International Myeloma Working Group immunotherapy committee consensus guidelines and recommendations for optimal use of T-cell-engaging bispecific antibodies in multiple myeloma.

Multiple myeloma remains an incurable disease, despite the development of numerous drug classes and combinations that have contributed to improved overall survival. Immunotherapies directed against cancer cell-surface antigens, such as chimeric antigen receptor (CAR) T-cell therapy and T-cell-redirecting bispecific antibodies, have recently received regulatory approvals and shown unprecedented efficacy. However, these immunotherapies have unique mechanisms of action and toxicities that are different to previous treatments for myeloma, so experiences from clinical trials and early access programmes are essential for providing specific recommendations for management of patients, especially as these agents become available across many parts of the world. Here, we provide expert consensus clinical practice guidelines for the use of bispecific antibodies for the treatment of myeloma. The International Myeloma Working Group is also involved in the collection of prospective real-time data of patients treated with such immunotherapies, with the aim of learning continuously and adapting clinical practices to optimise the management of patients receiving immunotherapies.

Minimal residual disease status is the prognostic determinant following high-dose treatment for patients with multiple myeloma.

BACKGROUND: The presence of minimal residual disease (MRD+) following autologous stem cell transplantation (ASCT) in multiple myeloma represents a poor prognostic factor for progression-free survival (PFS) and overall survival (OS). METHODS: At our department, we recommend lenalidomide maintenance for patients who are MRD+ after ASCT, while MRD-negative (MRD-) patients, after information about the national guidelines, were not advised to follow this regimen. RESULTS: Out of the total 228 patients, 175 received ASCT following first-line induction (MRD- 92 (53%), MRD+ 83 (47%), at 2 months post-ASCT), while 53 underwent ASCT after second-line treatment (MRD- 27 (51%), MRD+ 26 (49%), at the same time point). Comparatively, MRD- patients who did not receive maintenance demonstrated better OS than MRD+ patients who received upfront ASCT and maintenance treatment (96% vs. 86%, p = 0.030, at 3 years). However, nonsignificant difference was found in PFS (76% vs. 62%, at 3 years). Furthermore, second-line ASCT, MRD- non-maintained patients exhibited significantly better PFS than MRD+ (71% vs. 27%, p > 0.001, at 3 years). However, OS was better but nonsignificant (96% vs. 76%, at 3 years). Fluorescence in situ hybridization (FISH) analysis was performed on 141 out of the 228 patients. Of these, 85 (60%) patients were deemed standard risk (SR), and 56 (40%) were classified as high risk (HR). In the SR cohort, MRD- patients exhibited better PFS and OS than MRD+ patients (71% vs. 59% and 100% vs. 85%, respectively). In the HR cohort, the MRD- patients showed superior PFS but similar OS compared to MRD+ patients (66% vs. 42% and 81% vs. 80%, respectively). CONCLUSIONS: Our results indicate that being MRD- is a more crucial prognostic factor for the 3-year PFS and OS than the presence of high-risk cytogenetic markers or undergoing maintenance treatment. The latter appears insufficient, particularly for MRD+ patients following ASCT in the second-line setting, suggesting that these patients may require a more intensive treatment approach.

Conditioning with melphalan 200 mg/m2 and subsequent ASCT improves progression-free and overall survival in elderly myeloma patients compared to standard of care.

OBJECTIVES: Despite the effectiveness of newer drugs for the treatment of multiple myeloma (MM), the outcomes are further improved by subsequent autologous stem cell transplantation (ASCT). Data on effectiveness in older patients are limited. We compared outcomes in patients aged 65-75 years depending on whether they were treated with ASCT or not and compared those to outcomes in patients <65 years. METHODS: This was a retrospective, single-center study. We compared progression-free survival (PFS) and overall survival (OS) for all MM patients below and above the age of 65 years treated ± ASCT at the Karolinska University Hospital between 2010 and 2020. PFS and OS were calculated by the Kaplan-Meier method. Variables affecting PFS and OS were evaluated using Cox regression model. RESULTS: Both PFS and OS were improved in the group 65-75 years treated +ASCT compared to those treated pharmacologically (p = 0.008 and p < 0.001, respectively). There were no significant differences between patients <65 years and those 65-75 years treated with ASCT. CONCLUSION: The findings indicate that even patients >65 years should be evaluated as candidates for ASCT. An individualized approach supported by a frailty/geriatric assessment score could assist clinicians to select the appropriate treatment for each patient.

Autologous NK cells as consolidation therapy following stem cell transplantation in multiple myeloma.

Few approaches have been made toward exploring autologous NK cells in settings of cancer immunotherapy. Here, we demonstrate the feasibility of infusing multiple doses of ex vivo activated and expanded autologous NK cells in patients with multiple myeloma (MM) post-autologous stem cell transplantation. Infused NK cells were detected in circulation up to 4 weeks after the last infusion. Elevations in plasma granzyme B levels were observed following each consecutive NK cell infusion. Moreover, increased granzyme B levels were detected in bone marrow 4 weeks after the last infusion. All measurable patients had objective, detectable responses after NK cell infusions in terms of reduction in M-component and/or minimal residual disease. The present study demonstrates that autologous NK cell-based immunotherapy is feasible in a setting of MM consolidation therapy. It opens up the possibility for usage of autologous NK cells in clinical settings where patients are not readily eligible for allogeneic NK cell-based immunotherapies.

Phase II Trial of Allogeneic Transplantation Plus Novel Drugs in Multiple Myeloma: Effect of Intensifying Reduced-Intensity Conditioning with Bortezomib and Adding Maintenance Treatment.

The use of reduced-intensity conditioning (RIC) regimens has decreased the risk of nonrelapse mortality (NRM) after allogeneic stem cell transplantation (alloSCT). In contrast, disease relapse remains the most frequent cause of treatment failure and death. Owing to both their antimyeloma effect and immunomodulatory properties, novel drugs could improve outcomes after alloSCT. This phase II European Myeloma Network trial was designed to evaluate the combination of alloSCT with novel agents. The study was conducted to evaluate the toxicity and efficacy of RIC intensified with bortezomib (Bz) prior to alloSCT for high-risk (HR) multiple myeloma (MM) patients, as well as the efficacy of post-transplantation maintenance with Bz and lenalidomide (Len). Patients received RIC with Bz on days -9 and -2, fludarabine on days -6 to -4, and melphalan on day -3. Patients who were in complete response (CR) or near CR at day +100 post-transplantation received 6 cycles of Bz every 56 days, and the remaining received Bz, Len, and dexamethasone. Len maintenance was started on day +180 at a dose of 5 mg and continued until relapse or toxicity occurred. Of the 24 patients included, 21 were evaluable on day +100, including 12 in CR, 4 in very good partial response, 3 in partial response, and 2 with relapse or progression. The cumulative incidence (CuI) of relapse was 13.6% (95% confidence interval [CI], 3.2% to 31.3%) at 1 year and 28.5% (95% CI, 11.1% to 48.9%) at 2 years. The CuI of NRM was 21.1% (95% CI, 7.4% to 39.4%) at 2 years. With a median follow-up of 39 months (range, 1 to 67 months), the median event-free survival (EFS) was 29 months, and median overall survival (OS) was not reached. EFS and OS at 3 years were 42.5% (95% CI, 21.9% to 61.7%) and 74.01% (95% CI, 50.9% to 87.5%), respectively. The use of Bz within an RIC regimen allows for a high response rate after alloSCT. Maintenance with Bz and Len is feasible and provides remarkable results in terms of EFS and OS in HR MM patients.

Primary plasma cell leukemia: consensus definition by the International Myeloma Working Group according to peripheral blood plasma cell percentage.

Primary plasma cell leukemia (PCL) has a consistently ominous prognosis, even after progress in the last decades. PCL deserves a prompt identification to start the most effective treatment for this ultra-high-risk disease. The aim of this position paper is to revisit the diagnosis of PCL according to the presence of circulating plasma cells in patients otherwise meeting diagnostic criteria of multiple myeloma. We could identify two retrospective series where the question about what number of circulating plasma cells in peripheral blood should be used for defining PCL. The presence of ≥5% circulating plasma cells in patients with MM had a similar adverse prognostic impact as the previously defined PCL. Therefore, PCL should be defined by the presence of 5% or more circulating plasma cells in peripheral blood smears in patients otherwise diagnosed with symptomatic multiple myeloma.

Expert review on soft-tissue plasmacytomas in multiple myeloma: definition, disease assessment and treatment considerations.

In this review, two types of soft-tissue involvement in multiple myeloma are defined: (i) extramedullary (EMD) with haematogenous spread involving only soft tissues and (ii) paraskeletal (PS) with tumour masses arising from skeletal lesions. The incidence of EMD and PS plasmacytomas at diagnosis ranges from 1·7% to 4·5% and 7% to 34·4% respectively. EMD disease is often associated with high-risk cytogenetics, resistance to therapy and worse prognosis than in PS involvement. In patients with PS involvement a proteasome inhibitor-based regimen may be the best option followed by autologous stem cell transplantation (ASCT) in transplant eligible patients. In patients with EMD disease who are not eligible for ASCT, a proteasome inhibitor-based regimen such as lenalidomide-bortezomib-dexamethasone (RVD) may be the best option, while for those eligible for high-dose therapy a myeloma/lymphoma-like regimen such as bortezomib, thalidomide and dexamethasone (VTD)-RVD/cisplatin, doxorubicin, cyclophosphamide and etoposide (PACE) followed by SCT should be considered. In both EMD and PS disease at relapse many strategies have been tried, but this remains a high-unmet need population.

Improved survival in multiple Myeloma patients undergoing autologous stem cell transplantation is entirely in the standard cytogenetic risk groups.

INTRODUCTION: Novel drugs and drug combinations have improved outcomes for multiple myeloma patients. However, subgroups of patients still have a poor progression-free survival (PFS) and overall survival (OS). In an attempt to identify how the novel drugs affect the outcome in standard-risk and high-risk patients, respectively, we have investigated 715 multiple myeloma (MM) patients who have undergone high dose treatment followed by autologous stem cell transplantation at our center during 1995 - 2020. Outcomes during three time periods, 1995-1999 (period I), 2000-2009 (period II), and 2010-2020 (period III), were compared separately for standard-risk and high-risk patients. Risk stratification was based on chromosome analysis for periods II and III. RESULTS: The whole cohort of patients showed significantly improved OS with time during the three periods being at a median of 5.8, 7.0, and 10.0 years, respectively. There is also a weak tendency for improved PFS, that is, a median of 2.4, 2.6, and 2.9 years, respectively, during the same periods. However, the separate analysis of standard-risk and high-risk patients showed that the overall improvement with time was due to improved standard-risk patients (median OS 8.4 years for the period I and not reached for period II and III). In contrast, no significant improvement was seen in high-risk patients. For patients with del17p, PFS was even worse during period III as compared to period II (median 1.6 vs 3.2 years respectively). CONCLUSION: Our results show that the dramatic improvement in outcome for MM patients during the last 20 years only applies for standard-risk patients, while high-risk MM patients still are doing poorly, indicating that the novel drugs developed during this time are preferentially effective in standard-risk patients. New treatment modalities like CAR-T cells, CAR-NK cells, and/or bispecific antibodies should be tried in clinical studies early in the course of the disease, especially in patients with high-risk cytogenetics.

Allogeneic Transplantation in Multiple Myeloma-Does It Still Have a Place?

Novel drugs have improved survival for patients with multiple myeloma in recent years. However, the disease is still fatal. Allogeneic stem cell transplantation (Allo) has proven to cure some patients with the disease, but its role is controversial due to relatively high transplant-related toxicity and mortality (nonrelapse mortality, NRM). Using nonmyeloablative reduced-intensity conditioning (RIC), both toxicity and NRM can be reduced, and RICAllo is, therefore, an option for subgroups of patients. Upfront tandem autologous/RICAllo (Auto/RICAllo) was shown to be superior to single Auto or tandem Auto/Auto in both progression-free (PFS) and overall survival (OS) in two prospective studies with long-term follow-up, while three similarly designed studies did not detect a difference. A recent update of pooled patient data from four of these studies showed significantly superior PFS and OS with Auto/RICAllo. Importantly, none of these studies showed inferior results with Auto/RICAllo in patients less than 70 years of age. Auto/RICAllo appears to overcome some poor risk cytogenetic markers. Encouraging results have also been seen in treatment of relapsed patients. Combining Allo with new proteasome inhibitors and immunomodulatory drugs may further improve results. Other encouraging new cell therapies such as with CAR T-cells, NK- and CAR NK-cells may well have a place in combination with RICAllo. Such studies are warranted.

Are Autologous Stem Cell Transplants Still Required to Treat Myeloma in the Era of Novel Therapies? A Review from the Chronic Malignancies Working Party of the EBMT.

Melphalan at a myeloablative dose followed by autologous stem cell transplantation (ASCT) remains the standard of care for transplant-eligible patients with myeloma. However, therapies such as new immunomodulatory drugs and proteasome inhibitors and, more recently, monoclonal antibodies and chimeric antigen receptor T cells are challenging the traditional role of ASCT. Which patients benefit from ASCT? Can its use be delayed until first relapse? The field is moving rapidly as novel agents lead to new patient care strategies. The place of ASCT in this changing landscape will be reviewed and reassessed.

Long-term survival of 1338 MM patients treated with tandem autologous vs. autologous-allogeneic transplantation.

Contrary to tandem autologous transplant (auto-auto), autologous followed by reduced intensity conditioning allogenic transplantation (auto-allo) offers graft-versus-myeloma (GVM) effect but with higher toxicity. Trials comparing these two strategies relied on availability of HLA-matched sibling donors for arm allocation (biological randomization) and yielded conflicting results. A pooled analysis of multiple trials with extended follow up provides an opportunity to compare these strategies. We obtained individual patient data from participants of four trials comparing auto-auto vs. auto-allo after induction therapy. There were 899 patients in auto-auto and 439 in auto-allo. Median follow up of survivors was 118.5 months. Median overall survival (OS) was 78.0 months in auto-auto and 98.3 months in auto-allo (HR = 0.84, P = 0.02). OS was 36.4% vs. 44.1% at 10 years (P = 0.01) for auto-auto and auto-allo, respectively. Progression-free survival was also improved in auto-allo (HR = 0.84, P = 0.004). Risk of non-relapse mortality was higher in auto-allo (10 year 8.3% vs. 19.7%, P < 0.001), while risk of disease progression was higher in auto-auto (10 year 77.2% vs. 61.6%, P < 0.001). Median post relapse survival was 41.5 months in auto-auto and 62.3 months in auto-allo (HR = 0.71, P < 0.001). This supports the existence of durable GVM effect enhancing myeloma control with subsequent therapies.

Translocation (11;14) in newly diagnosed multiple myeloma, time to reclassify this standard risk chromosomal aberration?

OBJECTIVES: The most common translocation in multiple myeloma (MM) is t(11;14)(q13;q32), and its importance as prognostic factor has been controversial. The aim was to analyze its prognostic value. METHOD: In this retrospective study of 469 newly diagnosed myeloma patients, outcomes in patients with (11;14) and standard risk (t(11;14)SR) or high risk (t(11;14)HR) cytogenetics were compared to outcomes of patients without t(11;14) and SR (non-t(11;14)SR) or HR (non-t(11;14)HR), respectively. RESULTS: Overall progression-free survival (PFS) was shorter in t(11;14)SR than non-t(11;14)SR (median 28.9 vs 35.3 months); however, the difference was not significant (P = .2). Overall survival (OS) did not differ significantly between the groups. In the subgroup of patients that did not receive high-dose treatment, PFS was shorter for t(11;14)SR compared to non-t(11;14)SR, 10.6 vs 24.6 months (P = .01). Although OS were shorter for t(11,14)SR compared to non-t(11;14)SR (5-year OS 41.7% vs 63.8%), the difference was not significant (P = .1). In HDT patients, no significant difference was observed for OS or PFS between those with or without t(11;14). CONCLUSION: This study shows that t(11;14) is associated with poorer outcome in MM, particularly in non-high-dose-treated SR patients. It should be considered an intermediate or high-risk marker in these patients.

Upfront bortezomib, lenalidomide, and dexamethasone compared to bortezomib, cyclophosphamide, and dexamethasone in multiple myeloma.

OBJECTIVES: At our center, patients with multiple myeloma (MM) were treated upfront with bortezomib, cyclophosphamide, and dexamethasone (VCD) until cyclophosphamide was replaced with lenalidomide in the combination (VRD). These treatments have never been compared head-to-head in large real-life patient material. METHOD: A retrospective analysis of patients treated with VRD and VCD in the first line, both with and without subsequent high-dose treatment (HDT) and autologous stem cell transplantation. A total of 681 patients were included, 117 receiving VRD (71 with, 46 without HDT) and 564 receiving VCD (351 with, 213 without HDT). RESULTS: Overall response rate (≥partial response) was higher with VRD compared to VCD in the entire VRD group (98% vs 88%, P < 0.001) and in the non-HDT group (98% vs 79%, P < 0.001). Progression-free survival (PFS) at 18 months was longer with VRD compared to VCD in the entire VRD group, the non-HDT group and the HDT group (88% vs 63%, 82% vs 32% and 91% vs 73%, respectively). Overall survival at 18 months was better for VRD-treated patients in the entire VRD group (95% vs 89%, P = 0.048). CONCLUSION: Upfront VRD gives better responses and longer PFS compared to VCD in MM patients with or without subsequent HDT.

Infectious complications and NK cell depletion following daratumumab treatment of Multiple Myeloma.

Treatment with Daratumumab (Dara), a monoclonal anti-CD38 antibody of IgG1 subtype, is effective in patients with multiple myeloma (MM). However, Dara also impairs the cellular immunity, which in turn may lead to higher susceptibility to infections. The exact link between immune impairment and infectious complications is unclear. In this study, we report that nine out of 23 patients (39%) with progressive MM had infectious complications after Dara treatment. Five of these patients had viral infections, two developed with bacterial infections and two with both bacterial and viral infections. Two of the viral infections were exogenous, i.e. acute respiratory syncytial virus (RSV) and human metapneumovirus (hMPV), while five consisted of reactivations, i.e. one herpes simplex (HSV), 1 varicella-zoster (VZV) and three cytomegalovirus (CMV). Infections were solely seen in patients with partial response or worse. Assessment of circulating lymphocytes indicated a selective depletion of NK cells and viral reactivation after Dara treatment, however this finding does not exclude the multiple components of viral immune-surveillance that may get disabled during this monoclonal treatment in this patient cohort. These results suggest that the use of antiviral and antibacterial prophylaxis and screening of the patients should be considered.

Lenalidomide versus lenalidomide + dexamethasone prolonged treatment after second-line lenalidomide + dexamethasone induction in multiple myeloma.

Lenalidomide (Len) plus dexamethasone (Dex) is approved for the treatment of relapsed or refractory multiple myeloma (RRMM). It is possible that single-agent Len may be effective as prolonged treatment regimen in RRMM once patients demonstrate an initial response to Len+Dex induction. Patients with RRMM who responded to first-line Len+Dex in an observational study (NCT01430546) received up to 24 cycles of either Len (25 mg/day) or Len+Dex (25 mg/day and 40 mg/week) as prolonged treatment in a subsequent phase 2 clinical trial (NCT01450215). In the observational study (N = 133), median time to response was 1.7 (range 0.6-9.6) months. A complete response to all treatments received in both studies was observed in 11% of patients; very good partial response and partial response rates were 31% and 38%, respectively. Corresponding response rates in the subgroup of patients who did not enter the phase 2 trial (n = 71) were 3%, 18%, and 39%, respectively. Rates of disease progression at 2 years in the phase 2 trial were 47% versus 31% for Len versus Len+Dex (P = 0.14). After 36 months median follow-up in surviving patients, median time to progression was not reached with Len+Dex and was 24.9 months (95% confidence interval 12.5-not calculable, P < 0.001) with Len. Three-year OS among the total observational study population was 61% (95% CI, 52-69%). The corresponding rate among patients who entered the phase 2 clinical trial was 73% (95% CI, 60-83%) and was significantly lower among those patients who achieved ≥PR but did not proceed into the phase 2 trial (55%; P = 0.01). In the phase 2 trial, OS was 73% in both treatment arms (P = 0.70). Neutropenia and thrombocytopenia were more common with prolonged (phase 2 trial) versus short-term (observational study) Len administration but remained manageable. Prolonged treatment with Len with or without Dex provides sustained, clinically relevant responses and demonstrates an acceptable safety profile.

Case Report: Treatment of light-chain amyloidosis with daratumumab monotherapy in two patients.

Immunoglobulin light-chain amyloidosis (AL) affects multiple organs, most prominently the kidney and the heart. Renal and cardiac impairment are both associated with poor prognosis and most patients die as a consequence of renal or cardiac failure. Monoclonal antibodies such as daratumumab (human IgG1 anti-CD38) and elotuzumab (anti-SLAMF7) have shown promising efficacy for the treatment of relapsed and refractory multiple myeloma. In this case report we show 2 patients with severe AL, one with severe heart failure and one with heart and renal failure, undergoing treatment with daratumumab. Both patients showed a rapid decrease in FLC in response to daratumumab infusions, with few associated adverse events. Using therapeutic CD38 antibodies as a front-line treatment for AL could induce rapid responses while maintaining a tolerable safety profile in these ultra-fragile patients.