Exhibit 10.1

THIRD AMENDMENT OF LEASE

THIS THIRD AMENDMENT OF LEASE (hereinafter “Amendment”) is entered into to be
effective as of the 31st day of May 2017, by BHX, LLC, a Massachusetts limited
liability company, as Trustee of 784 Realty Trust (hereinafter “Landlord”), and
INFINITY PHARMACEUTICALS, INC., a Delaware corporation (hereinafter “Tenant”).

WITNESSETH

WHEREAS, Landlord and Tenant are parties to a Lease dated September 25, 2014
(the “Original Lease”), as amended by that certain Amendment of Lease dated as
of March 27, 2017 (the “First Amendment”), as amended by that certain Second
Amendment of Lease dated as of May 1, 2017 and, together with the Original Lease
and the First Amendment, the “Lease”), pursuant to which Landlord has leased to
Tenant space in the building located at and commonly known as 784 Memorial
Drive, Cambridge Massachusetts. All capitalized terms used in this Amendment
which are defined in the Lease and not otherwise defined in this Amendment have
the meanings given in the Lease; and

WHEREAS, the “Termination Contingencies Date,” as set forth in the First
Amendment and Second Amendment, is May 31, 2017. Landlord and Tenant desire to
amend the Lease to extend the Termination Contingencies Date to June 15, 2017,
on the terms set forth herein.

Statement of Amendment

NOW, THEREFORE, in consideration of the undertakings of the parties as set forth
below and other good and valuable consideration, the receipt and sufficiency of
which consideration is hereby acknowledged by both Landlord and Tenant, Landlord
and Tenant hereby agree as follows:

1.    The “Termination Contingencies Date,” as defined in Section 3 of the First
Amendment and as amended in Section 1 of the Second Amendment, is hereby amended
to be June 15, 2017. The “Early Termination Date”, as defined in Section 2(a) of
the First Amendment and as amended by Section 1 of the Second Amendment, is
hereby amended to be August 31, 2017. The date “August 1, 2017”, as appearing in
Section 7 of the First Amendment and as amended by Section 1 of the Second
Amendment is hereby amended to be September 1, 2017.

2.     This Amendment, together with the First Amendment and the Second
Amendment, constitutes the entire agreement between the parties hereto regarding
the early termination of the Lease and supersedes all prior negotiations
regarding the subject matter hereof. This Amendment will be governed by and
construed in accordance with the laws of the Commonwealth of Massachusetts.

3.    To the extent that the provisions of this Amendment are inconsistent with
the provisions of the Lease, the provisions of this Amendment will control, and
the Lease will be deemed to be amended hereby. Except as amended by this
Amendment, the provisions of the Lease remain in full force and effect.

4.    This Amendment may be executed in multiple counterparts, each of which
will be an original, but all of which, taken together, will constitute one and
the same Amendment. This Amendment may be signed by facsimile signatures or
other electronic delivery of an image file reflecting the execution hereof, and
if so signed, may be relied on by all parties as if the document were a manually
signed original and will be binding on the undersigned for all purposes.

[Remainder of page intentionally blank; signature page follows.]

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

IN WITNESS WHEREOF, Landlord and Tenant have executed this Amendment as of the
date first set forth above.

 

BHX, LLC, as Trustee of 784 Realty Trust By:  

/s/ Robert Schlager

Name:   Robert Schlager Title:   Member INFINITY PHARMACEUTICALS, INC. By:  

/s/ Lawrence Bloch, M.D., J.D.

Name:   Lawrence Bloch, M.D., J.D. Title:   President