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 <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">8-K</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; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>CURRENT
REPORT </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Pursuant to Section&nbsp;13 or 15(d) </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>of the Securities Exchange Act of 1934 </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Date of Report (Date of Earliest Event Reported): December&nbsp;31, 2018 </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>Proteostasis Therapeutics, 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>
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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">001-37695</FONT></B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"><B><FONT STYLE="white-space:nowrap">20-8436652</FONT></B></TD></TR>
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<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</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>of incorporation)</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>(Commission</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>File Number)</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 VALIGN="top" COLSPAN="3" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>80 Guest Street, Suite 500</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Boston, MA</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" ALIGN="center"><B>02135</B></TD></TR>
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<TD VALIGN="top" COLSPAN="3" 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>Registrant&#146;s telephone number, including area code
<FONT STYLE="white-space:nowrap">(617)&nbsp;225-0096</FONT> </B></P> <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Former name or former address, if changed since last report) </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">Check the appropriate box below if the Form <FONT STYLE="white-space:nowrap">8-K</FONT> filing is intended to simultaneously satisfy the filing obligation of
the registrant under any of the following provisions: </P> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Written communications pursuant to Rule&nbsp;425 under the Securities Act (17 CFR 230.425)
</P></TD></TR></TABLE> <P STYLE="font-size:6pt;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="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Soliciting material pursuant to <FONT STYLE="white-space:nowrap">Rule&nbsp;14a-12</FONT> under the Exchange Act
(17 CFR <FONT STYLE="white-space:nowrap">240.14a-12)</FONT> </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><FONT STYLE="white-space:nowrap">Pre-commencement</FONT> communications pursuant to <FONT
STYLE="white-space:nowrap">Rule&nbsp;14d-2(b)</FONT> under the Exchange Act (17 CFR <FONT STYLE="white-space:nowrap">240.14d-2(b))</FONT> </P></TD></TR></TABLE> <P STYLE="font-size:6pt;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="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><FONT STYLE="white-space:nowrap">Pre-commencement</FONT> communications pursuant to <FONT
STYLE="white-space:nowrap">Rule&nbsp;13e-4(c)</FONT> under the Exchange Act (17 CFR <FONT STYLE="white-space:nowrap">240.13e-4(c))</FONT> </P></TD></TR></TABLE>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (&#167;230.405 of this
chapter) or Rule <FONT STYLE="white-space:nowrap">12b-2</FONT> of the Securities Exchange Act of 1934 <FONT STYLE="white-space:nowrap">(&#167;240.12b-2</FONT> of this chapter). </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Emerging growth company&nbsp;&nbsp;&#9746; </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; 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;13(a) of the Exchange
Act.&nbsp;&nbsp;&#9746; </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>
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<TD WIDTH="12%" VALIGN="top" ALIGN="left"><B>Item&nbsp;8.01</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>Other Events. </B></P></TD></TR></TABLE>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The Company has completed a phase 1 study of <FONT STYLE="white-space:nowrap">PTI-428</FONT> as an add on to subjects who are currently on Kalydeco<SUP
STYLE="font-size:85%; vertical-align:top">&reg;</SUP>. <FONT STYLE="white-space:nowrap">The&nbsp;two-center,</FONT> double blinded and&nbsp;placebo-controlled study investigated four doses (10, 25, 50, 100mg) of
<FONT STYLE="white-space:nowrap">PTI-428</FONT> in cystic fibrosis (CF) subjects on background Kalydeco therapy. Across the four dose levels and placebo,&nbsp;15 subjects total were dosed with <FONT STYLE="white-space:nowrap">PTI-428</FONT> or
placebo for two weeks.</P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The study met the primary and secondary objectives and&nbsp;confirmed&nbsp;that the safety and pharmacokinetic profile of the drug
was as expected.&nbsp;Exploratory analyses were not performed due to the small number of enrolled subjects. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Safe Harbor </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">To the extent that statements in this report are not historical facts, they are forward-looking statements reflecting the current beliefs and expectations of
management made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.&nbsp;Words such as &#147;aim,&#148; &#147;may,&#148; &#147;will,&#148; &#147;expect,&#148; &#147;anticipate,&#148; &#147;estimate,&#148;
&#147;intend,&#148; and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements.&nbsp;Examples of forward-looking statements made in this
report include, without limitation, statements regarding the potential of our proprietary candidate as an add on therapy for the treatment of CF, and the potential benefit to patients of our proprietary candidate as an add on therapy.
Forward-looking statements made in this release involve substantial risks and uncertainties that could cause actual results to differ materially from those expressed or implied by the forward-looking statements, and we, therefore cannot assure you
that our plans, intentions, expectations or strategies will be attained or achieved.&nbsp;Such risks and uncertainties include, without limitation, the possibility final or future results from our drug candidate trials (including, without
limitation, longer duration studies) do not achieve positive results or are materially and negatively different from or not indicative of the preliminary results reported by the Company (noting that these results are based on a small number of
patients and small data set), uncertainties inherent in the execution and completion of clinical trials (including, without limitation, the possibility&nbsp;that FDA&nbsp;comments delay, change or do not permit trial commencement, or intended label,
or the&nbsp;FDA&nbsp;requires us to run cohorts sequentially or conduct additional cohorts or <FONT STYLE="white-space:nowrap">pre-clinical</FONT> or clinical studies), in the enrollment of CF patients in our clinical trials in a competitive
clinical environment, in the timing of availability of trial data, in the results of the clinical trials, in possible adverse events from our trials, in the actions of regulatory agencies, in the endorsement, if any, by therapeutic development arms
of CF patient advocacy groups (and the maintenance thereof), and those set forth in our Quarterly Report on Form <FONT STYLE="white-space:nowrap">10-Q</FONT> for the quarter ended&nbsp;September 30, 2018&nbsp;and our
other&nbsp;SEC&nbsp;filings.&nbsp;We assume no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Kalydeco<SUP STYLE="font-size:85%; vertical-align:top">&reg;</SUP> is a trademark of&nbsp;Vertex Pharmaceuticals Incorporated. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The above information is not an admission as to the materiality of any information therein. The Company undertakes no duty or obligation to update or revise
the information contained in this report, although it may do so from time to time as its management believes is appropriate. Any such updating may be made through the filing of other reports or documents with the SEC, through press releases or
through other public disclosures. </P>
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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>SIGNATURES </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned
hereunto duly authorized. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="top">Date: December&nbsp;31, 2018</TD>
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<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="3"><B>PROTEOSTASIS THERAPEUTICS, INC.</B></TD></TR>
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<TD VALIGN="top">By:</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Meenu Chhabra</P></TD></TR>
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<TD VALIGN="bottom"></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">Meenu Chhabra</TD></TR>
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<TD VALIGN="bottom">&nbsp;</TD>
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<TD VALIGN="bottom">President and Chief Executive Officer</TD></TR>
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Form 8-K
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM
8-K
CURRENT
REPORT
Pursuant to Section 13 or 15(d)
of the Securities Exchange Act of 1934
Date of Report (Date of Earliest Event Reported): December 31, 2018
Proteostasis Therapeutics, Inc.
(Exact name of registrant as specified in its charter)
Delaware
001-37695
20-8436652
(State or other jurisdiction
of incorporation)
(Commission
File Number)
(I.R.S. Employer
Identification No.)
80 Guest Street, Suite 500
Boston, MA
02135
(Address of principal executive offices)
(Zip Code)
Registrant's telephone number, including area code
(617) 225-0096
(Former name or former address, if changed since last report)
Check the appropriate box below if the Form
8-K
filing is intended to simultaneously satisfy the filing obligation of
the registrant under any of the following provisions:
☐
Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐
Soliciting material pursuant to
Rule 14a-12
under the Exchange Act
(17 CFR
240.14a-12)
☐
Pre-commencement
communications pursuant to
Rule 14d-2(b)
under the Exchange Act (17 CFR
240.14d-2(b))
☐
Pre-commencement
communications pursuant to
Rule 13e-4(c)
under the Exchange Act (17 CFR
240.13e-4(c))
Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this
chapter) or Rule
12b-2
of the Securities Exchange Act of 1934
(§240.12b-2
of this chapter).
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 13(a) of the Exchange
Act.  ☒
Item 8.01
Other Events.
The Company has completed a phase 1 study of
PTI-428
as an add on to subjects who are currently on Kalydeco
®
.
The two-center,
double blinded and placebo-controlled study investigated four doses (10, 25, 50, 100mg) of
PTI-428
in cystic fibrosis (CF) subjects on background Kalydeco therapy. Across the four dose levels and placebo, 15 subjects total were dosed with
PTI-428
or
placebo for two weeks.
The study met the primary and secondary objectives and confirmed that the safety and pharmacokinetic profile of the drug
was as expected. Exploratory analyses were not performed due to the small number of enrolled subjects.
Safe Harbor
To the extent that statements in this report are not historical facts, they are forward-looking statements reflecting the current beliefs and expectations of
management made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Words such as "aim," "may," "will," "expect," "anticipate," "estimate,"
"intend," and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. Examples of forward-looking statements made in this
report include, without limitation, statements regarding the potential of our proprietary candidate as an add on therapy for the treatment of CF, and the potential benefit to patients of our proprietary candidate as an add on therapy.
Forward-looking statements made in this release involve substantial risks and uncertainties that could cause actual results to differ materially from those expressed or implied by the forward-looking statements, and we, therefore cannot assure you
that our plans, intentions, expectations or strategies will be attained or achieved. Such risks and uncertainties include, without limitation, the possibility final or future results from our drug candidate trials (including, without
limitation, longer duration studies) do not achieve positive results or are materially and negatively different from or not indicative of the preliminary results reported by the Company (noting that these results are based on a small number of
patients and small data set), uncertainties inherent in the execution and completion of clinical trials (including, without limitation, the possibility that FDA comments delay, change or do not permit trial commencement, or intended label,
or the FDA requires us to run cohorts sequentially or conduct additional cohorts or
pre-clinical
or clinical studies), in the enrollment of CF patients in our clinical trials in a competitive
clinical environment, in the timing of availability of trial data, in the results of the clinical trials, in possible adverse events from our trials, in the actions of regulatory agencies, in the endorsement, if any, by therapeutic development arms
of CF patient advocacy groups (and the maintenance thereof), and those set forth in our Quarterly Report on Form
10-Q
for the quarter ended September 30, 2018 and our
other SEC filings. We assume no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.
Kalydeco
®
is a trademark of Vertex Pharmaceuticals Incorporated.
The above information is not an admission as to the materiality of any information therein. The Company undertakes no duty or obligation to update or revise
the information contained in this report, although it may do so from time to time as its management believes is appropriate. Any such updating may be made through the filing of other reports or documents with the SEC, through press releases or
through other public disclosures.
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned
hereunto duly authorized.
Date: December 31, 2018
PROTEOSTASIS THERAPEUTICS, INC.
By:
/s/ Meenu Chhabra
Meenu Chhabra
President and Chief Executive Officer