A Study of Tanespimycin (KOS-953) in Patients With Relapsed-refractory Multiple Myeloma

Phase 2/3 combination study comparing bortezomib plus one of three doses of tanespimycin in
patients with relapsed-refractory multiple myeloma after failure of at least three prior
anti-cancer therapy regimens. Prior therapy must include bortezomib and lenalidomide.
Primary objective is to assess the dose-response relationship of objective response rate
(ORR) using EBMT/IBMTR criteria of any three dose levels of tanespimycin (KOS-953) in
combination with bortezomib after four treatment cycles.

Inclusion Criteria:

- Good performance status

- Histologic evidence of multiple myeloma

- Have had at least three prior treatment regimens for multiple myeloma that included
both bortezomib and lenalidomide

- No prior treatment with a heat shock 90 inhibitor or an investigational proteasome
inhibitor

- No known infections of HAV, HBV, HCV, or HIV

- No chemotherapy, radiation therapy, or immune therapy for three weeks prior to
enrollment.