Impact of second autologous stem-cell transplantation at relapsed multiple myeloma: A French multicentric real-life study

A second autologous stem-cell transplantation (ASCT2) is considered for relapsed multiple myeloma (RMM) patients showing prolonged response after a first ASCT. However, given breakthrough treatments like anti-CD38 and immunotherapy, its role remains debated. We conducted a real-life study in 10 French centers (1996-2017) involving 267 RMM patients receiving ASCT2. The median age was 61 years, with 49% females. Most patients received melphalan 200 mg/m² before ASCT2, with low early mortality (1%). Very good partial response or better (VGPR+) rate post ASCT2 was 78%. Post ASCT2, 48% received consolidation therapy and 40% maintenance therapy. Median event-free survival (EFS) after ASCT2 was 2.6 years (95% confidence interval [CI]: 2.3-2.8), and 2-year EFS estimate was 63% (95% CI: 57-70). Median overall survival (OS) was 8.1 years (95% CI: 5.9-NA), and 2-year OS estimate was 92% (95% CI: 88-95). Multivariate analysis revealed that VGPR+ status and maintenance therapy post ASCT2 were associated with better EFS (hazard ratio [HR]: 0.6; 95% CI: 0.3-0.9, p = 0.012 and HR: 0.4; 95% CI: 0.3-0.6, p < 0.001, respectively) and OS (HR: 0.4; 95% CI: 0.2-0.9, p = 0.017 and HR: 0.2; 95% CI: 0.1-0.4, p < 0.001, respectively), while male sex correlated with poorer outcomes for EFS (HR: 2.5; 95% CI: 1.7-3.7, p < 0.001) and OS (HR: 2.7; 95% CI: 1.4-4.9, p = 0.002). Overall, ASCT2 appeared efficient with low toxicity in RMM. Maintenance therapy was associated with extended EFS and OS, particularly in patients with VGPR+ status post ASCT2. These findings underscore ASCT2's potential in RMM when coupled with maintenance therapy in selected patients.

Trends in utilization of stored cryopreserved autologous peripheral hematopoietic cells intended for a second (or beyond) autologous hematopoietic cell transplantation in patients with multiple myeloma: a single center experience

Due to the advent of effective novel therapies for multiple myeloma (MM), the use of cryopreserved autologous peripheral blood hematopoietic cells (APBHC) for a salvage autologous transplant (auto-HCT) is in decline. We evaluated utilization trends and costs associated with cryopreserved APBHC in patients with MM. We retrospectively evaluated the clinicopathologic data from 440 patients with MM who underwent APBHC mobilization and collection at Mayo Clinic Florida between 2010 and 2019. Based on institution-specific charges as of May 2021, the cost of 1 session of APBHC collection/apheresis was $4,680 and the cost of 1 year of APBHC cryopreservation was $4,790 per patient. Out of 347 patients who had APBHC in cryopreservation, 5 (1.4%) underwent a salvage auto-HCT and 61% of patients had ≥1 excess collection sessions for APBHC that ultimately went unused. The median cost of excess collection sessions was $4,680 per patient (range, $4,680-$32,760) and the median total cost for excess collection sessions plus costs for storage was $23,840 per patient (range, $4,680-$85,450). The sum of costs of excess collection sessions was $2,077,920 and the sum of costs of cryopreservation was $5,812,665. Institutional policies regarding universal APBHC collection and long-term storage should be reevaluated in the era of novel therapeutics.

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.

The first relapse in multiple myeloma: how to pick the next best thing

The choice of treatment for patients with multiple myeloma (MM) at first relapse/progression is based on many factors: (1) treatment-related factors, which include the regimen used during first induction, the quality and duration of first response achieved, toxicities from the first treatment, whether the patient underwent autologous stem cell transplant, and whether the patient was on maintenance at the time of relapse/progression; (2) disease-related factors, including disease presentation and pace of progression; and (3) patient-related factors, including functional age and performance status. The learning objectives are to present the treatment options for patients with MM upon their first relapse and to learn about various strategies for selecting an optimal treatment regimen.

The changing landscape of relapsed and/or refractory multiple myeloma (MM): fundamentals and controversies

The increase in the number of therapeutic alternatives for both newly diagnosed and relapsed/refractory multiple myeloma (RRMM) patients has widened the clinical scenario, leading to a level of complexity that no algorithm has been able to cover up to date. At present, this complexity increases due to the wide variety of clinical situations found in MM patients before they reach the status of relapsed/refractory disease. These different backgrounds may include primary refractoriness, early relapse after completion of first-line therapy with latest-generation agents, or very late relapse after chemotherapy or autologous transplantation. It is also important to bear in mind that many patient profiles are not fully represented in the main randomized clinical trials (RCT), and this further complicates treatment decision-making. In RRMM patients, the choice of previously unused drugs and the number and duration of previous therapeutic regimens until progression has a greater impact on treatment efficacy than the adverse biological characteristics of MM itself. In addition to proteasome inhibitors, immunomodulatory drugs, anti-CD38 antibodies and corticosteroids, a new generation of drugs such as XPO inhibitors, BCL-2 inhibitors, new alkylators and, above all, immunotherapy based on conjugated anti-BCMA antibodies and CAR-T cells, have been developed to fight RRMM. This comprehensive review addresses the fundamentals and controversies regarding RRMM, and discusses the main aspects of management and treatment. The basis for the clinical management of RRMM (complexity of clinical scenarios, key factors to consider before choosing an appropriate treatment, or when to treat), the arsenal of new drugs with no cross resistance with previously administered standard first line regimens (main phase 3 clinical trials), the future outlook including the usefulness of abandoned resources, together with the controversies surrounding the clinical management of RRMM patients will be reviewed in detail.

Maintenance therapy after second autologous hematopoietic cell transplantation for multiple myeloma. A CIBMTR analysis

The role of maintenance therapy after high-dose chemotherapy and first autologous transplantation in multiple myeloma (MM) is well established. We explored the effect of maintenance therapy on outcomes after salvage second autologous hematopoietic cell transplant (AHCT2) using the Center for International Blood and Marrow Transplant Research registry. Outcomes of interest included non-relapse mortality (NRM), relapse/progression (REL), progression-free and overall survival (PFS, OS). Of 522 patients who underwent AHCT2 between 2010 and 2018, 342 received maintenance therapy and 180 did not. Maintenance regimens included lenalidomide (42%), pomalidomide (13%), and bortezomib (13%). Median follow up was 58 months in the maintenance group and 61.5 months in the no-maintenance group. Univariate analysis showed superior outcomes at 5 years in maintenance compared to the no-maintenance group: NRM 2 (0.7-3.9)% vs 9.9 (5.9-14.9)%, (p < 0.01), REL 70.2 (64.4-75.8)% vs 80.3 (73.6-86.3)% (p < 0.01), PFS 27.8 (22.4-33.5)% vs. 9.8 (5.5-15.2)% (p < 0.01), and OS 54 (47.5-60.5)% vs 30.9 (23.2-39.2)% (p < 0.01), respectively. Use of maintenance therapy retained its association with improved outcomes in multivariate analysis. There was no difference in second cancers in the two groups (p = 0.39). We conclude that maintenance after AHCT2 is associated with improved 5-year outcomes.

Carfilzomib and dexamethasone maintenance following salvage ASCT in multiple myeloma: A randomised phase 2 trial by the Nordic Myeloma Study Group

Objective

We investigated the efficacy and safety of carfilzomib‐containing induction before salvage high‐dose melphalan with autologous stem‐cell transplantation (salvage ASCT) and maintenance with carfilzomib and dexamethasone after salvage ASCT in multiple myeloma.

Methods

This randomised, open‐label, phase 2 trial included patients with first relapse of multiple myeloma after upfront ASCT who were re‐induced with four cycles of carfilzomib, cyclophosphamide and dexamethasone. Two months after salvage, ASCT patients were randomised to either observation or maintenance therapy with iv carfilzomib 27 → 56 mg/sqm and p.o. dexamethasone 20 mg every second week. The study enrolled 200 patients of which 168 were randomised to either maintenance with carfilzomib and dexamethasone (n = 82) or observation (n = 86).

Results

Median time to progression (TTP) after randomisation was 25.1 months (22.5‐NR) in the carfilzomib‐dexamethasone maintenance group and 16.7 months (14.4–21.8) in the control group (HR 0.46, 95% CI 0.30–0.71; P = .0004). The most common adverse events during maintenance were thrombocytopenia, anaemia, hypertension, dyspnoea and bacterial infections.

Conclusion

In summary, maintenance therapy with carfilzomib and dexamethasone after salvage ASCT prolonged TTP with 8 months. The maintenance treatment was in general well‐tolerated with manageable toxicity.

Dose-intensified bendamustine and melphalan (BenMel) conditioning before second autologous transplantation in myeloma patients

Consolidation in myeloma patients with high-dose melphalan chemotherapy (Mel HDCT) and autologous transplantation (ASCT) is standard of care since more than 2 decades. However, definite cure remains exceptional despite intensive treatment, and improving effectiveness of HDCT remains an unmet clinical need. Combining intensified bendamustine with melphalan may represent an option. We analyzed safety and efficacy of combining dose-intensified bendamustine (200 mg/m² on days -4/-3) with high-dose melphalan (100 mg/m² on days -2/-1) before a second (tandem) ASCT in adverse risk myeloma patients after Mel HDCT/ASCT1. Twelve patients received BenMel conditioning before ASCT2 because of high-risk cytogenetics and/or failure to achieve complete remission (CR) after Mel HDCT/ASCT1. Comparing Mel HDCT/ASCT1 and BenMel HDCT/ASCT2, we observed no differences in hematologic recovery and tolerance. Acute renal injury after BenMel conditioning occurred in 3 (25%) patients, but was reversible in all patients, and there were no treatment related deaths. Complete remission rates were increasing from 42% after Mel/ASCT1 to 75% after BenMel/ASCT2. PFS 1 year after ASCT2 was 67%, and OS was 83%. These data suggest that dose-intensified bendamustine with melphalan conditioning is safe and warrants a prospective randomized comparison to standard melphalan HDCT in myeloma patients.