&nbsp;21, 2024 </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="right"><B>Registration No.&nbsp;333-&#8195;&#8195;&#8195; </B></P> <P STYLE="font-size:4pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>
  <P STYLE="margin-top:4pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>UNITED STATES </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>SECURITIES
  AND EXCHANGE COMMISSION </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Washington, D.C. 20549 </B></P>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>FORM <FONT STYLE="white-space:nowrap">S-8</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>REGISTRATION STATEMENT </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B><I>UNDER </I></B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B><I>THE
  SECURITIES ACT OF 1933 </I></B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:24pt; font-family:Times New Roman" ALIGN="center"><B>Tectonic Therapeutic, Inc. </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(Exact name of registrant as specified in its charter) </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
  <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">
  
  
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  <TD VALIGN="top" ALIGN="center"><B>Delaware</B></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"><B><FONT STYLE="white-space:nowrap">83-0710585</FONT></B></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(State or other jurisdiction of</B></P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>incorporation or organization)</B></P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(I.R.S. Employer</B></P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Identification No.)</B></P></TD></TR>
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  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
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  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>490 Arsenal Way</B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Suite 210</B></P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Watertown,
  MA</B></P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center"><B>02472</B></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="top" ALIGN="center"><B>(Address of Principal Executive Offices)</B></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"><B>(Zip Code)</B></TD></TR>
  </TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>2019 Equity Incentive Plan </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>2024 Equity Incentive Plan </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>2024 Employee Stock Purchase Plan </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Full titles of the plans) </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Daniel Lochner </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Chief
  Financial Officer </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>490 Arsenal Way </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Suite 210 </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Watertown, MA
  02472 </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(339) <FONT STYLE="white-space:nowrap">666-3320</FONT> </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Name, address, including zip code, and telephone number, including area code, of agent for service) </B></P>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Copies to: </I></B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Marc
  A. Recht </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Courtney T. Thorne </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Katherine Denby </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Cooley
  LLP </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>500 Boylston Street, 14<SUP STYLE="font-size:75%; vertical-align:top">th</SUP> Floor </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Boston, MA 02116 </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(617) <FONT
  STYLE="white-space:nowrap">937-2300</FONT> </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
  <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Indicate by
  check mark whether the registrant is a large accelerated filer, an accelerated filer, a <FONT STYLE="white-space:nowrap">non-accelerated</FONT> filer, a smaller reporting company or an emerging growth company. See the definitions of &#147;large
  accelerated filer,&#148; &#147;accelerated filer,&#148; &#147;smaller reporting company,&#148; and &#147;emerging growth company&#148; in Rule <FONT STYLE="white-space:nowrap">12b-2</FONT> of the Exchange Act. </P>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">
  
  
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  <TD VALIGN="bottom">Large&nbsp;accelerated&nbsp;filer</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9744;</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom">Accelerated&nbsp;Filer</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9744;</TD></TR>
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  <TD VALIGN="bottom">Non-accelerated filer</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9746;</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom">Smaller&nbsp;reporting&nbsp;company</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9746;</TD></TR>
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  <TD VALIGN="bottom">&nbsp;</TD>
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  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom">Emerging&nbsp;growth&nbsp;company</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9744;</TD></TR>
  </TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended
  transition period for complying with any new or revised financial accounting standards provided pursuant to Section&nbsp;7(a)(2)(B) of the Securities Act.&#8194;&#9744; </P> <P STYLE="font-size:10pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>
  </DIV></Center>
  
  
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   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>EXPLANATORY NOTE </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">On June&nbsp;20, 2024 (the &#147;Closing Date&#148;), Tectonic Therapeutic, Inc., a Delaware corporation (previously named AVROBIO, Inc. and
  our predecessor company (&#147;AVROBIO&#148;)), consummated the previously announced merger (the &#147;Merger&#148;) pursuant to the terms of the Agreement and Plan of Merger and Reorganization, dated as of January&nbsp;30, 2024 (the &#147;Merger
  Agreement&#148;), by and among AVROBIO, Alpine Merger Subsidiary, Inc., a Delaware corporation and direct wholly owned subsidiary of AVROBIO (&#147;Merger Sub&#148;), and Tectonic Operating Company, Inc., a Delaware corporation (previously named
  Tectonic Therapeutic, Inc. (&#147;Legacy Tectonic&#148;)). </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">In accordance with the Merger Agreement, on the Closing Date, each outstanding
  stock option to purchase shares of Legacy Tectonic common stock (each a &#147;Legacy Tectonic Option&#148;) originally granted under the Legacy Tectonic 2019 Equity Incentive Plan (the &#147;2019 Plan&#148;) was assumed by the Registrant and was
  converted into, and became, a stock option to purchase shares of common stock of the Registrant and the Registrant assumed the 2019 Plan. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The Registrant is filing this Registration Statement on Form <FONT STYLE="white-space:nowrap">S-8</FONT> for the purpose of registering: (i)
  696,907 shares of common stock under the 2019 Plan; (ii) 1,938,799 shares of common stock under the Registrant&#146;s 2024 Equity Incentive Plan; and (iii) 147,343 shares of common stock under the Registrant&#146;s 2024 Employee Stock Purchase Plan.
  </P>
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   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>PART I </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>ITEM&#8201;1.</B></TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>PLAN INFORMATION. </B></P></TD></TR></TABLE>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Not required to be filed with this Registration Statement. </P> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>ITEM&#8201;2.</B></TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION. </B></P></TD></TR></TABLE>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Not required to be filed with this Registration Statement. </P>
  <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>PART II </B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>INFORMATION
  REQUIRED IN THE REGISTRATION STATEMENT </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>ITEM&#8201;3.</B></TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>INCORPORATION OF DOCUMENTS BY REFERENCE. </B></P></TD></TR></TABLE>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The Registrant hereby incorporates by reference into this Registration Statement the following documents previously filed by the Registrant
  with the Securities and Exchange Commission (&#147;SEC&#148;): </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(a) Annual Report on <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000095017024031635/avro-20231231.htm">Form
   <FONT STYLE="white-space:nowrap">10-K</FONT></A> for the year ended December&nbsp;31, 2023, filed with the SEC on March&nbsp;14, 2024; </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(b) Quarterly Reports on Form <FONT STYLE="white-space:nowrap">10-Q</FONT> for the periods ended March&nbsp;31, 2024 and June&nbsp;30, 2024,
  filed with the SEC on <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000095017024057091/avro-20240331.htm">May&nbsp;
  9, 2024</A> and <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000119312524200609/d878693d10q.htm">August&nbsp;14, 2024</A>, respectively; </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(c) Current Reports on Form <FONT STYLE="white-space:nowrap">8-K,</FONT> which were filed with the SEC on <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/0001681087/000119312524018812/d221662d8k.htm">January&nbsp;30,
   2024</A>, <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000119312524153749/d825208d8k.htm">June&nbsp;
  4, 2024</A>, <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000119312524159168/d849908d8k.htm">June&nbsp;
  11, 2024</A>, <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000119312524161663/d844856d8k.htm">June&nbsp;
  14, 2024</A>, <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000119312524163207/d834577d8ka.htm">June&nbsp;
  18, 2024</A>, <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000119312524164480/d852858d8k.htm">June&nbsp;
  20, 2024</A>, <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000119312524168273/d822923d8k.htm">June&nbsp;
  26, 2024</A>, <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000119312524175599/d859790d8k.htm">July&nbsp;
  5, 2024</A> and <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1681087/000119312524188881/d783068d8k.htm">July&nbsp;30, 2024</A> (except that, with respect to the foregoing Current Reports, any portions thereof
  which are furnished and not filed shall not be deemed incorporated by reference); and </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(d) the description of the Registrant&#146;s common
  stock in the Registrant&#146;s registration statement on <A HREF="http://www.sec.gov/Archives/edgar/data/1681087/000119312518195637/d562006d8a12b.htm">Form <FONT STYLE="white-space:nowrap">8-A</FONT></A> filed with the SEC on June&nbsp;11, 2018,
  including any amendments or reports filed for the purpose of updating such description, including as <A HREF="http://www.sec.gov/Archives/edgar/data/1681087/000156459020011144/avro-ex43_591.htm">Exhibit 4.3</A> to the Registrant&#146;s Annual Report
  on Form <FONT STYLE="white-space:nowrap">10-K</FONT> for the fiscal year ended December&nbsp;31, 2019. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">All documents, reports and
  definitive proxy or information statements filed pursuant to Section&nbsp;13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended (the &#147;Exchange Act&#148;), other than current reports furnished under Item 2.02 or Item 7.01
  of <FONT STYLE="white-space:nowrap">Form&nbsp;8-K&nbsp;and</FONT> exhibits furnished on such form that relate to such items, after the date of this Registration Statement and prior to the filing of a post-effective amendment which indicates that all
  securities offered hereby have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference into this Registration Statement and to be a part hereof from the date of filing of such documents;
  provided, however, that documents, reports and definitive proxy or information statements, or portions thereof, which are furnished and not filed in accordance with the rules of the SEC shall not be deemed incorporated by reference into this
  Registration Statement. Any statement contained in a document incorporated or deemed to be incorporated herein by reference shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement
  herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein modifies or supersedes that statement. Any such statement so modified or superseded shall not constitute a part of this Registration
  Statement, except as so modified or superseded. </P> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>ITEM&#8201;4.</B></TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>DESCRIPTION OF SECURITIES. </B></P></TD></TR></TABLE>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Not applicable. </P>
   <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">1 </P>
  
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
  
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>ITEM&#8201;5.</B></TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>INTERESTS OF NAMED EXPERTS AND COUNSEL. </B></P></TD></TR></TABLE>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Not applicable. </P> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>ITEM&#8201;6.</B></TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>INDEMNIFICATION OF DIRECTORS AND OFFICERS. </B></P></TD></TR></TABLE>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Section&nbsp;145 of the Delaware General Corporation Law (the &#147;DGCL&#148;) authorizes a corporation to indemnify its directors and
  officers against liabilities arising out of actions, suits and proceedings to which they are made or threatened to be made a party by reason of the fact that they have served or are currently serving as a director or officer to a corporation. The
  indemnity may cover expenses (including attorneys&#146; fees) judgments, fines and amounts paid in settlement actually and reasonably incurred by the director or officer in connection with any such action, suit or proceeding. Section&nbsp;145
  permits corporations to pay expenses (including attorneys&#146; fees) incurred by directors and officers in advance of the final disposition of such action, suit or proceeding. In addition, Section&nbsp;145 provides that a corporation has the power
  to purchase and maintain insurance on behalf of its directors and officers against any liability asserted against them and incurred by them in their capacity as a director or officer, or arising out of their status as such, whether or not the
  corporation would have the power to indemnify the director or officer against such liability under Section&nbsp;145. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Section&nbsp;102(b)(7) of the DGCL provides that a corporation&#146;s certificate of incorporation may contain a provision eliminating or
  limiting the personal liability of a director or officer to the corporation or its stockholders for monetary damages for breach of fiduciary duty, provided that such provision shall not eliminate or limit the liability (i)&nbsp;for any breach of the
  duty of loyalty to the corporation or its stockholders, (ii)&nbsp;for acts or omissions not in good faith or that involve intentional misconduct or a knowing violation of law, (iii)&nbsp;under Section&nbsp;174 of the DGCL, or (iv)&nbsp;for any
  transaction from which an improper personal benefit was derived. Our Amended and Restated Bylaws (the &#147;Bylaws&#148;) provide that we will indemnify each person who was or is a party or threatened to be made a party to any threatened, pending or
  completed action, suit or proceeding (other than an action by or in the right of us) by reason of the fact that he or she is or was, or has agreed to become, a director or officer, or is or was serving, or has agreed to serve, at our request as a
  director, officer, partner, employee or trustee of, or in a similar capacity with, another corporation, partnership, joint venture, trust or other enterprise (all such persons being referred to as an &#147;Indemnitee&#148;), or by reason of any
  action alleged to have been taken or omitted in such capacity, against all expenses (including attorneys&#146; fees), judgments, fines and amounts paid in settlement actually and reasonably incurred in connection with such action, suit or proceeding
  and any appeal therefrom, if such Indemnitee acted in good faith and in a manner he or she reasonably believed to be in, or not opposed to, our best interests, and, with respect to any criminal action or proceeding, he or she had no reasonable cause
  to believe his or her conduct was unlawful. The Bylaws provide that we will indemnify any Indemnitee who was or is a party to an action or suit by or in the right of us to procure a judgment in our favor by reason of the fact that the Indemnitee is
  or was, or has agreed to become, a director or officer, or is or was serving, or has agreed to serve, at our request as a director, officer, partner, employee or trustee of, or in a similar capacity with, another corporation, partnership, joint
  venture, trust or other enterprise, or by reason of any action alleged to have been taken or omitted in such capacity, against all expenses (including attorneys&#146; fees) and, to the extent permitted by law, amounts paid in settlement actually and
  reasonably incurred in connection with such action, suit or proceeding, and any appeal therefrom, if the Indemnitee acted in good faith and in a manner he or she reasonably believed to be in, or not opposed to, our best interests, except that no
  indemnification shall be made with respect to any claim, issue or matter as to which such person shall have been adjudged to be liable to us, unless a court determines that, despite such adjudication but in view of all of the circumstances, he or
  she is entitled to indemnification of such expenses. Notwithstanding the foregoing, to the extent that any Indemnitee has been successful, on the merits or otherwise, he or she will be indemnified by us against all expenses (including
  attorneys&#146; fees) actually and reasonably incurred in connection therewith. Expenses must be advanced to an Indemnitee under certain circumstances. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">We have entered into indemnification agreements with each of our directors and officers. These indemnification agreements may require us,
  among other things, to indemnify our directors and officers for some expenses, including attorneys&#146; fees, judgments, fines and settlement amounts incurred by a director or officer in any action or proceeding arising out of his or her service as
  one of our directors or officers, or any of our subsidiaries or any other company or enterprise to which the person provides services at our request. </P>
   <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">2 </P>
  
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">We also maintain general liability insurance that covers certain liabilities of our
  directors and officers arising out of claims based on acts or omissions in their capacities as directors or officers, including liabilities under the Securities Act. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Under the Merger Agreement, from the effective time of the Merger through the sixth anniversary of the date of the effective time, we agreed
  to indemnify and hold harmless each person who was, as of January&nbsp;30, 2024, the signing date of the Merger Agreement, or had been at any time prior, or who becomes prior to the effective time of the Merger, a director or officer of our company
  or Legacy Tectonic, against all claims, losses, liabilities, damages, judgments, fines and reasonable fees, costs and expenses, including attorneys&#146; fees and disbursements, pertaining to claims arising out of the fact that such person was a
  director or officer of our company or Legacy Tectonic, at or prior to the effective time of the merger, to the fullest extent permitted under the DGCL. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Under the Merger Agreement, we agreed not to amend, modify or repeal provisions in the Fourth Amended and Restated Certificate of
  Incorporation and the Bylaws that were in effect as of January&nbsp;30, 2024, the date of the Merger Agreement, with respect to indemnification, advancement of expenses and exculpation of our present and former directors and officers for a period of
  six years from the effective time of the Merger in a manner that would adversely affect the rights of such individuals who at the effective time of the Merger were our officers or directors. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">In connection with the Merger, we purchased an insurance policy in effect for six years from the effective time of the Merger, providing no
  less favorable coverage as the current directors&#146; and officers&#146; liability insurance policies maintained by us with respect to any actual or alleged error, misstatement, misleading statement, act, omission, neglect, breach of duty or any
  matter claimed against our current and former officers and directors. </P> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>ITEM&#8201;7.</B></TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>EXEMPTION FROM REGISTRATION CLAIMED. </B></P></TD></TR></TABLE>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Not applicable. </P> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>ITEM&#8201;8.</B></TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>EXHIBITS. </B></P></TD></TR></TABLE> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">
  
  
  <TR>
  
  <TD></TD>
  
  <TD VALIGN="bottom" WIDTH="4%"></TD>
  <TD WIDTH="92%"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>Exhibit</B><br><B>Number</B></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Description</B></P></TD></TR>
  
  
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;&#8199;4.1</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1681087/000119312524200609/d878693dex31.htm">Fourth Amended and Restated Certificate of Incorporation, as amended through June<U></U>&nbsp;
  20, 2024 (incorporated by reference to Exhibit 3.1 to the Registrant&#146;s Quarterly Report on Form <FONT STYLE="white-space:nowrap">10-Q</FONT> (File No.<U></U><FONT STYLE="white-space:nowrap">&nbsp;
  001-38537),</FONT> filed with the SEC on August<U></U>&nbsp;14, 2024).</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;&#8199;4.2</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1681087/000119312518202460/d153924dex32.htm">Amended and Restated Bylaws (incorporated by reference to Exhibit 3.2 to the Registrant&#146;s Current Report on Form <FONT
  STYLE="white-space:nowrap">8-K</FONT> (File No.<U></U><FONT STYLE="white-space:nowrap">&nbsp;001-38537),</FONT> filed with the SEC on June<U></U>&nbsp;25, 2018).</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;&#8199;5.1</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d820499dex51.htm">Opinion of Cooley LLP. </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;23.1</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d820499dex231.htm">Consent of Deloitte&nbsp;&amp; Touche LLP, independent registered public accounting firm of Tectonic Therapeutic, Inc. </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;23.2</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d820499dex51.htm">Consent of Cooley LLP. Reference is made to Exhibit 5.1. </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;24.1</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d820499ds8.htm#sig">Power of Attorney. Reference is made to the signature page hereto. </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;99.1</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1681087/000119312524034461/d770053dex1042.htm">Tectonic Therapeutic, Inc. 2019 Equity Incentive Plan and forms of award agreements thereunder (incorporated by reference to Exhibit 10.42 to
   the Registrant&#146;s Registration Statement on Form <FONT STYLE="white-space:nowrap">S-4,</FONT> filed with the SEC on February<U></U>&nbsp;14, 2024).</A></TD></TR></TABLE>
   <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">3 </P>
  
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
  
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">
  
  
  <TR>
  
  <TD></TD>
  
  <TD VALIGN="bottom" WIDTH="4%"></TD>
  <TD WIDTH="92%"></TD></TR>
  
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>Exhibit</B><br><B>Number</B></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Description</B></P></TD></TR>
  
  
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;99.2</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1681087/000119312524164480/d852858dex106.htm">Tectonic Therapeutic, Inc. 2024 Equity Incentive Plan (incorporated by reference to Exhibit 10.6 to the Registrant&#146;s Current Report on Form
   <FONT STYLE="white-space:nowrap">8-K</FONT> (File No.<U></U><FONT STYLE="white-space:nowrap">&nbsp;001-38537),</FONT> filed with the SEC on June<U></U>&nbsp;20, 2024).</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;99.3</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1681087/000119312524164480/d852858dex107.htm">Forms of Option Grant Notice, Option Agreement and Notice of Exercise under Tectonic Therapeutic, Inc. 2024 Equity Incentive Plan (incorporated
   by reference to Exhibit 10.7 to the Registrant&#146;s Current Report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File No.<U></U><FONT STYLE="white-space:nowrap">&nbsp;001-38537),</FONT> filed with the SEC on June<U></U>&nbsp;20,
  2024).</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>&#8199;99.4</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1681087/000119312524164480/d852858dex108.htm">Tectonic Therapeutic, Inc. 2024 Employee Stock Purchase Plan (incorporated by reference to Exhibit 10.8 to the Registrant&#146;s Current Report
   on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File No.<U></U><FONT STYLE="white-space:nowrap">&nbsp;001-38537),</FONT> filed with the SEC on June<U></U>&nbsp;20, 2024).</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>107</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d820499dexfilingfees.htm">Filing Fee Table. </A></TD></TR>
  </TABLE> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>ITEM&#8201;9.</B></TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>UNDERTAKINGS. </B></P></TD></TR></TABLE>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(a) The undersigned Registrant hereby undertakes: </P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:9%; font-size:10pt; font-family:Times New Roman">(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement: </P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:13%; font-size:10pt; font-family:Times New Roman">(i) To include any prospectus required by Section&nbsp;10(a)(3) of the Securities Act of 1933, as amended (the &#147;Securities Act&#148;);
  </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:13%; font-size:10pt; font-family:Times New Roman">(ii) To reflect in the prospectus any facts or events arising after the effective date of the Registration Statement (or the most recent
  post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the Registration Statement. Notwithstanding the foregoing, any increase or decrease in volume of securities
  offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC
  pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the &#147;Calculation of Registration Fee&#148; table in the effective
  Registration Statement; </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:13%; font-size:10pt; font-family:Times New Roman">(iii) To include any material information with respect to the plan of distribution not previously disclosed in
  the Registration Statement or any material change to such information in the Registration Statement; </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><I>Provided, however,</I> that paragraphs (a)(1)(i)
  and (a)(1)(ii) do not apply if the Registration Statement is on Form <FONT STYLE="white-space:nowrap">S-8,</FONT> and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or
  furnished to the SEC by the Registrant pursuant to Section&nbsp;13 or Section&nbsp;15(d) of the Exchange Act that are incorporated by reference in the Registration Statement; and </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:9%; font-size:10pt; font-family:Times New Roman">(2) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a
  new registration statement relating to the securities offered herein, and the offering of such securities at that time shall be deemed to be the initial<I> bona fide</I> offering thereof. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:9%; font-size:10pt; font-family:Times New Roman">(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the
  termination of the offering. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(b) The undersigned Registrant hereby undertakes that, for purposes of determining any liability under the
  Securities Act, each filing of the Registrant&#146;s annual report pursuant to Section&nbsp;13(a) or Section&nbsp;15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan&#146;s annual report pursuant to
  Section&nbsp;15(d) of the Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new registration statement relating to the securities offered herein, and the offering of such securities at that time
  shall be deemed to be the initial<I> bona fide</I> offering thereof. </P>
   <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">4 </P>
  
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(c) Insofar as indemnification for liabilities arising under the Securities Act may be
  permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed
  in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the
  Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the
  matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final
  adjudication of such issue. </P>
   <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">5 </P>
  
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  
  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><A NAME="sig"></A>SIGNATURES </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe
  that it meets all of the requirements for filing on Form <FONT STYLE="white-space:nowrap">S-8</FONT> and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Watertown,
  Commonwealth of Massachusetts, on August&nbsp;21, 2024. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><DIV ALIGN="right">
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt">
  
  
  <TR>
  
  <TD WIDTH="5%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="94%"></TD></TR>
  
  
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" COLSPAN="3"><B>TECTONIC THERAPEUTIC, INC.</B></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top">By</TD>
  <TD VALIGN="bottom" STYLE=" BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
  <TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><I>/s/ Alise Reicin</I></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top">Alise Reicin</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom"></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">President and Chief Executive Officer</TD></TR>
  </TABLE></DIV> <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>POWER OF ATTORNEY </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Alise Reicin and Daniel Lochner,
  and each of them, as true and lawful <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">attorneys-in-fact</FONT></FONT> and agents, with full powers of substitution and resubstitution, for them and in their name, place and stead, in
  any and all capacities, to sign any and all amendments (including post-effective amendments) to this registration statement, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and
  Exchange Commission, and generally to do all such things in their names and behalf in their capacities as officers and directors to enable Tectonic Therapeutic, Inc. to comply with the provisions of the Securities Act of 1933, as amended, and all
  requirements of the Securities and Exchange Commission, granting unto said <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">attorneys-in-fact</FONT></FONT> and agents, and each of them, full power and authority to do and perform
  each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he might or could do in person, ratifying and confirming all that said <FONT STYLE="white-space:nowrap"><FONT
  STYLE="white-space:nowrap">attorneys-in-fact</FONT></FONT> and agents, or any of them, or their or his substitutes or substitute, may lawfully do or cause to be done by virtue hereof. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Act of 1933, as amended, this registration statement on Form
  <FONT STYLE="white-space:nowrap">S-8</FONT> has been signed by the following persons in the capacities and on the dates indicated. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt">
  
  
  <TR>
  
  <TD WIDTH="38%"></TD>
  
  <TD VALIGN="bottom"></TD>
  <TD WIDTH="44%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="16%"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Signature</B></P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Title</B></P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Date</B></P></TD></TR>
  
  
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Alise Reicin</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Alise Reicin</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">President, Chief Executive Officer and Director</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><I>(Principal Executive Officer)</I></P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP ALIGN="center">August&nbsp;21, 2024</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Daniel Lochner</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Daniel Lochner</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Chief Financial Officer</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><I>(Principal Financial Officer and Principal Accounting Officer)</I></P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP ALIGN="center">August&nbsp;21, 2024</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Terrance McGuire</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Terrance McGuire</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP ALIGN="center">August&nbsp;21, 2024</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Stefan Vitorovic</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Stefan Vitorovic</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP ALIGN="center">August&nbsp;21, 2024</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Timothy A. Springer</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Timothy A. Springer</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP ALIGN="center">August&nbsp;21, 2024</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Praveen Tipirneni</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Praveen Tipirneni</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP ALIGN="center">August&nbsp;21, 2024</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Phillip B. Donenberg</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Phillip B. Donenberg</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" NOWRAP ALIGN="center">August&nbsp;21, 2024</TD></TR>
  </TABLE>
  </DIV></Center>
  
  </BODY></HTML>
metadata_documents: [{"type": "S-8", "sequence": "1", "filename": "d820499ds8.htm", "description": "S-8", "secsgml_size_bytes": 58863}]
metadata_filer: {"company-data": {"conformed-name": "Tectonic Therapeutic, Inc.", "cik": "0001681087", "assigned-sic": "2836", "organization-name": "03 Life Sciences", "irs-number": "810710585", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-281690", "film-number": "241229428"}, "business-address": {"street1": "490 ARSENAL WAY", "street2": "SUITE 210", "city": "WATERTOWN", "state": "MA", "zip": "02472", "phone": "(339) 666-3320"}, "mail-address": {"street1": "490 ARSENAL WAY", "street2": "SUITE 210", "city": "WATERTOWN", "state": "MA", "zip": "02472"}, "former-company": [{"former-conformed-name": "AVROBIO, Inc.", "date-changed": "20180131"}, {"former-conformed-name": "AvroBio, Inc.", "date-changed": "20160729"}]}
text: S-8
  As filed with the Securities and Exchange Commission on August 21, 2024
  Registration No. 333-
  UNITED STATES
  SECURITIES
  AND EXCHANGE COMMISSION
  Washington, D.C. 20549
  FORM
  S-8
  REGISTRATION STATEMENT
  UNDER
  THE
  SECURITIES ACT OF 1933
  Tectonic Therapeutic, Inc.
  (Exact name of registrant as specified in its charter)
  Delaware
  83-0710585
  (State or other jurisdiction of
  incorporation or organization)
  (I.R.S. Employer
  Identification No.)
  490 Arsenal Way
  Suite 210
  Watertown,
  MA
  02472
  (Address of Principal Executive Offices)
  (Zip Code)
  2019 Equity Incentive Plan
  2024 Equity Incentive Plan
  2024 Employee Stock Purchase Plan
  (Full titles of the plans)
  Daniel Lochner
  Chief
  Financial Officer
  490 Arsenal Way
  Suite 210
  Watertown, MA
  02472
  (339)
  666-3320
  (Name, address, including zip code, and telephone number, including area code, of agent for service)
  Copies to:
  Marc
  A. Recht
  Courtney T. Thorne
  Katherine Denby
  Cooley
  LLP
  500 Boylston Street, 14
  th
  Floor
  Boston, MA 02116
  (617)
  937-2300
  Indicate by
  check mark whether the registrant is a large accelerated filer, an accelerated filer, a
  non-accelerated
  filer, a smaller reporting company or an emerging growth company. See the definitions of "large
  accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule
  12b-2
  of the Exchange Act.
  Large accelerated filer
  ☐
  Accelerated Filer
  ☐
  Non-accelerated filer
  ☒
  Smaller reporting company
  ☒
  Emerging growth company
  ☐
  If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended
  transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐
  EXPLANATORY NOTE
  On June 20, 2024 (the "Closing Date"), Tectonic Therapeutic, Inc., a Delaware corporation (previously named AVROBIO, Inc. and
  our predecessor company ("AVROBIO")), consummated the previously announced merger (the "Merger") pursuant to the terms of the Agreement and Plan of Merger and Reorganization, dated as of January 30, 2024 (the "Merger
  Agreement"), by and among AVROBIO, Alpine Merger Subsidiary, Inc., a Delaware corporation and direct wholly owned subsidiary of AVROBIO ("Merger Sub"), and Tectonic Operating Company, Inc., a Delaware corporation (previously named
  Tectonic Therapeutic, Inc. ("Legacy Tectonic")).
  In accordance with the Merger Agreement, on the Closing Date, each outstanding
  stock option to purchase shares of Legacy Tectonic common stock (each a "Legacy Tectonic Option") originally granted under the Legacy Tectonic 2019 Equity Incentive Plan (the "2019 Plan") was assumed by the Registrant and was
  converted into, and became, a stock option to purchase shares of common stock of the Registrant and the Registrant assumed the 2019 Plan.
  The Registrant is filing this Registration Statement on Form
  S-8
  for the purpose of registering: (i)
  696,907 shares of common stock under the 2019 Plan; (ii) 1,938,799 shares of common stock under the Registrant's 2024 Equity Incentive Plan; and (iii) 147,343 shares of common stock under the Registrant's 2024 Employee Stock Purchase Plan.
  PART I
  INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS
  ITEM 1.
  PLAN INFORMATION.
  Not required to be filed with this Registration Statement.
  ITEM 2.
  REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION.
  Not required to be filed with this Registration Statement.
  PART II
  INFORMATION
  REQUIRED IN THE REGISTRATION STATEMENT
  ITEM 3.
  INCORPORATION OF DOCUMENTS BY REFERENCE.
  The Registrant hereby incorporates by reference into this Registration Statement the following documents previously filed by the Registrant
  with the Securities and Exchange Commission ("SEC"):
  (a) Annual Report on
  Form
  10-K
  for the year ended December 31, 2023, filed with the SEC on March 14, 2024;
  (b) Quarterly Reports on Form
  10-Q
  for the periods ended March 31, 2024 and June 30, 2024,
  filed with the SEC on
  May 
  9, 2024
  and
  August 14, 2024
  , respectively;
  (c) Current Reports on Form
  8-K,
  which were filed with the SEC on
  January 30,
   2024
  ,
  June 
  4, 2024
  ,
  June 
  11, 2024
  ,
  June 
  14, 2024
  ,
  June 
  18, 2024
  ,
  June 
  20, 2024
  ,
  June 
  26, 2024
  ,
  July 
  5, 2024
  and
  July 30, 2024
  (except that, with respect to the foregoing Current Reports, any portions thereof
  which are furnished and not filed shall not be deemed incorporated by reference); and
  (d) the description of the Registrant's common
  stock in the Registrant's registration statement on
  Form
  8-A
  filed with the SEC on June 11, 2018,
  including any amendments or reports filed for the purpose of updating such description, including as
  Exhibit 4.3
  to the Registrant's Annual Report
  on Form
  10-K
  for the fiscal year ended December 31, 2019.
  All documents, reports and
  definitive proxy or information statements filed pursuant to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), other than current reports furnished under Item 2.02 or Item 7.01
  of
  Form 8-K and
  exhibits furnished on such form that relate to such items, after the date of this Registration Statement and prior to the filing of a post-effective amendment which indicates that all
  securities offered hereby have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference into this Registration Statement and to be a part hereof from the date of filing of such documents;
  provided, however, that documents, reports and definitive proxy or information statements, or portions thereof, which are furnished and not filed in accordance with the rules of the SEC shall not be deemed incorporated by reference into this
  Registration Statement. Any statement contained in a document incorporated or deemed to be incorporated herein by reference shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement
  herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein modifies or supersedes that statement. Any such statement so modified or superseded shall not constitute a part of this Registration
  Statement, except as so modified or superseded.
  ITEM 4.
  DESCRIPTION OF SECURITIES.
  Not applicable.
  1
  ITEM 5.
  INTERESTS OF NAMED EXPERTS AND COUNSEL.
  Not applicable.
  ITEM 6.
  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
  Section 145 of the Delaware General Corporation Law (the "DGCL") authorizes a corporation to indemnify its directors and
  officers against liabilities arising out of actions, suits and proceedings to which they are made or threatened to be made a party by reason of the fact that they have served or are currently serving as a director or officer to a corporation. The
  indemnity may cover expenses (including attorneys' fees) judgments, fines and amounts paid in settlement actually and reasonably incurred by the director or officer in connection with any such action, suit or proceeding. Section 145
  permits corporations to pay expenses (including attorneys' fees) incurred by directors and officers in advance of the final disposition of such action, suit or proceeding. In addition, Section 145 provides that a corporation has the power
  to purchase and maintain insurance on behalf of its directors and officers against any liability asserted against them and incurred by them in their capacity as a director or officer, or arising out of their status as such, whether or not the
  corporation would have the power to indemnify the director or officer against such liability under Section 145.
  Section 102(b)(7) of the DGCL provides that a corporation's certificate of incorporation may contain a provision eliminating or
  limiting the personal liability of a director or officer to the corporation or its stockholders for monetary damages for breach of fiduciary duty, provided that such provision shall not eliminate or limit the liability (i) for any breach of the
  duty of loyalty to the corporation or its stockholders, (ii) for acts or omissions not in good faith or that involve intentional misconduct or a knowing violation of law, (iii) under Section 174 of the DGCL, or (iv) for any
  transaction from which an improper personal benefit was derived. Our Amended and Restated Bylaws (the "Bylaws") provide that we will indemnify each person who was or is a party or threatened to be made a party to any threatened, pending or
  completed action, suit or proceeding (other than an action by or in the right of us) by reason of the fact that he or she is or was, or has agreed to become, a director or officer, or is or was serving, or has agreed to serve, at our request as a
  director, officer, partner, employee or trustee of, or in a similar capacity with, another corporation, partnership, joint venture, trust or other enterprise (all such persons being referred to as an "Indemnitee"), or by reason of any
  action alleged to have been taken or omitted in such capacity, against all expenses (including attorneys' fees), judgments, fines and amounts paid in settlement actually and reasonably incurred in connection with such action, suit or proceeding
  and any appeal therefrom, if such Indemnitee acted in good faith and in a manner he or she reasonably believed to be in, or not opposed to, our best interests, and, with respect to any criminal action or proceeding, he or she had no reasonable cause
  to believe his or her conduct was unlawful. The Bylaws provide that we will indemnify any Indemnitee who was or is a party to an action or suit by or in the right of us to procure a judgment in our favor by reason of the fact that the Indemnitee is
  or was, or has agreed to become, a director or officer, or is or was serving, or has agreed to serve, at our request as a director, officer, partner, employee or trustee of, or in a similar capacity with, another corporation, partnership, joint
  venture, trust or other enterprise, or by reason of any action alleged to have been taken or omitted in such capacity, against all expenses (including attorneys' fees) and, to the extent permitted by law, amounts paid in settlement actually and
  reasonably incurred in connection with such action, suit or proceeding, and any appeal therefrom, if the Indemnitee acted in good faith and in a manner he or she reasonably believed to be in, or not opposed to, our best interests, except that no
  indemnification shall be made with respect to any claim, issue or matter as to which such person shall have been adjudged to be liable to us, unless a court determines that, despite such adjudication but in view of all of the circumstances, he or
  she is entitled to indemnification of such expenses. Notwithstanding the foregoing, to the extent that any Indemnitee has been successful, on the merits or otherwise, he or she will be indemnified by us against all expenses (including
  attorneys' fees) actually and reasonably incurred in connection therewith. Expenses must be advanced to an Indemnitee under certain circumstances.
  We have entered into indemnification agreements with each of our directors and officers. These indemnification agreements may require us,
  among other things, to indemnify our directors and officers for some expenses, including attorneys' fees, judgments, fines and settlement amounts incurred by a director or officer in any action or proceeding arising out of his or her service as
  one of our directors or officers, or any of our subsidiaries or any other company or enterprise to which the person provides services at our request.
  2
  We also maintain general liability insurance that covers certain liabilities of our
  directors and officers arising out of claims based on acts or omissions in their capacities as directors or officers, including liabilities under the Securities Act.
  Under the Merger Agreement, from the effective time of the Merger through the sixth anniversary of the date of the effective time, we agreed
  to indemnify and hold harmless each person who was, as of January 30, 2024, the signing date of the Merger Agreement, or had been at any time prior, or who becomes prior to the effective time of the Merger, a director or officer of our company
  or Legacy Tectonic, against all claims, losses, liabilities, damages, judgments, fines and reasonable fees, costs and expenses, including attorneys' fees and disbursements, pertaining to claims arising out of the fact that such person was a
  director or officer of our company or Legacy Tectonic, at or prior to the effective time of the merger, to the fullest extent permitted under the DGCL.
  Under the Merger Agreement, we agreed not to amend, modify or repeal provisions in the Fourth Amended and Restated Certificate of
  Incorporation and the Bylaws that were in effect as of January 30, 2024, the date of the Merger Agreement, with respect to indemnification, advancement of expenses and exculpation of our present and former directors and officers for a period of
  six years from the effective time of the Merger in a manner that would adversely affect the rights of such individuals who at the effective time of the Merger were our officers or directors.
  In connection with the Merger, we purchased an insurance policy in effect for six years from the effective time of the Merger, providing no
  less favorable coverage as the current directors' and officers' liability insurance policies maintained by us with respect to any actual or alleged error, misstatement, misleading statement, act, omission, neglect, breach of duty or any
  matter claimed against our current and former officers and directors.
  ITEM 7.
  EXEMPTION FROM REGISTRATION CLAIMED.
  Not applicable.
  ITEM 8.
  EXHIBITS.
  Exhibit
  Number
  Description
  4.1
  Fourth Amended and Restated Certificate of Incorporation, as amended through June
  20, 2024 (incorporated by reference to Exhibit 3.1 to the Registrant's Quarterly Report on Form
  10-Q
  (File No.
  001-38537),
  filed with the SEC on August
  14, 2024).
  4.2
  Amended and Restated Bylaws (incorporated by reference to Exhibit 3.2 to the Registrant's Current Report on Form
  8-K
  (File No.
  001-38537),
  filed with the SEC on June
  25, 2018).
  5.1
  Opinion of Cooley LLP.
  23.1
  Consent of Deloitte & Touche LLP, independent registered public accounting firm of Tectonic Therapeutic, Inc.
  23.2
  Consent of Cooley LLP. Reference is made to Exhibit 5.1.
  24.1
  Power of Attorney. Reference is made to the signature page hereto.
  99.1
  Tectonic Therapeutic, Inc. 2019 Equity Incentive Plan and forms of award agreements thereunder (incorporated by reference to Exhibit 10.42 to
   the Registrant's Registration Statement on Form
  S-4,
  filed with the SEC on February
  14, 2024).
  3
  Exhibit
  Number
  Description
  99.2
  Tectonic Therapeutic, Inc. 2024 Equity Incentive Plan (incorporated by reference to Exhibit 10.6 to the Registrant's Current Report on Form
  8-K
  (File No.
  001-38537),
  filed with the SEC on June
  20, 2024).
  99.3
  Forms of Option Grant Notice, Option Agreement and Notice of Exercise under Tectonic Therapeutic, Inc. 2024 Equity Incentive Plan (incorporated
   by reference to Exhibit 10.7 to the Registrant's Current Report on Form
  8-K
  (File No.
  001-38537),
  filed with the SEC on June
  20,
  2024).
  99.4
  Tectonic Therapeutic, Inc. 2024 Employee Stock Purchase Plan (incorporated by reference to Exhibit 10.8 to the Registrant's Current Report
   on Form
  8-K
  (File No.
  001-38537),
  filed with the SEC on June
  20, 2024).
  107
  Filing Fee Table.
  ITEM 9.
  UNDERTAKINGS.
  (a) The undersigned Registrant hereby undertakes:
  (1) To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:
  (i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933, as amended (the "Securities Act");
  (ii) To reflect in the prospectus any facts or events arising after the effective date of the Registration Statement (or the most recent
  post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the Registration Statement. Notwithstanding the foregoing, any increase or decrease in volume of securities
  offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC
  pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the "Calculation of Registration Fee" table in the effective
  Registration Statement;
  (iii) To include any material information with respect to the plan of distribution not previously disclosed in
  the Registration Statement or any material change to such information in the Registration Statement;
  Provided, however,
  that paragraphs (a)(1)(i)
  and (a)(1)(ii) do not apply if the Registration Statement is on Form
  S-8,
  and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or
  furnished to the SEC by the Registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in the Registration Statement; and
  (2) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a
  new registration statement relating to the securities offered herein, and the offering of such securities at that time shall be deemed to be the initial
  bona fide
  offering thereof.
  (3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the
  termination of the offering.
  (b) The undersigned Registrant hereby undertakes that, for purposes of determining any liability under the
  Securities Act, each filing of the Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan's annual report pursuant to
  Section 15(d) of the Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new registration statement relating to the securities offered herein, and the offering of such securities at that time
  shall be deemed to be the initial
  bona fide
  offering thereof.
  4
  (c) Insofar as indemnification for liabilities arising under the Securities Act may be
  permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed
  in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the
  Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the
  matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final
  adjudication of such issue.
  5
  SIGNATURES
  Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe
  that it meets all of the requirements for filing on Form
  S-8
  and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Watertown,
  Commonwealth of Massachusetts, on August 21, 2024.
  TECTONIC THERAPEUTIC, INC.
  By
  /s/ Alise Reicin
  Alise Reicin
  President and Chief Executive Officer
  POWER OF ATTORNEY
  KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Alise Reicin and Daniel Lochner,
  and each of them, as true and lawful
  attorneys-in-fact
  and agents, with full powers of substitution and resubstitution, for them and in their name, place and stead, in
  any and all capacities, to sign any and all amendments (including post-effective amendments) to this registration statement, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and
  Exchange Commission, and generally to do all such things in their names and behalf in their capacities as officers and directors to enable Tectonic Therapeutic, Inc. to comply with the provisions of the Securities Act of 1933, as amended, and all
  requirements of the Securities and Exchange Commission, granting unto said
  attorneys-in-fact
  and agents, and each of them, full power and authority to do and perform
  each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he might or could do in person, ratifying and confirming all that said
  attorneys-in-fact
  and agents, or any of them, or their or his substitutes or substitute, may lawfully do or cause to be done by virtue hereof.
  Pursuant to the requirements of the Securities Act of 1933, as amended, this registration statement on Form
  S-8
  has been signed by the following persons in the capacities and on the dates indicated.
  Signature
  Title
  Date
  /s/ Alise Reicin
  Alise Reicin
  President, Chief Executive Officer and Director
  (Principal Executive Officer)
  August 21, 2024
  /s/ Daniel Lochner
  Daniel Lochner
  Chief Financial Officer
  (Principal Financial Officer and Principal Accounting Officer)
  August 21, 2024
  /s/ Terrance McGuire
  Terrance McGuire
  Director
  August 21, 2024
  /s/ Stefan Vitorovic
  Stefan Vitorovic
  Director
  August 21, 2024
  /s/ Timothy A. Springer
  Timothy A. Springer
  Director
  August 21, 2024
  /s/ Praveen Tipirneni
  Praveen Tipirneni
  Director
  August 21, 2024
  /s/ Phillip B. Donenberg
  Phillip B. Donenberg
  Director
  August 21, 2024