Five Prime Therapeutics, Inc. (NASDAQ:FPRX) Files An 8-K Entry into a Material Definitive Agreement

Item1.01

On December12, 2016, Five Prime Therapeutics, Inc. (FivePrime)
and HCP Oyster Point III LLC (Landlord) entered into the Lease
(the Lease), effective December12, 2016 (the Effective Date), for
FivePrimes lease of 115,466 square feet of office and laboratory
space located at 111 Oyster Point Drive, South San Francisco,
California (the Premises). The term of the Lease begins on the
later to occur of (i)January1, 2018 and (ii)30 days after the
Premises are ready for occupancy, which requires Landlords
delivery of the Premises to FivePrime and completion of certain
tenant improvements to the Premises (the Rent Commencement Date),
and ends on the 10-year anniversary of the Rent Commencement Date
(the Lease Term), subject to FivePrimes one-time option to extend
the Lease Term for an additional five years (the Option Term).
FivePrime expects Landlord will deliver the Premises, the tenant
improvements to the Premises will be completed and the Premises
will be ready for occupancy by FivePrime on or around December1,
2017. The Premises are located in an office and laboratory
complex at The Cove at Oyster Point (the Project).

FivePrime is obligated to pay Landlord monthly base rent in an
initial amount of (i)$282,891.70 for the first six months of the
Lease Term and (ii)$565,783.40 for the second six months of the
Lease Term. The base rent for the first year of the Lease Term is
calculated at a rate of $4.90 per rentable square foot, with the
first six months calculated as if the Premises contained only
57,773 rentable square feet. Following the first year of the
Lease Term, the monthly base rent will increase as follows:

If FivePrime exercises its one-time option to extend the Lease
Term for an additional five years, FivePrime would pay Landlord
during the Option Term base rent equal to the fair rental value
(as determined in accordance with the Lease) as of the
commencement date of the Option Term for comparable space in
similar life sciences buildings located in South San Francisco,
California and the surrounding commercial area.

In addition to FivePrimes monthly base rent obligations,
FivePrime is obligated to pay to Landlord as additional rent a
portion of the operating expenses of the Project and certain
taxes, assessments and fees incurred in connection with the
ownership, leasing and operation of the Project that Landlord
pays or accrues for.

FivePrime is entitled to a one-time tenant improvement allowance
of $14,433,250, or $125 per square foot of the Premises, from
Landlord for costs relating to the design and construction of
improvements to the Premises, subject to the terms and conditions
of a work letter attached to the Lease.

to the Lease, FivePrime delivered to Landlord an irrevocable
letter of credit in the amount of $1,542,625.76 as security for
FivePrimes performance of the terms of the Lease, which amount is
subject to reduction under certain circumstances starting in the
sixth year of the Lease.

to the Lease, during the first five years of the Lease Term,
FivePrime has, subject to the rights of certain other tenants in
the Project, a right of first offer to lease space located at 151
or 171 Oyster Point Boulevard following the termination or
earlier expiration of (i)any lease existing as of the Rent
Commencement Date with respect to any space located 151 Oyster
Point Boulevard and (ii)the initial lease of any space located in
171 Oyster Point Boulevard, including any renewals of any such
leases. In addition, during the first five years of the Lease
Term, FivePrime has a right of first negotiation, subject to the
rights of certain other tenants in the Project, to lease space
that becomes available on a multi-tenant basis in the buildings
located at 121, 151 or 171 Oyster Point Boulevard or the
buildings to be constructed at 131, 161 or 181 Oyster Point
Boulevard.

2

The Lease contains customary provisions allowing Landlord to
terminate the Lease if FivePrime fails to remedy a breach of any
of its obligations within specified time periods.

The foregoing description of the Lease is qualified in its
entirety by reference to the full text of the Lease, a copy of
which FivePrime plans to file as an exhibit to its Annual Report
on Form 10-K for its fiscal year ending December31, 2016.

3

About Five Prime Therapeutics, Inc. (NASDAQ:FPRX)

Five Prime Therapeutics, Inc. (Five Prime) is a clinical-stage biotechnology company focused on discovering and developing protein therapeutics. The Company has three product candidates in clinical development covering multiple potential indications. It focuses on immuno-oncology, an area in which it has clinical and discovery programs, and product and discovery collaborations. The Company seeks to engage third-party collaborators to assist it in developing companion diagnostics for its clinical programs. The Company’s product candidates include FPA008, FPA144 and FP-1039/GSK3052230. The FPA008 is an antibody that inhibits colony stimulating factor-1 (CSF1), receptor (CSF1R). The FPA144 is an antibody that inhibits fibroblast growth factor receptor 2b (FGFR2b). FP-1039 is a protein therapeutic designed to trap and neutralize cancer-promoting fibroblast growth factors (FGFs).

Five Prime Therapeutics, Inc. (NASDAQ:FPRX) Recent Trading Information

Five Prime Therapeutics, Inc. (NASDAQ:FPRX) closed its last trading session down -1.54 at 48.96 with 780,070 shares trading hands.