Treatment of patients with multiple myeloma progressing on frontline-therapy with lenalidomide

Characteristics and Outcomes of Patients With Relapsed/Refractory Multiple Myeloma After Exposure to Lenalidomide in First Line of Therapy: A Single Center Database Review in Greece

BACKGROUND

The increasing use of lenalidomide (Len) in first-line (1L) therapy of multiple myeloma (MM) has led to a significant proportion of patients becoming Len-refractory following 1L treatment. However, there are limited real-world data on treatment strategies and outcomes of patients who become Len-refractory following 1L therapy.

PATIENTS AND METHODS

This real-world retrospective cohort study analyzed Len-refractory and non-Len-refractory patients who received 1L Len and initiated second-line (2L) therapy at a Greek MM center. The Len-exposed cohort (n = 249) included 55.4% Len-refractory patients after 1L.

RESULTS

Compared to non-Len-refractory patients, Len-refractory patients more frequently had high-risk cytogenetics and Revised-International Staging System-3 disease stage at diagnosis, and had shorter progression-free survival (PFS) following 1L therapy. Len-refractory versus non-Len-refractory patients more frequently received triplets (59% vs. 40%), anti-CD38 agents (20% vs. 9%) and pomalidomide (22% vs. 13%). The overall response rate was 53% for Len-refractory patients and 64% for non-Len-refractory patients in 2L therapy; median PFS was 10.7 vs. 18.3 months, respectively. Median overall survival (OS) was shorter for Len-refractory patients vs non-Len-refractory patients (23.8 vs. 53.6 months). Len refractoriness was an independent prognostic factor for both PFS and OS in Len-exposed patients.

CONCLUSION

In this real-world Len-exposed cohort, Len-refractory patients receiving 1L Len experienced poorer survival outcomes than non-Len-refractory patients, highlighting the unmet need in this patient population which has driven the development of novel therapies.

Belantamab Mafodotin, Pomalidomide, and Dexamethasone in Multiple Myeloma

BACKGROUND

Triplet or quadruplet therapies incorporating proteasome inhibitors, immunomodulators, and anti-CD38 antibodies have led to prolonged survival among patients with newly diagnosed multiple myeloma; however, most patients have a relapse. Frontline lenalidomide therapy has increased the number of patients with lenalidomide-refractory disease at the time of the first relapse.

METHODS

In this phase 3, randomized, open-label trial, we evaluated belantamab mafodotin, pomalidomide, and dexamethasone (BPd), as compared with pomalidomide, bortezomib, and dexamethasone (PVd), in lenalidomide-exposed patients who had relapsed or refractory myeloma after at least one line of therapy. The primary end point was progression-free survival. Disease response and safety were also assessed.

RESULTS

A total of 302 patients underwent randomization; 155 were assigned to the BPd group, and 147 to the PVd group. At a median follow-up of 21.8 months (range, <0.1 to 39.2), the 12-month estimated progression-free survival with BPd was 71% (95% confidence interval [CI], 63 to 78), as compared with 51% (95% CI, 42 to 60) with PVd (hazard ratio for disease progression or death, 0.52; 95% CI, 0.37 to 0.73; P<0.001). Data on overall survival were immature. The percentage of patients with a response to treatment (partial response or better) was 77% (95% CI, 70 to 84) in the BPd group and 72% (95% CI, 64 to 79) in the PVd group; 40% (95% CI, 32 to 48) and 16% (95% CI, 11 to 23), respectively, had a complete response or better. Grade 3 or higher adverse events occurred in 94% of the patients in the BPd group and 76% of those in the PVd group. Ocular events occurred in 89% of the patients who received BPd (grade 3 or 4 in 43%) and 30% of those who received PVd (grade 3 or 4 in 2%); ocular events in the BPd group were managed with belantamab mafodotin dose modification. Ocular events led to treatment discontinuation in 9% of the patients in the BPd group and in no patients in the PVd group.

CONCLUSIONS

Among lenalidomide-exposed patients with relapsed or refractory myeloma, BPd conferred a significantly greater benefit than PVd with respect to progression-free survival, as well as deeper, more durable responses. Ocular events were common but were controllable by belantamab mafodotin dose modification. (Funded by GSK; DREAMM-8 ClinicalTrials.gov number, NCT04484623; EudraCT number, 2018-00434-21.).

Carfilzomib, daratumumab, and dexamethasone (KdD) vs. lenalidomide-sparing pomalidomide-containing triplet regimens for relapsed/refractory multiple myeloma: an indirect treatment comparison

Nearly all patients with multiple myeloma eventually relapse or become refractory to treatment. Lenalidomide is increasingly administered in the frontline until disease progression or intolerance to therapy, resulting in the need for highly effective, lenalidomide-sparing options. In this study, carfilzomib plus daratumumab and dexamethasone were evaluated against lenalidomide-sparing, pomalidomide-containing triplets using matching-adjusted indirect comparison in the absence of head-to-head data. The analyses utilized long-term follow-up data from the CANDOR study (NCT03158688). Treatment with carfilzomib, daratumumab, and dexamethasone resulted in significantly longer progression-free survival (hazard ratio 0.60 [95% confidence interval: 0.37, 0.88])vs. pomalidomide plus bortezomib and dexamethasone, and numerically longer progression-free survival (hazard ratio 0.77 [95% confidence interval: 0.50, 1.08]) vs. daratumumab plus pomalidomide and dexamethasone in patients with relapsed/refractory multiple myeloma and previous lenalidomide exposure, the majority of whom were lenalidomide refractory. Carfilzomib plus daratumumab and dexamethasone offers a highly effective, lenalidomide-sparing treatment option for this population.

Efficacy and Safety of Anti-CD38 Monoclonal Antibodies in Patients with Relapsed or Refractory Multiple Myeloma: A Meta-Analysis of Randomized Clinical Trials

The benefit of associating anti-CD38 monoclonal antibodies to proteasome inhibitor (PI)/immunomodulatory agent (IA) and dexamethasone in the treatment of patients with relapsed or refractory multiple myeloma (MM) remains unclear. PubMed, Embase, and Cochrane Library databases were searched for randomized controlled trials that investigated the addition of anti-CD38 monoclonal antibodies to a therapy composed of PI/IA and dexamethasone versus PI/IA and dexamethasone alone for treating relapsed or refractory MM. Hazard ratios (HRs) or risk ratios (RRs) were computed for binary endpoints, with 95% confidence intervals (CIs). Six studies comprising 2191 patients were included. Anti-CD38 monoclonal antibody significantly improved progression-free survival (HR 0.52; 95% CI 0.43-0.61; p < 0.001) and overall survival (HR 0.72; 95% CI 0.63-0.83; p < 0.001). There was a significant increase in hematological adverse events, such as neutropenia (RR 1.41; 95% CI 1.26-1.58; p < 0.01) and thrombocytopenia (RR 1.14; 95% CI 1.02-1.27; p = 0.02), in the group treated with anti-CD38 monoclonal antibody. Also, there was a significant increase in non-hematological adverse events, such as dyspnea (RR 1.72; 95% CI 1.38-2.13; p < 0.01) and pneumonia (RR 1.34; 95% CI 1.13-1.59; p < 0.01), in the group treated with anti-CD38 monoclonal antibody. In conclusion, the incorporation of an anti-CD38 monoclonal antibody demonstrated a promising prospect for reshaping the established MM treatment paradigms.

Pomalidomide, Bortezomib, and Dexamethasone in Lenalidomide-Pretreated Multiple Myeloma: A Subanalysis of OPTIMISMM by Frailty and Bortezomib Dose Adjustment

INTRODUCTION

A proportion of patients with multiple myeloma (MM) are older and/or have comorbidities, requiring dose adjustments. Data from OPTIMISMM (NCT01734928) supported the use of pomalidomide, bortezomib, and dexamethasone (PVd) for treating relapsed/refractory MM. This subanalysis of OPTIMISMM assessed outcome by frailty and/or bortezomib dose adjustment.

METHODS

Patient frailty (nonfrail vs. frail) was classified using age, Charlson Comorbidity Index, and Eastern Cooperative Oncology Group performance status. Data from patients requiring a bortezomib dose reduction, interruption, and/or withdrawal during PVd treatment were assessed.

RESULTS

Among 559 patients, 93 of 281 (33.1%) and 93 of 278 (33.5%) patients who received PVd and bortezomib and dexamethasone (Vd), respectively, were frail. Overall response rate (ORR) and median progression-free survival (PFS) were higher in nonfrail vs. frail with PVd treatment (ORR, 82.8% vs. 79.6%; PFS, 14.7 vs. 9.7 months); significantly higher than with Vd regardless of frailty. Grade ≥ 3 treatment-emergent adverse events (TEAEs) were higher with PVd vs. Vd, regardless of frailty. Discontinuations of PVd were lower in nonfrail vs. frail patients (19.2% vs. 30.1%); the median duration of treatment was similar (DoT; 8.8 vs. 8.9 months, respectively). Patients who received PVd with a bortezomib dose adjustment (n = 240) had a longer median DoT (9.3 vs. 4.5 months) and PFS (12.1 vs. 8.4 months) vs. those without.

CONCLUSION

Frail patients treated with PVd demonstrated a higher ORR and a longer PFS and DoT vs. Vd, despite a higher frequency of grade ≥ 3 TEAEs leading to pomalidomide, bortezomib, and/or dexamethasone discontinuation. Therefore, PVd treatment may improve patient outcomes, regardless of frailty.

A real-life study of daratumumab-bortezomib-dexamethasone (D-VD) in lenalidomide exposed/refractory multiple myeloma patients: a report from the Triveneto Myeloma Working Group

Treatment of lenalidomide refractory (Len-R) multiple myeloma (MM) patients still represents an unmet clinical need. In the last years, daratumumab-bortezomib-dexamethasone (D-VD) combination was extensively used in this setting, even though only a small fraction of Len-R patients was included in the pivotal trial. This real-life study aimed to evaluate the efficacy and safety of the D-VD regimen in a cohort that exclusively enrolled Len exposed or refractory MM patients. The study cohort included 57 patients affected by relapsed/refractory MM. All patients were previously exposed to Len, with 77.2% being refractory. The overall response rate (ORR) was 79.6% with 43% of cases obtaining at least a very good partial response (VGPR). The D-VD regimen showed a favorable safety profile, with low frequency of grade 3-4 adverse events, except for thrombocytopenia observed in 21.4% of patients. With a median follow-up of 13 months, median progression-free survival (PFS) was 17 months. No significant PFS differences were observed according to age, ISS, LDH levels, type of relapse, and high-risk FISH. Len exposed patients displayed a PFS advantage as compared to Len refractory patients (29 vs 16 months, p = 0.2876). Similarly, patients treated after Len maintenance showed a better outcome as compared to patients who had received a full-dose Len treatment (23 vs 13 months, p = 0.1728). In conclusion, our real-world data on D-VD combination showed remarkable efficacy in Len-R patients, placing this regimen as one of the standards of care to be properly taken into account in this MM setting.

Predicting line of therapy transition via similar patient augmentation

Analyzing large EHR databases to predict cancer progression and treatments has become a hot trend in recent years. An increasing number of modern deep learning models have been proposed to find the milestones of essential patient medical journey characteristics to predict their disease status and give healthcare professionals valuable insights. However, most of the existing methods are lack of consideration for the inter-relationship among different patients. We believe that more valuable information can be extracted, especially when patients with similar disease statuses visit the same doctors. Towards this end, a similar patient augmentation-based approach named SimPA is proposed to enhance the learning of patient representations and further predict lines of therapy transition. Our experiment results on a real-world multiple myeloma dataset show that our proposed approach outperforms state-of-the-art baseline approaches in terms of standard evaluation metrics for classification tasks.

A Meta-Analysis of the Efficacy of Pomalidomide-Based Regimens for the Treatment of Relapsed/Refractory Multiple Myeloma After Lenalidomide Exposure

INTRODUCTION

The objective was to assess the benefit of pomalidomide-based combination regimens in patients with relapsed/refractory multiple myeloma (RRMM) previously treated with lenalidomide. A pooled estimate was obtained for efficacy outcomes including overall response rate (ORR), complete response (CR) rate, and progression-free survival (PFS) based on multiple trials conducted in this patient population.

PATIENTS AND METHODS

A literature search was conducted on March 22, 2022 for relevant trials published between January 1, 2016 and the search date. The search identified 12 eligible trials with publications dated between 2016 and 2021. The meta-analyses were conducted among the intention-to-treat (ITT) population (patients treated in all lines of therapy) and 2 subpopulations: 2L (only patients treated in the second line [2L]) and ≥2L (patients treated in the 2L and beyond).

RESULTS

From the meta-analyses, ORR was 69.9% for ITT, 74.4% for ≥2L, and 87.2% for 2L. CR rate was 12.1% for ITT, 17.6% for ≥2L, and 29.7% for 2L. One-year PFS rates were 55.1% for ITT, 59.1% for ≥2L, and 74.0% for 2L. Two-year PFS rates were 29.3% for ITT, 36.0% for ≥2L, and 41.9% for 2L.

CONCLUSION

Pomalidomide-based combination regimens were effective in patients with RRMM previously treated with lenalidomide and tended to be associated with better outcomes when used earlier in the treatment pathway. A drug class switch may not always be necessary when making treatment decisions for patients with RRMM for whom the benefits of lenalidomide have been exhausted, although this must be supported by comparative studies.

Predictors of Lenalidomide Refractory Relapse Timing With Newly Diagnosed Multiple Myeloma: A FIRST Trial Subanalysis

INTRODUCTION/BACKGROUND

Multiple myeloma (MM) is considered an incurable cancer. Patients with newly diagnosed MM (NDMM) are at risk for relapse within 1 year of frontline therapy. The immunomodulatory agent lenalidomide combined with dexamethasone (Rd) may be used as treatment for NDMM or relapsed MM, including in patients ineligible for autologous stem cell transplant.

PATIENTS

This subanalysis of the phase III FIRST trial characterized patients with transplant-ineligible NDMM who experienced relapse while receiving Rd therapy by relapse timing (early [<12 months] versus late [≥12 months]) and type (CRAB vs. non-CRAB).

METHODS

The Kaplan-Meier product limit method was used to estimate time-to-event endpoints, including progression-free survival (PFS) and overall survival (OS). Factors associated with the odds of late relapse were identified by logistic regression with univariate and multivariate analyses using a binary outcome (relapse at <12 vs. ≥12 months) in patient-, disease-, and treatment-specific baseline variables.

RESULTS

Patients with early refractory relapse had functionally high-risk disease and inferior outcomes. In patients with early relapse versus those with late relapse, median OS (95% CI) was 26.8 months (21.9-32.8) versus 63.9 months (57.0-78.0), median OS from disease progression to death was 19.9 months (16.0-25.5) versus 36.4 months (27.9-47.0), and median PFS from randomization to second progression was 19.1 months (17.3-22.5) versus 42.1 months (37.4-44.9). Lactate dehydrogenase, baseline β2 microglobulin, and myeloma subtype were shown to predict time to relapse.

CONCLUSIONS

Clinicians could use these factors to consider more aggressive treatment regimens for those at highest risk of early relapse.

c-FOS is an integral component of the IKZF1 transactivator complex and mediates lenalidomide resistance in multiple myeloma

BACKGROUND

The immunomodulatory drug lenalidomide, which is now widely used for the treatment of multiple myeloma (MM), exerts pharmacological action through the ubiquitin-dependent degradation of IKZF1 and subsequent down-regulation of interferon regulatory factor 4 (IRF4), a critical factor for the survival of MM cells. IKZF1 acts principally as a tumour suppressor via transcriptional repression of oncogenes in normal lymphoid lineages. In contrast, IKZF1 activates IRF4 and other oncogenes in MM cells, suggesting the involvement of unknown co-factors in switching the IKZF1 complex from a transcriptional repressor to an activator. The transactivating components of the IKZF1 complex might promote lenalidomide resistance by residing on regulatory regions of the IRF4 gene to maintain its transcription after IKZF1 degradation.

METHODS

To identify unknown components of the IKZF1 complex, we analyzed the genome-wide binding of IKZF1 in MM cells using chromatin immunoprecipitation-sequencing (ChIP-seq) and screened for the co-occupancy of IKZF1 with other DNA-binding factors on the myeloma genome using the ChIP-Atlas platform.

RESULTS

We found that c-FOS, a member of the activator protein-1 (AP-1) family, is an integral component of the IKZF1 complex and is primarily responsible for the activator function of the complex in MM cells. The genome-wide screening revealed the co-occupancy of c-FOS with IKZF1 on the regulatory regions of IKZF1-target genes, including IRF4 and SLAMF7, in MM cells but not normal bone marrow progenitors, pre-B cells or mature T-lymphocytes. c-FOS and IKZF1 bound to the same consensus sequence as the IKZF1 complex through direct protein-protein interactions. The complex also includes c-JUN and IKZF3 but not IRF4. Treatment of MM cells with short-hairpin RNA against FOS or a selective AP-1 inhibitor significantly enhanced the anti-MM activity of lenalidomide in vitro and in two murine MM models. Furthermore, an AP-1 inhibitor mitigated the lenalidomide resistance of MM cells.

CONCLUSIONS

C-FOS determines lenalidomide sensitivity and mediates drug resistance in MM cells as a co-factor of IKZF1 and thus, could be a novel therapeutic target for further improvement of the prognosis of MM patients.

Final analysis of carfilzomib, dexamethasone, and daratumumab vs carfilzomib and dexamethasone in the CANDOR study

CANDOR (NCT03158688) is a phase 3, randomized, open-label trial comparing carfilzomib, daratumumab, and dexamethasone (KdD) vs carfilzomib and dexamethasone (Kd) in adults with relapsed/refectory multiple myeloma (RRMM) with 1 to 3 prior therapies. The CANDOR study met its primary end point of progression-free survival (PFS) in the primary analysis. Here, we report the final analysis of the study, including secondary end points and subgroup analyses thereof. The median follow-up was 50 months. Patients treated with KdD had higher minimal residual disease-negative (MRD-) achievement rates (28% vs 9%; odds ratio [OR], 4.22; 95% confidence interval [95% CI], 2.28-7.83) and MRD- complete response rates (22% vs 8%; OR, 3.55; 95% CI, 1.83-6.88) than those treated with Kd. Median PFS was 28.4 months for KdD vs 15.2 months for Kd (hazard ratio [HR], 0.64; 95% CI, 0.49-0.83). Median overall survival (OS) for KdD was 50.8 months vs 43.6 months for Kd (HR, 0.78 [0.60-1.03]; P = .042). Trends toward improved OS occurred in predefined subgroups, including patients refractory to lenalidomide (KdD, not reached vs Kd, 38.2 months; HR, 0.69 [0.43-1.11]) and refractory to proteasome inhibitor (KdD, 43.2 months vs Kd, 30.0 months; HR, 0.70 [0.45-1.09]), and there was significant improvement in patients with high-risk cytogenetics (KdD, 34.3 months vs Kd: 17.1 months; HR, 0.52 [0.29-0.94]). No new safety signals were identified. In summary, the final analysis of CANDOR confirmed the PFS benefit and showed a trend in OS benefit with KdD vs Kd. These findings reinforce KdD as a standard of care for RRMM, especially in clinically relevant patient subgroups. This trial was registered at www.clinicaltrials.gov as #NCT03158688.

Clinical evidence for immune-based strategies in early-line multiple myeloma: current challenges in decision-making for subsequent therapy

Almost all patients with multiple myeloma (MM) will eventually develop disease that has relapsed with or become refractory to available treatments and will require additional therapy. However, data are still lacking on how best to sequence regimens in the relapsed/refractory (RR) setting after the failure of early-line lenalidomide, bortezomib, and/or daratumumab, the most commonly used agents in clinical practice today. With the treatment landscape rapidly changing in response to emerging clinical trial data and approvals of several new drugs and additional combinations, it is critically important to focus on patients with RRMM. Variability in patient baseline characteristics, such as the number of prior lines of treatment, refractoriness to prior treatments, prior stem cell transplant, and timing and dosing of prior lenalidomide, makes it difficult to select the best options for patients with RRMM for whom first-line treatments have failed. The aim of this review is to provide both an overview of current therapies and future directions within the RRMM treatment landscape, and a framework for clinicians to choose the most promising next treatment option.

How to Manage Patients with Lenalidomide-Refractory Multiple Myeloma

Although lenalidomide-based combinations, such as lenalidomide plus a proteasome inhibitor or an anti-CD38 monoclonal antibody, improve the overall response rate, progression-free survival, and overall survival of patients with relapsed/refractory multiple myeloma (RRMM), there is a tendency to use these regimens as a frontline treatment. This strategy has led to the development of refractoriness early in the disease course, usually after the patient's first treatment. Since lenalidomide-free regimens have so far shown limited efficacy in lenalidomide-refractory patients, there is an unmet need for other treatment options. In this review, we discuss the therapeutic options available to treat the general population of lenalidomide-refractory patients (mono, double and triple refractory) and the subpopulation of patients with other high-risk features such as renal failure, extramedullary disease, and high-risk cytogenetics. Moreover, new promising individual therapies and the possible impact of immunotherapy in RRMM patients are debated.

Panobinostat in combination with bortezomib and dexamethasone in multiply relapsed and refractory myeloma; UK routine care cohort

The combination of panobinostat, bortezomib and dexamethasone (PanBorDex) is available as a treatment option for relapsed refractory multiple myeloma (RRMM) based on the PANORAMA-1 trial which investigated this triplet in early relapse. In routine clinical care, PanBorDex is used primarily in later relapses and is commonly administered in attenuated dosing schedules to mitigate the treatment-related toxicity. We set out to evaluate efficacy and safety outcomes with PanBorDex later in the disease course and evaluate the role of attenuated dosing schedules. This was a retrospective evaluation of patients treated in routine clinical practice between 2016–2019 across seven heamatology centres in the UK; patients who received at least one dose of PanBorDex were eligible for inclusion. The dosing schedule of panobinostat (10mg, 15mg or 20mg, twice or three times a week) and bortezomib (0.7mg/m2, 1mg/m2 or 1.3mg/m2 once or twice weekly) was as per treating physician choice. Patients received treatment until disease progression or unacceptable toxicity. The primary outcome is response rates according to IMWG criteria. Key secondary endpoints include progression-free survival (PFS) and overall survival (OS). Other secondary endpoints include rates of adverse events according to CTCAE criteria. In total, 61 patients were eligible for inclusion and received PanBorDex primarily as ≥5th line of treatment. One third of patients received PanBorDex at full dose, for the remaining two thirds, treatment was given in reduced dose intensities. The overall response rate was 44.2%, including 14.7% very good partial response (VGPR) rates; 68.8% of patients derived clinical benefit with stable disease or better. The median PFS was 3.4 months; non-refractory patients and those who achieved VGPR benefited from prolonged PFS of 11.4 months and 17.7 months, respectively. The median OS was 9.5 months. The triplet was associated with 45% and 18% incidence of grade 3–4 thrombocytopenia and diarrhea, respectively.

A Phase 1/2 Study of the Oral Janus Kinase 1 Inhibitors INCB052793 and Itacitinib Alone or in Combination With Standard Therapies for Advanced Hematologic Malignancies

BACKGROUND

The Janus kinase (JAK)/signal transducers and activators of transcription pathway has been implicated in the pathogenesis and progression of various hematologic malignancies. JAK1-regulated cytokines stimulate proliferation and growth of malignant cells and resistance to certain therapies.

PATIENTS AND METHODS

This phase 1/2 study evaluated 2 oral, novel JAK1 inhibitors (INCB052793 and itacitinib) in advanced hematologic malignancies. Phase 1a assessed dose escalation and expansion of INCB052793 monotherapy. Phase 1b evaluated INCB052793 plus standard therapy in relapsed/refractory multiple myeloma, acute myeloid leukemia (AML), or myelodysplastic syndrome (MDS). Phase 2 evaluated INCB052793 or itacitinib plus azacitidine in DNA methyltransferase inhibitor (DNMTi)-refractory AML or MDS. Primary endpoints included safety and tolerability for phase 1, and objective response rate for phase 2.

RESULTS

Fifty-eight patients were enrolled, all received study treatment and discontinued either treatment or participation in the study. The most common reasons for treatment discontinuation were progressive disease (35.4% and 50.0%) and adverse events (22.9% and 20.0%) for INCB052793 and itacitinib plus azacitidine, respectively. In phase 1, 12 of 39 patients (31%) achieved an objective response; 35 mg once daily was selected as the phase 2 dose. Two patients with DNMTi-refractory disease had an objective response in phase 2. The study was terminated for lack of efficacy.

CONCLUSION

Inhibition of JAK1 with INCB052793 (monotherapy or combination therapy) or itacitinib plus azacitidine did not demonstrate clinically meaningful responses in these patients with hematopoietic malignancies.

Pomalidomide, dexamethasone, and daratumumab immediately after lenalidomide-based treatment in patients with multiple myeloma: updated efficacy, safety, and health-related quality of life results from the phase 2 MM-014 trial

Patients with relapsed/refractory multiple myeloma (RRMM) need proven subsequent therapies after early-line lenalidomide treatment failure. The phase 2 MM-014 trial (NCT01946477) investigated pomalidomide, dexamethasone, and daratumumab after 1 to 2 prior treatment lines (62.5%, 1 prior line) in patients with RRMM and prior lenalidomide (75.0%, lenalidomide refractory). With a median follow-up of 28.4 months, overall response rate was 77.7% (52.7% achieved very good partial response or better) and median progression-free survival was 30.8 months. For patients with lenalidomide-refractory disease, these outcomes were 76.2%, 47.6%, and 23.7 months, respectively. No new safety signals were observed; 64.3% experienced grade 3/4 neutropenia. Health-related quality of life was preserved or trended toward improvement through 12 treatment cycles. Pomalidomide, dexamethasone, and daratumumab given immediately after early-line lenalidomide-based treatment continues to demonstrate safety and efficacy, supporting pomalidomide-dexamethasone as a foundation of combination therapy in RRMM and providing evidence that the immunomodulatory agent class delivers benefit after lenalidomide treatment failure.

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

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

A combination of carfilzomib, dexamethasone, and daratumumab for treatment of adult patients with relapsed/refractory multiple myeloma in two dosing regimens: once-weekly and twice-weekly

INTRODUCTION

Despite the development of new therapeutic agents, relapsed/refractory multiple myeloma (RRMM) is associated with poor survival outcomes. Furthermore, many patients develop resistance to immunomodulatory drugs (IMiD), creating a need for IMiD-free regimens. Areas covered: This review focuses on the combination of carfilzomib, dexamethasone, and daratumumab (KdD or DKd) which has shown promising results in patients with RRMM who have tried multiple lines of therapy, and has been approved in the U.S., EU, and Japan. The KdD triplet has two recommended dosage regimens, carfilzomib once-weekly (KdD70 QW) and carfilzomib twice-weekly (KdD56 BIW), with comparable efficacy and safety profiles. Expert opinion: These options provide flexibility to patients and healthcare providers, especially in the era of COVID-19. Carfilzomib-based regimens remain a standard of care based on multiple randomized phase 3 studies. Additional studies are currently underway investigating carfilzomib-based regimens such as KdD combined with novel agents. Nevertheless, KdD is one of the most efficacious options for patients with RRMM.

Pomalidomide, bortezomib, and dexamethasone at first relapse in lenalidomide-pretreated myeloma: A subanalysis of OPTIMISMM by clinical characteristics

Objective

We evaluated the efficacy and safety of pomalidomide, bortezomib, and dexamethasone (PVd) vs bortezomib and dexamethasone (Vd) by age, renal function, and high‐risk cytogenetic abnormalities in lenalidomide‐pretreated patients with multiple myeloma at first relapse.

Methods

OPTIMISMM was a phase 3, multicenter, open‐label, randomized study (NCT01734928; N = 559). The primary endpoint was progression‐free survival (PFS).

Results

Overall, 226 patients had received one prior line of therapy. PVd significantly prolonged PFS vs Vd in patients aged ≤65 years (median, 22.0 vs 13.1 months; P = .0258) and >65 years (median, 17.6 vs 9.9 months; P = .0369). Median PFS in patients with renal impairment (RI; creatinine clearance <60 mL/min) was 15.1 months with PVd vs 9.5 months with Vd (hazard ratio [HR], 0.67 [95% CI, 0.34‐1.34]). In patients without RI, median PFS was 22.0 vs 13.1 months (HR, 0.45 [95% CI, 0.27‐0.76]). In patients with high‐risk cytogenetics, median PFS was 14.7 vs 9.9 months (HR, 0.39 [95% CI, 0.13‐1.17]). PVd significantly improved overall response rate vs Vd in all subgroups. The safety profile of PVd was consistent with previous reports.

Conclusions

These findings confirmed the benefits of PVd at first relapse, including in patients with poor prognostic factors.

Carfilzomib, dexamethasone, and daratumumab in Asian patients with relapsed or refractory multiple myeloma: post hoc subgroup analysis of the phase 3 CANDOR trial

BACKGROUND

Due to increasing use of frontline lenalidomide, effective and safe lenalidomide-free therapies for relapsed/refractory multiple myeloma (RRMM) are needed in Asia. This subgroup analysis of phase 3 CANDOR study evaluated efficacy and safety of KdD vs Kd in Asian patients with RRMM.

METHODS

Self-identified Asian patients with RRMM (KdD = 46; Kd = 20) with 1‒3 prior therapies were included. The primary endpoint of progression-free survival was estimated by stratified Cox regression.

RESULTS

Baseline demographics and patient characteristics were balanced in both arms. KdD reduced the risk of progression or death by 25% vs Kd [hazard ratio (HR) = 0.75; 95% CI 0.259, 2.168] in the Asian subgroup, compared with 37% vs Kd (0.63; 0.464, 0.854) in the overall CANDOR population. Percentage of patients who reported grade ≥ 3 treatment-emergent adverse events (TEAEs) in the KdD and Kd arms was 95.7 and 90.0%, respectively. Serious AEs were observed in 58.7 and 40.0% of patients in the KdD and Kd arms, respectively. There were two (4.3%) fatal TEAEs in the KdD arm due to infections.

CONCLUSIONS

There was a trend toward better efficacy and a favorable benefit-risk profile for KdD vs Kd in Asian patients with RRMM. Cautious interpretation is warranted due to small patient size.

Spotlight on Melphalan Flufenamide: An Up-and-Coming Therapy for the Treatment of Myeloma

Despite recent therapeutic advances, multiple myeloma (MM) patients experience relapses as they become resistant to various classes and combinations of treatment. Melphalan (L-PAM) is an ageless drug. However, its use in the autologous stem cell transplantation (ASCT) setting and the innovative quadruplet regimen as well as daratumumab, bortezomib, and prednisone make this old drug current yet. Melflufen is a peptide-conjugated alkylator belonging to a novel class of compounds, representing an overcoming of L-PAM in terms of mechanism of action and effectiveness. The improved melflufen cytotoxicity is related to aminopeptidase activity, notably present in normal and neoplastic cells and remarkably heavily overexpressed in MM cells. Upon entering a cell, melflufen is cleaved by aminopeptidases, ultimately releasing the L-PAM payload and eliciting further the inflow and cleavage of the conjugated peptide. This virtuous loop persists until all extracellular melflufen has been utilized. The aminopeptidase-driven accumulation results in a 50-fold increase in L-PAM cell enrichment as compared with free alkylator. This condition produces selective cytotoxicity, increased on-target cell potency, and decreased off-target cell toxicity, ultimately overcoming resistance pathways triggered by previous treatments, including alkylators. Due to its distinct mechanism of action, melflufen plus dexamethasone as a doublet, and in combination with other novel drugs, has the potential to be beneficial for a broad range of patients with relapsed/refractory (RR) MM in third- or even in second-line therapy. The safety profile of melflufen has been consistent across studies, and no new safety concerns have been identified when melflufen was administered in doublet and triplet combinations. Based on growing clinical evidence, melflufen could be not only a good addition in the fight against RRMM but also a drug with a very favorable tolerability profile.

Novel antigens of CAR T cell therapy: New roads; old destination

Chimeric antigen receptor T cell (CAR-T) therapy has so far proved itself as a reliable therapeutic option for the treatment of relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL), diffuse large B-cell lymphoma (DLBCL), multiple myeloma (MM), and mantle cell lymphoma (MCL). However, this picture is not as colorful when it comes to the treatment of solid tumors mainly due to the lack of definitive tumor antigens, as well as the immunosuppressive tumor microenvironments and poor CAR-T infiltration. The recent developments in bioinformatics and cell biology, such as single-cell RNA sequencing, have offered silver linings in the subject of tumor antigen discovery. In the current review, we summarize the development of some CAR-T therapies that target novel tumor antigens, rather than the traditionally CAR-T-targeted ones, and briefly discuss the clinical antitumor achievements of those evaluated in patients, so far. Furthermore, we propose some tumor antigens that might someday be therapeutically beneficial while targeted by CAR-Ts based on the experimental evaluations of their specific monoclonal antibodies.

The safety and clinical effects of administering a multiantigen-targeted T cell therapy to patients with multiple myeloma

Multiple myeloma (MM) is an almost always incurable malignancy of plasma cells. Despite the advent of new therapies, most patients eventually relapse or become treatment-refractory. Consequently, therapies with nonoverlapping mechanisms of action that are nontoxic and provide long-term benefit to patients with MM are greatly needed. To this end, we clinically tested an autologous multitumor-associated antigen (mTAA)-specific T cell product for the treatment of patients with high-risk, relapsed or refractory MM. In this study, we expanded polyclonal T cells from 23 patients with MM. T cells whose native T cell receptors were reactive toward five myeloma-expressed target TAAs (PRAME, SSX2, MAGEA4, Survivin, and NY-ESO-1) were enriched ex vivo. To date, we have administered escalating doses of these nonengineered mTAA-specific T cells (0.5 × 10⁷ to 2 × 10⁷ cells/m²) to 21 patients with MM, 9 of whom were at high risk of relapse after a median of 3 lines of prior therapy and 12 with active, relapsed or refractory disease after a median of 3.5 prior lines. The cells were well tolerated, with only two transient, grade III infusion-related adverse events. Furthermore, patients with active relapsed or refractory myeloma enjoyed a longer than expected progression-free survival and responders included three patients who achieved objective responses concomitant with detection of functional TAA-reactive T cell clonotypes derived from the infused mTAA product.

Orthogonal targeting of osteoclasts and myeloma cells for radionuclide stimulated dynamic therapy induces multidimensional cell death pathways

Rationale: Multiple myeloma (MM) is a multifocal malignancy of bone marrow plasma cells, characterized by vicious cycles of remission and relapse that eventually culminate in death. The disease remains mostly incurable largely due to the complex interactions between the bone microenvironment (BME) and MM cells (MMC). In the “vicious cycle” of bone disease, abnormal activation of osteoclasts (OCs) by MMC causes severe osteolysis, promotes immune evasion, and stimulates the growth of MMC. Disrupting these cancer-stroma interactions would enhance treatment response.

Methods: To disrupt this cycle, we orthogonally targeted nanomicelles (NM) loaded with non-therapeutic doses of a photosensitizer, titanocene (TC), to VLA-4 (α4ß1, CD49d/CD29) expressing MMC (MM1.S) and αvß3 (CD51/CD61) expressing OC. Concurrently, a non-lethal dose of a radiopharmaceutical, ¹⁸F-fluorodeoxyglucose ([¹⁸F]FDG) administered systemically interacted with TC (radionuclide stimulated therapy, RaST) to generate cytotoxic reactive oxygen species (ROS). The in vitro and in vivo effects of RaST were characterized in MM1.S cell line, as well as in xenograft and isograft MM animal models.

Results: Our data revealed that RaST induced non-enzymatic hydroperoxidation of cellular lipids culminating in mitochondrial dysfunction, DNA fragmentation, and caspase-dependent apoptosis of MMC using VLA-4 avid TC-NMs. RaST upregulated the expression of BAX, Bcl-2, and p53, highlighting the induction of apoptosis via the BAK-independent pathway. The enhancement of multicopper oxidase enzyme F5 expression, which inhibits lipid hydroperoxidation and Fenton reaction, was not sufficient to overcome RaST-induced increase in the accumulation of irreversible function-perturbing α,ß-aldehydes that exerted significant and long-lasting damage to both DNA and proteins. In vivo, either VLA-4-TC-NM or αvß3-TC-NMs RaST induced a significant therapeutic effect on immunocompromised but not immunocompetent MM-bearing mouse models. Combined treatment with both VLA-4-TC-NM and αvß3-TC-NMs synergistically inhibited osteolysis, reduced tumor burden, and prevented rapid relapse in both in vivo models of MM.

Conclusions: By targeting MM and bone cells simultaneously, combination RaST suppressed MM disease progression through a multi-prong action on the vicious cycle of bone cancer. Instead of using the standard multidrug approach, our work reveals a unique photophysical treatment paradigm that uses nontoxic doses of a single light-sensitive drug directed orthogonally to cancer and bone cells, followed by radionuclide-stimulated generation of ROS to inhibit tumor progression and minimize osteolysis in both immunocompetent murine and immunocompromised human MM models.

The role of idecabtagene vicleucel in patients with heavily pretreated refractory multiple myeloma

The development of several treatment options over the last 2 decades has led to a notable improvement in the survival of patients with multiple myeloma. Despite these advances, the disease remains incurable for most patients. Moreover, standard combinations of alkylating agents, immunomodulatory drugs, proteasome inhibitors, and monoclonal antibodies targeting CD38 and corticoids are exhausted relatively fast in a proportion of high-risk patients. Such high-risk patients account for over 20% of cases and currently represent a major unmet medical need. The challenge of drug resistance requires the development of highly active new agents with a radically different mechanism of action. Several immunotherapeutic modalities, including antibody-drug conjugates and T-cell engagers, appear to be promising choices for patients who develop resistance to standard combinations. Chimeric antigen-receptor-modified T cells (CAR-Ts) targeting B-cell maturation antigen have demonstrated encouraging efficacy and an acceptable safety profile compared with alternative options. Multiple CAR-Ts are in early stages of clinical development, but the first phase III trials with CAR-Ts are ongoing for two of them. After the recent publication of the results of a phase II trial confirming a notable efficacy and acceptable safety profile, idecabtagene vicleucel is the first CAR-T to gain regulatory US Food and Drug Administration approval to treat refractory multiple myeloma patients who have already been exposed to antibodies against CD38, proteasome inhibitors, and immunomodulatory agents and who are refractory to the last therapy. Here, we will discuss the preclinical and clinical development of idecabtagene vicleucel and its future role in the changing treatment landscape of relapsed and refractory multiple myeloma.

Survival and treatment patterns of patients with relapsed or refractory multiple myeloma in France - a cohort study using the French National Healthcare database (SNDS)

Over the past decade, several drugs have been approved for the treatment of relapsed or refractory multiple myeloma (RRMM). This retrospective study, using the French National Healthcare database (SNDS), describes the treatment patterns and outcomes of patients with RRMM treated in real-world clinical practice in France. Patients were adults, with a diagnosis of multiple myeloma, who initiated second-line (2L) treatment approved for use in France between 2014 and 2018; this included bortezomib, carfilzomib, daratumumab, ixazomib, lenalidomide, or pomalidomide. Data were analyzed overall, by first-line (1L) autologous stem cell transplant (ASCT) status and by lenalidomide treatment status at 2L. In total, 12987 patients with RRMM were included in the study (mean age 69.5 years); 27% received an ASCT at 1L, and 30% received a lenalidomide-sparing regimen at 2L. Overall, and among the ASCT and non-ASCT subgroups, most patients received a bortezomib-based regimen at 1L, whereas lenalidomide-based regimens were most common at 2L. Among patients who received a lenalidomide-sparing regimen at 2L, this was most often a proteasome inhibitor-based regimen. Mortality rate was 26.1/100 person-years, and median (95% confidence interval) survival from 2L initiation was 32.4 (31.2-33.6) months. Survival differed by various factors, shorter survival was reported in the non-ASCT group, those receiving a lenalidomide-sparing regimen at 2L, older patients (≥ 70 years), and those with multiple comorbidities. This analysis provides insight into the real-world use of approved novel MM treatments and highlights an ongoing unmet need to improve outcomes, particularly for selected patient groups.

Promoting effects of MiR-135b on human multiple myeloma cells via regulation of the Wnt/β-catenin/Versican signaling pathway

MicroRNA (MiR)-135b and its mediated Wnt/β-catenin signaling pathway are involved in human malignancies. However, their roles in multiple myeloma (MM) remained poorly understood. Our study aimed to uncover their roles in MM. MiR-135b and Versican expressions were measured using quantitative real-time polymerase chain reaction (qRT-PCR). MM cell proliferation, apoptosis, migration and invasion were detected by cell counting kit-8 (CCK-8) assay, flow cytometry, wound healing assay and transwell assay, respectively. Relative expression of Wnt/β-catenin signaling pathway-related protein was quantified by Western blot. MiR-135b was upregulated in the serum of MM patients, and miR-135b upregulation promoted MM cell proliferation, migration and invasion but suppressed apoptosis. Also, miR-135b upregulation promoted activation of Wnt/β-catenin signaling pathway. However, downregulation of miR-135b caused an opposite effect. After incubating cells with miR-135b inhibitor and Wnt/β-catenin signaling pathway agonist Lithium chloride (LiCl), which reversed the effects of downregulating miR-135b. Versican is the downstream effector of the Wnt/β-catenin signaling pathway, and its silencing reversed the effects of LiCl on MM cells. In conclusion, miR-135b and its mediated Wnt/β-catenin signaling pathway promoted proliferation, migration and invasion but suppressed apoptosis of MM cells through regulating Versican, providing a possible treatment for MM.

Immune Functions of Signaling Lymphocytic Activation Molecule Family Molecules in Multiple Myeloma

Simple Summary

Multiple myeloma (MM) is an incurable hematological malignancy characterized by an increase in abnormal plasma cells. Disease progression, drug resistance, and immunosuppression in MM are associated with immune-related molecules, such as immune checkpoint and co-stimulatory molecules, present in the tumor microenvironment. Novel agents targeting these cell-surface molecules are currently under development, including monoclonal antibodies, bispecific monoclonal antibodies, and chimera antigen receptor T-cell therapies. In this review, we focus on the signaling lymphocytic activation molecule family receptors and provide an overview of their biological functions and novel therapies in MM.

Abstract

The signaling lymphocytic activation molecule (SLAM) family receptors are expressed on various immune cells and malignant plasma cells in multiple myeloma (MM) patients. In immune cells, most SLAM family molecules bind to themselves to transmit co-stimulatory signals through the recruiting adaptor proteins SLAM-associated protein (SAP) or Ewing’s sarcoma-associated transcript 2 (EAT-2), which target immunoreceptor tyrosine-based switch motifs in the cytoplasmic regions of the receptors. Notably, SLAMF2, SLAMF3, SLAMF6, and SLAMF7 are strongly and constitutively expressed on MM cells that do not express the adaptor proteins SAP and EAT-2. This review summarizes recent studies on the expression and biological functions of SLAM family receptors during the malignant progression of MM and the resulting preclinical and clinical research involving four SLAM family receptors. A better understanding of the relationship between SLAM family receptors and MM disease progression may lead to the development of novel immunotherapies for relapse prevention.

CRISPR/Cas9 mediated knock-out of VPREB1 gene induces a cytotoxic effect in myeloma cells

BACKGROUND

Multiple Myeloma (MM) is a heterogeneous, hematological neoplasm that accounts 2% of all cancers. Although, autologous stem cell transplantation and chemotherapy are currently the most effective therapy, it carries a notable hazards, in addition for being non curative. Recently, the Clustered Regular Interspaced Short Palindromic Repeats (CRISPR-cas9) has been successfully tried at the experimental level, for the treatment of several hematological malignancies.

OBJECTIVES

We aimed to investigate the in-vitro effect of CRISPR-cas9-mediated knock-out of V-set pre B-cell surrogate light chain 1"VPREB1" gene on the malignant proliferation of primary cultured myeloma cells.

METHODS

Bioinformatics' analysis was performed to explore the gene expression profile of MM, and the VPREB1 gene was selected as a target gene for this study. We knocked-out the VPREB1 gene in primary cultured myeloma cells using CRISPR-cas9, the VPREB1 gene editing efficacy was verified by determining VPREB1 gene expression at both the mRNA and protein levels by qPCR and immunofluorescence, respectively. Furthermore, the cytotoxic effect on primary myeloma cells proliferation was evaluated using cytotoxicity assay.

RESULTS

There was a statistically significant reduction of both VPREB1 mRNA and protein expression levels (p<0.01). knock-out of VPREB1 gene in myeloma cell line resulted in a statistically significant reduction of myeloma cell proliferation.

CONCLUSION

CRISPR-cas9-mediated knock-out of VPREB1 gene is effective for inhibiting the proliferation of primary myeloma cells. This would provide a basis for a promising therapeutic strategy for patients with multiple myeloma.

Sequencing multiple myeloma therapies with and after antibody therapies

In multiple myeloma (MM), treatment selection and sequencing become increasingly complex with the increasing number of therapeutic options, including antibodies. Choice of treatment is dependent on various factors including patient- and tumor-related features. In addition, treatment-related factors, such as type and response to prior therapy, are also critical in terms of the selection of a new treatment regimen. Furthermore, approval status and reimbursement policies influence treatment choice. At the time of first relapse, patients who received a bortezomib-based regimen can switch to lenalidomide-based treatment, whereas patients who received lenalidomide until progression can switch to a proteasome inhibitor-based therapy. Alternatively, there is increasing evidence that pomalidomide-based triplets are also effective following the development of lenalidomide-refractory disease both in early and later relapse settings. Patients who become refractory to immunomodulatory drugs, proteasome inhibitors, and CD38 antibodies have a poor prognosis. These triple-class refractory patients may benefit from novel, recently approved agents such as XPO1 inhibitors or from participation in a clinical trial. Furthermore, retreatment with agents that were received in previous lines of therapy can also be considered in heavily pretreated patients, for example, in combination with classic cytotoxic drugs. Importantly, with the increasing use of CD38 antibodies in newly diagnosed and early relapsed/refractory MM, more information is needed on the potential value of retreatment with CD38 antibodies. With the introduction of new immunotherapies with novel modes of action, we also need a better understanding of sequencing of immunotherapeutic agents by taking into account the effect of prior therapy on immune function.

Efficacy and safety of weekly carfilzomib (70 mg/m2), dexamethasone, and daratumumab (KdD70) is comparable to twice-weekly KdD56 while being a more convenient dosing option: a cross-study comparison of the CANDOR and EQUULEUS studies

The regimen of carfilzomib, daratumumab, and dexamethasone (KdD) shows activity in patients with relapsed/refractory multiple myeloma. KdD at the twice-weekly 56 mg/m² carfilzomib dose (KdD56) was used in the randomized phase 3 CANDOR study (NCT03158688), whereas KdD at the once-weekly 70 mg/m² carfilzomib dose (KdD70) was used in the phase 1 b EQUULEUS study (NCT01998971). We analyzed efficacy data from comparable CANDOR and EQUULEUS patients using inverse probability of treatment weighting (IPTW)-adjusted models. These weights were calculated from propensity scores derived to balance prespecified baseline covariates. The side-by-side and adjusted comparisons showed similar efficacy for overall response rates and progression-free survival in the two groups, with a series of sensitivity analyses showing consistent findings. Safety data were generally consistent with the known safety profiles of each individual drug. Once-weekly KdD70 is comparable to twice-weekly KdD56 in terms of efficacy and safety while being a more convenient dosing option.

Melflufen for relapsed and refractory multiple myeloma

INTRODUCTION

The overall survival of patients with multiple myeloma has improved with the advent of novel agents; however, multiple myeloma remains incurable. Combinations of standard-of-care agents such as immunomodulators, proteasome inhibitors, and anti-CD38 monoclonal antibodies are increasingly used in earlier lines of therapy. Patients with disease that is refractory to multiple novel agents represent a population with high unmet medical need and for whom therapies with new mechanisms of action could be beneficial. Melphalan flufenamide (melflufen) has demonstrated encouraging activity in patients with relapsed and refractory multiple myeloma.

AREAS COVERED

This review provides an overview of the mechanism of action of melflufen, a first-in-class peptide-drug conjugate that targets aminopeptidases and rapidly delivers alkylating agents into tumor cells. It reviews key Phase I and II clinical trial data for melflufen in combination with dexamethasone as well as in triplet combinations with daratumumab or bortezomib. The safety profile of melflufen, which is characterized primarily by clinically manageable hematologic adverse events, is described.

EXPERT OPINION

Melflufen has potential to fill a gap in the myeloma treatment landscape by providing a new mechanism of action with clinically meaningful efficacy and a favorable safety profile in patients refractory to multiple novel agents.

Melflufen: A Peptide-Drug Conjugate for the Treatment of Multiple Myeloma

Despite the availability of new therapies that have led to improved outcomes for patients with multiple myeloma, most patients will eventually relapse. With triplet and even quadruplet combination therapies becoming standard in the first and second line, many patients will have few treatment options after second-line treatment. Melflufen (melphalan flufenamide) is a first-in-class peptide-drug conjugate (PDC) that targets aminopeptidases and rapidly releases alkylating agents into tumor cells. Once inside the tumor cells, melflufen is hydrolyzed by peptidases to release alkylator molecules, which become entrapped. Melflufen showed anti-myeloma activity in myeloma cells that were resistant to bortezomib and the alkylator melphalan. In early phase studies (O-12-M1 and HORIZON [OP-106]), melflufen plus dexamethasone has demonstrated encouraging clinical activity and a manageable safety profile in heavily pretreated patients with relapsed/refractory multiple myeloma, including those with triple-class refractory disease and extramedullary disease. The Phase III OCEAN study (OP-104) is further evaluating melflufen plus dexamethasone in patients with relapsed/refractory multiple myeloma. The safety profile of melflufen is characterized primarily by clinically manageable hematologic adverse events. Melflufen, with its novel mechanism of action, has the potential to provide clinically meaningful benefits to patients with relapsed/refractory multiple myeloma, including those with high unmet needs.

Old and new generation proteasome inhibitors in multiple myeloma

Proteasome inhibitors (PIs) represent a recently developed drug class that inhibit the ubiquitin-proteasome system, thus interfering with the intracellular machinery who has the duty of misfolded proteins disposal. Myeloma plasma cells are structurally aimed at the production of large quantities of immunoglobulins. This explains their vulnerability to any perturbation of intracellular protein homeostasis. Bortezomib is the first-in-class PI and nowadays, in combination with other compounds, is the cornerstone of multiple myeloma (MM) treatment in several settings. Bortezomib has several attractive features for its inclusion in the induction phase of therapy: high efficacy, rapid cytoreduction, absence of nephrotoxicity, fast reduction of plasmacytomas, and fast pain control. However, the safety profile of bortezomib is characterized by a not negligible peripheral neuropathy. Newer PIs, such as carfilzomib and ixazomib, have been developed and each offers specific advantages. Carfilzomib is extremely efficient in proteasome inhibition. This results in high efficacy but suffers from a significant cardiotoxicity. Ixazomib is the first oral PI with a proteasome inhibition profile similar to bortezomib, with lower neurotoxicity. PIs mechanism of action is complementary with other drug classes, and this explains the synergism between PIs and other drugs, in particular steroids and immunomodulators. PIs are frequently used in doublets and triplets. Also, they can be associated with anti-CD38 monoclonal antibodies. This review summarizes the principal biological and clinical features of PIs in the MM treatment.

Pomalidomide, bortezomib, and dexamethasone for multiple myeloma previously treated with lenalidomide (OPTIMISMM): outcomes by prior treatment at first relapse

In the phase 3 OPTIMISMM trial, pomalidomide, bortezomib, and dexamethasone (PVd) demonstrated superior efficacy vs bortezomib and dexamethasone (Vd) in patients with relapsed or refractory multiple myeloma previously treated with lenalidomide, including those refractory to lenalidomide. This analysis evaluated outcomes in patients at first relapse (N = 226) by lenalidomide-refractory status, prior bortezomib exposure, and prior stem cell transplant (SCT). Second-line PVd significantly improved PFS vs Vd in lenalidomide-refractory (17.8 vs 9.5 months; P = 0.0276) and lenalidomide-nonrefractory patients (22.0 vs 12.0 months; P = 0.0491), patients with prior bortezomib (17.8 vs 12.0 months; P = 0.0068), and patients with (22.0 vs 13.8 months; P = 0.0241) or without (16.5 vs 9.5 months; P = 0.0454) prior SCT. In patients without prior bortezomib, median PFS was 20.7 vs 9.5 months (P = 0.1055). Significant improvement in overall response rate was also observed with PVd vs Vd in lenalidomide-refractory (85.9% vs 50.8%; P < 0.001) and lenalidomide-nonrefractory (95.7% vs 60.0%; P < 0.001) patients, with similar results regardless of prior bortezomib or SCT. No new safety signals were observed. These data demonstrate the benefit of PVd at first relapse, including immediately after upfront lenalidomide treatment failure and other common first-line treatments.

Elotuzumab, pomalidomide, and dexamethasone is a very well tolerated regimen associated with durable remission even in very advanced myeloma: a retrospective study from two academic centers

Background

The anti-SLAMF7 monoclonal antibody, elotuzumab (elo), plus lenalidomide (len) and dexamethasone (dex) is approved for relapsed/refractory MM in the U.S. and Europe. Recently, a small phase 2 study demonstrated an advantage in progression-free survival (PFS) for elo plus pomalidomide (pom)/dex compared to pom/dex alone and resulted in licensing of this novel triplet combination, but clinical experience is still limited.

Purpose

To analyze the efficacy and safety of elo/pom/dex in a “real world” cohort of patients with advanced MM, we queried the databases of the university hospitals of Würzburg and Vienna.

Findings

We identified 22 patients with a median number of five prior lines of therapy who received elo/pom/dex prior to licensing within an early access program. Patients received a median number of 5 four-week treatment cycles. Median PFS was 6.4 months with 12-month and 18-month PFS rates of 35% and 28%, respectively. The overall response rate was 50% and 64% of responding patients who achieved a longer PFS with elo/pom/dex compared to their most recent line of therapy. Objective responses were also seen in five patients who had been pretreated with pomalidomide. Low tumor burden was associated with improved PFS (13.5 months for patients with ISS stage I/II at study entry v 6.4 months for ISS III), although this difference did not reach statistical significance. No infusion-related reactions were reported. The most frequent grade 3/4 adverse events were neutropenia and pneumonia.

Conclusion

Elo/pom/dex is an active and well-tolerated regimen in highly advanced MM even after pretreatment with pomalidomide.

Carfilzomib, dexamethasone, and daratumumab versus carfilzomib and dexamethasone for patients with relapsed or refractory multiple myeloma (CANDOR): results from a randomised, multicentre, open-label, phase 3 study

BACKGROUND

Lenalidomide and bortezomib frontline exposure has raised a growing need for novel treatments for patients with relapsed or refractory multiple myeloma. Carfilzomib in combination with daratumumab has shown substantial efficacy with tolerable safety in relapsed or refractory multiple myeloma in a phase 1 study. In this study, we aimed to compare the efficacy and safety of carfilzomib, dexamethasone, and daratumumab versus carfilzomib and dexamethasone in patients with relapsed or refractory multiple myeloma.

METHODS

In this randomised, multicentre, open-label, phase 3 study, 466 patients recruited from 102 sites across North America, Europe, Australia, and Asia with relapsed or refractory multiple myeloma were randomly assigned 2:1 to carfilzomib, dexamethasone, and daratumumab (KdD) or carfilzomib and dexamethasone (Kd). All patients received twice per week carfilzomib at 56 mg/m² (20 mg/m²; days 1 and 2 during cycle 1). Daratumumab (8 mg/kg) was administered intravenously on days 1 and 2 of cycle 1 and at 16 mg/kg weekly for the remaining doses of the first two cycles, then every 2 weeks for four cycles (cycles 3-6), and every 4 weeks thereafter. Patients received 40 mg dexamethasone weekly (20 mg for patients ≥75 years old starting on the second week). The primary endpoint was progression-free survival assessed by intention to treat. Adverse events were assessed in the safety population. This trial (NCT03158688) is registered with ClinicalTrials.gov, and is active but not recruiting.

FINDINGS

Between June 13, 2017, and June 25, 2018, 466 patients of 569 assessed for eligibility were enrolled. After median follow-up of approximately 17 months, median progression-free survival was not reached in the KdD group versus 15·8 months in the Kd group (hazard ratio 0·63; 95% CI 0·46-0·85; p=0·0027). Median treatment duration was longer in the KdD versus the Kd group (70·1 vs 40·3 weeks). Grade 3 or higher adverse events were reported in 253 (82%) patients in the KdD group and 113 (74%) patients in the Kd group. The frequency of adverse events leading to treatment discontinuation was similar in both groups (KdD, 69 [22%]; Kd, 38 [25%]).

INTERPRETATION

KdD significantly prolonged progression-free survival versus Kd in patients with relapsed or refractory multiple myeloma and was associated with a favourable benefit-risk profile.

FUNDING

Amgen.

Pomalidomide, dexamethasone, and daratumumab in relapsed refractory multiple myeloma after lenalidomide treatment

Patients with multiple myeloma who have relapsed after or become refractory to lenalidomide in early treatment lines represent a clinically important population in need of effective therapies. The safety and efficacy of pomalidomide, low-dose dexamethasone, and daratumumab was evaluated in lenalidomide-pretreated patients with relapsed or refractory multiple myeloma (RRMM) after one to two prior treatment lines in the phase 2 MM-014 study. Patients received pomalidomide 4 mg daily from days 1-21 and dexamethasone 40 mg weekly (28-day cycles). Daratumumab 16 mg/kg was administered per label. Primary endpoint was overall response rate (ORR); secondary endpoints included progression-free survival (PFS) and safety. Per protocol, all patients (N = 112) had received lenalidomide in their most recent prior regimen (75.0% lenalidomide refractory). ORR was 77.7% (76.2% in lenalidomide-refractory patients); median follow-up was 17.2 months. Median PFS was not reached (1-year PFS rate 75.1%). The most common hematologic grade 3/4 treatment-emergent adverse event was neutropenia (62.5%). Grade 3/4 infections were reported in 31.3% of patients, including 13.4% with grade 3/4 pneumonia. These results demonstrate the safety and efficacy of pomalidomide-based therapy as early as second line in patients with RRMM, even immediately after lenalidomide failure, indicating that switching from the immunomodulatory agent class is not necessary.

Pomalidomide-bortezomib-dexamethasone in relapsed or refractory multiple myeloma: Japanese subset analysis of OPTIMISMM

In the phase 3 OPTIMISMM trial, pomalidomide, bortezomib and dexamethasone (PVd) significantly improved the progression-free survival (PFS) and the overall response rate (ORR) vs bortezomib and dexamethasone (Vd) in patients with relapsed or refractory multiple myeloma. All patients were previously treated with lenalidomide (70% refractory to lenalidomide) and had received one to three prior regimens. Here we report the first efficacy and safety analysis of PVd vs Vd in Japanese patients with relapsed or refractory multiple myeloma. Seventeen patients enrolled in the OPTIMISMM trial in Japan. With a median follow-up of 14.8 months, the median PFS was 17.6 months with PVd (n = 12) vs 4.4 months with Vd (n = 5), and the ORR was 100% vs 60.0%, respectively. The safety profile was as expected for PVd. Toxicities were managed with dose reductions and interruptions, and no patients discontinued PVd due to treatment-emergent adverse events. These results are consistent with those in the overall OPTIMISMM patient population and confirm the clinical benefit of PVd in Japanese patients.

G protein-coupled receptor 68 increases the number of B lymphocytes

G protein-coupled receptor 68 (GPR68) is a proton sensor that is activated upon binding to extracellular protons. We have previously found that GPR68 induces a proapoptotic pathway in bone marrow (BM) cells from the patients with myelodysplastic syndromes (MDS) after treated with lenalidomide. However, the function of GPR68 in normal hematopoietic cells remains unclear. With genetic loss of function approach, we found reduced frequency and number of B lymphocytes in the peripheral blood (PB) of whole body Gpr68^-/- mice compared to control littermates upon aging. During hematopoietic regeneration, such as in response to fluorouracil (5-FU), we also found reduced frequency and number of B lymphocytes in Gpr68^-/- mice compared to wild type mice. Mechanism studies revealed that Gpr68 expression was upregulated in B lymphocytes of BM during aging and in hematopoietic progenitor cells after treatment with 5-FU. In addition, activation of Gpr68 by its activators increased the frequency and number of B lymphocytes. Our studies indicate that Gpr68 expression is upregulated in hematopoietic cells upon aging and during hematopoietic regeneration that ends up with increased number of B lymphocytes.

Limited treatment options in refractory multiple myeloma: promising therapeutic developments

Introduction: Combinations of proteasome inhibitors, immunomodulators, and monoclonal antibodies are highly active against multiple myeloma. Consequently, several combinations have moved from the relapsed to the front-line setting. In the context of lenalidomide and bortezomib being used upfront, salvage options need to be evaluated.Areas covered: This manuscript reviews available data for the treatment of patients progressing on optimal frontline strategies, with a focus on the role of second-generation proteasome inhibitors and immunomodulators, monoclonal antibodies and immunotherapy.Expert opinion: Remarkable progress has been made in myeloma treatment due to the integration of immunomodulators, proteasome inhibitors and more recently monoclonal antibodies in the front-line setting. However, we work on the assumption that most individuals will eventually relapse. Optimized upfront therapy negatively selects more resistant patients among still relapsing individuals. Bortezomib and lenalidomide-exposed patients are under-represented in trials leading to currently approved combinations. Evidence needs to be reviewed taking into account how the improvement of frontline therapy has modified the characteristics of patients at the time of relapse. Second generation immunomodulatory agents and proteasome inhibitors, monoclonal antibodies and other agents have shown efficacy in this new landscape. Immunotherapeutic agents, including CAR-T cells are promising for patients failing standard combinations, despite current data are still immature.

Isatuximab plus pomalidomide and low-dose dexamethasone versus pomalidomide and low-dose dexamethasone in patients with relapsed and refractory multiple myeloma (ICARIA-MM): a randomised, multicentre, open-label, phase 3 study

BACKGROUND

Isatuximab is a monoclonal antibody that binds a specific epitope on the human CD38 receptor and has antitumour activity via multiple mechanisms of action. In a previous phase 1b study, around 65% of patients with relapsed and refractory multiple myeloma achieved an overall response with a combination of isatuximab with pomalidomide and low-dose dexamethasone. The aim of this study was to determine the progression-free survival benefit of isatuximab plus pomalidomide and dexamethasone compared with pomalidomide and dexamethasone in patients with relapsed and refractory multiple myeloma.

METHODS

We did a randomised, multicentre, open-label, phase 3 study at 102 hospitals in 24 countries in Europe, North America, and the Asia-Pacific regions. Eligible participants were adult patients with relapsed and refractory multiple myeloma who had received at least two previous lines of treatment, including lenalidomide and a proteasome inhibitor. Patients were excluded if they were refractory to previous treatment with an anti-CD38 monoclonal antibody. We randomly assigned patients (1:1) to either isatuximab 10 mg/kg plus pomalidomide 4 mg plus dexamethasone 40 mg (20 mg for patients aged ≥75 years), or pomalidomide 4 mg plus dexamethasone 40 mg. Randomisation was done using interactive response technology and stratified according to the number of previous lines of treatment (2-3 vs >3) and age (<75 years vs ≥75 years). Treatments were assigned based on a permuted blocked randomisation scheme with a block size of four. The isatuximab-pomalidomide-dexamethasone group received isatuximab intravenously on days 1, 8, 15, and 22 in the first 28-day cycle, then on days 1 and 15 in subsequent cycles. Both groups received oral pomalidomide on days 1 to 21 in each cycle, and oral or intravenous dexamethasone on days 1, 8, 15, and 22 of each cycle. Treatment continued until disease progression, unacceptable toxicity, or consent withdrawal. Dose reductions for adverse reactions were permitted for pomalidomide and dexamethasone, but not for isatuximab. The primary endpoint was progression-free survival, determined by an independent response committee and assessed in the intention-to-treat population. Safety was assessed in all participants who received at least one dose of study drug. This study is registered at ClinicalTrials.gov, number NCT02990338.

FINDINGS

Between Jan 10, 2017, and Feb 2, 2018, we randomly assigned 307 patients to treatment: 154 to isatuximab-pomalidomide-dexamethasone, and 153 to pomalidomide-dexamethasone. At a median follow-up of 11·6 months (IQR 10·1-13·9), median progression-free survival was 11·5 months (95% CI 8·9-13·9) in the isatuximab-pomalidomide-dexamethasone group versus 6·5 months (4·5-8·3) in the pomalidomide-dexamethasone group; hazard ratio 0·596, 95% CI 0·44-0·81; p=0·001 by stratified log-rank test. The most frequent treatment-emergent adverse events (any grade; isatuximab-pomalidomide-dexamethasone vs pomalidomide-dexamethasone) were infusion reactions (56 [38%] vs 0), upper respiratory tract infections (43 [28%] vs 26 [17%]), and diarrhoea (39 [26%] vs 29 [20%]). Adverse events with a fatal outcome were reported in 12 patients (8%) in the isatuximab-pomalidomide-dexamethasone group and 14 (9%) in the pomalidomide-dexamethasone group. Deaths due to treatment-related adverse events were reported for one patient (<1%) in the isatuximab-pomalidomide-dexamethasone group (sepsis) and two (1%) in the pomalidomide-dexamethasone group (pneumonia and urinary tract infection).

INTERPRETATION

The addition of isatuximab to pomalidomide-dexamethasone significantly improves progression-free survival in patients with relapsed and refractory multiple myeloma. Isatuximab is an important new treatment option for the management of relapsed and refractory myeloma, particularly for patients who become refractory to lenalidomide and a proteasome inhibitor.

FUNDING

Sanofi. VIDEO ABSTRACT.

Daratumumab, Bortezomib, and Dexamethasone Versus Bortezomib and Dexamethasone in Patients With Previously Treated Multiple Myeloma: Three-year Follow-up of CASTOR

BACKGROUND

In the phase III CASTOR study in relapsed or refractory multiple myeloma, daratumumab, bortezomib, and dexamethasone (D-Vd) demonstrated significant clinical benefit versus Vd alone. Outcomes after 40.0 months of median follow-up are discussed.

PATIENTS AND METHODS

Eligible patients had received ≥ 1 line of treatment and were administered bortezomib (1.3 mg/m²) and dexamethasone (20 mg) for 8 cycles with or without daratumumab (16 mg/kg) until disease progression.

RESULTS

Of 498 patients in the intent-to-treat (ITT) population (D-Vd, n = 251; Vd, n = 247), 47% had 1 prior line of treatment (1PL; D-Vd, n = 122; Vd, n = 113). Median progression-free survival (PFS) was significantly prolonged with D-Vd versus Vd in the ITT population (16.7 vs. 7.1 months; hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.25-0.40; P < .0001) and the 1PL subgroup (27.0 vs. 7.9 months; HR, 0.22; 95% CI, 0.15-0.32; P < .0001). In lenalidomide-refractory patients, the median PFS was 7.8 versus 4.9 months (HR, 0.44; 95% CI, 0.28-0.68; P = .0002) for D-Vd (n = 60) versus Vd (n = 81). Minimal residual disease (MRD)-negativity rates (10^-5) were greater with D-Vd versus Vd (ITT: 14% vs. 2%; 1PL: 20% vs. 3%; both P < .0001). PFS2 was significantly prolonged with D-Vd versus Vd (ITT: HR, 0.48; 95% CI, 0.38-0.61; 1PL: HR, 0.35; 95% CI, 0.24-0.51; P < .0001). No new safety concerns were observed.

CONCLUSION

After 3 years, D-Vd maintained significant benefits in patients with relapsed or refractory multiple myeloma with a consistent safety profile. D-Vd provided the greatest benefit at first relapse and increased MRD-negativity rates.

Pomalidomide plus low-dose dexamethasone in relapsed refractory multiple myeloma after lenalidomide treatment failure

Patients with relapsed/refractory multiple myeloma (RRMM) for whom the benefits of lenalidomide have been exhausted in early treatment lines need effective therapies. In cohort A of the phase 2 MM‐014 trial, we examined the safety and efficacy of pomalidomide plus low‐dose dexamethasone immediately after lenalidomide‐based treatment failure in patients with RRMM and two prior lines of therapy. Pomalidomide 4 mg was given on days 1 to 21 of 28‐day cycles. Dexamethasone 40 mg (20 mg for patients aged >75 years) was given on days 1, 8, 15 and 22 of 28‐day cycles. The primary endpoint was overall response rate (ORR), and secondary endpoints included progression‐free survival (PFS), overall survival (OS) and safety. The intention‐to‐treat population comprised 56 patients; all received prior lenalidomide (87·5% lenalidomide refractory) and 39 (69·6%) received prior bortezomib. ORR was 32·1% (28·2% in the prior‐bortezomib subgroup). Median PFS was 12·2 months (7·9 months in the prior‐bortezomib subgroup). Median OS was 41·7 months (38·6 months in the prior‐bortezomib subgroup). The most common grade 3/4 treatment‐emergent adverse events were anaemia (25·0%), pneumonia (14·3%) and fatigue (14·3%). These findings support earlier sequencing of pomalidomide‐based therapy in lenalidomide‐pretreated patients with RRMM, including those who have become refractory to lenalidomide.

Trial registration: http://www.ClinicalTrials.gov identifier NCT01946477.

Treatment of relapsed multiple myeloma: Evidence-based recommendations

The practice of choosing the next best therapy for patients with relapsed and/or refractory multiple myeloma (RRMM) is becoming increasingly complex. There is no clear consensus regarding the best treatment sequence for RRMM. With the approval of novel proteasome inhibitors (ixazomib and carfilzomib), immunomodulatory agents (pomalidomide), monoclonal antibodies (daratumumab and elotuzumab), and other targeted therapies, multiple combination regimens utilizing these agents are being studied with the goal of enhancing disease control, prolonging progression-free survival, and improving overall survival. We, herein, describe a review of FDA-approved regimens for RRMM patients and offer a paradigm in selecting subsequent treatment regimens, focusing on patient specific morbidity, treatment toxicity, and disease-specific characteristics.