An Open-Label Phase I Study of the Safety and Efficacy of RAD001 in Combination with Lenalidomide in the Treatment of Patients with Relapsed and Relapsed/Refractory Multiple Myeloma.

Lenalidomide (Revlimid^®, Len) plus dexamethasone (Dex) is approved for the treatment of relapsed or refractory multiple myeloma (MM) patients following ≥1 prior therapy. mTOR inhibitor RAD001 has been studied as a single agent in MM, and although well tolerated, did not have single agent activity. Given the increased toxicity noted with pulsed high dose steroids, we sought to study a non-steroid containing oral regimen for the treatment of relapsed MM predicated upon our previous studies which demonstrated synergistic anti-MM activity of mTOR inhibitors when combined with len. Here, we extended our in vitro observations to a phase I clinical trial combining RAD001 with len in patients with relapsed or refractory MM. The primary objective was to assess toxicity of this combination and to determine the maximum tolerated dose (MTD). The secondary objective was to determine the activity of this combination.

Patients with relapsed and refractory MM were assigned to len and RAD001 to be taken for 21 days of a 28 day cycle. Dose escalation followed a modified Fibonacci design. Patients were allowed to continue therapy until disease progression or unacceptable toxicity. Patients received concomitant anti-thrombotic (aspirin 81 or 325 mg/day) therapy. Response was assessed according to modified EBMT and Uniform Criteria, and toxicities were assessed using NCI CTCAE v3.0.

Eighteen MM patients have been enrolled to date. One patient in cohort 1 (Len: 10mg and RAD001: 5 mg x 21 days) developed grade 3 neutropenia requiring expansion of the cohort. Cohort 2 (Len: 15mg and RAD001: 5 mg x 21 days) also required expansion because of grade 4 thrombocytopenia noted in 1 patient. Dose limiting toxicities included grade 4 neutropenia and thrombocytopenia in 2/3 patients in cohort 3 (Len: 20mg and RAD001: 5 mg x 21 days). The MTD for patients with MM was therefore declared at 15 mg of len and 5mg of RAD001 for 21 days with a 7 day rest period. Apart from the hematological toxicities expected with the combination, patients otherwise tolerated the regimen well. Most common (≥10%) grade 1 / 2 events included nausea, fatigue, dyspnea, diarrhea, constipation, neuropathy and muscle cramps, all of which were manageable with supportive care. No thromboembolic events were noted. Grade 3 / 4 adverse events ≥ 5% included thrombocytopenia (11%) and neutropenia (22%). Fifteen patients have finished at least 2 cycles of therapy: 8 of 15 patients have either stable disease (SD: 1), minimal response (MR: 5) or a partial response (PR: 2), including 7 of 9 patients treated at the recommended MTD for an overall response rate (MR or better) of 50% (90% CI: [30.76%]). One patient with SD continued therapy for a total of 10 cycles, without significant toxicities.

The combination of Len plus RAD001 is a well tolerated regimen with predictable hematological toxicities. Promising responses were noted in this heavily pretreated patient population. This combination provides an oral steroid free combination alternative strategy which warrants future evaluation in phase II studies.

Raje:Astrazeneca : Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Millenium: Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees. Off Label Use: RAD001 not labelled for use in myeloma. Richardson:Keryx: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Johnson and Johnson: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Hari:Celgene: Research Funding, Speakers Bureau. Laubach:Novartis:. Ghobrial:Millennium: Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau. Adams:Novartis: Employment. Makrides:Celgene: Employment.