SARC023: Ganetespib and Sirolimus in Patients With MPNST (Malignant Peripheral Nerve Sheath Tumors)

Previously, no targeted agents have been able to cause tumor regression in a genetically engineered MPNST mouse model or human MPNST. Recently published data from Dr. Cichowski's laboratory demonstrated using Hsp90 inhibitors to enhance endoplasmic reticulum stress coupled with the mammalian target of rapamycin (mTOR) inhibitor sirolimus led to dramatic tumor shrinkage in a transgenic MPNST mouse model, which correlated with profound damage to the endoplasmic reticulum and cell death. Ganetespib is a novel, injectable, small molecule inhibitor of Hsp90 and is currently being investigated in adults with a broad range of tumor types with a favorable safety profile and promising early results. Ganetespib has been studied in preclinical in vivo models with a variety of targeted agents with no marked apparent pharmacological interactions. Sirolimus is a commercially available orally administered mTOR inhibitor and is the active metabolite of temsirolimus, which is FDA approved agent for advanced metastatic renal cell carcinoma. Sirolimus has been studied and tolerated in combination with multiple cytotoxic and targeted agents in a variety of tumor types. Based on strong preclinical rationale, the investigators hypothesize that ganetespib in combination with sirolimus will cause tumor regression in patients with refractory MPNSTs. The investigators propose a multi-institutional open label phase I/II trial of ganetespib in combination with sirolimus in patients with refractory sarcoma including MPNST. Hsp90 inhibitors and mTOR inhibitors have also both demonstrated benefit in a variety of preclinical bone and soft tissue sarcoma models. The investigators hypothesize that these agents that work on separate and potentially synergistic pathways will also be beneficial for other refractory bone and soft tissue sarcomas. Thus, the phase I component will be open to patients with refractory sarcomas, which will also expedite enrollment. Upon determination of the recommended dosing, a phase II study will be conducted. The phase II study population will be limited to patients with a diagnosis of MPNST.