Early versus Late Discontinuation of Maintenance Therapy in Multiple Myeloma

In-class transition from bortezomib-based therapy to IRd is an effective approach in newly diagnosed multiple myeloma

Aim: To compare the effectiveness of in-class transition to all-oral ixazomib-lenalidomide-dexamethasone (IRd) following parenteral bortezomib (V)-based induction versus continued V-based therapy in US oncology clinics. Patients & methods: Non-transplant eligible patients with newly diagnosed multiple myeloma (MM) receiving in-class transition to IRd (N = 100; US MM-6), or V-based therapy (N = 111; INSIGHT MM). Results: Following inverse probability of treatment weighting, overall response rate was 73.2% with IRd versus 57.5% with V-based therapy (p < 0.0001). Median duration of treatment was 10.8 versus 5.3 months (p < 0.0001). Overall, 18/24% of patients discontinued IRd/V-based therapy due to adverse events. Conclusion: IRd after V-based induction was associated with significantly improved overall response rate and duration of treatment than continued V-based combination therapy. Clinical Trial Registration: US MM-6: NCT03173092; INSIGHT MM: NCT02761187 (ClinicalTrials.gov).

Predictors of lenalidomide maintenance duration after autologous stem cell transplant in patients with multiple myeloma

BACKGROUND

For patients with multiple myeloma (MM) who have undergone autologous stem cell transplant (auto-SCT), the immunomodulatory agent lenalidomide is a first-line option for maintenance therapy. Because longer durations of lenalidomide maintenance are associated with improved survival, identifying strategies to avoid premature cessation of maintenance is an important priority in the post-transplant setting.

OBJECTIVES

The primary objective of this analysis was to identify specific clinical predictors of lenalidomide treatment duration that could guide optimal medication management. Key secondary objectives included predictors of intolerable toxicity, rationale for lenalidomide dose reduction/discontinuation, and characterization of dose adjustments.

STUDY DESIGN

This retrospective, multi-center cohort study included adults with MM who underwent auto-SCT and initiated maintenance lenalidomide between 01/01/2012 and 02/28/2021. Variables assessed as potential predictors of maintenance duration or intolerable toxicity included age, body mass index (BMI), Eastern Cooperative Oncology Group (ECOG) performance status at time of auto-SCT, renal function, initial lenalidomide dose, use of combination maintenance therapy, and cytogenetic risk category.

RESULTS

Among 299 patients included, the median age at time of auto-SCT was 62 years (range 30-77). The majority of patients had standard-risk cytogenetics (64%) and an ECOG performance status of 0 or 1 (72%). In the overall population, the median duration of maintenance was 1.3 years (range 0.3-8.6 years). The median initial dose of lenalidomide was 10 mg daily (range 2.5-25 mg). During the study period, 35% of patients had a dose reduction due to toxicity, 21% stopped lenalidomide due to disease progression, and 19% stopped due to toxicity. Multivariate linear regression analyses did not identify any significant predictors of lenalidomide duration or discontinuation due to intolerable toxicity. The most frequently reported toxicities leading to discontinuation were cytopenias, rash, and fatigue.

CONCLUSION

This analysis did not identify any significant risk factors to predict the duration of lenalidomide maintenance or discontinuation for toxicity following auto-SCT in patients with MM. While limited by the retrospective design and relatively small sample size, our findings suggest that a priori lenalidomide dose reductions based on patient co-morbidities or performance status may not substantially affect the duration of lenalidomide maintenance.

Single-agent lenalidomide maintenance after upfront autologous stem cell transplant for newly diagnosed multiple myeloma: The MD Anderson experience

The optimal duration of lenalidomide (Len) maintenance for patients with multiple myeloma (MM) after autologous stem cell transplantation (autoHCT) is unknown. We conducted a retrospective single-center analysis of adult MM patients that received upfront autoHCT between 2005 and 2021, followed by single-agent Len maintenance. A total of 1167 patients were included with a median age of 61.4 (range 25.4-82.3) years, and high-risk chromosomal abnormalities in 19%. Median duration of maintenance was 22.3 (range 0.03-139.6) months. After a median follow-up of 47.9 (range 2.9-171.7) months, median PFS and OS for the entire cohort were 56.6 (95% CI 48.2-61.4) months and 111.3 (95% CI 101.7-121.5) months, respectively. In MVA, high-risk cytogenetics was associated with a worse PFS (HR 1.91) and OS (HR 1.73) (p < .001 for both). Use of KRD induction and achievement of MRD-negative ≥ VGPR before autoHCT were associated with an improved PFS (HR 0.53 and HR 0.57, respectively; p < .001 for both). Longer maintenance duration, even with a 5-year cutoff, was associated with superior PFS and OS (HR 0.17 and 0.12, respectively; p < .001 for both). A total of 106 patients (9%) developed a second primary malignancy (SPM), mostly solid tumors (39%) and myeloid malignancies (30%). Longer maintenance duration was associated with a higher risk of SPM, reaching statistical significance after >2 years (odds ratio 2.25; p < .001). In conclusion, outcomes with Len maintenance were comparable to those reported in large clinical trials. Longer duration of maintenance, even beyond 5 years, was associated with improved survival.