In the dose-escalation and dose-expansion stages of the trial assesing TH-302 and low-dose dexamethasone without bortezomib, patients were heavily-pretreated, and objective responses were observed in 5/16 patients treated at the maximum-tolerated dose of the prodrug.
Dana-Farber/Brigham and Women’s Cancer Center medical oncologist and principal investigator of the Phase I/II trial Irene Ghobrial said data seen thus far is encouraging using the combination of TH-302 and low-dose dexamethasone in patients with relapsed/refractory multiple myeloma.
"I would like to acknowledge the Blood Cancer Research Partnership for their significant role in facilitating rapid accrual of patients to this study," Ghobrial said.
"We are excited to initiate this final stage in which patients will receive TH-302, bortezomib, and dexamethasone, particularly in light of preclinical research demonstrating synergistic cytotoxicity of TH-302 and bortezomib."
Objectives of the ongoing Phase I/II trial include evaluation of safety and tolerability, determination of dose-limiting toxicities and the maximum-tolerated dose of TH-302, as well as the evaluation of preliminary efficacy these patients.
In patients with relapsed/refractory multiple myeloma, the most common adverse events related to TH-302 were nausea and fatigue that occurred in about 25% of the patients, while the most common Grade 3/4 hematologic adverse events related to TH-302 were thrombocytopenia (29%) and leukopenia (25%).
Currently, TH-302 is being evaluated in two Phase III trials: one in combination with doxorubicin versus doxorubicin alone in patients with soft tissue sarcoma, and the other in combination with gemcitabine versus gemcitabine and placebo in patients with advanced pancreatic cancer (the MAESTRO trial).