Efficacy of Isatuximab With Pomalidomide and Dexamethasone in Relapsed Myeloma: Results of a UK-Wide Real-World Dataset

Abstract

Real-world data on the efficacy and tolerability of isatuximab with pomalidomide and dexamethasone (IsaPomDex) in relapsed/refractory myeloma patients have not been reported. In this UK-wide retrospective study, IsaPomDex outcomes were evaluated across 24 routine care cancer centers. The primary endpoint was overall response rate (ORR). Secondary endpoints included progression-free survival (PFS), duration of response (DOR) for patients who achieved an objective response (≥partial response [PR]), and adverse events (AEs). In a total cohort 107 patients, median follow up (interquartile range [IQR]) was 12.1 months (10.1-18.6 mo), median age (IQR) was 69 years (61-77). Median (IQR) Charlson Comorbidity Index (CCI) score was 3 (2-4); 43% had eGFR <60 mL/min. Median (IQR) number of prior therapies was 3 (3-3). Median (IQR) number of IsaPomDex cycles administered was 7 (3-13). ORR was 66.4%, with responses categorized as ≥ very good partial response: 31.8%, PR: 34.6%, stable disease: 15.9%, progressive disease: 15%, and unknown 2.8%. Median PFS was 10.9 months. Median DOR was 10.3 months. There was no statistical difference in median PFS by age (<65: 10.2 versus 65-74 13.2 versus ≥75: 8.5 mo, log-rank P = 0.4157), by CCI score (<4: 10.2 mo versus ≥4: 13.2, log-rank P = 0.6531), but inferior PFS was observed with renal impairment (≥60: 13.2 versus <60: 7.9 mo, log-rank P = 0.0408). Median OS was 18.8 months. After a median of 4 cycles, any grade AEs were experienced by 87.9% of patients. The most common ≥G3 AEs were neutropenia (45.8%), infections (18.7%), and thrombocytopenia (14%). Our UK-wide IsaPomDex study demonstrated encouraging efficacy outcomes in the real world, comparable to ICARIA-MM trial.

Figure 1.

PFS in the total cohort. IPD = isatuximab with pomalidomide and dexamethasone; PFS = progression-free survival.

Figure 2.

PFS 3-month landmark analysis by myeloma response (<PR vs ≥PR). IPD = isatuximab with pomalidomide and dexamethasone; PFS = progression-free survival; PR = partial response.

Figure 3.

DOR to IsaPomDex, presented as cumulative incidence of relapse for responding patients (≥PR), from time of best response to time of myeloma relapse. DOR = duration of response; PR = partial response.

Figure 4.

OS in the total cohort. IPD = isatuximab with pomalidomide and dexamethasone; OS = overall survival.