Exhibit 10.1

FIRST AMENDMENT TO LEASE

THIS FIRST AMENDMENT TO LEASE (this “Amendment”) is entered into as of this 1st
day of May, 2013, by and between BMR-ROGERS STREET LLC, a Delaware limited
liability company (“Landlord”), and IDENIX PHARMACEUTICALS, INC., a Delaware
corporation (“Tenant”).

RECITALS

A. WHEREAS, Landlord and Tenant entered into that certain Lease dated as of
September 25, 2012, as the same may have been amended, supplemented or modified
from time to time, the “Lease”), whereby Tenant leases certain premises (the
“Premises”) from Landlord in the building at 320 Bent Street in Cambridge,
Massachusetts (the “Building”);

B. WHEREAS, Landlord and Tenant desire to provide a written description of the
Phase 3 Tenant Improvements (as defined in the Lease); and

C. WHEREAS, Landlord and Tenant desire to modify and amend the Lease only in the
respects and on the conditions hereinafter stated.

AGREEMENT

NOW, THEREFORE, Landlord and Tenant, in consideration of the mutual promises
contained herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, and intending to be legally bound,
agree as follows:

1. Definitions. For purposes of this Amendment, capitalized terms shall have the
meanings ascribed to them in the Lease unless otherwise defined herein. The
Lease, as amended by this Amendment, is referred to herein as the “Amended
Lease.”

2. Phase 3 Tenant Improvements. Pursuant to Section 4.4(a) of the Lease,
Landlord and Tenant hereby agree that the Phase 3 Tenant Improvements shall
include those items listed on Exhibit A attached hereto and shall be in
accordance with the fit plan attached hereto as Exhibit B.

3. Broker. Tenant represents and warrants that it has not dealt with any broker
or agent in the negotiation for or the obtaining of this Amendment and agrees to
indemnify, defend and hold Landlord harmless from any and all cost or liability
for compensation claimed by any such broker or agent employed or engaged by it
or claiming to have been employed or engaged by it.

4. No Default. Tenant represents, warrants and covenants that, to the best of
Tenant’s knowledge, Landlord and Tenant are not in default of any of their
respective obligations under the Lease and no event has occurred that, with the
passage of time or the giving of notice (or both) would constitute a default by
either Landlord or Tenant thereunder.

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

5. Effect of Amendment. Except as modified by this Amendment, the Lease and all
the covenants, agreements, terms, provisions and conditions thereof shall remain
in full force and effect and are hereby ratified and affirmed. The covenants,
agreements, terms, provisions and conditions contained in this Amendment shall
bind and inure to the benefit of the parties hereto and their respective
successors and, except as otherwise provided in the Lease, their respective
assigns. In the event of any conflict between the terms contained in this
Amendment and the Lease, the terms herein contained shall supersede and control
the obligations and liabilities of the parties. From and after the date hereof,
the term “Lease” as used in the Lease shall mean the Lease, as modified by this
Amendment.

6. Miscellaneous. This Amendment becomes effective only upon execution and
delivery hereof by Landlord and Tenant. The captions of the paragraphs and
subparagraphs in this Amendment are inserted and included solely for convenience
and shall not be considered or given any effect in construing the provisions
hereof. All exhibits hereto are incorporated herein by reference. Submission of
this instrument for examination or signature by Tenant does not constitute a
reservation of or option for a lease, and shall not be effective as a lease,
lease amendment or otherwise until execution by and delivery to both Landlord
and Tenant.

7. Counterparts. This Amendment may be executed in one or more counterparts,
each of which, when taken together, shall constitute one and the same document.

[REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK]

 

2

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

IN WITNESS WHEREOF, Landlord and Tenant have hereunto set their hands as of the
date and year first above written as a sealed Massachusetts instrument, and
acknowledge that they possess the requisite authority to enter into this
transaction and to execute this Amendment.

LANDLORD:

BMR-ROGERS STREET LLC,

a Delaware limited liability company

 

By:

 

/s/ William Kane

Name:

  William Kane

Title:

  Vice President, Leasing and Development

TENANT:

IDENIX PHARMACEUTICALS, INC.,

a Delaware corporation

 

By:

 

/s/ Maria Stahl

Name:

  Maria Stahl

Title:

  SVP, General Counsel

 

3

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

EXHIBIT A

PHASE 3 TENANT IMPROVEMENTS

 

  •  

Install new glass entrance

 

  •  

Office areas

 

  •  

Flooring to be carpet tiles

 

  •  

Ceilings to be ACT

 

  •  

Walls to be painted

 

  •  

Ready for installation of furniture to suit tenant program

 

  •  

Conference rooms

 

  •  

Flooring to be carpet tiles

 

  •  

Ceilings to be ACT

 

  •  

Walls to be painted

 

  •  

Restrooms

 

  •  

Showers to include tile

 

  •  

Ceilings to be ACT

 

  •  

Walls to be painted

 

  •  

Locker room

 

  •  

Kitchenette

 

  •  

Cabinets to be installed

 

  •  

VCT flooring

 

  •  

Ceilings to be ACT

 

  •  

Walls to be painted

 

A-1

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

EXHIBIT B

FIT PLAN OF PHASE 3 TENANT IMPROVEMENTS

Attached on file at Company

 

B-1