Outcomes of Daratumumab, Pomalidomide, and Dexamethasone, Followed by High-dose Chemotherapy and Autologous Stem Cell Transplantation, in Patients With Relapsed/Refractory Multiple Myeloma

Treatment pattern and outcomes of re-induction therapy prior to stem cell transplantation in patients with relapsed/refractory multiple myeloma in Germany

There are limited data guiding choice of re-induction therapies for patients with relapsed/refractory multiple myeloma (RRMM) prior to stem cell transplantation (SCT). We performed a retrospective medical chart review of 171 patients with RRMM in Germany who received re-induction therapy in second line (78%; n = 134) or third line (22%; n = 37) prior to re-SCT. Index therapy was defined as first completed re-induction therapy for planned myeloablative conditioning and SCT in second/third line within the eligibility period (1/2016-12/2019). Most common pre-index first line and maintenance therapy used were bortezomib-based combinations (91%; n = 155/171) and lenalidomide (55%; n = 29/53), respectively. Median duration of index therapy line was 9 months; carfilzomib-based combinations were the most widely used in second/third line re-induction therapy (49%; n = 83/171), followed by daratumumab-based combinations (21%; n = 36/171). Overall response rates in second/third line were 87% after re-induction and 96% after SCT; median time to next treatment line after start of index therapy was 31 months; median progression-free survival (PFS) was 29 months; and median overall survival after index date was not reached. Based on these data, re-induction therapy with salvage SCT appears to be beneficial in selected patients with RRMM in clinical practice in Germany, translating into deep responses, long PFS and prolonged time to next treatment.

Outcomes after delayed and second autologous stem cell transplant in patients with relapsed multiple myeloma

We evaluated the outcomes of 168 patients undergoing delayed or second autologous stem cell transplant (ASCT) for relapsed multiple myeloma (MM) from 2010 to 2019. Overall, 21% (n = 35) patients had received a prior transplant and 69% (n = 116) underwent transplant at first relapse. Overall, 27% patients had high-risk cytogenetics and 15% had ISS stage III disease. Stem cell collection was performed after relapse in 72% and 35% of patients received maintenance therapy. Median PFS from salvage treatment and transplant were 28 and 19 months, respectively. Median OS from salvage treatment and transplant was 69 and 55 months. Multivariate analysis revealed that ASCT in first relapse was associated with superior PFS (HR 0.63, p = 0.03) and OS (HR 0.59, p = 0.04) compared to later lines of therapy. In addition, PFS of ≥36 months with prior therapy was associated with improved PFS (HR 0.62, p = 0.04) and OS (HR 0.41, p = 0.01). Ninety-five patients underwent delayed transplant at first relapse, median PFS and OS from start of therapy was 30 and 69 months, and median OS from diagnosis was 106 months. These data may serve as a guide when counseling patients undergoing ASCT for relapsed MM and provide a benchmark in designing clinical trials of transplantation/comparative treatments for relapsed MM.