Effectiveness and infectious complications of BCMA T-cell engagers in treating multiple myeloma: Real-world evidence from Sweden

BACKGROUND

Multiple myeloma (MM), an incurable disease characterized by frequent relapses and a need for multiple treatments, often progresses to a relapse/refractory status resistant to all available drugs and drug classes. Bispecific antibodies, specifically BCMA T-cell engagers, have emerged as effective treatments for MM, demonstrating impressive efficacy. However, these treatments can adversely affect the immune system, increasing vulnerability to infections.

METHODS/RESULTS

This study evaluated the efficacy and safety of BCMA T-cell engagers in 58 Swedish patients with poor MM prognosis. The patients exhibited a 69% overall response rate, with 69% survival and 60% progression-free survival at 15 months.

CONCLUSIONS

Despite the risk of infectious complications, the prognosis of MM patients can be significantly improved with vigilant monitoring and proactive management of infections. This real-world data highlight the potential of BCMA T-cell engagers in treating MM, emphasizing the need for careful patient monitoring to mitigate infection risks.

Ixazomib, Lenalidomide, and Dexamethasone (IRD) Treatment with Cytogenetic Risk-Based Maintenance in Transplant-Eligible Myeloma: A Phase 2 Multicenter Study by the Nordic Myeloma Study Group

Scarce data exist on double maintenance in transplant-eligible high-risk (HR) newly diagnosed multiple myeloma (NDMM) patients. This prospective phase 2 study enrolled 120 transplant-eligible NDMM patients. The treatment consisted of four cycles of ixazomib-lenalidomide-dexamethasone (IRD) induction plus autologous stem cell transplantation followed by IRD consolidation and cytogenetic risk-based maintenance therapy with lenalidomide + ixazomib (IR) for HR patients and lenalidomide (R) alone for NHR patients. The main endpoint of the study was undetectable minimal residual disease (MRD) with sensitivity of <10-5 by flow cytometry at any time, and other endpoints were progression-free survival (PFS) and overall survival (OS). We present the preplanned analysis after the last patient has been two years on maintenance. At any time during protocol treatment, 28% (34/120) had MRD < 10-5 at least once. At two years on maintenance, 66% of the patients in the HR group and 76% in the NHR group were progression-free (p = 0.395) and 36% (43/120) were CR or better, of which 42% (18/43) had undetectable flow MRD <10-5. Altogether 95% of the patients with sustained MRD <10-5, 82% of the patients who turned MRD-positive, and 61% of those with positive MRD had no disease progression at two years on maintenance (p < 0.001). To conclude, prolonged maintenance with all-oral ixazomib plus lenalidomide might improve PFS in HR patients.

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.

Synergistic effects of low-dose belantamab mafodotin in combination with a gamma-secretase inhibitor (nirogacestat) in patients with relapsed/refractory multiple myeloma (RRMM): DREAMM-5 study

8019

Background: Preclinical data demonstrate that nirogacestat, a gamma-secretase inhibitor, may increase cell-surface levels of a B-cell maturation antigen (BCMA) and reduce soluble BCMA levels, which could enhance anti-BCMA agent activity in multiple myeloma. In the DREAMM-5 (NCT04126200) Phase I/II platform trial belantamab mafodotin (belamaf; BLENREP), a BCMA-targeting antibody-drug conjugate, is being evaluated in combination with nirogacestat to determine if the combination can result in similar efficacy and an improved ocular safety profile compared to the currently approved belamaf schedule (single agent dose 2.5 mg/kg Q3W) in patients with RRMM which showed a 31% overall response rate (ORR) and 44.5% Gr3/4 keratopathy (BLENREP US prescribing information). Methods: This cohort within the DREAMM-5 nirogacestat combination sub-study has a sequential dose-exploration (DE) phase evaluating 0.95 mg/kg Q3W belamaf with 100 mg BID nirogacestat continuously, followed by a randomized cohort expansion (CE) comparing the combination to a belamaf 2.5 mg/kg Q3W arm. Results: Preliminary results from the 10 patients (pts) in the DE cohort with low-dose belamaf + nirogacestat are presented in this abstract. Pts had a median (range) of 4.5 (3–10) prior lines of therapy. At time of data cut-off (Nov 15, 2021), pts received a median (range) of 7 cycles (1–26). The ORR was 60% (n=6/10) and 20% (n=2) achieved a very good partial response (Table). The key emergent adverse events (AEs) included ocular events (n=7 [70%]; ≥Grade [Gr] 3, n=2 [20%] of which Gr 3 keratopathy was reported in 1 pt [10%]), diarrhea (n=7 [70%]; Gr 3, n=1 [10%]) and hypophosphatemia (n=7 [70%]; Gr 3, n=1, [10%]). There were 2 Grade 5 AEs, neither of which were related to study treatment. No pt permanently discontinued study due to treatment related AEs. Conclusions: Encouraging clinical activity and a manageable safety profile is observed with low dose belamaf (0.95 mg/kg Q3W) + nirogacestat (100 mg BID continuously) in pts with RRMM. This ongoing sub-study is actively recruiting patients and will continue to evaluate belamaf + nirogacestat efficacy and safety. Updated results will be reported at the congress. Funding: GSK (208887); drug linker technology licensed from Seagen Inc.; mAb produced using POTELLIGENT Technology licensed from BioWa. Clinical trial information: NCT04126200. [Table: see text]

Low dose venetoclax as a single agent treatment of plasma cell malignancies harboring t(11;14)

Approximately 20% of newly diagnosed multiple myeloma (NDMM) patients harbor t(11;14), a marker of inferior prognosis, resulting in up-regulation of CCND1. These patients respond to BCL2 inhibitor experimental drug venetoclax. Furthermore, t(11;14) is reported to be associated with increased BCL2/MCL1 ratio. We investigated the use of venetoclax (400 mg daily) in a cohort of 25 multiple myeloma (MM) and AL-amyloidosis patients harboring t(11;14) and assessed safety and efficacy. Efficacy was assessed by response rate (RR) and time on treatment. Furthermore, immunohistochemistry (IHC), for BCL2 family member expression was assessed at diagnosis and relapse in the venetoclax-treated group and analyzed for correlation with clinical RR. Additionally, patient material from venetoclax non-treated group including non-t(11;14) diagnosis (n = 27), t(11;14) diagnosis (n = 17), t(11;14) relapse (n = 7), hyperdiploidy (n = 6) and hyperdiploidy + t(11;14) (n = 6) was used for RNA sequencing (RNASeq) and validation by qPCR. Venetoclax treatment in t(11;14) patients demonstrated manageable safety and promising efficacy. Partial responses or better were observed in eleven patients (44%). Responding patients had significantly higher BCL2/MCL1 (p = 0.031) as well as BCL2/BCL-XL (p = 0.021) ratio, regardless of time of measurement before venetoclax treatment. Furthermore, an IRF5 motif was enriched (p < .001) in the downregulated genes in t(11;14) relapses vs diagnoses. The RR with single agent venetoclax was 71% in AL-amyloidosis and 33% in MM, and IHC proved useful in prediction of treatment outcome. We could also demonstrate possible resistance mechanisms of t(11;14), downregulation of IRF5 targeted genes, which can be exploited for therapeutic advantages.

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.

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.

Incidence, characteristics, and outcome of solitary plasmacytoma and plasma cell leukemia. Population-based data from the Swedish Myeloma Register

Solitary plasmacytoma (SP) and plasma cell leukemia (PCL) are uncommon (3-6%) types of plasma cell disease. The risk of progression to symptomatic multiple myeloma (MM) is probably important for the outcome of SP. PCL is rare and has a dismal outcome. In this study, we report on incidence and survival in PCL/SP, and progression to MM in SP, using the prospective observational Swedish Multiple Myeloma Register designed to document all newly diagnosed plasma cell diseases in Sweden since 2008. Both solitary bone plasmacytoma (SBP) (n=124) and extramedullary plasmacytoma (EMP) (n=67) have better overall survival (OS) than MM (n=3549). Progression to MM was higher in SBP than in EMP (35% and 7% at 2 years, respectively), but this did not translate into better survival in EMP. In spite of treatment developments, the OS of primary PCL is still dismal (median of 11 months, 0% at 5 years). Hence, there is a great need for diagnostic and treatment guidelines as well as prospective studies addressing the role for alternative treatment options, such as allogeneic stem cell transplantation and monoclonal antibodies in the treatment of PCL.

Deletion of Chromosomal Region 8p21 Confers Resistance to Bortezomib and Is Associated with Upregulated Decoy TRAIL Receptor Expression in Patients with Multiple Myeloma

Loss of the chromosomal region 8p21 negatively effects survival in patients with multiple myeloma (MM) that undergo autologous stem cell transplantation (ASCT). In this study, we aimed to identify the immunological and molecular consequences of del(8)(p21) with regards to treatment response and bortezomib resistance. In patients receiving bortezomib as a single first line agent without any high-dose therapy, we have observed that patients with del(8)(p21) responded poorly to bortezomib with 50% showing no response while patients without the deletion had a response rate of 90%. In vitro analysis revealed a higher resistance to bortezomib possibly due to an altered gene expression profile caused by del(8)(p21) including genes such as TRAIL-R4, CCDC25, RHOBTB2, PTK2B, SCARA3, MYC, BCL2 and TP53. Furthermore, while bortezomib sensitized MM cells without del(8)(p21) to TRAIL/APO2L mediated apoptosis, in cells with del(8)(p21) bortezomib failed to upregulate the pro-apoptotic death receptors TRAIL-R1 and TRAIL-R2 which are located on the 8p21 region. Also expressing higher levels of the decoy death receptor TRAIL-R4, these cells were largely resistant to TRAIL/APO2L mediated apoptosis. Corroborating the clinical outcome of the patients, our data provides a potential explanation regarding the poor response of MM patients with del(8)(p21) to bortezomib treatment. Furthermore, our clinical analysis suggests that including immunomodulatory agents such as Lenalidomide in the treatment regimen may help to overcome this negative effect, providing an alternative consideration in treatment planning of MM patients with del(8)(p21).

Addition of thalidomide to melphalan and prednisone treatment prolongs survival in multiple myeloma--a retrospective population based study of 1162 patients

The combination of melphalan and prednisone (MP) has been the standard treatment of multiple myeloma (MM). Since the introduction of novel agents, the clinical outcome in MM has improved. Six randomized prospective studies with thalidomide combined with melphalan and prednisone (MPT) compared to MP have been performed, most of them showing that MPT gives a better response rate and median overall survival (OS). Amongst 1843 MM patients admitted to 15 Swedish centres, we selected all patients treated with MP and MPT in first, second, third or fourth line of therapy, in total 888 patients treated with MP and 274 with MPT. Patients were evaluated for response rate, OS and Time to Next Treatment. Multivariate Cox model analysis was made to adjust for different criteria at time for MM-diagnosis. The median OS from beginning of first line of treatment was 2.2/4.2 yrs after MP/MPT respectively, and in second, third and fourth line of treatment 1.8/2.9, 1.4/1.6 and 1.1/1.9 yrs (P < 0.0001, 0.003, 0.74 and 0.235). The relative risk for death in the MPT group vs. the MP group was 0.61 (95% CI: 0.45-0.84) in first and 0.55 (0.38-0.83), P < 0.01) in second line. Treatment with MPT gave a significantly better OS rate after both first and second line of therapy when compared with treatment with MP only.

A combination regimen of bortezomib, cyclophosphamide and betamethasone gives quicker, better and more durable response than VAD/CyBet regimens: results from a Swedish retrospective analysis

BACKGROUND

Induction therapy for multiple myeloma (MM) and remission status before high-dose treatment (HDT) have been shown to be prognostic factors for survival outcome, although the optimal induction therapy is yet to be defined.

METHODS

We conducted a retrospective analysis of the impact of induction therapy on survival outcome before and after HDT in MM patients. The study included 236 consecutive patients who underwent HDT.

RESULTS

One hundred and forty-two patients (62%) were treated with vincristine, doxorubicin and dexamethasone (VAD) or cyclophosphamide and betamethasone (CyBet) and 94 (38%) were treated with bortezomib, cyclophosphamide and betamethasone (VCB) as induction. Time to first and time to best response was faster in the VCB group than in the VAD/CyBet group, with 42 versus 75 (p < 0.001) and 54 versus 88 days (p < 0.001), respectively. After induction therapy, 49% of the patients in the VCB group and 38% in the VAD/CyBet group achieved a very good partial response or better. Multivariate analysis revealed younger age, lower International Staging System stage and induction treatment with VCB as variables associated with favourable time to progression.

CONCLUSIONS

Outcome measured as response and time to progression before and after HDT in MM differs depending on type of induction treatment and suggests that VCB is a highly effective induction regimen that confers a post-HDT advantage.