A couple of resources here that I think help to resolve some of our questions about the relationship of the Clinical Steering Committee (CSC) to the Data Safety Monitoring Board (DSMB), and how to put the Sample Size Re-estimation Analysis (SSRA) in the context of these two groups. Long story short, I think what Sarah conveyed about the CSC conducting the SSRA is technically true. It is the CSC that makes important decisions regarding the trial. However, if the CSC chooses to do the SSRA, it would instruct the independent DSMB to perform this interim analysis. The DSMB would then make recommendations to the CSC. The CSC would then report back to the Sponsor (Resverlogix), who would likely make any final decision. 

Slide 7 of the first link below (I've shared this one before) does a great job of illustrating the relationship amongst Sponsor (Resverlogix), CSC, DSMB and an independent statistical team. It also highlights the importance of which groups should remain blinded. The second link below has a great overview of the roles of the DSMB and CSC and I found the part on pages 6-7 "3.2. Clinical Trial Steering Committees" very helpful. 

Statistical considerations in confirmatory clinical trials

Guidance for Clinical Trial Sponsors: Establishment and Operation of Clinical Trial Data Monitoring Committees

"In some clinical trials the sponsor may choose to appoint a steering committee; this committee may include investigators, other experts not otherwise involved in the trial, and, usually, representatives of the sponsor. A sponsor may delegate to a steering committee the primary responsibility for designing the study, maintaining the quality of study conduct, ongoing monitoring of individual toxicities and adverse events, and, in many cases, writing study publications. When there is a steering committee, the sponsor may elect to have the DMC communicate with this committee rather than directly with the sponsor. Interactions between the steering committee and the DMC consist primarily of discussions during "open sessions" (see Section 4.3) of DMC meetings and the communication of recommendations following each DMC review of the trial. More extensive interactions might occur when early termination is being considered, or when external forces (e.g., announcement of results of related studies) impact the ongoing trial."