MM-501 Domestic Opportunity in Heavily Pretreated Multiple Myeloma Not Eligible for Hospital-Based Treatment: Role of Pomalidomide-Dexamethasone

Abstract

Pomalidomide is a new generation IMID, with very good compliance, thanks to oral administration, which can be used in heavily pretreated patients in a domestic setting. Retrospective observational trial, which evaluated efficacy and tolerance of pomalidomide plus dexamethasone (PD) as salvage regimen in heavily pretreated patients with relapsed and refractory MM (rrMM), whose prognosis is particularly severe. 57 patients (31 M/26 F), with rrMM, median age at diagnosis 69 years (r. 52-86), and median age at start of treatment 76 years (r. 56-90) treated with several lines of treatments (median 7, r. 2-11), refractory to all drugs previously received (also bortezomib, thalidomide and lenalidomide), received pomalidomide-dexamethasone (pomalidomide 4 mg for 21 days, dexamethasone 40 mg days 1, 8, 15, 22, pegfilgrastim day +8) every 28 days, until progression. 63% (36/57) had undergone at least one ASCT. All patients were relapsed and refractory to last therapies received before PD. Pomalidomide was well tolerated, with grade 3-4 transfusion-dependent anemia in 58% (33/57) of patients, 44% (23/57) grade 3-4 neutropenia (pegfilgrastim in primary prophylaxis was given, no hospitalization was required, no septic shocks were observed), 40% (23/57) grade 3-4 thrombocytopenia without hemorrhagic events and transfusion-dependence. No severe extra-hematologic toxicity was observed. ORR1 (≥PR) was 47.3% (27/57: 5 CR, 11 VGPR, 7 PR, 4 MR). Considering this is a cohort of heavily pretreated patients with poor prognosis, another parameter should be considered; ORR2 (≥SD), considering stable disease as a successful result in progressive MM. ORR2 was 77.1% (17 SD) in this subset. Response, when present, is always fast (median time to response: 2 months (r.1-6)), median OS from diagnosis was 94 months (range 21-234), median OS from start of pomalidomide was 9 months (range 1-25). Nine patients have achieved a notable response (3 VGPR, 4 PR, 2 MR) after failure of novel agents (i.e., carfilzomib, daratumumab and pomalidomide). Pomalidomide-dexamethasone has shown significant efficacy and a very good compliance, thanks to oral administration, in a particularly severe setting of heavily pretreated patients, relapsed and refractory to all available therapeutic resources, also after failure of novel agents.