AGREEMENT

Exhibit 99.1

AGREEMENT

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree that only one statement containing the information required by Schedule 13G need be filed with respect to the ownership by each of the undersigned of the shares of Common Stock of Intralinks Holdings, Inc.

Dated: February 9, 2011

RHO VENTURES IV(QP), L.P.
RHO VENTURES IV, L.P.
BY: RHO MANAGEMENT VENTURES IV, L.L.C.
ITS: GENERAL PARTNER

/s/ Xxxxxxx X. Xxxxxx  

Xxxxxxx X. Xxxxxx, Authorized Signer 

RHO MANAGEMENT VENTURES IV, L.L.C.
 

/s/ Xxxxxxx X. Xxxxxx  

Xxxxxxx X. Xxxxxx, Authorized Signer 

RHO VENTURES IV GMBH & CO. BETEILIGUNGS KG
BY: RHO CAPITAL PARTNERS VERWALTUNGS GMBH
ITS: GENERAL PARTNER  

/s/ Xxxxxxx X. Xxxxxx  

Xxxxxxx X. Xxxxxx, Authorized Signer 

RHO CAPITAL PARTNERS VERWALTUNGS GMBH
 

/s/ Xxxxxxx X. Xxxxxx  

Xxxxxxx X. Xxxxxx, Authorized Signer 

RHO MANAGEMENT TRUST I
BY: RHO CAPITAL PARTNERS, INC.
ITS: INVESTMENT ADVISOR  

/s/ Xxxxxxx X. Xxxxxx  

Xxxxxxx X. Xxxxxx, Authorized Signer 

RHO CAPITAL PARTNERS, INC.
 

/s/ Xxxxxxx X. Xxxxxx  

Xxxxxxx X. Xxxxxx, Authorized Signer
 

/s/ Xxxxxxx X. Xxxxxx  

Xxxxxxx X. Xxxxxx, Authorized Signer for Xxxxxx Xxxx
 

/s/ Xxxxxxx X. Xxxxxx  

Xxxxxxx X. Xxxxxx, Authorized Signer for Xxxx Xxxxxxx
 

/s/ Xxxxxxx X. Xxxxxx  

Xxxxxxx X. Xxxxxx, Authorized Signer for Xxxxx Xxxxxxx