UMRX Unum Therapeutics Inc

CUSIP NO: 19240Q201   13G         PAGE 2 OF 5 PAGES

1.  NAME OF REPORTING PERSON: STATE STREET CORPORATION
    I.R.S. IDENTIFICATION NO. OF THE ABOVE PERSON: 04-2456637

2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
    NOT APPLICABLE

3.  SEC USE ONLY

4.  CITIZENSHIP OR PLACE OF ORGANIZATION
    BOSTON, MASSACHUSETTS

5.  SOLE VOTING POWER
    0 SHARES

6.  SHARED VOTING POWER
    4,196,781

7.  SOLE DISPOSITIVE POWER
    0 SHARES

8.  SHARED DISPOSITIVE POWER
    4,261,381

9.  AGGREGATED AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
    4,261,381

10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
    NOT APPLICABLE

11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
    6.10%

12. TYPE OF REPORTING PERSON
    HC

CUSIP NO: 19240Q201   13G         PAGE 3 OF 5 PAGES

ITEM 1.
    (A)         NAME OF ISSUER
        COGENT BIOSCIENCES INC

(B)     ADDRESS OF ISSUER`S PRINCIPAL EXECUTIVE OFFICES
200 CAMBRIDGE PARK DRIVE SUITE 3100 CAMBRIDGE MA 02142 UNITED STATES

ITEM 2.
    (A)         NAME OF PERSON FILING
        STATE STREET CORPORATION

    (B)         ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE,
        RESIDENCE
        STATE STREET FINANCIAL CENTER
        ONE LINCOLN STREET
        BOSTON, MA 02111
        (FOR ALL REPORTING PERSONS)

    (C)         CITIZENSHIP: SEE ITEM 4 (CITIZENSHIP OR PLACE OF
        ORGANIZATION) OF COVER PAGES

    (D)         TITLE OF CLASS OF SECURITIES
        COMMON STOCK

    (E) CUSIP NUMBER:
        19240Q201

ITEM 3.
        IF THIS STATEMENT IS FILED PURSUANT TO RULE 13D-1(B), OR 13D-2(B)
        OR (C), CHECK WHETHER THE PERSON FILING IS A:
        SEE ITEM 12(TYPE OF REPORTING PERSON) OF THE COVER PAGE
        FOR EACH REPORTING PERSON AND THE TABLE BELOW, WHICH EXPLAINS
        THE MEANING OF THE TWO LETTER SYMBOLS APPEARING IN ITEM 12 OF
        THE COVER PAGES.
        SYMBOL        CATEGORY
          BK            BANK AS DEFINED IN SECTION 3(A) (6) OF THE ACT.
          IC            INSURANCE COMPANY AS DEFINED IN SECTION 3 (A) (19)
                        OF THE ACT
          IC            INVESTMENT COMPANY REGISTERED UNDER SECTION 8 OF
                        THE INVESTMENT COMPANY ACT OF 1940.
          IA            AN INVESTMENT ADVISOR IN ACCORDANCE WITH RULE
                        13D-1(B) (1) (II) (E).
          EP            AN EMPLOYEE BENEFIT PLAN OR ENDOWMENT FUND IN
                        ACCORDANCE WITH RULE 13D-1(B) (1) (II) (F) .
          HC            A PARENT HOLDING COMPANY OR CONTROL PERSON IN
                        ACCORDANCE WITH RULE 13D-1(B)(1)(II) (G).
          SA            A SAVINGS ASSOCIATIONS AS DEFINED IN SECTION 3(B)
                        OF THE FEDERAL DEPOSIT INSURANCE ACT (12 U.S.C. 1813).
          CP            A CHURCH PLAN THAT IS EXCLUDED FROM THE DEFINITION OF
                        AN INVESTMENT COMPANY UNDER SECTION 3(C)(14) OF THE
                        INVESTMENT COMPANY ACT OF 1940.

CUSIP NO: 19240Q201   13G         PAGE 4 OF 5 PAGES

ITEM 4.   OWNERSHIP
          THE INFORMATION SET FORTH IN ROWS 5 THROUGH 11 OF THE COVER PAGE
          HERETO FOR EACH OF THE REPORTING PERSONS IS INCORPORATED
          HEREIN BY REFERENCE.

ITEM 5.   OWNERSHIP OF FIVE PERCENT OR LESS OF CLASS
          NOT APPLICABLE

ITEM 6.   OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON
          NOT APPLICABLE

ITEM 7.   IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH
          ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING
          COMPANY OR CONTROL PERSON
          SEE EXHIBIT 1 ATTACHED HERETO

ITEM 8.   IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP
          NOT APPLICABLE

ITEM 9.   NOTICE OF DISSOLUTION OF GROUP
          NOT APPLICABLE
























CUSIP NO: 19240Q201   13G                  PAGE 5 OF 5 PAGES
ITEM 10.  CERTIFICATION

          BY SIGNING BELOW I CERTIFY THAT, TO THE BEST OF MY KNOWLEDGE
AND BELIEF, THE SECURITIES REFERRED TO ABOVE WERE ACQUIRED AND ARE
HELD IN THE ORDINARY COURSE OF BUSINESS AND WERE NOT ACQUIRED AND ARE
NOT HELD FOR THE PURPOSE OR WITH THE EFFECT OF CHANGING OR INFLUENCING
THE CONTROL OF THE ISSUER OF THE SECURITIES AND WERE NOT ACQUIRED AND
ARE NOT HELD IN CONNECTION WITH OR AS A PARTICIPANT IN ANY TRANSACTION
HAVING THAT PURPOSE OR EFFECT.

SIGNATURES

           AFTER REASONABLE INQUIRY AND TO THE BEST OF HIS KNOWLEDGE AND
BELIEF, EACH OF THE UNDERSIGNED CERTIFIES THAT THE INFORMATION SET FORTH
IN THIS STATEMENT IS TRUE, COMPLETE AND CORRECT.


STATE STREET CORPORATION


ELIZABETH SCHAEFER
SENIOR VICE PRESIDENT, DEPUTY CONTROLLER


                                   EXHIBIT 1



   THE FOLLOWING TABLE LISTS THE IDENTITY AND ITEM 3 CLASSIFICATION
OF EACH SUBSIDIARY OF STATE STREET CORPORATION, THE PARENT HOLDING
COMPANY, THAT BENEFICIALLY OWNS THE ISSUER`S SECURITIES. PLEASE
REFER TO ITEM 3 OF THE ATTACHED SCHEDULE 13G FOR A DESCRIPTION OF
EACH OF THE TWO-LETTER SYMBOLS REPRESENTING THE ITEM 3 CLASSIFICATION
BELOW.

SUBSIDIARY                                                      ITEM 3 CLASSIFICATION
SSGA FUNDS MANAGEMENT, INC.                                     IA
STATE STREET GLOBAL ADVISORS EUROPE LIMITED                     IA
STATE STREET GLOBAL ADVISORS TRUST COMPANY                      IA


NOTE: ALL OF THE LEGAL ENTITIES ABOVE ARE DIRECT OR INDIRECT SUBSIDIARIES
OF STATE STREET CORPORATION.