The Role of Salvage Second Autologous Hematopoietic Cell Transplantation in Relapsed Multiple Myeloma

The efficacy and safety of second salvage autologous transplantation in myeloma patients

Despite the availability of many novel therapies for multiple myeloma, it remains an incurable disease with relapse fated in almost all patients. In the era of modern agents, second autologous stem cell transplantation still holds its role in patients relapsing after first-line autologous transplant. The authors reviewed a single-center experience with a second auto-SCT for relapsed multiple myeloma. Thirty patients had received a salvage auto-SCT at the institution. The median follow-up after diagnosis was 86 months, and the median time between transplants was 59.1 months. Response before second ASCT was the following: CR - 11 cases, VGPR - 9 cases, PR - 10 cases. Most patients received reduced dose (140 mg/m2) of melphalan as a conditioning regimen for the second auto-SCT. Treatment-related mortality was 3%. With a median follow-up time of 34 months after the second transplant, median progression-free survival was 24 months. The median PFS in the patients achieving CR or VGPR at day 100 after the second transplantation was 32 months. By 15 months, all patients achieved only partial remission progressed, with a median PFS of 8.5 months. During the follow-up period, no MDS or AML developed, and the frequency of second malignancy was also low, 3%. In conclusion, second autologous stem cell transplantation is a well-tolerated and effective treatment option for relapsed multiple myeloma in selected patients, though with a shorter PFS than in first remission.

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.

Daratumumab, pomalidomide, and dexamethasone (DPd) followed by high dose chemotherapy-Autologous Stem Cell Transplantation leads to superior outcomes when compared to DPd-alone for patients with Relapsed Refractory Multiple Myeloma

BACKGROUND AND OBJECTIVES

While the role of autologous stem cell transplant (ASCT) in the first line therapy for newly diagnosed multiple myeloma is well established, efficacy of ASCT for patients with relapsed refractory multiple myeloma (RRMM) in the era of novel therapeutic agents remains unknown. In this single center retrospective analysis, we evaluated and compared the efficacy and safety outcomes of patients with RRMM treated with daratumumab pomalidomide dexamethasone (DPd) alone versus (vs) DPd followed by ASCT.

METHODS

A total of 83 patients with RRMM who were treated with and achieved at least partial response (PR) with DPd were evaluated by electronic medical records. All patients who responded to DPd and were deemed eligible for ASCT proceeded with high dose melphalan followed by autologous stem cell infusion (DPd + ASCT group). Remaining patients continued DPd until disease progression or intolerable toxicities (DPd-alone group). Responses were evaluated using the International Myeloma Working Group response criteria and toxicities were graded using National Cancer Institute Common Terminology Criteria for Adverse Events. Patient and disease characteristics, as well as efficacy and safety outcomes were summarized using descriptive statistics. Kaplan-Meier analyses were used to estimate progression-free survival (PFS) and overall survival (OS).

RESULTS

A total of 21/83 (25%) patients with RRMM who achieved at least PR to DPd underwent ASCT (DPd + ASCT group) while the remaining 62/83 (75%) continued DPd without ASCT (DPd-alone group). For the entire patient population, median age was 66 years (42-81), 49 (59%) patients were male, 54 (65%) patients had IgG isotype, 21 (25%) patients had R-ISS stage III disease, 51 (61%) patients had high-risk cytogenetics, and 17 (20%) patients had extramedullary disease. Patient age, disease stage, cytogenetic risk profile were well balanced between two groups. A stringent complete response was seen in 10 (16%) and 12 (57%) patients in the DPd-alone and DPd + AST groups, respectively. Median PFS was 17.5 months in the DPd-alone vs 42.2 months (p=0.006) in the DPd + ASCT group. Median OS was 38.1 months in the DPd-alone group vs not reached in the DPD + ASCT group (p=0.009). The most common grade 3 or 4 treatment-related adverse events (TRAE) were myelosuppression and gastrointestinal toxicities, more commonly seen in the DPd + ASCT group. No treatment-related mortalities were observed in either group.

CONCLUSION

Patients with RRMM who responded to DPd and underwent HDT-ASCT demonstrated superior depth and duration of remission compared to those who received DPd-alone. Although DPd followed by ASCT is associated with more cytopenias and gastrointestinal toxicities, this treatment appears to be overall safe for patients with RRMM.

Outcomes After Salvage Autologous Hematopoietic Cell Transplant for Patients With Relapsed/Refractory Multiple Myeloma: A Single-Institution Experience

BACKGROUND

The role of salvage autologous hematopoietic cell transplantation (sAHCT2) for patients with relapsed/refractory multiple myeloma (RRMM) in the era of modern therapeutics is unclear. As prospective data is limited, we conducted a retrospective analysis to determine the outcomes of sAHCT2.

PATIENTS AND METHODS

We conducted a single-institution, retrospective analysis of patients who received sAHCT2 at The Ohio State University from 2000 to 2018. Patients who received a second transplant as part of a planned tandem or autologous-allogeneic transplant were excluded.

RESULTS

Fifty-seven patients were treated with sAHCT2. Patients had a median of 2 lines of therapy after AHCT1 prior to their sAHCT2; 70% had prior immunomodulatory imide drugs, 82% had prior proteasome inhibitor, and 20% had prior anti-CD38 monoclonal antibodies as part of re-induction therapy. Forty-two percent of patients attained ≥VGPR prior to sAHCT2. Seventy-four were treated with melphalan 200 mg/m² as conditioning regimen before infusion of a median of 3.8 × 10⁶ CD34+ cells/kg. Fifty-eight percent patients had maintenance therapy and 81% patients attained CR/VGPR as the best response after sAHCT2. The median PFS and OS after sAHCT2 were 1.6 and 3.6 years, respectively. On multivariable analysis, high-risk cytogenetics, not having attained CR/VGPR, and having more than 2 lines of therapy post-AHCT1 were associated with inferior PFS. Melphalan 140 mg/m² compared to melphalan 200 mg/m² and no maintenance therapy compared to maintenance therapy were not associated with inferior PFS. There was no transplant-related mortality in this patient cohort.

CONCLUSIONS

For MM patients deriving durable remission after their AHCT1, sAHCT2 was safe and resulted in deep and durable remissions.

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.

Bridging advanced myeloma patients to subsequent treatments and clinical trials with classical chemotherapy and stem cell support

Rapidly progressing relapsed/refractory multiple myeloma (RRMM) patients with compromised marrow have limited treatment options. Thus, non-myeloablative chemotherapy with a stem cell boost (SCB) may provide disease control and hematopoietic improvement as bridge to subsequent therapies. We identified 96 patients who received a SCB between January 2011 and December 2019 at the Mount Sinai Hospital. Patients had a median age of 64 years, received a median of 7 prior lines of therapy and 68 and 42% were triple-class and penta-drug refractory, respectively. Chemotherapy included melphalan (MEL) (n = 16), melphalan + carmustine (BCNU/MEL) (n = 52) or a variant of DCEP (dexamethasone, cyclophosphamide, etoposide, cisplatin) (n = 28). Median time to neutrophil recovery was 10 days and was significantly lower with DCEP (8 days) compared to MEL and BCNU/MEL (10-11 days) (p = 0.0047). Time to progression, progression-free survival and overall survival were 3.19, 2.7 and 8.38 months, respectively. The BCNU/MEL group had the highest response rate of 85% (p = 0.05), clinical benefit rate of 94% (p = 0.0014), progression-free survival of 3.3 months (p = 0.4) and overall survival of 8.7 months (p = 0.5). Sixty-six patients (69%) were bridged to new lines of therapy, including clinical trials. Non-myeloablative chemotherapy with SCB provides rapid disease control and marrow recovery with potential to receive further therapy.

Bortezomib-thalidomide-dexamethasone-cisplatin-doxorubicin-cyclophosphamide-etoposide as a Salvage and Bridging Regimen before Hematopoietic Stem Cell Transplantation for Relapsed or Refractory Multiple Myeloma

Objective Currently, treatment of relapsed or refractory multiple myeloma is challenging. Although bortezomib-thalidomide-dexamethasone-cisplatin-doxorubicin-cyclophosphamide-etoposide (VTD-PACE), a potent combination of a proteasome inhibitor, immunomodulatory drug, and conventional chemotherapeutics, is a widely used regimen, its efficacy and safety are unclear. Methods We retrospectively analyzed the clinical data of 35 patients treated with VTD-PACE. Results The overall response rate was 65.7% (complete response, 5.7%). The median progression-free survival (PFS) and overall survival (OS) were 8.0 [95% confidence interval (CI), 0.9-15.0] and 20.0 (95% CI, 17.5-22.5) months, respectively. Twenty-two (62.9%) patients developed grade 3-4 infections, and no therapy-related deaths occurred. Sixteen of 25 patients (64%) underwent stem cell harvest successfully with more than 2.0×10⁶/kg of CD34 cells after VTD-PACE. Twenty-two patients underwent autologous or allogeneic stem cell transplantation (SCT). The response and survival durations were short in patients without SCT after VTD-PACE [median PFS: 4.0 (95% CI, 2.7-5.3) months; OS: 14.0 (6.9-21.0) months]; however, these responses significantly improved with SCT following VTD-PACE. The PFS was 8.0 (NA) months (p=0.024), and the OS was 21.0 (19.1-22.8) months (p=0.019). Conclusion VTD-PACE is an effective and tolerable salvage regimen and feasible bridging therapy for SCT.

Gaps and opportunities in the treatment of relapsed-refractory multiple myeloma: Consensus recommendations of the NCI Multiple Myeloma Steering Committee

A wide variety of new therapeutic options for Multiple Myeloma (MM) have recently become available, extending progression-free and overall survival for patients in meaningful ways. However, these treatments are not curative, and patients eventually relapse, necessitating decisions on the appropriate choice of treatment(s) for the next phase of the disease. Additionally, an important subset of MM patients will prove to be refractory to the majority of the available treatments, requiring selection of effective therapies from the remaining options. Immunomodulatory agents (IMiDs), proteasome inhibitors, monoclonal antibodies, and alkylating agents are the major classes of MM therapies, with several options in each class. Patients who are refractory to one agent in a class may be responsive to a related compound or to a drug from a different class. However, rules for selection of alternative treatments in these situations are somewhat empirical and later phase clinical trials to inform those choices are ongoing. To address these issues the NCI Multiple Myeloma Steering Committee formed a relapsed/refractory working group to review optimal treatment choices, timing, and sequencing and provide recommendations. Additional issues considered include the role of salvage autologous stem cell transplantation, risk stratification, targeted approaches for genetic subsets of MM, appropriate clinical trial endpoints, and promising investigational agents. This report summarizes the deliberations of the working group and suggests potential avenues of research to improve the precision, timing, and durability of treatments for Myeloma.

Cellular Interaction Analysis Characterizing Immunosuppressive Microenvironment Functions in MM Tumorigenesis From Precursor Stages

Cell–cell interaction event (CCEs) dysregulation may relate to the heterogeneity of the tumor microenvironment (TME) and would affect therapeutic responses and clinical outcomes. To reveal the alteration of the immune microenvironment in bone marrow from a healthy state to multiple myeloma (MM), scRNA-seq data of the four states, including healthy state normal bone marrow (NBM) and three disease states (MGUS, SMM, and MM), were collected for analysis. With immune microenvironment reconstruction, the cell types, including NK cells, CD8⁺ T cells, and CD4⁺ T cells, with a higher percentage in disease states were associated with prognosis of MM patients. Furthermore, CCEs were annotated and dysregulated CCEs were identified. The number of CCEs were significantly changed between disease states and NBM. The dysregulated CCEs participated in regulation of immune cell proliferation and immune response, such as MIF-TNFRSF14 interacted between early B cells and CD8⁺ T cells. Moreover, CCE genes related to drug response, including bortezomib and melphalan, provide candidate therapeutic markers for MM treatment. Furthermore, MM patients were separated into three risk groups based on the CCE prognostic signature. Immunoregulation-related differentiation and activation of CD4⁺ T cells corresponded to the progression status with moderate risk. These results provide a comprehensive understanding of the critical role of intercellular communication in the immune microenvironment over the evolution of premalignant MM, which is related to the tumorigenesis and progression of MM, which moreover, suggests a way of potential target selection for clinical intervention.

Carfilzomib, Lenalidomide, and Dexamethasone Followed by Salvage Autologous Stem Cell Transplant with or without Maintenance for Relapsed or Refractory Multiple Myeloma

Salvage high-dose chemotherapy and autologous stem cell transplantation (HDCT/ASCT) is a treatment option for relapsed and/or refractory multiple myeloma (RRMM). No data are available on salvage HDCT/ASCT following re-induction treatment with state-of-the-art triplet regimens. We retrospectively report on 44 patients receiving salvage HDCT/ASCT following re-induction with carfilzomib/lenalidomide/dexamethasone (KRd). All patients received frontline HDCT/ASCT with median time to progression (TTP1) of 2.9 (1.2-13.5) years, enabling paired comparison of frontline and salvage HDCT/ASCT. After re-induction and before salvage transplant, 25/44 patients (57%) attained ≥ very good partial response (VGPR), which increased to 34/44 (77%) at best response after salvage HDCT/ASCT. Median progression-free survival (PFS) was 23.3 months from salvage HDCT/ASCT. Patients with ≥ VGPR at the time of salvage HDCT/ASCT and those receiving maintenance treatment post salvage HDCT/ASCT had significantly superior PFS (hazard ratio (HR) 0.19, p = 0.001 and HR 0.20, p = 0.009). In patients achieving at least an equal depth of response before salvage HDCT/ASCT as before frontline HDCT/ASCT, PFS after salvage HDCT/ASCT was comparable to the frontline situation (p = 0.3). This is the first report of state-of-the-art triplet re-induction and salvage HDCT/ASCT for RRMM after frontline transplantation. Deep remissions achieved with KRd translate into prolonged PFS following salvage HDCT/ASCT and are enhanced by maintenance treatment.

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.

Second Autologous Stem Cell Transplant as Salvage in Multiple Myeloma - The Oregon Health and Science University Experience

BACKGROUND

Second autologous transplants (SAT) are routinely performed in the setting of myeloma relapse, though data on outcomes are lacking. We conducted a single-center review of all multiple myeloma patients at OHSU who received SAT (excluding tandems) with responses assessed by International Myeloma Working Group (IMWG) criteria.

RESULTS

Sixty-eight patients received SAT between 1999 and 2019. Risk by IMWG was available for 50 patients (10 high-risk). Median age at SAT was 61 (45-74). Median time between 1st and 2nd Autologous stem cell transplantation (ASCT) was 5.5 years (1.1 - 15.2). Median progression-free survival (PFS) after 1st ASCT (available for 53 pts) was 2.5 years (0.3 - 10). The average # of lines of therapy prior to SAT was 2.8 (1-14). SAT prep regimens (available for 67 pts) were: Fifty-one (87%) melphalan 200 mg/m², 6 (9%) melphalan 140 mg/m², 1 (2%) BEAM, 1 (2%) melphalan 200 mg/m² and bortezomib. All used PBSC mobilization. Median overall survival (OS) after SAT was 4.68 years, and median PFS was 1.72 years. By treatment era (1999-2009 vs. 2010-2019), median OS was 1.97 vs. 5.52 years (P = .15). When analyzed by IMWG group (standard/low vs. high risk) median PFS and OS were not significantly different (1.87 vs. 1.61 years and 3.58 vs. 5.91 years, respectively). Treatment-Related Mortality (TRM) occurred in 1 patient (2%).

CONCLUSION

Our experience with SAT for multiple myeloma (MM) shows that it has low TRM and is effective, with median OS >4.5 years, though with a shorter PFS than after 1st ASCT.

Long-acting granulocyte colony-stimulating factor pegfilgrastim (lipegfilgrastim) for stem cell mobilization in multiple myeloma patients undergoing autologous stem cell transplantation

Autologous stem cell transplantation (ASCT) is a standard of care in newly-diagnosed multiple myeloma (MM) patients. Several studies before the introduction of novel therapies in MM, demonstrated a pegylated G-CSF to be successful in mobilizing peripheral blood stem cells (PBSCs). Lipegfilgrastim is a novel long-acting G-CSF that is produced by the conjugation of a single 20-kDa polyethelene glycol to the natural O-glycosylation site of G-CSF. Twenty-four MM patients were included for PBSCs mobilization with a single SC injection of 6 mg lipegfilgrastim. PBSC collection was started when the CD34⁺ count was > 10 × 10⁶ cells/L. The target progenitor cells were 6 × 10⁶ cells/kg. The median day of apheresis was + 3 (range 2-5) following lipegfilgrastim. Median peripheral blood CD34⁺ count pre-mobilization was of 22.65 (range 3.36-105) × 10⁶ cells/L. The median number of leukaphaeresis procedures was 2 (range 1-4). The median mobilized CD34⁺ cells/kg were 8.26 (range 0.77-12.42). One patient failed to mobilize and two patients mobilized < 6 × 10⁶ cells/kg. Toxicity was mild and transient. Twenty-three patients underwent ASCT following high dose melphalan. All patients engrafted. As lipegfilgrastim is administered only once, it is conceivable that it improves both compliance and quality-of-life (NCT02488382).

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.

Use of Backup Stem Cells for Stem Cell Boost and Second Transplant in Patients with Multiple Myeloma Undergoing Autologous Stem Cell Transplantation

Autologous hematopoietic stem cell transplantation (ASCT) is a standard treatment for multiple myeloma (MM). Consensus guidelines recommend collecting sufficient stem cells in case there is a need for stem cell boost for delayed/poor engraftment or for future second ASCT. However, collecting and storing backup stem cells in all patients requires significant resources and cost, and the rates of backup stem cell utilization are not well studied. We sought to examine the utilization of backup stem cells (BSCs) in patients with MM undergoing ASCT. Patients with MM aged ≥18 years old who underwent first ASCT at our institution from January 2010 through December 2015 and collected sufficient stem cells for at least 2 transplants were included in this single-center retrospective study. This timeframe was selected to allow for adequate follow-up. A total of 393 patients were included. The median age was 58 years (range, 25-73). After a median follow-up of 6 years, the median progression-free survival (PFS) of the cohort was 3 years. Sixty-one percent (n = 240) of patients progressed or relapsed. Chemotherapy-based mobilization was used in almost all patients (98%). The median total CD34+ cells collected was 18.2 × 106/kg (range, 3.4-112.4). A median of 5.7 × 106 CD34+ cells/kg (range, 1.8-41.9) was infused during the first ASCT, and a median of 10.1 × 106 CD34+ cells/kg (range, 1.5-104.5) was cryopreserved for future use. Of the patients, 6.9% (n = 27) used backup stem cells, with 2.3% (n = 10) using them for stem cell boost, 4.6% (n = 18) for a second salvage ASCT, including 1 patient for both stem cell boost and second ASCT. Rates of backup stem cell use among patients aged <60, 60-69, and ≥70 years were 7.8%, 5.7%, and 5.9%, respectively. There was a trend toward higher rates of backup stem cell use for second ASCT in patients who were younger, had suboptimal disease control at time of first ASCT, and longer PFS. The median dose of stem cell boost given was 5.6 × 106 CD34+ cells/kg (range, 1.9-20). The median time from stem cell boost to neutrophil, hemoglobin, and platelet engraftment was 4 (range, 2-11), 15 (range, 4-34), and 12 (range, 0-34) days, respectively. Lower CD34+ dose and older age at time of ASCT predicted need for stem cell boost. With new salvage therapies for relapsed MM, the rates of second ASCT are very low. The low rates of use suggest that institutional policies regarding universal BSC collection and long-term storage should be reassessed and individualized. However, need for stem cell boost in 2.3% of patients may present a challenge to that.

Current Treatment Strategies for Multiple Myeloma

The treatment of multiple myeloma (MM) continues to evolve with the approval of numerous agents over the past decade. Advances in treatment have led to the incorporation of these newer therapies into the treatment paradigm, with improvements in overall survival and the possibility of deep responses including a minimal residual disease-negative state. The strategy of triplet therapies for patients with newly diagnosed MM, followed by high-dose chemotherapy and autologous stem-cell transplantation for eligible patients, and subsequently consolidation and maintenance therapy, is the current treatment roadmap for patients. However, patients with MM will ultimately develop refractoriness to antimyeloma therapies. In this article, we summarize our current practice of managing patients with MM. We highlight our approach to patients with newly diagnosed MM who are transplantation eligible and ineligible and highlight risk-adapted strategies for these patients. In addition, we discuss our approach to the management of patients with relapsed or refractory MM. Last, we review standard therapies and emerging strategies such as targeted approaches, immune-based therapies, and drugs with novel mechanisms of action. Trials evaluating chimeric antigen receptor T cells targeting B-cell maturation antigen are ongoing and are only one of several novel approaches targeting cell maturation antigen, which include the use of bispecific T-cell engager antibodies and antibody drug conjugates. Emerging therapies offer the promise of more individualized approaches in the management of patients with MM and ultimately may result in the possibility of being one step closer to curing patients with MM.

Busulfan, melphalan, and bortezomib compared to melphalan as a high dose regimen for autologous hematopoietic stem cell transplantation in multiple myeloma: long term follow up of a novel high dose regimen

Melphalan at a dose of 200 mg/m² (MEL200) remains the standard high dose therapy before autologous stem cell transplantation (ASCT) for multiple myeloma (MM). Intensifying the high dose regimen has shown promising results. We report here 7-year follow up of our novel high dose regimen of busulfan and melphalan followed by bortezomib (BuMelVel). Forty-three MM patients received BuMelVel high dose therapy with pharmacokinetic adjusted busulfan. Outcomes were compared to a matched control cohort from the CIBMTR database (n = 162) receiving MEL200. The primary endpoint was progression free survival. Five year PFS was 47% v 30% (95% CI; 32-62) in favor or the BuMelVel group (95% CI; 23-37) (p = 0.05). In multivariate analysis for PFS, BuMelVel (HR 0.65; 95% CI 0.44-0.97)(p = 0.036) was predictive. Similar to recent reports of double alkylator therapy, although depth of response was similar between the BuMelVel group and MEL200, the BUMELVEL group experienced an improved PFS.

KRD (carfilzomib and lenalidomide plus dexamethasone) for the treatment of relapsed or refractory multiple myeloma in the real-life: a retrospective survey in 123 patients

From April 2016, carfilzomib, in combination with lenalidomide and dexamethasone (KRD), became available for use in the daily practice in Italy for patients with relapsed or refractory multiple myeloma (RRMM). We performed a retrospective survey at 14 different institutions from Southern Italy in order to evaluate patient characteristics and treatment results from an unselected series of patients treated accordingly so far. One hundred and twenty-three consecutive patients were included, with a median of 2 previous lines of therapy (range 1-9) and a median age of 63 years (range 39-82). At the time of analysis, median number of courses administered is 11 (range 1-34), and all patients are evaluable for response. Overall response rate including complete remission, very good partial remission, and partial remission is 85%. After a median follow-up of 27 months, median overall and progression-free survival are 33 and 23 months, respectively. Sixty-three patients are alive and between them, 45 (37%) are in continuous remission. Sixty patients have died (49%), mainly from progressive disease. There were 6 treatment-related deaths (5% of the whole patient population). Overall, hematological and non-hematological toxicity were manageable, mostly on outpatient basis. Arterial hypertension has been observed in 43 cases (35%) but did not lead to treatment interruption. Our data demonstrate that in real life, KRD is highly effective and well tolerated in the majority of patients with RRMM.

Incorporating hematopoietic stem-cell transplantation after second-line carfilzomib-lenalidomide-dexamethasone (KRd)

Background:

Traditionally believed to be an integral part of multiple myeloma (MM) treatment, the role of hematopoietic stem-cell transplantation (HSCT) is being challenged. As such, we sought to evaluate the impact of HSCT in the era of novel agents.

Methods:

A multicenter, retrospective, longitudinal cohort study was carried out between January 2016 and December 2018. A total of 55 patients who received VTD (bortezomib-thalidomide-dexamethasone) as first-line treatment and KRd (carfilzomib-lenalidomide-dexamethasone) as second-line treatment were analyzed for outcomes.

Results:

The enrolled patients were divided into Group 1, defined as those who continued KRd treatment until progression (n = 41), versus Group 2, defined as those who underwent HSCT after a certain number of cycles of KRd (n = 14). Both groups showed a generally favorable response to KRd, with overall response rate (ORR) of 87.9% and clinical benefit rate of 92.8% after a median of seven cycles in Group 1, and ORR 92.8% and clinical benefit rate 100% after median of five cycles in Group 2. However, significantly poorer progression-free survival (PFS) (p = 0.004) was observed in Group 1 (median 12 months) compared with Group 2 (median not reached). Multivariate analyses identified HSCT after KRd as potential risk factors associated with PFS. Also, in Group 1, bortezomib refractoriness was associated with significantly shorter PFS compared with those who were responsive (median 12 months versus 14 months, respectively, p = 0.039).

Conclusions:

In conclusion, even with the advent of novel agents, HSCT still remains a valuable treatment modality with additive efficacy.

Long-Term Follow-up of CALGB (Alliance) 100001: Autologous Followed by Nonmyeloablative Allogeneic Transplant for Multiple Myeloma

CALGB (Alliance) 100001 was a phase II study evaluating autologous stem cell transplant (ASCT) followed by nonmyeloablative allogeneic stem cell transplant (alloSCT) in patients with multiple myeloma who had received no more than 18 months of prior therapy and had experienced no more than 1 prior progression event. Conditioning for ASCT was with high-dose melphalan (200 mg/m²). The alloSCT reduced-intensity conditioning (RIC) regimen consisted of fludarabine (30 mg/m²/d i.v. on days -7 through -3) and cyclophosphamide (1 g/m²/d i.v. on days -4 through -3). The primary objective was to determine the 6-month post-alloSCT treatment-related mortality (TRM) rate. Additional objectives included determining the proportion of patients who could complete this tandem ASCT-alloSCT approach in a cooperative group setting, overall response rates, rates of donor chimerism, rates of graft-versus-host disease (GVHD), disease-free survival, and overall survival (OS). Sixty patients were enrolled, of whom 57 (95%) completed ASCT and 49 (82%) completed tandem ASCT-alloSCT. The TRM rate was 2% (1/49; 90% confidence interval, 0.10% to 9.3%). Moderate to severe (grades 2 to 3) acute GVHD was observed in 13 of 49 alloSCT patients (27%). One patient died due to GVHD within 9 months of alloSCT. Twenty-seven of the 49 patients (55%) who underwent alloSCT reported chronic GVHD as either limited (15/49; 31%) or extensive (12/49; 24%) in the first year post-alloSCT and prior to the start of nonprotocol therapy for progressive disease. With a median follow-up for survival of 11 years, the median OS time is 6.6 years and the median time to disease progression is 3.6 years. Similar to other studies, this study confirmed that tandem ASCT/alloSCT is associated with durable disease control in a subset of patients. This study demonstrated the feasibility of performing tandem ASCT/alloSCT in a cooperative group setting and determined that a fludarabine/cyclophosphamide RIC regimen is associated with a very low TRM rate.

How I treat a refractory myeloma patient who is not eligible for a clinical trial

Myeloma patients not eligible for clinical trials have many treatment options. Choosing the next best therapy starts with careful assessment of the biology and dynamics of the disease at relapse, as well as the condition and situation of the patient. Fit patients should be considered for triplet regimens, whereas intermediate and frail patients warrant dose-reduced triplets or doublets. An indolent serologic relapse may be treated with dose intensification, especially in a maintenance situation, whereas a rapid relapse requires a more aggressive approach with drug class change or a second-generation immunomodulatory drug (IMID) or proteasome inhibitor (PI). Monoclonal antibodies, in combination with PIs and IMIDs, have proven highly efficacious in early and late relapse. Key elements of supportive care include infection prevention, bone health, thromboprophylaxis, and management of active symptoms, such as pain and distress.