Retrospective study of treatment patterns and outcomes post-lenalidomide for multiple myeloma in Canada

Efficacy and safety of daratumumab with ixazomib and dexamethasone in lenalidomide-exposed patients after one prior line of therapy: Final results of the phase 2 study DARIA

The use of lenalidomide in frontline therapy for patients with newly diagnosed multiple myeloma (MM) has increased the number of those who become refractory to lenalidomide at second line. In this context, we assessed the efficacy of daratumumab in combination with ixazomib and dexamethasone (Dara-Ixa-dex) in the prospective phase 2 study DARIA. Eligible patients had relapsed/refractory MM (RRMM) after one prior line with a lenalidomide-based regimen. The primary endpoint was overall response rate (ORR). Secondary endpoints included survival outcomes, safety and changes in biomarkers of bone metabolism. Overall, 50 patients were enrolled (median age 69 years, 56% males). 32 (64%) patients were refractory to lenalidomide, and 17 (34%) had undergone autologous transplant. The ORR was 64% (n = 32); whereas 17 (34%) had a very good partial response or better. The median time to first response was 1.0 month. After a median follow-up of 23.4 months, the median PFS and OS were 8.1 and 39.2 months, respectively. Furthermore, significant changes in markers of bone metabolism became evident as early as at 6 months on treatment. Regarding safety, 21 (42%) patients had ≥1 grade 3/4 adverse event (AE); the most common was thrombocytopenia (n = 9, 18%). 14 (28%) patients had ≥1 serious AE (SAE), the most common being acute kidney injury and pneumonia (n = 2, each). Four patients died due to infections. In conclusion, second-line treatment with Dara-Ixa-dex in patients with RRMM pre-treated with a lenalidomide-based regimen resulted in rapid responses along with a favorable effect on bone metabolism.

Post Salvage Therapy Autologous Transplant for Relapsed Myeloma, Ongoing Relevance within Modern Treatment Paradigms?

BACKGROUND

Salvage transplant has been historically considered effective therapy for myeloma patients relapsing after first transplant, if they achieved adequate remission duration. However, the efficacy of novel agent combinations has called this paradigm into question.

MATERIALS AND METHODS

We performed a retrospective analysis in a homogeneously treated cohort of 106 patients undergoing ASCT2 at our institution, all of whom received novel agent-based chemotherapy (immunomodulatory agent [IMiD] and/or proteasome inhibitor [PI]) for both induction and relapse. As an exploratory objective we assessed whether predictive thresholds of progression free survival post first transplant (ASCT1) for benefit post ASCT2 vary with use of IMiD maintenance post ASCT1.

RESULTS

The overall response rate (ORR) was 98% post-ASCT2 and treatment-related mortality (TRM) was low at 1.8%. With a median follow-up of 26 months (range 0.5-85) from ASCT2, median overall survival (OS) is estimated at 80 months (95% CI: ≥ 49-months) and median progression-free survival after ASCT2 (PFS2) at 24 months (95% CI 19-39). PFS post first transplant (PFS1) at >/= 50 months was associated with improved OS. Predictors of PFS2 included PFS1 ≤42 months and progression on IMiD-based maintenance post- ASCT1.

CONCLUSION

ASCT2 continues to offer acceptable outcomes for most patients treated within modern day treatment paradigms, with longer PFS after ASCT1 and IMiD non-refractory disease being associated with improved outcomes.

Efficacy of Daratumumab-Containing Regimens Among Patients With Multiple Myeloma Progressing on Lenalidomide Maintenance: Retrospective Analysis

Background

Daratumumab, a monoclonal antibody directed against CD38 is a recent class of drugs introduced into the multiple myeloma therapeutic landscape. While clinical trial data have shown a remarkable impact on outcomes, the efficacy of daratumumab combination therapies in specific clinically relevant subgroups including among patients refractory to lenalidomide maintenance remains unknown.

Methods

In this study, retrospective data were reviewed from the Canadian Myeloma Research Group and the German Munster Myeloma databases to identify patients that received daratumumab in combination with pomalidomide (DPd), lenalidomide (DRd), and bortezomib (DVd) in a population that had relapsed on lenalidomide maintenance postautologous stem cell transplant. The primary aim of the study was to look at outcomes of these patients in different daratumumab combinations.

Results

A total of 73 patients were identified. The median age of the patients at the time of daratumumab initiation was 60 (38-72) and 64.4% (n = 47) were men. In the selected cohort, 43.8% (n = 32) were treated with DRd, 31.5% (n = 23) with DVd, and 24.7% (n = 18) with DPd regimen. The median progression-free survival (PFS) of the entire cohort was 15.8 months (95% CI, 12.9–37.1 months). The median PFS of the individual regimens was as follows: DPd 18.9 months (95% CI, 13.7-not reached), DRd 21.7 months (95% CI, 11.6-not reached), and DVd 12.9 months (95% CI, 3.1-not reached).

Conclusions

Daratumumab-containing therapies are effective regimens in patients progressing on lenalidomide maintenance. Additional studies are required to decide the optimal regimen post-lenalidomide maintenance.

How I Treat Relapsed Multiple Myeloma

Despite recent advances multiple myeloma remains an incurable disease for most of the patients and initial remission will be followed by relapses requiring therapy. For many, there will be several remissions and relapses until resistance develops to all available therapies. With the introduction of several new agents, myeloma treatment has changed drastically and there are new options for the management of relapsed or refractory disease, including new drug classes with distinct mechanisms of action and cellular therapies. However, resistance to major drug classes used in first line remain the most critical factor for the choice of treatment at relapse. Continuous lenalidomide-based therapy is used extensively at first line and resistance to lenalidomide has become the key factor for the choice of salvage therapy. Daratumumab is increasingly used in first line and soon patients that relapse while on daratumumab will become a common challenge. Three-drug regimens are standard approach to manage relapsed disease. Adding drugs with new mechanisms of activity can improves outcomes and overcomes class resistance but, until now, while the biology is important, can offer only limited guidance for the choice of therapy.