Lenalidomide and dexamethasone in patients with POEMS syndrome: results of a prospective, open-label trial.

Given its anti-angiogenic activity, lenalidomide may have a role in the treatment of POEMS (Peripheral neuropathy, Organomegaly, Endocrinopathy, Monoclonal plasma cell disorder and Skin changes) syndrome. This prospective, open-label, pilot study evaluated the combination of lenalidomide + dexamethasone (RD) in 18 POEMS syndrome patients (13 pre-treated, 5 newly-diagnosed but ineligible for high-dose therapy). Treatment consisted of six cycles of lenalidomide (25 mg/day for 21 days followed by 7 days rest) plus dexamethasone (40 mg/once a week). Patients responding after six cycles continued treatment until progression or unbearable toxicity. The primary endpoint was the proportion of patients with either neurological or clinical improvement. The RD combination was considered as deserving further evaluation if 9 of the first 15 patients responded. Ten responses were observed among the first 15 enrolled patients, meeting the primary endpoint. Fifteen of 18 patients (83%) completed six RD cycles: 13 (72%) patients responded and nine had both clinical and neurological improvement. Among the 15 patients who completed the six RD cycles, four were still on treatment after a 25-month follow-up. At 39 months of follow-up, all patients were alive with a 3-year progression-free survival of 59%. No patient discontinued RD for toxicity. Overall, the RD regimen showed a high incidence of prolonged symptoms improvement and was well tolerated in most POEMS patients.