<PAGE>   1


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                        UNDER THE SECURITIES ACT OF 1933
                        --------------------------------
                                 Alkermes, Inc.
             ------------------------------------------------------
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

                 Pennsylvania                                    23-2472830
---------------------------------------------                -------------------
(STATE OR OTHER JURISDICTION OF INCORPORATION                 (I.R.S. EMPLOYER
OR ORGANIZATION)                                             IDENTIFICATION NO.)

            64 Sidney Street
        Cambridge, Massachusetts                                 02139-4234
----------------------------------------                         ----------
(ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                         (ZIP CODE)

                                 Alkermes, Inc.
                            Amended and Restated 1990
                      Omnibus Stock Option Plan, as Amended
                      -------------------------------------
                            (FULL TITLE OF THE PLAN)

                                 Richard F. Pops
                             Chief Executive Officer
                                 Alkermes, Inc.
                                64 Sidney Street
                       Cambridge, Massachusetts 02139-4234
                     ---------------------------------------
                     (NAME AND ADDRESS OF AGENT FOR SERVICE)

                                 (617) 494-0171
          -------------------------------------------------------------
          (TELEPHONE NUMBER, INCLUDING AREA CODE, OF AGENT FOR SERVICE)

                                with a copy to:

                          Morris Cheston, Jr., Esquire
                             Martha J. Hays, Esquire
                     Ballard Spahr Andrews & Ingersoll, LLP
                               1735 Market Street
                      Philadelphia, Pennsylvania 19103-7599
                                 (215) 665-8500

                         CALCULATION OF REGISTRATION FEE
                         -------------------------------

--------------------------------------------------------------------------------
                                       Proposed      Proposed
Title of                               Maximum       Maximum
Securities            Amount           Offering      Aggregate      Amount of
to be                 to be            Price Per     Offering       Registration
Registered            Registered(1)    Share(2)      Price(2)       Fee
--------------------------------------------------------------------------------
Common Stock,        
par value $.01       
per share             750,000          $23.1875      $17,390,625    $5,131

--------------------------------------------------------------------------------

(1)      In addition, pursuant to Rule 416(a) under the Securities Act of 1933,
         this registration statement shall be deemed to cover an indeterminate
         number of additional shares of Common Stock issuable in the event the
         number of outstanding shares of the Company is increased by split-up,
         reclassification, stock dividend and the like.

(2)      Estimated solely for the purpose of calculating the registration fee.
         In accordance with Rule 457(h), the price shown is based upon the
         average of the high and low price of Alkermes, Inc. Common Stock on
         April 14, 1998, $23.1875 as reported on the Nasdaq National Market for
         securities of the same class as those to be offered.




<PAGE>   2






                  Part I and Items 4-7 and 9 of Part II of Alkermes, Inc.'s
Registration Statement on Form S-8 (File No. 33-44752) are incorporated by
reference herein pursuant to Instruction E of Form S-8.

          PART II - INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.   INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE.

                  The following documents filed with the Securities and Exchange
Commission (the "Commission") pursuant to the Securities Exchange Act of 1934
(the "Exchange Act") by Alkermes, Inc. (the "Company") (File No. 0-19267) or
pursuant to the Securities Act of 1933, as amended (the "Securities Act") are
incorporated herein by reference:

                  (a)      Annual Report on Form 10-K for the fiscal year ended 
                           March 31, 1997;

                  (b)      Quarterly Reports on Form 10-Q for the quarters ended
                           June 30, 1997, September 30, 1997 and December 31, 
                           1997;

                  (c)      Current Reports on Form 8-K dated September 30, 1997,
                           February 18, 1998, February 27, 1998 and April 15,
                           1998; and

                  (d)      Item 1 of Registration Statement of the Company on
                           Form 8-A dated June 28, 1991, as amended by a Report
                           on Form 8-A/A dated January 17, 1997.

                  All documents filed by the Company pursuant to Sections 13(a),
13(c), 14 or 15(d) of the Exchange Act, after the date of this Prospectus and
prior to the termination of the offering shall be deemed to be incorporated by
reference herein and to be part hereof from the date of filing such documents.
Any statement contained herein or in a document incorporated by reference or
deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this Prospectus to the extent that such statement is
modified or superseded by any other subsequently filed document which is
incorporated or is deemed to be incorporated by reference herein. Any such
statement so modified or superseded shall not be deemed, except as so modified
or superseded, to constitute a part of this Prospectus.

ITEM 8.  EXHIBITS.

         4.1      Specimen of Stock Certificate of Alkermes, Inc. (Incorporated
                  by reference to Exhibit 4 to the Registrant's Registration
                  Statement on Form S-1 as amended (File No. 33-40250)).

         4.2      Specimen of Preferred Stock Certificate of Alkermes, Inc. 
                  (Incorporated by reference to Exhibit 4.1 to the Registrant's
                  Registration Statement on Form S-3 (File No. 333-50157)).

         4.3      Second Amended and Restated Articles of Incorporation of
                  Alkermes, Inc. effective July 23, 1991. (Incorporated by
                  reference to Exhibit 4.1(a) to the Registrant's Report on Form
                  10-Q for the quarter ended June 30, 1991).


                                      II-2


<PAGE>   3


         4.4      Amendment to Second Amended and Restated Articles of
                  Incorporation, as filed with the Pennsylvania Secretary of
                  State on November 1, 1991. (Incorporated by reference to
                  Exhibit 4.1(c) to the Registrant's Report on Form 10-Q for the
                  quarter ended September 30, 1991).

         4.5      Amendment to the Second Amended and Restated Articles of
                  Incorporation, as amended, as filed with the Pennsylvania
                  Secretary of State on February 12, 1993. (Incorporated by
                  reference to Exhibit 4.1(d) to the Registrant's Report on form
                  10-Q for the quarter ended December 31, 1992).

         4.6      Amendment to Second Amended and Restated Articles of
                  Incorporation, as filed with the Pennsylvania Secretary of
                  State on February 26, 1998 (Incorporated by reference to
                  Exhibit 4.6 to the Registrant's Registration Statement on Form
                  S-3 (File No. 333- 50157)).

         4.7      Indenture, dated as of March 1, 1998, between the Registrant
                  and State Street Bank and Trust Company, as trustee
                  (Incorporated by reference to Exhibit 4.7 to the Registrant's
                  Registration Statement on Form S-3 (File No. 333-50157)).

         5        Opinion of Ballard Spahr Andrews & Ingersoll, LLP as to the 
                  legality of the securities to be offered.

         23.1     Consent of Ballard Spahr Andrews & Ingersoll, LLP (included as
                  part of Exhibit 5).

         23.2     Consent of Deloitte & Touche LLP.


                                      II-3


<PAGE>   4


                                   SIGNATURES

                  Pursuant to the requirements of the Securities Act of 1933,
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 Cambridge, Commonwealth of Massachusetts, on April 17, 1998.


                                              ALKERMES, INC.


                                              By /s/ Richard F. Pops
                                                 -------------------------------
                                                 Richard F. Pops
                                                 Chief Executive Officer

                  Pursuant to the requirements of the Securities Act of 1933,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.

                  Each person whose signature appears below in so signing also
makes, constitutes and appoints Richard F. Pops and Michael J. Landine, and each
of them, his true and lawful attorney-in-fact, with full power of substitution,
for him in any and all capacities, to execute and cause to be filed with the
Securities and Exchange Commission any and all amendments and post-effective
amendments to this Registration Statement, with exhibits thereto and other
documents in connection therewith, and hereby ratifies and confirms all that
said attorney-in-fact or his substitute or substitutes may do or cause to be
done by virtue hereof.

         Signature                  Title                       Date
         ---------                  -----                       ----

/s/ Michael A. Wall            Director and                 April 17, 1998
-------------------------      Chairman of the 
Michael A. Wall                Board


/s/ Richard F. Pops            Director and Chief           April 17, 1998
-------------------------      Executive Officer 
Richard F. Pops                (Principal        
                               Executive Officer)


/s/ Robert A. Breyer           Director, President          April 17, 1998
-------------------------      and Chief Operating
Robert A. Breyer               Officer


                                      II-4


<PAGE>   5






/s/ Michael J. Landine         Senior Vice President,          April 17, 1998
-------------------------      Chief Financial Officer and  
Michael J. Landine             Treasurer
                               (Principal Financial Officer 
                               and Principal Accounting     
                               Officer)


/s/ Floyd Bloom                Director                        April 17, 1998
-------------------------
Floyd Bloom


/s/ John K. Clarke             Director                        April 17, 1998
-------------------------
John K. Clarke


/s/ Robert S. Langer           Director                        April 17, 1998
-------------------------
Robert S. Langer


/s/ Alexander Rich             Director                        April 17, 1998
-------------------------
Alexander Rich


/s/ Paul Schimmel              Director                        April 17, 1998
-------------------------
Paul Schimmel



                                      II-5


<PAGE>   6






                                  EXHIBIT INDEX

Number                                Exhibit
------                                -------

5                 Opinion of Ballard Spahr Andrews & Ingersoll, LLP as to the
                  legality of the securities to be offered.

23.1              Consent of Ballard Spahr Andrews & Ingersoll, LLP (included as
                  part of Exhibit 5).

23.2              Consent of Deloitte & Touche LLP.
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{"company-data": {"conformed-name": "ALKERMES INC", "cik": "0000874663", "assigned-sic": "2834", "irs-number": "232472830", "state-of-incorporation": "PA", "fiscal-year-end": "0331"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-50357", "film-number": "98596336"}, "business-address": {"street1": "64 SIDNEY ST", "city": "CAMBRIDGE", "state": "MA", "zip": "02139-4136", "phone": "6174940171"}}
1

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                        UNDER THE SECURITIES ACT OF 1933
                        --------------------------------
                                 Alkermes, Inc.
             ------------------------------------------------------
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

                 Pennsylvania                                    23-2472830
---------------------------------------------                -------------------
(STATE OR OTHER JURISDICTION OF INCORPORATION                 (I.R.S. EMPLOYER
OR ORGANIZATION)                                             IDENTIFICATION NO.)

            64 Sidney Street
        Cambridge, Massachusetts                                 02139-4234
----------------------------------------                         ----------
(ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                         (ZIP CODE)

                                 Alkermes, Inc.
                            Amended and Restated 1990
                      Omnibus Stock Option Plan, as Amended
                      -------------------------------------
                            (FULL TITLE OF THE PLAN)

                                 Richard F. Pops
                             Chief Executive Officer
                                 Alkermes, Inc.
                                64 Sidney Street
                       Cambridge, Massachusetts 02139-4234
                     ---------------------------------------
                     (NAME AND ADDRESS OF AGENT FOR SERVICE)

                                 (617) 494-0171
          -------------------------------------------------------------
          (TELEPHONE NUMBER, INCLUDING AREA CODE, OF AGENT FOR SERVICE)

                                with a copy to:

                          Morris Cheston, Jr., Esquire
                             Martha J. Hays, Esquire
                     Ballard Spahr Andrews & Ingersoll, LLP
                               1735 Market Street
                      Philadelphia, Pennsylvania 19103-7599
                                 (215) 665-8500

                         CALCULATION OF REGISTRATION FEE
                         -------------------------------

--------------------------------------------------------------------------------
                                       Proposed      Proposed
Title of                               Maximum       Maximum
Securities            Amount           Offering      Aggregate      Amount of
to be                 to be            Price Per     Offering       Registration
Registered            Registered(1)    Share(2)      Price(2)       Fee
--------------------------------------------------------------------------------
Common Stock,        
par value $.01       
per share             750,000          $23.1875      $17,390,625    $5,131

--------------------------------------------------------------------------------

(1)      In addition, pursuant to Rule 416(a) under the Securities Act of 1933,
         this registration statement shall be deemed to cover an indeterminate
         number of additional shares of Common Stock issuable in the event the
         number of outstanding shares of the Company is increased by split-up,
         reclassification, stock dividend and the like.

(2)      Estimated solely for the purpose of calculating the registration fee.
         In accordance with Rule 457(h), the price shown is based upon the
         average of the high and low price of Alkermes, Inc. Common Stock on
         April 14, 1998, $23.1875 as reported on the Nasdaq National Market for
         securities of the same class as those to be offered.
2

                  Part I and Items 4-7 and 9 of Part II of Alkermes, Inc.'s
Registration Statement on Form S-8 (File No. 33-44752) are incorporated by
reference herein pursuant to Instruction E of Form S-8.

          PART II - INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.   INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE.

                  The following documents filed with the Securities and Exchange
Commission (the "Commission") pursuant to the Securities Exchange Act of 1934
(the "Exchange Act") by Alkermes, Inc. (the "Company") (File No. 0-19267) or
pursuant to the Securities Act of 1933, as amended (the "Securities Act") are
incorporated herein by reference:

                  (a)      Annual Report on Form 10-K for the fiscal year ended 
                           March 31, 1997;

                  (b)      Quarterly Reports on Form 10-Q for the quarters ended
                           June 30, 1997, September 30, 1997 and December 31, 
                           1997;

                  (c)      Current Reports on Form 8-K dated September 30, 1997,
                           February 18, 1998, February 27, 1998 and April 15,
                           1998; and

                  (d)      Item 1 of Registration Statement of the Company on
                           Form 8-A dated June 28, 1991, as amended by a Report
                           on Form 8-A/A dated January 17, 1997.

                  All documents filed by the Company pursuant to Sections 13(a),
13(c), 14 or 15(d) of the Exchange Act, after the date of this Prospectus and
prior to the termination of the offering shall be deemed to be incorporated by
reference herein and to be part hereof from the date of filing such documents.
Any statement contained herein or in a document incorporated by reference or
deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this Prospectus to the extent that such statement is
modified or superseded by any other subsequently filed document which is
incorporated or is deemed to be incorporated by reference herein. Any such
statement so modified or superseded shall not be deemed, except as so modified
or superseded, to constitute a part of this Prospectus.

ITEM 8.  EXHIBITS.

         4.1      Specimen of Stock Certificate of Alkermes, Inc. (Incorporated
                  by reference to Exhibit 4 to the Registrant's Registration
                  Statement on Form S-1 as amended (File No. 33-40250)).

         4.2      Specimen of Preferred Stock Certificate of Alkermes, Inc. 
                  (Incorporated by reference to Exhibit 4.1 to the Registrant's
                  Registration Statement on Form S-3 (File No. 333-50157)).

         4.3      Second Amended and Restated Articles of Incorporation of
                  Alkermes, Inc. effective July 23, 1991. (Incorporated by
                  reference to Exhibit 4.1(a) to the Registrant's Report on Form
                  10-Q for the quarter ended June 30, 1991).

                                      II-2
3

         4.4      Amendment to Second Amended and Restated Articles of
                  Incorporation, as filed with the Pennsylvania Secretary of
                  State on November 1, 1991. (Incorporated by reference to
                  Exhibit 4.1(c) to the Registrant's Report on Form 10-Q for the
                  quarter ended September 30, 1991).

         4.5      Amendment to the Second Amended and Restated Articles of
                  Incorporation, as amended, as filed with the Pennsylvania
                  Secretary of State on February 12, 1993. (Incorporated by
                  reference to Exhibit 4.1(d) to the Registrant's Report on form
                  10-Q for the quarter ended December 31, 1992).

         4.6      Amendment to Second Amended and Restated Articles of
                  Incorporation, as filed with the Pennsylvania Secretary of
                  State on February 26, 1998 (Incorporated by reference to
                  Exhibit 4.6 to the Registrant's Registration Statement on Form
                  S-3 (File No. 333- 50157)).

         4.7      Indenture, dated as of March 1, 1998, between the Registrant
                  and State Street Bank and Trust Company, as trustee
                  (Incorporated by reference to Exhibit 4.7 to the Registrant's
                  Registration Statement on Form S-3 (File No. 333-50157)).

         5        Opinion of Ballard Spahr Andrews & Ingersoll, LLP as to the 
                  legality of the securities to be offered.

         23.1     Consent of Ballard Spahr Andrews & Ingersoll, LLP (included as
                  part of Exhibit 5).

         23.2     Consent of Deloitte & Touche LLP.

                                      II-3
4

                                   SIGNATURES

                  Pursuant to the requirements of the Securities Act of 1933,
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 Cambridge, Commonwealth of Massachusetts, on April 17, 1998.

                                              ALKERMES, INC.

                                              By /s/ Richard F. Pops
                                                 -------------------------------
                                                 Richard F. Pops
                                                 Chief Executive Officer

                  Pursuant to the requirements of the Securities Act of 1933,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.

                  Each person whose signature appears below in so signing also
makes, constitutes and appoints Richard F. Pops and Michael J. Landine, and each
of them, his true and lawful attorney-in-fact, with full power of substitution,
for him in any and all capacities, to execute and cause to be filed with the
Securities and Exchange Commission any and all amendments and post-effective
amendments to this Registration Statement, with exhibits thereto and other
documents in connection therewith, and hereby ratifies and confirms all that
said attorney-in-fact or his substitute or substitutes may do or cause to be
done by virtue hereof.

         Signature                  Title                       Date
         ---------                  -----                       ----

/s/ Michael A. Wall            Director and                 April 17, 1998
-------------------------      Chairman of the 
Michael A. Wall                Board

/s/ Richard F. Pops            Director and Chief           April 17, 1998
-------------------------      Executive Officer 
Richard F. Pops                (Principal        
                               Executive Officer)

/s/ Robert A. Breyer           Director, President          April 17, 1998
-------------------------      and Chief Operating
Robert A. Breyer               Officer

                                      II-4
5

/s/ Michael J. Landine         Senior Vice President,          April 17, 1998
-------------------------      Chief Financial Officer and  
Michael J. Landine             Treasurer
                               (Principal Financial Officer 
                               and Principal Accounting     
                               Officer)

/s/ Floyd Bloom                Director                        April 17, 1998
-------------------------
Floyd Bloom

/s/ John K. Clarke             Director                        April 17, 1998
-------------------------
John K. Clarke

/s/ Robert S. Langer           Director                        April 17, 1998
-------------------------
Robert S. Langer

/s/ Alexander Rich             Director                        April 17, 1998
-------------------------
Alexander Rich

/s/ Paul Schimmel              Director                        April 17, 1998
-------------------------
Paul Schimmel

                                      II-5
6

                                  EXHIBIT INDEX

Number                                Exhibit
------                                -------

5                 Opinion of Ballard Spahr Andrews & Ingersoll, LLP as to the
                  legality of the securities to be offered.

23.1              Consent of Ballard Spahr Andrews & Ingersoll, LLP (included as
                  part of Exhibit 5).

23.2              Consent of Deloitte & Touche LLP.