High-dose Melphalan Research Articles

Busulfan and cyclophosphamide for autologous stem cell transplantation in patients with multiple myeloma after proteasome inhibitor and/or immunomodulatory drug treatment.

High-dose melphalan at 200mg/m2 (MEL-200) is the standard conditioning regimen before autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM). Busulfan (BU) and cyclophosphamide (CY) can be used as alternatives when MEL is unavailable. However, most studies on BU/CY conditioning regimens were conducted before proteasome inhibitors (PIs) and immunomodulatory drugs (IMIDs) were available. This non-interventional comparative cohort study compared progression-free survival (PFS) between the MEL-200 and BU/CY in patients with MM treated with PIs and/or IMIDs. A total of 137 patients were analyzed (MEL-200,113 patients; BU/CY, 24 patients). The BU/CY group had a higher rate of PI and/or IMID use and very good partial response (VGPR) or complete remission (CR) at ASCT and post-ASCT maintenance. Median PFS was 29.7 and 46.8months in the MEL-200 and BU/CY groups, respectively. In the multivariate analysis, PFS was significantly better in the BU/CY group. International Staging System Stage I and VGPR or CR at ASCT were significantly associated with longer PFS. No treatment-related mortality was observed in either group by day 100. The BU/CY conditioning regimen may be a viable alternative to the MEL-200 regimen in patients with MM who undergo ASCT after treatment with PIs and/or IMIDs.

A Role for Germline Variants in Multiple Myeloma?

In Blood Cancer Discovery, Thibaud and colleagues report the incidence of pathogenic germline variants (PGV) in patients with multiple myeloma and that these PGVs are associated with DNA repair pathway genes, including BRCA1 and BRCA2. They find an association of patients with PGVs and previous family or personal history of cancer, and that these patients are diagnosed slightly earlier than those without PGVs. Patients with PGVs had a longer progression-free survival than those without PGVs when they received high-dose melphalan and autologous stem cell transplant, providing a therapeutic rationale for diagnostic germline testing in myeloma. See related article by Thibaud et al., p. 428.

Multiple Myeloma Risk and Outcomes Are Associated with Pathogenic Germline Variants in DNA Repair Genes.

First-degree relatives of patients with multiple myeloma are at increased risk for the disease, but the contribution of pathogenic germline variants (PGV) in hereditary cancer genes to multiple myeloma risk and outcomes is not well characterized. To address this, we analyzed germline exomes in two independent cohorts of 895 and 786 patients with multiple myeloma. PGVs were identified in 8.6% of the Discovery cohort and 11.5% of the Replication cohort, with a notable presence of high- or moderate-penetrance PGVs (associated with autosomal dominant cancer predisposition) in DNA repair genes (3.6% and 4.1%, respectively). PGVs in BRCA1 (OR = 3.9, FDR < 0.01) and BRCA2 (OR = 7.0, FDR < 0.001) were significantly enriched in patients with multiple myeloma when compared with 134,187 healthy controls. Five of the eight BRCA2 PGV carriers exhibited tumor-specific copy number loss in BRCA2, suggesting somatic loss of heterozygosity. PGVs associated with autosomal dominant cancer predisposition were associated with younger age at diagnosis, personal or familial cancer history, and longer progression-free survival after upfront high-dose melphalan and autologous stem-cell transplantation (P < 0.01). Significance: Our findings suggest up to 10% of patients with multiple myeloma may have an unsuspected cancer predisposition syndrome. Given familial implications and favorable outcomes with high-dose melphalan and autologous stem-cell transplantation in high-penetrance PGV carriers, genetic testing should be considered for young or newly diagnosed patients with a personal or family cancer history. See related commentary by Walker, p. 375.

Modest survival benefits of autologous stem cell transplantation in multiple myeloma with renal impairment: a critical appraisal of the pre-antibody era

The benefit of high-dose melphalan followed by autologous hematopoietic stem cell transplantation (HDM-ASCT) for multiple myeloma (MM) patients with renal insufficiency (RI) is debated. A systematic review and meta-analysis were conducted to assess the safety and efficacy of HDM-ASCT in MM patients with RIs, and the findings were compared with real-world data. The study included 26 articles, 13 of which were pooled for meta-analysis. We compared three different types of MM patients with RI against MM patients with normal renal function (NRF). These patients were: MM patients with RI at the time of transplantation; MM patients with RI at the time of diagnosis; MM patients with RI at diagnosis but with NRF at transplantation. The meta-analysis indicated that MM patients with RIs conditioned with melphalan ≤ 140 mg/m2 followed by ASCT had transplant-related mortality rates comparable to those without RIs. The complete response rates post-ASCT were similar between MM patients with RIs and those with NRF. Although progression-free survival (PFS) was statistically similar between the groups, MM patients with RIs had significantly poorer overall survival (OS) than those with NRF. The real-world data supported these findings. With a reduced dose of melphalan, ASCT is safe and effective for MM patients with RI. MM patients with RI have similar complete response rates and PFS after ASCT compared to MM patients with NRF. The lower OS in MM patients with RI indicates the need for further research to improve OS in these patients.

Dr. Raymond Alexanian: Pioneering Contributions to Multiple Myeloma Research, Treatment, and the Concept of Curability

Multiple myeloma is a challenging hematological malignancy, with ongoing efforts toward finding a cure. Dr. Raymond Alexanian has been instrumental in advancing the understanding and treatment of multiple myeloma through his pioneering research. Trained at Dartmouth College and Harvard Medical School, Dr. Alexanian MD Anderson Cancer Center career spanned nearly 5 decades. He developed the highly effective MP (melphalan-prednisone) regimen, which became a standard treatment for years. Dr. Alexanian's exploration of steroids, particularly high-dose dexamethasone, and the collaboration with Dr. Bart Barlogie led to the development of the VAD (vincristine, doxorubicin, and dexamethasone) regimen, significantly improving outcomes for refractory cases. He also contributed to the establishment of high-dose melphalan with autologous stem cell transplantation. Dr. Alexanian's work identified critical prognostic factors and contributed understanding indolent and localized myeloma. His efforts in evaluating new agents, including thalidomide and bortezomib, further enhanced treatment options. Beyond research, his compassionate patient care and advocacy have had a profound impact. Dr. Alexanian's legacy continues to inspire advancements in multiple myeloma treatment, with his innovative approaches reshaping the field and fostering the pursuit of a cure.

Outcomes of melphalan 140mg/m2 followed by autologous stem cell transplantation in multiple myeloma patients with co-morbidities: Single-centre experience.

High-dose melphalan followed by stem cell rescue is the standard consolidative therapy for transplant-eligible patients with multiple myeloma (MM) in the United Kingdom. A melphalan dose of 200mg/m2 (Mel200) is considered the "gold standard" for autologous stem cell transplant (ASCT) conditioning for fit patients ≤70 years old; however, with a peak diagnosis incidence at 80-89 years old in the UK dose adjustments will be inevitable to limit toxicities. In this single-centre UK-based retrospective analysis, data was collected from patients with plasma cell dyscrasias who underwent a first reduced-intensity, Mel140, ASCT from 2006 to 2019, a total of 81 patients. We found that the procedure was overall safe with seven (9%) of patients requiring ITU admission and a single transplant-related death within the initial autograft admission. The progression-free survival (PFS) and overall survival were comparable with those previously reported in the literature with median PFS for our cohort of 31 months. Univariate analysis of our data showed an inferior PFS for patients aged ≥70 years. In conclusion, although this is a retrospective analysis, it demonstrates that dose-reduced melphalan conditioning is safe and effective in patients deemed unfit for standard-intensity conditioning.

Curative Strategy for High-Risk Smoldering Myeloma: Carfilzomib, Lenalidomide, and Dexamethasone (KRd) Followed by Transplant, KRd Consolidation, and Rd Maintenance.

Early treatment of high-risk smoldering myeloma has been shown to delay progression to multiple myeloma (MM). We conducted this trial with curative intention using a treatment approach employed for newly diagnosed patients with MM. Patients with high-risk smoldering myeloma (>50% progression risk at 2 years) and transplant candidates were included and received induction therapy with carfilzomib, lenalidomide, and dexamethasone (KRd), six cycles, followed by high-dose melphalan (200 mg/m2) autologous stem-cell transplantation (HDM-ASCT), two KRd consolidation cycles, and Rd maintenance for 2 years. The primary end point was undetectable measurable residual disease (uMRD) rate by next-generation flow after ASCT. Sustained uMRD 4 years after ASCT was the secondary end point. Between June 2015 and June 2017, 90 patients were included, and 31% met at least one SixtyLightchain MRI (SLiM)-hypercalcemia, renal impairment, anemia, bone disease (CRAB) criterion. After a median follow-up of 70.1 months, 3 months after ASCT, in the intention-to-treat population, 56 (62%) of 90 patients had uMRD, and 4 years later, it was sustained in 29 patients (31%). Five patients progressed to MM, and the 70-month progression rate was 94% (95% CI, 84 to 89). The presence of any SLiM CRAB criteria predicted progression to MM (four of the five patients; hazard ratio, 0.12; 95% CI, 0.14 to 1.13; P = .03). Thirty-six patients showed biochemical progression, and failure to achieve uMRD at the end of treatment predicted it. The 70-month overall survival was 92% (95% CI, 82 to 89). Neutropenia and infections were the most frequent adverse events during treatment, resulting in one treatment-related death. Three second primary malignancies have been reported. Although a longer follow-up is needed, this curative approach is encouraging and more effective than active MM, with 31% of the patients maintaining the uMRD 4 years after HDM-ASCT.

Molecular Long-Term Analysis of the GMMG-HD4 Trial in Multiple Myeloma-Patterns of Association of Chromosomal Aberrations with Response and Proliferation Determining Survival in Selecting Treatments in View of Limited Resources in Low- and Middle-Income Countries.

Based on the lack of differences in progression-free and overall survival after a median follow-up of 93 months in our HOVON-65/GMMG-HD4 trial (German part; n = 395) randomizing VAD induction (vincristin/adriamycin/dexamthasone)/tandem-transplantation/thalidomide-maintenance vs. PAD induction (bortezomib/adriamycin/dexamethasone)/tandem transplantation/bortezomib maintenance, we discern how chromosomal aberrations determine long-term prognosis by different patterns of association with proliferation and treatment-dependent response, whether responses achieved by different regimens are equal regarding prognosis, and whether subpopulations of patients could be defined as treatable without upfront "novel agents" in cases of limited resources, e.g., in low- or middle-income countries. Serum parameters and risk factors were assessed in 395 patients. CD138-purified plasma cells were subjected to fluorescence in situ hybridization (n = 354) and gene expression profiling (n = 204). We found chromosomal aberrations to be associated in four patterns with survival, proliferation, and response: deletion (del) del17p13, del8p21, del13q14, (gain) 1q21+, and translocation t(4;14) (all adverse) associate with higher proliferation. Of these, del17p is associated with an adverse response (pattern 1), and 1q21+, t(4;14), and del13q14 with a treatment-dependent better response (pattern 2). Hyperdiploidy associates with lower proliferation without impacting response or survival (pattern 3). Translocation t(11;14) has no association with survival but a treatment-dependent adverse response (pattern 4). Significantly fewer patients reach a near-complete response or better with "conventional" (VAD) vs. bortezomib-based treatment after induction or high-dose melphalan. These patients, however, show significantly better median progression-free and overall survival. Molecularly, patients responding to the two regimens differ in gene expression, indicating distinct biological properties of the responding myeloma cells. Patients with normal renal function (89.4%), low cytogenetic risk (72.5%), or low proliferation rate (37.9%) neither benefit in progression-free nor overall survival from bortezomib-based upfront treatment. We conclude that response level, the treatment by which it is achieved, and molecular background determine long-term prognosis. Chromosomal aberrations are associated in four patterns with proliferation and treatment-dependent responses. Associations with faster and deeper responses can be deceptive in the case of prognostically adverse aberrations 1q21+ and t(4;14). Far from advocating a return to "outdated" treatments, if resources do not permit state-of-the-art-treatment, normal renal function and/or molecular profiling identifies patient subpopulations doing well without upfront "novel agents".

Response adaptive salvage treatment with daratumumab-lenalidomide-dexamethasone for newly diagnosed transplant-eligible multiple myeloma patients failing front-line bortezomib-based induction therapy-ALLG MM21.

In Australia, bortezomib-based induction (V-IND) is used in >90% of newly diagnosed transplant-eligible multiple myeloma (MM) patients. Four cycles of V-IND with bortezomib-cyclophosphamide-dexamethasone or bortezomib-lenalidomide-dexamethasone are available via the Pharmaceutical Benefits Scheme prior to autologous stem cell transplantation (ASCT). Patients who demonstrate suboptimal response or who are refractory to V-IND demonstrate inferior survival, representing a subgroup of MM where an unmet need persists. We evaluated an early, response-adapted approach in these patients by switching to an intensive sequential therapeutic strategy incorporating daratumumab-lenalidomide-dexamethasone-based (DRd) salvage, high-dose melphalan ASCT followed by DRd consolidation and R maintenance. The overall response rate following four cycles of DRd salvage was 72% (95% credible interval: 57.9-82.4); prespecified, dual, Bayesian proof-of-concept criteria were met. Euro-flow minimal residual disease (MRD) negativity was 46% in the intention-to-treat population and 79% in the evaluable population following 12 cycles of DRd consolidation. At the 24-month follow-up, median progression-free survival and overall survival were not reached. DRd salvage was well tolerated with grade 3 and 4 events reported in 24% and 8% respectively. Response-adapted DRd combined with ASCT achieves high rates of MRD negativity and durable disease control in this functional high-risk group.

Overall survival after isolated hepatic perfusion in combination with ipilimumab and nivolumab in patients with uveal melanoma metastases (the SCANDIUM II trial).

9533 Background: Uveal melanoma (UM) is a rare disease, that commonly metastases to the liver metastases and has a very poor prognosis. In patients with metastatic UM to the liver, a one-time treatment with isolated hepatic perfusion (IHP) with high dose melphalan has shown response rates of 40%, while immune checkpoint blockade with ipilimumab (3 mg/kg) in combination with nivolumab (1 mg/kg) (IPI3/NIVO1) has shown response rates of 11-18%. The impact of these treatments on overall survival (OS), if combined, is unclear. In the SCANDIUM II trial, we investigated the safety and tolerability of combination of IHP and IPI3/NIVO1. Methods: In this multicenter open, randomized, controlled, phase Ib trial, patients with liver dominant metastatic uveal melanoma were randomized to receive either IHP followed by combination immunotherapy (four cycles IPI3/NIVO1) (Arm A) or one cycle of IPI3/NIVO1 before IHP followed by three cycles IPI3/NIVO1 (Arm B). Thereafter, patients in both Arm A and B received monotherapy with nivolumab (480 mg q4w) for up to 1 year. Isolated hepatic perfusion was performed using melphalan 1mg/kg perfused through the liver for 60 minutes under hyperthermia (40°C). The primary endpoint was incidence and severity of adverse events. Results: In total, 18 patients were included in the trial, 9 randomized to Arm A and 9 to Arm B. 78% were treatment naïve; 28% had both hepatic and extra-hepatic metastases. Three patients did not undergo IHP as planned, one in arm A and two in arm B. Patients received a mean of 2.4 cycles of IPI/NIVO in Arm A and 3.0 cycles in Arm B. There were more IPI/NIVO related adverse events (grade I-IV) in arm B (48 vs. 86). The overall response rate was 38%, 57% in arm A and 22% in arm B, and the median duration of response was 11.9 months (95% CI, 8.2-NE, n = 6). At a minimum follow-up of 18 months, the overall survival rate was 50% (95% CI, 31.5-79.4%) in the whole study population, 56% (95% CI, 31-99%) in arm A and 44% (95% CI, 21-92%) in arm B. The median OS in arm A was 18.2 months (95% CI, 13.2-NA months) and 17.2 months (95% CI, 14.0-NA months) in arm B. The primary endpoint of adverse events has been reported previously. Conclusions: In patients with liver dominant metastatic uveal melanoma, combining IHP with IPI3/NIVO1 is a feasible treatment. One dose of IPI3/NIVO1 before IHP had no obvious benefit in response or OS, but was associated with higher rates of toxicity. There was no apparent survival advantage compared to patients in the SCANDIUM trial with IHP only, however, sample size and non-overlapping patient characteristics severely hamper comparison between the trials. The numerically higher response rate in Arm A warrants a larger randomized study that is designed to detect a difference between IPI/NIVO with or without IHP. Clinical trial information: NCT01785316 .

Long-term overall survival after isolated liver perfusion with melphalan in patients with isolated liver metastases of uveal melanoma (SCANDIUM trial).

9532 Background: Uveal melanoma is a rare subtype of melanoma characterized by frequent metastases to the liver. The median survival for patients with liver metastases is less than one year, and there are few systemic treatment options available, providing only small survival benefits. Patients with liver metastases of uveal melanoma were in the SCANDIUM trial randomized to a one-time treatment with isolated hepatic perfusion (IHP) with high dose melphalan and investigator´s choice. We have previously reported that IHP gave significantly superior response rates and progression-free survival compared to best alternative care Furthermore, the primary endpoint, overall survival (OS) rate at 24 months was numerically higher for the IHP treated group (46.5% vs 29.5%), but the difference was not statistically significant. Here we present extended OS follow-up. Methods: In this randomized, controlled, phase III trial, treatment naïve Swedish patients with isolated liver metastases from uveal melanoma were between 2013 and 2021 randomly assigned in a 1:1 ratio to receive a one-time treatment with IHP or best alternative care (control group). No crossover from the control group to the IHP group was allowed. Results: A total of 87 patients were randomized and assigned to either IHP (43 patients) or control (44 patients). In the IHP group, 41 (89%) patients received IHP. In the control group, the first-line treatment was chemotherapy (49%), immunotherapy (39%) or localized treatment interventions (9%). The overall response rate was 40% in the IHP group, with a median duration of response of 13.7 months (95% CI, 11.6-18.3, n=17). At a minimum follow-up of 36 months, the 3-year OS rate was 18.6% (95% CI, 10.0-34.8%) in the IHP group compared to 9.1% (95% CI, 3.6-23.1%) in the control group (p=0.23, fisher exact test), and the 5-year OS rate was 16.3% (95% CI, 8.3-32.1%) compared to 6.8% (95% CI, 2.3-20.3%). The median OS in the IHP group was 21.4 months (95% CI, 19.0-30.4 months) compared to 17.3 months (95% CI, 13.8-22.3 months) in the control group (p=0.11, log-rank test). Conclusions: This extended analysis from the SCANDIUM trial supports long-term efficacy of a one-time treatment with IHP compared to best alternative care in patients with isolated liver metastases of uveal melanoma. Clinical trial information: NCT01785316 .

Real world outcomes of high dose melphalan conditioning prior to autologous stem cell transplant in extramedullary multiple myeloma vs. multiple myeloma without extramedullary involvement: A single center experience.

7550 Background: Extramedullary multiple myeloma (EMM) is defined as the presence of multiple myeloma plasma cells, which develop outside of the bone marrow. It is an aggressive form of multiple myeloma that is associated with a poor prognosis. The current standard of care for multiple myeloma consists of induction, high dose melphalan autologous stem cell transplant (ASCT), followed by maintenance. However, there is limited data on the outcome of patients with extramedullary multiple myeloma who undergo ASCT. Therefore, we examined the outcomes of high dose melphalan conditioning prior to ASCT in EMM patients compared to multiple myeloma patients without extramedullary involvement (non-EMM) at an academic institution in Los Angeles. Methods: We retrospectively reviewed 246 multiple myeloma patients who underwent ASCT after receiving high dose melphalan conditioning at USC Norris Comprehensive Cancer Center from Jan 2017 to Dec 2022. The cohort was subdivided into 70 EMM patients and 176 non-EMM patients. Outcomes were measured as the status of disease response, which was evaluated at 100 days (D+100) and 365 days (D+365) after the date of transplant. Results: In the EMM group, 1.43% (n=1) was found to have progression at D+100 and 12.86% (n=9) at D+365. In the non-EMM group, 0.57% (n=1) was found to have progression at D+100 and 11.93% (n=21) at D+365. There was no statistical significance between the EMM and non-EMM groups for progression free survival at D+100 (p-0.50) and D+365 (p-0.75). Regarding overall survival, there were 0 deaths observed at D+100 in both the EMM and non-EMM groups. For D+365, the overall survival was 98.57% (n=69) for the EMM group and 99.43% (n=175) for the non-EMM group. There was no statistical significance between the overall survival at D+365 (p-0.14). Conclusions: The EMM cohort exhibited similar rates of progression free survival (87.14% vs. 88.07%) and overall survival (98.57% vs. 99.43%) compared to the non-EMM cohort at one year post ASCT after receiving high dose melphalan conditioning. We observed that there was no significant statistical difference between the EMM and non-EMM cohorts regarding progression-free survival (p-0.75) and overall survival (p-0.14) on day 365. According to our data, high dose melphalan conditioning prior to autologous stem cell transplant is equally as effective for patients with multiple myeloma with or without extramedullary involvement. Future studies with long-term follow-up are recommended to further explore these findings. [Table: see text]

Effect of dose-adjusted melphalan on MRD-negativity to full dose melphalan in patients with multiple myeloma post-autologous stem cell transplant.

7557 Background: Despite significant therapeutic advancements, Multiple Myeloma (MM) remains an incurable disease. Autologous stem cell transplantation (ASCT) is a standard treatment for eligible patients, with high-dose melphalan (MEL200) as the preferred conditioning regimen. Reduced-dose melphalan (MEL140) is used for older or less fit patients. However, this was not prospectively studied and there has been ongoing debate about the efficacy of reduced dosing. This study aimed to investigate the impact of melphalan dose on minimal residual disease (MRD) negativity rates in MM patients undergoing upfront ASCT. Methods: We conducted a retrospective, single-center study involving 74 MM patients who underwent ASCT between 2018 and 2022 at UHCMC, Cleveland, OH and had MRD testing done after transplant. MRD testing was performed using the ClonoSEQ next generation sequencing platform. Results: Median age was higher in the MEL140 group compared to MEL200 (70.3 vs 59.8 years), both groups were similar in terms of sex and race distribution, BMI and KPS scores. Both groups have comparable ISS staging and high-risk cytogenetics. Similar numbers of lines of treatment prior to transplant were seen, with approximately 64% having only one line. First-line induction therapy included triplet therapy (Lenalidomide, Bortezomib, and Dexamethasone) in 73% of patients. Depth of remission at transplant was comparable between groups. MRD negativity rates at 10-5 and 10-6 were comparable between MEL140 and MEL200 groups (64% and 39% in MEL140; 61% and 41% in MEL200; p=0.8 and 0.7 respectively). Sustained MRD negativity at 10-5 over at least 12 months was also comparable (43% in MEL140; 50% in MEL200, p=0.8). After a median follow-up of 37 months, PFS was not reached for either group (p=0.69). Patients achieving MRD negativity at levels of 10-5 had a not reached median PFS, while those not achieving MRD negativity had a median PFS of 41 months (95%CI 23-NR; p=0.024). There was no significant difference in hospital stay duration, time to neutrophil engraftment, readmission rate, or infections within 100 days post-transplant between the MEL140 and MEL200 groups. Conclusions: Our real-world analysis demonstrates that MEL140 yields similar deep post-transplant remissions as MEL200, translating to improved PFS for patients achieving MRD negativity, regardless of the dose used. This is the first report to our knowledge of MRD negativity rate in patients receiving MEL140. [Table: see text]

Twice-weekly induction with ixazomib-lenalidomide-dexamethasone (IRd) combination followed by extended IRd consolidation and lenalidomide maintenance in transplant-eligible patients with newly diagnosed multiple myeloma: Results of the phase 2 study IFM2014-03.

Therapeutic strategies for patients with newly diagnosed multiple myeloma (NDMM) have considerably improved during the last 10 years. The IFM2014-03 trial proposed an all-oral triplet induction/consolidation regimen in transplant-eligible NDMM patients, followed by lenalidomide maintenance. Induction consisted of three 21-day cycles of ixazomib, lenalidomide and dexamethasone (IRd), before high-dose Melphalan with transplant followed by eight 28-day cycles of IRd consolidation before 13 cycles of lenalidomide maintenance. Forty-six patients were enrolled and received at least one dose of therapy, and 39 entered the maintenance phase. The primary end-point was stringent complete response after consolidation, and was achieved in nine patients (20.9%, 90% CI 11.4-33.7; p = 0.998). Ten patients (24.4%) had an undetectable minimal residual disease. The overall response rate was 95.7%. The 3-year progression-free survival was 66.3%. No unexpected toxicities were recorded, and only eight patients suspended from any study drug. Of note, 21 (45.7%) patients reported peripheral neuropathy (PN) (grades 1-2 with no serious adverse events). IRd induction and consolidation with transplant before lenalidomide maintenance shows lower response rates compared to other triplet therapies. It could be an alternative for patients who require an all-oral regimen and/or with pre-existent PN, especially if quadruplet regimens including anti-CD38 antibody are not available.

Does early granulocyte colony-stimulating factor administration in autologous peripheral blood stem cell transplantation shorten the duration of hospitalization in patients with multiple myeloma?

Aims: Autologous peripheral blood stem cell transplantation (PBSCT), performed with high-dose melphalan support following induction therapy is still the gold standard method of treatment for multipl myeloma (MM)patients suitable for transplantation. It was aimed, with this retrospective study, to investigate the effects of early (1 day after PBSCT) and late (5 days after PBSCT) initiation of granulocyte colony-stimulating factor (G-CSF) support following PBSCT on engraftment time, febrile neutropenia, and length of hospital stay (LOS) in MM patients. Methods: This study included 70 patients with MM, who underwent PBSCT in Erciyes University. Two groups were administered 5µg/kg filgrastim, subcutaneously, either 1 day or 5 days after PBSCT, until neutrophil engraftment was reached. Results: Both neutrophil and platelet engraftment occurred in significantly shorter times in the early G-CSF group compared to late G-CSF group; the median times to neutrophil engraftment were 10 (8-13) and 11 (7-15) days, respectively, and the median times to platelet engraftment were 11 (10- 16) and 13 (11- 21) days (p=0.001). Also, the median LOS was also significantly shorter in the early G-CSF group compared to late G-CSF group; 14 (10-22) vs 16 (11- 33) days, respectively (p=0.016). No significant difference was found between the groups in terms of frequency of febrile neutropenia. Conclusion: The initiation of G-CSF support early, following PBSCT in MM patients, accelerated neutrophil and platelet engraftment and shortened the LOS as compared to the initiation of G-CSF support late, with no significant difference in the frequency of febrile neutropenia.

Assessing Outcomes in Patients With Multiple Myeloma Postautologous Stem Cell Transplantation: Contrasting the Effects of Melphalan Dosages at 200 mg/m2 versus 140 mg/m2

BackgroundNo standard criteria for dose reduction exists for high-dose melphalan for autologous stem cell transplantation (ASCT) for multiple myeloma (MM) due to limited and conflicting evidence. ObjectiveTo evaluate efficacy and safety of standard dose (200 mg/m2 = Mel200) versus reduced dose 140 mg/m2 = Mel140) of melphalan in patients with MM undergoing ASCT. DesignA single-center retrospective review of adults with MM for their first ASCT between January 1, 2010, and November 1, 2022, who received Mel200 or Mel140 as conditioning. Primary endpoint was progression-free survival (PFS). Secondary safety and efficacy endpoints included overall survival (OS), incidence of febrile neutropenia and acute kidney injury, and time to engraftment. Subgroup analyses were performed based on patient age and renal function. ResultsA total of 322 patients were included in the study, 240 in the Mel200 group and 82 in the Mel140 group. Baseline demographics were similar except patients receiving Mel140 were on average older and had worse kidney function. PFS at 2 years was not different between groups (P = .2335). No difference existed in 2 year PFS or OS for patients < 65 years of age versus ≥ 65 years of age or for patients with CrCl 30-59 mL/min versus CrCl ≥ 60 mL/min within either Mel200 group or Mel140 group (all P > .05). No differences existed between groups across all secondary outcomes. ConclusionReduced doses melphalan showed no differences in safety or efficacy outcomes versus standard dose even when analyzed based on age and renal function. Larger randomized controlled trials need to be performed to validate these findings.

Acute kidney injury during autologous stem cell transplantation in light chain amyloidosis with kidney involvement and their impact on prognosis.

Acute kidney injury (AKI) is a complication related to important organ dysfunction during autologous stem cell transplantation (ASCT) in light chain (AL) amyloidosis. This study aims to validate the risk factors of AKI during different periods of ASCT and the impact of AKI on long-term outcomes. 302 patients with AL amyloidosis and kidney involvement who underwent ASCT were included. The procedures from stem cell mobilization to 30 days after transplantation were categorized into four periods: Period 0 (stem cell mobilization and harvest), Period 1 (preparation), Period 2 (conditioning and transplantation), and Period 3 (engraftment). The incidence of AKI during ASCT was 27.15% (0.66% in Period 0, 6.62% in Period 1, 15.23% in Period 2, and 6.95% in Period 3). The major causes of AKI were capillary leak syndrome in Period 0, ganciclovir or sulfamethoxazole/trimethoprim in Period 1, high-dose melphalan in Period 2, and engraftment syndrome in Period 3. AKI in different periods had distinct risk factors and predictive models. AKI was a risk factor for both kidney survival and overall survival (OS). Even recovered AKI reduced 10-year kidney survival from 91.7% to 68.4% (p = 0.002) and 10-year OS from 91.1% to 77.7% (p = 0.005).

The Role of Autologous Stem Cell Transplantation in the Treatment of Newly Diagnosed Multiple Myeloma: Is It Time to Rethink the Paradigm in the Era of Targeted Therapy?

High-dose melphalan (HDM) plus autologous stem cell transplant (ASCT) remains a standard-of-care treatment approach for eligible patients with newly diagnosed multiple myeloma (NDMM) based on demonstrated superiority in terms of progression-free survival (PFS) versus nontransplant approaches. Very high rates of minimal residual disease (MRD)-negative responses are also being seen with novel triplet and quadruplet induction regimens plus HDM-ASCT. However, recent clinical trials have shown no overall survival benefit with transplant versus nontransplant approaches. Furthermore, HDM is associated with several important downsides, including acute and long-term toxicities, transient decreases in quality of life, the need for hospitalization, an increased mutational burden at relapse, and an elevated risk of second primary malignancies. In this context, given the highly heterogeneous nature of MM in the NDMM patient population, as well as the continued emergence of novel agents and treatment approaches, there is an increasing rationale for considering deferred HDM-ASCT approaches in selected patients. Approaches under investigation include MRD-adapted therapy and the use of novel immune-based therapies as alternatives to HDM-ASCT. Ongoing developments in understanding the pathobiology and prognostic factors in NDMM, plus immune profiling and routine MRD evaluation, will result in novel, HDM-sparing treatment paradigms, enabling further improvement in patient outcomes.

Nationwide implementation of lenalidomide maintenance in multiple myeloma: A retrospective, real-world study.

Lenalidomide maintenance (LM) has shown benefit in progression-free survival (PFS) and overall survival (OS) in clinical trials. LM is the recommended standard of care in patients with newly diagnosed multiple myeloma (MM) after high-dose melphalan and autologous stem cell transplantation (HDM-ASCT). In Denmark, LM has been approved and publicly funded for all patients treated with HDM-ASCT since June 2019. Patients with newly diagnosed MM treated with their first HDM-ASCT between June 2019 and March 2022 were included and followed until data cut-off in June 2023. To compare outcomes, a historical pre-LM cohort from the Danish MM Registry, consisting of 364MM patients treated with HDM-ASCT between June 2015 and June 2019, was used. Among 364 patients treated with HDM-ASCT after June 2019, 22.3% received consolidation therapy and 3.7% underwent tandem HDM-ASCT. During follow-up, 297 patients (81.6%) initiated maintenance therapy, with 277 (76.1%) receiving LM. Overall, 145 patients (52.3%) discontinued LM most commonly due to toxicity 75 (51.7%), with fatigue (30.7%), cytopenia (25.3%), and neuropathy (17.3%) being the main reasons. In a 6-month landmark analysis, early discontinuation did not negatively impact PFS or OS. The LM cohort had similar PFS, and OS compared to the pre-LM cohort. The 3-year PFS and OS rates in the LM cohort were 61% and 86%, respectively, while the pre-LM cohort had a 3-year PFS of 55% and a 3-year OS of 89%. In conclusion, the introduction of LM as a nationwide treatment option in Denmark did not lead to improved clinical outcomes.

Abstract 2958: Melphalan-treated multiple myeloma cells exhibit a senescent-like dormancy phenotype

Abstract Multiple myeloma (MM) is an incurable plasma cell (PC) cancer in which all patients are expected to relapse. Cytotoxic agents such as high-dose melphalan (HDM), which is used as a myeloablative agent prior to autologous stem cell transplant (ASCT) in MM, drive therapy-induced senescence (TIS) in non-cancerous tissues. We hypothesized that HDM similarly activates TIS pathways in surviving MM cells and this response may correlate with patient outcomes post-ASCT. To test this, we developed an in vitro model in which 5TGM1 mouse MM cells are cultured with 10uM melphalan (HDM) or vehicle (Veh) for 6 hours, followed by co-culture in normal media with primary mouse bone marrow stromal cells. Cultures were maintained for 10 days and imaged to quantify cumulative population doublings (CPDs). 5TGM1 were then isolated by FACS to measure telomere-associated DNA damage foci (TAFs), sensitivity to senolytic drugs, and senescence gene expression (RT-qPCR and scRNA-seq). To translate these studies, scRNA-seq was used to analyze CD138+ PCs from MM patient bone marrow post-ASCT. Additionally, longitudinal bone biopsies from MM patients at diagnosis and post-ASCT were stained for CD138+ PCs; PC burden was quantified using artificial intelligence assisted histology (HALO). HDM-5TGM1 exhibited stable growth arrest (decreased CPDs) and sustained DNA damage (increased TAFs) compared to Veh-5TGM1. HDM-5TGM1 were also significantly more sensitive to senolytic ablation (Dasatinib+Quercetin or Fisetin). HDM-5TGM1 showed increased senescence (Cdkn1a, Cdkn1c, Glb1), anti-apoptosis (Bcl2l1), and senescence associated secretory phenotype (Ccl5, Icam1, Mmp13) genes, as well as myeloid markers found to be increased in MM dormancy (Axl, Fcer1g, Mpeg1). Analysis by scRNA-seq revealed that HDM-5TGM1 were G0/G1 arrested, and gene set enrichment analysis (GSEA) confirmed upregulation of senescence pathways with downregulation of DNA replication and cell cycle pathways. Consistent with RT-qPCR results, these cells exhibited myeloid gene expression. Analysis of patient CD138+ PCs post-ASCT by scRNA-seq also revealed a myeloid-like cluster. Of interest, of the 491 genes upregulated in this cluster, 268 were also upregulated in HDM-5TGM1. CD138+ PCs could also be detected in patient bone biopsies post-ASCT, although PC burden was significantly reduced post-ASCT. Surprisingly, the percent reduction in PC burden post-ASCT was greater in relapsed (≤3 years) vs non-relapsed patients. Further, in relapsed patients, PC burden post-ASCT positively correlated with time in remission. Altogether, these findings demonstrate that HDM can induce senescence features and a myeloid-dormancy signature in surviving MM cells. This phenotype is associated with longer durable response, suggesting that activation of TIS may be a strategy to extend PFS. Further, senolytic therapy may be a novel approach to eliminate dormant MM cells and prevent relapse. Citation Format: Angelo Jose Guilatco, Marta Diaz-del-Castillo, Gabriel Alvares Borges, Neal I. Sannuli, Megan L. Ritting, Syed Mohammed Aalam, Nagarajan Kannan, Tamar Tchkonia, James L. Kirkland, Yi Lin, Taxiarchis Kourelis, Matthew T. Drake, Thomas Levin Andersen, Megan Weivoda. Melphalan-treated multiple myeloma cells exhibit a senescent-like dormancy phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2958.