Exhibit 10.20

SECOND AMENDMENT OF LEASE

AGREEMENT (“Second Amendment”) made this 15th day of December, 2015 by and
between CIP II/RJK 10-20 BMR Owner, LLC, 55 Cambridge Street, Burlington,
Massachusetts 01803 (hereinafter referred to as “Landlord”) and Flexion
Therapeutics, Inc. (hereinafter referred to as “Tenant”).

RECITALS

1. Pursuant to that certain Lease dated February 22, 2013 by and between
Landlord and Tenant, as amended by First Amendment of Lease dated July 13, 2015
(the “First Amendment, and together with the Lease, the “Existing Lease”),
Landlord is leasing to Tenant those certain premises known as 10 Burlington Mall
Road, situated in Burlington, Massachusetts 01803, together with all
improvements located thereon, consisting of 11,754 rentable square feet of area,
all as more particularly described in said Existing Lease (hereinafter referred
to as the “Original Premises”).

2. Pursuant to the First Amendment, the Tenant, among other things (i) has
agreed to lease additional space consisting of approximately 4,715 square feet
on the third floor of the Building contiguous to the Original Premises, as shown
on Exhibit A attached to the First Amendment, on the terms and conditions as set
forth in the Existing Lease (the “Phase I Expansion Space”); (ii) has agreed to
lease on a temporary basis approximately 6,748 square feet on the second floor
of the Building known as Suite 210 (the “Suite 210 Temporary Space”), on the
terms and conditions as set forth in the Existing Lease; and (iii) has the
option to lease additional space consisting of approximately 5,405 square feet
on the third floor of the Building contiguous to the Phase I Expansion Space, as
shown on Exhibit A attached to the First Amendment, on the terms and conditions
as set forth in the Existing Lease (the “Phase II Expansion Space”). The
Original Premises, the Phase I Expansion Space and the Phase II Expansion Space
collectively are hereinafter referred to as the “2016 Combined Space.”

3. Capitalized terms used herein and not defined herein shall have the meanings
ascribed to such terms in the Existing Lease and the Existing Lease as amended
by this Second Amendment is hereby known as the “Lease”.

4. The term “Premises” used in the Lease shall include where appropriate the
Original Premises, the Phase I Expansion Space, the Phase II Expansion Space,
and the Suite 210 Temporary Space.

IN CONSIDERATION of the mutual covenants contained herein, the parties agree as
follows:

 

A. Suite 210 Temporary Space.

Landlord and Tenant acknowledge and agree that Landlord delivered the Suite 210
Temporary Space to Tenant as of August 1, 2015, and Tenant has accepted and is
occupying the Suite 210 Temporary Space upon all of the terms and conditions of
the Lease, including without limitation the provisions expressly set forth in
the First Amendment.

 

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B. Phase II Expansion Space.

Landlord and Tenant acknowledge and agree that Tenant has validly exercised its
option to expand into the Phase II Expansion Space by delivering written notice
to Landlord exercising such option on September 30, 2015, and Tenant will lease
the Phase II Expansion Space upon all of the terms and conditions of the Lease,
including without limitation the provisions expressly set forth in the First
Amendment. As Tenant has timely exercised its option to expand into the Phase II
Expansion Space, Tenant now also shall have an exclusive right of first refusal
to lease the Suite 210 Temporary Space in accordance with the terms and
conditions set forth on Exhibit E attached to the First Amendment. In addition,
all references to “the Phase I Expansion Space” in Paragraph B(v) of the First
Amendment shall be amended to mean “both the Phase I Expansion Space and the
Phase II Expansion Space.”

 

C. Term of Phase I and Phase II Expansion Space.

The term for the Phase I Expansion Space and the Phase II Expansion Space
(collectively, the “Phase I and Phase II Expansion Space”) shall commence upon
substantial completion of Landlord’s Work, as hereinafter defined (the “Phase I
and Phase II Expansion Space Commencement Date”), which is anticipated to occur
on May 1, 2016 (the “Target Delivery Date”), and expire on October 31, 2019,
unless sooner terminated or otherwise extended in accordance with the terms and
provisions of the Lease.

 

D. Annual Fixed Rent.

Tenant and Landlord acknowledge and agree that Annual Fixed Rent for the
Original Premises shall be payable in the amount set forth in Section 1.1 of the
Existing Lease until October 31, 2016. Thereafter, Annual Fixed Rent for the
Original Premises shall be included in the following Annual Fixed Rent schedule
for the 2016 Combined Space, which replaces the Annual Fixed Rent schedule set
forth in Paragraph C of the First Amendment, and which shall be effective as of
the Phase I and Phase II Expansion Space Commencement Date:

(i) For the period from May 1, 2016 through July 31, 2016 the sum of $0, payable
in monthly installments of $0; *

(ii) For the period from August 1, 2016 through October 31, 2016, the sum of
$82,224.99 based on $32.50 per square foot, payable in monthly installments of
$27,408.33;

(iii) For the period from November 1, 2016 through October 31, 2017, the sum of
$732,779.00 based on $33.50 per square foot, payable in monthly installments of
$61,064.92; **

(iv) For the period from November 1, 2017 through October 31, 2018, the sum of
$754,653.00 based on $34.50 per square foot, payable in monthly installments of
$62,887.75; and **

 

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(v) For the period from November 1, 2018 through October 31, 2019, the sum of
$776,527.00 based on $35.50 per square foot, payable in monthly installments of
$64,710.58. **

 

* This schedule assumes the Phase I and Phase II Expansion Space Commencement
Date will occur on the Target Delivery Date. If for any reason the Phase I and
Phase II Expansion Space Commencement Date does not occur on the Target Delivery
Date, this schedule will be adjusted so that Annual Fixed Rent for the first
three months after the Phase I and Phase II Expansion Space Commencement Date
occurs is abated, provided, however, that the dates of the Annual Fixed Rent
increases set forth in the schedule above will remain unchanged.

** Includes the Original Premises

Monthly installments of Base Rent shall be payable in advance on the first day
of each month during the term of this Lease without deduction, set-off, prior
notice or demand in lawful money of the United States of America. The rent
payment for any fractional month at the commencement, termination or expiration
of the Lease term will be prorated.

 

E. Phase II Expansion Space Tenant Electricity.

Landlord and Tenant acknowledge and agree that the Phase II Expansion Space will
be check metered for electric usage and that Tenant shall pay for all
electricity usage related to and/or used respecting both the Phase I and Phase
II Expansion Space in accordance with the provisions of the First Amendment.

 

F. Phase II Expansion Space Real Estate Taxes.

Tenant shall pay Landlord’s Tax Expenses allocable to the Phase II Expansion
Space in accordance with the provisions of the First Amendment.

 

G. Phase II Expansion Space Operating Expenses.

Tenant shall pay Landlord’s Operating Expenses allocable to the Phase II
Expansion Space in accordance with the provisions of the First Amendment.

 

H. Landlord’s Work.

Landlord shall provide a turnkey build-out of the Phase I and Phase II Expansion
Space using the same finishes and materials (if available) as used in the
Original Premises (including, but not limited to, lighting, carpet, paint, doors
and sidelights), in accordance with the plan and scope of work attached hereto
as Exhibit A and Exhibit A-1.

 

I. Target Delivery Date; Delay in Commencement

Notwithstanding the Target Delivery Date, if for any reason Landlord cannot
deliver possession of the Phase I and Phase II Expansion Space to Tenant on or
before the Target Delivery Date, the provisions of Paragraph H of the First
Amendment shall apply.

 

J. Brokerage.

The Tenant has not dealt with any broker or agent other than The Shaffer Company
in connection with the negotiation or execution of this Second Amendment. Tenant
agrees to indemnify Landlord against any costs incurred by Landlord (including
reasonable attorneys’ fees) if the foregoing representation is untrue. The
foregoing indemnification obligation shall survive the expiration or any
termination of the Lease, as amended by this Second Amendment.

 

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K. Ratification of Lease.

Except as amended and modified by this Second Amendment, all the terms,
provisions, agreements, covenants and conditions of the Existing Lease are
hereby affirmed and ratified. From and after the date hereof, all references to
the Lease or Existing Lease shall mean the Lease or Existing Lease as amended
hereby and to the extent that there any inconsistencies between this Second
Amendment and the Existing Lease, this Second Amendment shall control. Landlord
and Tenant each hereby ratifies and confirms its obligations under the Lease,
and represents and warrants to the other that, to its knowledge, it has no
defenses thereto. Additionally, Landlord and Tenant further confirm and ratify
that, as of the date hereof, (a) the Landlord and Tenant are and remain in good
standing and the Lease is in full force and effect, and (b) neither Landlord nor
Tenant has any claims, counterclaims, set-offs or defenses against the other
arising out of the Lease or in any way relating thereto or arising out of any
other transaction between Landlord and Tenant.

 

L. Execution/Entire Agreement.

This Second Amendment, together with the Lease as affected hereby, constitutes
the entire agreement of the parties, and may not be amended except by written
instrument signed by all parties. This Second Amendment shall have the effect of
an agreement under seal and shall be binding upon and inure to the benefit of
the parties hereto and their respective successors and assigns. This Second
Amendment may be executed in counterparts all of which taken together shall
constitute an original executed document.

[Signatures on following page]

 

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The parties hereto have hereunto set their hands and seals the day and year
first above written.

 

LANDLORD: CIP II/RJK 10-20 BMR Owner, LLC /s/ Brandon Kelly BY: Brandon Kelly
ITS: TENANT: FLEXION THERAPEUTICS, INC. /s/ Frederick W. Driscoll BY: Frederick
W. Driscoll ITS: Chief Financial Officer

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EXHIBIT A

Plan of Phase I and Phase II Expansion Space

 

LOGO [g134391cm123.jpg]

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EXHIBIT A-1

Scope of work for Phase I and Phase II Expansion Space

 

1. Carpentry

 

  a. All new walls built to drop ceiling as shown on mutually agreed upon plan.

 

  b. Installation of kitchen cabinets (uppers and lowers) in kitchen area.

 

2. Millwork

 

  a. Kitchen – cabinets (uppers and lowers) as shown on Exhibit A. Cabinets to
have plastic laminate finish, specific layout to be mutually agreed upon by
Landlord and Tenant. Cabinet and countertop laminate to be mutually agreed upon
by Landlord and Tenant based on Landlord’s building standards.

 

3. Doors and hardware

 

  a. Provide 3’0” x 8’4” solid wood doors paint grade and building standard
bright chrome latch sets in new offices and conference rooms.

 

  b. Provide painted hollow metal door frames to match door size, as shown in
Exhibit A.

 

  c. All doors and frames shall be painted to match existing space.

 

  d. All electronic access control components and labor to be provided and
installed by the Tenant.

 

4. Glazing

 

  a. Provide Landlords upgraded sidelights to have  1⁄4 “tempered glass, framed
to match door frame from floor to door height, 48” wide in all new offices and
the conference rooms.

 

  b. Tenant shall, at Tenant’s expense, provide any necessary connections to
Premises main glass entry doors required to incorporate Tenant’s security access
system into the Building fire protection systems.

 

  c. All glazing film shall be purchased and installed by Landlord’s contractor
at Landlord’s expense. Landlord to provide glazing film to match existing space.

 

5. Ceilings

 

  a. Provide 2x2 Armstrong Dune Tegular ceiling tiles, style number 1774 (or
similar Landlord standard), on Armstrong 15/16” grid for all areas of drop
ceiling.

 

6. Flooring

 

  a. Provide Armstrong Commercial VCT in Kitchen and server room with 4” Vinyl
cove base, colors and pattern to be mutually agreed upon by Landlord and Tenant
based on Landlord’s building standards.

 

  b. Provide Carpet tile to be mutually agreed upon by Landlord and Tenant based
on Landlord’s building standards in all offices and open areas as shown in
Exhibit A. Landlord will provide a matching/coordinating carpet to Tenant’s
existing carpet.

 

  c. Transitions to be black vinyl as appropriate for materials.

 

7. Paint shall be Benjamin Moore or mutually agreed upon equivalent to match
Tenant’s existing paint colors.

 

8. Plumbing & Appliances

 

  a. Landlord shall provide a standard stainless steel sink and faucet for
Kitchen.

 

9. Fire Protection

 

  a. Landlord to provide complete sprinkler coverage as required by local codes.

 

  b. Landlord shall provide fire extinguishers as required by local regulations
and codes.

 

  c. Tenant, at its sole cost and expense, shall be responsible for all
equipment and installation of any dedicated supplemental fire protection systems
(preaction systems) in Server Room, if applicable.

 

10. HVAC

 

  a. Landlord shall rework existing HVAC as needed to provide adequate base
heating and cooling within the space.

 

  b. Tenant shall be responsible for any additional HVAC in server room or IT
rooms.

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  c. Landlord shall provide operable thermostats spaced according to existing
and reasonable zoning, and controls shall be tied into the existing building’s
energy management system.

 

  d. Landlord shall provide air balancing at completion of project.

 

11. Electrical

 

  a. Power

 

  i. Landlord shall equip each new office and conference room with a minimum of
2 duplex outlets.

 

  ii. Tenant to provide furniture that is prewired for power and is coordinated
with the electrician’s power plan.

 

  b. Lighting

 

  i. Landlord shall provide 2“x4” direct indirect LED light fixtures.

 

  ii. Landlord shall provide building standard emergency and night lighting as
required by local regulations and code.

 

12. All Furnishings are not included in the scope of work and shall be the
responsibility of the Tenant.

 

13. ALL WIRING WHIPS, WIRING WITHIN FURNITURE, AND ALL TELEPHONE AND DATA WIRING
ARE NOT INCLUDED IN THIS SCOPE OF WORK AND SHALL BE THE RESPONSIBILITY OF THE
TENANT.

Notes:

 

  •   All work to be completed in accordance with approved plans and
construction schedule.

 

  •   Legal removal and disposal of work related debris is included.

 

  •   We have assumed all work to be done between the hours of 7:00am to 5:00pm
unless otherwise specified. No Premium Time included.

 

  •   Mutually agreed upon substitutions for any products mentioned herein may
be used contingent upon product availability, supplier pricing increases and
timing.

 

  •   Any products and/or labor not stated to be performed in the above
description is not included in this scope of work. Any deviations from this
scope of work may result in a change order, the cost of which shall be paid for
by Tenant.