Conference Coverage

Ruxolitinib overcame lenalidomide resistance in myeloma



– The JAK 1/2 inhibitor ruxolitinib (Jakafi), in combination with lenalidomide and methylprednisolone, overcame resistance to lenalidomide in about half of 28 heavily pre-treated patients with relapsed/refractory multiple myeloma, based on phase I trial results presented at the annual meeting of the American Society of Clinical Oncology (ASCO).

The clinical trial is the first to demonstrate the activity of a JAK inhibitor in the treatment of myeloma patients, according to investigator James R. Berenson, MD, medical and scientific director for the Institute for Myeloma & Bone Cancer Research (IMBCR), West Hollywood, Calif.

James R. Berenson, MD, Medical & Scientific Director for the Institute for Myeloma & Bone Cancer Research (IMBCR), West Hollywood, Calif. Andrew Bowser/MDedge News

Dr. James R. Berenson

The all-oral combination was “very well tolerated” with few grade 3 or greater adverse events, including cytopenias, Dr. Berenson reported. All patients who had a response to the ruxolitinib, lenalidomide, and methylprednisolone combination were lenalidomide refractory.

“These promising results have led to the expansion of the current clinical trial and provide the basis for exploration of this and other JAK inhibitor-containing combinations for treating patients with myeloma and other malignant diseases,” he added.

The dose-escalation study enrolled 28 patients with relapsed/refractory multiple myeloma who had previous treatment with lenalidomide/steroids and a proteasome inhibitor. Subjects received ruxolitinib twice daily continuously, lenalidomide daily on days 1-21 of a 28-day cycle, and methylprednisolone orally every other day. A traditional 3+3 dose escalation design was used to enroll subjects in four cohorts. In DL0, patients received ruxolitinib 5 mg, lenalidomide 5 mg, and methylprednisolone 40 mg. In DL+1 and +2, both doses of lenalidomide and methylprednisolone remained unchanged, and ruxolitinib was escalated to 10 and 15 mg, respectively. In DL+3, lenalidomide was escalated to 10 mg with methylprednisolone unchanged and ruxolitinib at 15 mg. A total of 19 patients were treated at the highest dose level, which was ruxolitinib 15 mg twice daily on days 1-28, lenalidomide 10 mg daily on days 1-21, and methylprednisolone 40 mg every other day.

The overall response rate was 39% (10 of 26 evaluable patients), Dr. Berenson reported. The clinical benefit rate was 50% (13 of 26 patients), with a median duration of response of 5.6 months in that group.

There were no dose-limiting toxicities. Grade 3 toxicities reported included thrombocytopenia in 11% (3 patients, gastrointestinal bleeding in 11% (3 patients), and anemia in 7% (2 patients).


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