Ruxolitinib

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).

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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).

As of July 15, 2021, 27 patients were enrolled. The median age was 64 years (range, 46-85), and 17 (63%) were male. Patients received a median of 4 (range, 3-11) prior treatments including LEN and steroid-containing regimens to which they were all refractory. Twenty-six patients have completed at least 1 full cycle of therapy; and, thus, were evaluable for efficacy.

The ORR and CBR were 35% (n=9) and 39% (n=10), respectively. Notably, all 10 responding patients were refractory to LEN (i.e., progressed while on or within 8 weeks of last dosage). The remaining patients showed stable disease (n=12) or PD (n=4). The median follow-up was 13 months. The median progression-free survival was 4 months (range, 1-21). The median duration of response was 11 months (range, 1-20). Of 13 patients who progressed on the two-drug combination and had LEN added to their regimen, 6 patients responded (3 MR and 3 PR).

Nine patients experienced SAEs including sepsis (12%), sepsis with neutropenic fever (4%), thrombocytopenia (4%), hyperglycemia (4%), neutropenia (4%), anemia (4%), acute heart failure (4%), rotator cuff tear (4%), osteomyelitis (4%), aspiration pneumonia (4%), pneumonia and pneumothorax (4%), and deep venous thrombosis (4%). Two patients died (one each from pneumonia and PD).