Phase 1/1B trial of the heat shock protein 90 inhibitor NVP-AUY922 as monotherapy or in combination with bortezomib in patients with relapsed or refractory multiple myeloma.

Background: NVP-AUY922 (AUY; Luminespib) with or without bortezomib showed preclinical activity against multiple myeloma (MM) cells. This phase 1/1B study assessed NVP-AUY922 alone and with bortezomib in patients with relapsed or refractory MM.

Methods: Dose escalation was guided by an adaptive Bayesian logistic regression model. In phase 1, patients who progressed after 2 to 4 prior therapies received NVP-AUY922 intravenously once weekly. In phase 1B, patients who progressed after 2 or fewer prior therapies received NVP-AUY922 plus bortezomib. The primary objective was to determine the maximum tolerated dose (MTD) of NVP-AUY922.

Results: Twenty-four patients received NVP-AUY922 monotherapy at doses of 8 to 70 mg/m(2) . One dose-limiting toxicity (DLT) was observed (grade 3 blurred vision at 70 mg/m(2) ); no MTD was reached. The recommended phase 2 dose was 70 mg/m(2) . The most frequent drug-related adverse events (AEs) were diarrhea, nausea, and ocular toxicities. Grade 3/4 AEs were uncommon (<10%). Eight patients discontinued treatment because of AEs; 5 had ocular toxicities (≥45 mg/m(2) ). The best response was stable disease in 66.7% of the patients. There were no partial or complete responses. Five patients received NVP-AUY922 (which was started at 50 mg/m(2) ) plus bortezomib (1.3 mg/m(2) ). Three of these patients experienced DLT. No further dose escalation was performed; the MTD for NVP-AUY922 plus bortezomib was not established.

Conclusions: This study showed disease stabilization with NVP-AUY922 in patients with relapsed or refractory MM. The MTD for NVP-AUY922 was not reached, but reversible ocular toxicity has been reported at high dose levels. Bortezomib at the standard recommended dose plus NVP-AUY922 was not tolerated.