Introduction: Pomalidomide-dexamethasone (Pd) has been a standard of care treatment for myeloma since 2013. Due to the current treatment algorithms, pomalidomide is mostly used in patients already exposed to a CD38 antibody. However, the clinical performance of pomalidomide in the era of CD38 antibodies is largely unknown.
Methods: Here we describe the real-world use and efficacy of pomalidomide in a complete Danish, nationwide cohort of daratumumab-exposed patients. We conducted a nationwide retrospective review of the clinical course of all patients treated with a daratumumab-containing regimen prior to 1.1.2019. Treatment data were updated until 1.1.2021.
Results: We identified 328 patients that were treated with pomalidomide. Of these, 137 received Pd, 65 daratumumab-pomalidomide-dexamethasone (DPD), 43 pomalidomide-cyclophosphamide-dexamethasone (PCD), 19 carfilzomib-pomalidomide-dexamethasone (KPD), 11 pomalidomide-bortezomib-dexamethasone (PVD) and 52 pomalidomide in other combinations. Patients treated with Pd had a partial response or better rate (>=PR) of 35.8% and median time to next treatment (mTNT) of 4.9 months, almost identical to previous prospective clinical trials. Although treatment with the various pomalidomide-containing triplet regimens resulted in higher >=PR rates (PCD: 46.5%, PVD: 63.6%, DPD: 55.4%, KPD: 63.2%), the achieved mTNT was not significantly better than what was achieved with Pd (PCD: 5.4, PVD: 5.3, DPD: 4.7 months). The exemption to this was KPD (mTNT 7.4 months), but this regimen was used earlier in the course of the disease. The most important predictor of outcomes, rather than the choice of index regimen (p=0.72), was prior exposure (p=0.0116). Compared to CD38 antibody-naïve patients, patients previously treated with a CD38 antibody had reduced partial response or better rate (38.0% vs 47.3%), shorter median TNT (4.0 vs 5.9 months), and shorter median OS (12.4 vs 24.2 months) on pomalidomide treatment.
Conclusions: In this large real-world cohort, the clinical performance of Pd was almost identical to the results of prospective clinical trials. Although treatment with the various pomalidomide-containing triplet regimens resulted in higher response rates, the achieved TNT was not better than what was achieved with Pd. Compared to CD38 antibody-naïve patients, patients previously treated with a CD38 antibody achieved worse outcomes with pomalidomide.
