Daratumumab plus bortezomib and dexamethasone versus bortezomib and dexamethasone in relapsed or refractory multiple myeloma: updated analysis of CASTOR

Quality of life outcomes in multiple myeloma patients: a summary of recent clinical trials

Introduction: Management of multiple myeloma (MM) has improved over recent years. Health-related quality of life (HRQoL) data is becoming increasingly important, owing to improved survival outcomes. Areas covered: The authors performed an expert review of the literature to identify evidence-based data available on HRQoL in frontline and relapsed/refractory MM (RRMM) patients. Expert opinion: De-novo patients should be informed that the HRQoL is expected to improve during first-line treatment with different degrees of possible deterioration during the first cycles. Achievement of a maximal response should be strongly considered, particularly in the frontline setting, but must also be balanced with tolerability, HRQoL, and patient preferences. The same degree of improvement in HRQoL cannot be expected during conventional relapse treatments, where patients should be prepared only for stabilization of HRQoL. However, focusing attention only on measures such as toxicity may provide just a partial view of overall treatment effectiveness. Nonetheless, the authors believe the added value of taking into consideration the patient's perspectives and the importance of patient-reported outcomes in the evaluation of treatment effects should be considered mandatory. The incorporation of quality of life assessment into clinical and research practice has the potential of improving treatment outcomes.

High-dose bendamustine and melphalan conditioning for autologous stem cell transplantation for patients with multiple myeloma

High-dose melphalan (MEL200) followed by autologous stem cell transplantation (ASCT) remains a standard of care for multiple myeloma (MM). Bendamustine induces responses in MM resistant to other alkylators. Our prior Phase I trial adding bendamustine to MEL200 transplant conditioning resulted in no additional toxicity. We now report a single-arm, phase II study that evaluated the efficacy of bendamustine 225 mg/m² with MEL200 conditioning for ASCT in 18 patients with newly diagnosed MM (NDMM) and 17 with relapsed or refractory MM (RRMM). The primary end point was the complete response (CR/sCR) rate at day+ 100. Sample size was determined according to Simon's two-stage design. At stage 1, sixteen patients entered the study. As there were eight patients with CR/sCR, enrollment increased to 28 patients. Sixteen out of the first 28 evaluable patients achieved CR/sCR, meeting the design criteria. Enrollment was then expanded to a total of 35 patients. 51% achieved a CR/sCR. After a median follow-up of 65 months, 21 patients progressed, including 7 deaths. The median PFS for NDMM and RRMM was 48 and 45 months, respectively. Bendamustine/MEL200 conditioning resulted in excellent overall and depth of response as well as PFS, particularly in the RRMM patients, and is worthy of further investigation (NCT00916058).

Novel targets for the treatment of relapsing multiple myeloma

Introduction: Multiple myeloma (MM) is characterized by the high tendency to relapse and develop drug resistance. Areas covered: This review focused on the main novel targets identified to design drugs for the treatment of relapsing MM patients. CD38 and SLAMF7 are the main surface molecules leading to the development of monoclonal antibodies (mAbs) recently approved for the treatment of relapsing MM patients. B cell maturation antigen (BCMA) is a suitable target for antibody-drug conjugates, bispecific T cell engager mAbs and Chimeric Antigen Receptor (CAR)-T cells. Moreover, the programmed cell death protein 1 (PD)-1/PD-Ligand (PD-L1) expression profile by MM cells and their microenvironment and the use of immune checkpoints inhibitors in MM patients are reported. Finally, the role of histone deacetylase (HDAC), B cell lymphoma (BCL)-2 family proteins and the nuclear transport protein exportin 1 (XPO1) as novel targets are also underlined. The clinical results of the new inhibitors in relapsing MM patients are discussed. Expert opinion: CD38, SLAMF7, and BCMA are the main targets for different immunotherapeutic approaches. Selective inhibitors of HDAC6, BCL-2, and XPO1 are new promising compounds under clinical investigation in relapsing MM patients.

Bortezomib for the Treatment of Hematologic Malignancies: 15 Years Later

Bortezomib is a dipeptidyl boronic acid that selectively inhibits the ubiquitin proteasome pathway, which plays a role in the degradation of many intracellular proteins. It is the first-in-class selective and reversible inhibitor of the 26S proteasome, with antiproliferative and antitumor activity. It exerts its anti-neoplastic action mainly via the inhibition of the nuclear factor-κB pathway components associated with cell proliferation, apoptosis, and angiogenesis. The drug has revolutionized the treatment of multiple myeloma and, more recently, mantle cell lymphoma. In 2003, bortezomib received accelerated approval from the US Food and Drug Administration for the treatment of relapsed/refractory multiple myeloma and in 2008 for patients with previously untreated multiple myeloma. In 2006, bortezomib was approved for the treatment of refractory/relapsed mantle cell lymphoma and, in 2014, for previously untreated mantle cell lymphoma. Bortezomib has also demonstrated clinical efficacy both as a single drug and in combination with other agents in light chain amyloidosis, lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia, and peripheral T-cell lymphomas. Furthermore, continued clinical studies are required to confirm its value for patients with indolent and aggressive B-cell non-Hodgkin lymphomas and acute leukemias.

Daratumumab plus Lenalidomide and Dexamethasone for Untreated Myeloma

BACKGROUND

Lenalidomide plus dexamethasone is a standard treatment for patients with newly diagnosed multiple myeloma who are ineligible for autologous stem-cell transplantation. We sought to determine whether the addition of daratumumab would significantly reduce the risk of disease progression or death in this population.

METHODS

We randomly assigned 737 patients with newly diagnosed multiple myeloma who were ineligible for autologous stem-cell transplantation to receive daratumumab plus lenalidomide and dexamethasone (daratumumab group) or lenalidomide and dexamethasone alone (control group). Treatment was to continue until the occurrence of disease progression or unacceptable side effects. The primary end point was progression-free survival.

RESULTS

At a median follow-up of 28.0 months, disease progression or death had occurred in 240 patients (97 of 368 patients [26.4%] in the daratumumab group and 143 of 369 patients [38.8%] in the control group). The estimated percentage of patients who were alive without disease progression at 30 months was 70.6% (95% confidence interval [CI], 65.0 to 75.4) in the daratumumab group and 55.6% (95% CI, 49.5 to 61.3) in the control group (hazard ratio for disease progression or death, 0.56; 95% CI, 0.43 to 0.73; P<0.001). The percentage of patients with a complete response or better was 47.6% in the daratumumab group and 24.9% in the control group (P<0.001). A total of 24.2% of the patients in the daratumumab group, as compared with 7.3% of the patients in the control group, had results below the threshold for minimal residual disease (1 tumor cell per 10⁵ white cells) (P<0.001). The most common adverse events of grade 3 or 4 were neutropenia (50.0% in the daratumumab group vs. 35.3% in the control group), anemia (11.8% vs. 19.7%), lymphopenia (15.1% vs. 10.7%), and pneumonia (13.7% vs. 7.9%).

CONCLUSIONS

Among patients with newly diagnosed multiple myeloma who were ineligible for autologous stem-cell transplantation, the risk of disease progression or death was significantly lower among those who received daratumumab plus lenalidomide and dexamethasone than among those who received lenalidomide and dexamethasone alone. A higher incidence of neutropenia and pneumonia was observed in the daratumumab group. (Funded by Janssen Research and Development; MAIA ClinicalTrials.gov number, NCT02252172.).

Expression analysis of two SLAM family receptors, SLAMF2 and SLAMF7, in patients with multiple myeloma

Monoclonal antibodies against surface antigens on MM cells, such as anti-SLAMF7 and anti-CD38 antibodies, represent an attractive therapeutic modality for the eradication of multiple myeloma (MM) cells. However, further exploration of target molecules is urgently needed for the development of more effective therapies. In the present study, we studied the expression of CD48 in a total of 74 primary MM samples derived from patients to evaluate SLAMF2 (CD48) as a candidate in mAb therapy for MM. Of 74 samples, 39 were subjected to SLAMF7 analysis. Most of the MM cells, defined as CD38 and CD138 double-positive cells, showed strong expression of CD48 or SLAMF7 independent of disease stage or treatment history. In these 39 samples, most MM cells showed expression of both SLAMF7 and CD48; however, several samples showed expression of either only CD48 or only SLAMF7, including seven cases that were only highly positive for SLAMF7, and five that were only highly positive for CD48. Our study demonstrates that the immune receptor CD48 is overexpressed on MM cells together with SLAMF7, and that CD48 may be considered as an alternative target for treatment of MM in cases showing weak expression of SLAMF7.

Daratumumab plus carfilzomib and dexamethasone in patients with relapsed or refractory multiple myeloma

Patients with relapsed or refractory multiple myeloma (RRMM) have limited treatment options and poor survival outcomes. The increasing adoption of lenalidomide-based therapy for frontline treatment of multiple myeloma has resulted in a need for effective regimens for lenalidomide-refractory patients. This phase 1b study evaluated daratumumab plus carfilzomib and dexamethasone (D-Kd) in patients with RRMM after 1 to 3 prior lines of therapy, including bortezomib and an immunomodulatory drug; lenalidomide-refractory patients were eligible. Carfilzomib- and daratumumab-naïve patients (n = 85) received carfilzomib weekly on days 1, 8, and 15 of each 28-day cycle (20 mg/m² initial dose, escalated to 70 mg/m² thereafter) and dexamethasone (40 mg/wk). Of these, 10 patients received the first daratumumab dose as a single infusion (16 mg/kg, day 1 cycle 1), and 75 patients received a split first dose (8 mg/kg, days 1-2 cycle 1). Subsequent dosing was per the approved schedule for daratumumab. Patients received a median of 2 (range, 1-4) prior lines of therapy; 60% were lenalidomide refractory. The most common grade 3/4 treatment-emergent adverse events were thrombocytopenia (31%), lymphopenia (24%), anemia (21%), and neutropenia (21%). Infusion-related reactions were observed in 60% and 43% of single and split first-dose patients, respectively. Overall response rate was 84% (79% in lenalidomide-refractory patients). Median progression-free survival (PFS) was not reached; 12-month PFS rates were 74% for all treated patients and 65% for lenalidomide-refractory patients. D-Kd was well tolerated with low neutropenia rates, and it demonstrated deep responses and encouraging PFS, including in patients refractory to lenalidomide. The trial was registered at www.clinicaltrials.gov as #NCT01998971.

Evaluation of the safety and efficacy of daratumumab outside of clinical trials

Daratumumab-based therapy has been shown to have significant clinical efficacy in phase 3 trials of patients with relapse or refractory multiple myeloma. Outside of clinical trials, however, clinical data on daratumumab remain limited. We reviewed medical records of patients who received daratumumab combination therapy at our institute (median age 74 years; median lines of prior therapy 4). The overall response rate was 69.4%, and 36.7% of patients achieved complete response (CR) or better. The proportion of patients who attained CR or better was significantly higher among patients with < 4 prior therapies than those with ≥ 4 (56.5% vs 19.2%, P = 0.009). Estimated median progression-free survival (PFS) was 12.4 months (95% confidence interval 8.6-not reached). The median PFS was significantly worse in patients who were refractory to bortezomib and lenalidomide and had received ≥ 4 lines of prior therapy. Twelve of 49 patients attained negative minimal residual disease. Common adverse events included hematological toxicities including neutropenia and lymphopenia; however, the rate of febrile neutropenia was low (3.8%). Infusion-related reactions occurred in 32.1% of patients, but were grade 1 or 2. Daratumumab combination therapies therefore appear to be effective and safe as salvage regimens in clinical practice, especially when used in the early phase.

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

Over the last years, there has been great progress in the treatment of multiple myeloma with many new agents and combinations having been approved and being now routinely incorporated into treatment strategies. As a result, patients are experiencing benefits in terms of survival and better tolerance. However, the multitude of treatment options also presents a challenge to select the best options tailored to the specific patient situation. Lenalidomide is increasingly being used as part of frontline therapy in newly diagnosed multiple myeloma. This agent is typically administered until disease progression. It is currently unclear, how to best manage patients, who relapse while receiving lenalidomide as part of their frontline treatment. We conducted a review to summarize the available evidence in this setting. Our summary shows that there are very few data from current trials testing new combinations based on carfilzomib, pomalidomide, or daratumumab that address this specific patient population. Our review is aimed to summarize the available evidence to assist treatment decision making and to raise awareness of this lack of data to encourage further analyses and the incorporation of sequencing questions in future trial designs.

Phase 2 Study of Daratumumab in Relapsed/Refractory Mantle-Cell Lymphoma, Diffuse Large B-Cell Lymphoma, and Follicular Lymphoma

BACKGROUND

Daratumumab is a CD38 monoclonal antibody approved for treating relapsed/refractory and newly diagnosed multiple myeloma. Preclinical daratumumab studies demonstrated cytotoxic activity and reduced tumor growth in B-cell non-Hodgkin lymphoma (NHL) subtypes, including diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and mantle-cell lymphoma (MCL).

PATIENTS AND METHODS

This was a phase 2, open-label, multicenter, 2-stage trial. Patients with relapsed/refractory DLBCL, FL, or MCL with ≥ 50% CD38 expression were eligible for stage 1. Daratumumab (16 mg/kg; 28-day cycles) was administered intravenously weekly for 2 cycles, every 2 weeks for 4 cycles, and every 4 weeks thereafter. Overall response rate was the primary end point. Pharmacokinetic and safety were also evaluated. Stage 2 was planned to further assess daratumumab in larger populations of NHL subtypes if futility criteria were not met. The study was registered with ClinicalTrials.gov (NCT02413489).

RESULTS

The trial screened 138 patients resulting in accrual of 15 patients with DLBCL, 16 with FL, and 5 with MCL. Median CD38 expression across treated patients was 70%. Overall response rate was 6.7%, 12.5%, and not evaluable in DLBCL, FL, and MCL cohorts, respectively. The most common grade 3/4 treatment-emergent adverse event was thrombocytopenia (11.1%), and 4 (11.1%) patients discontinued treatment because of treatment-emergent adverse events. Infusion-related reactions occurred in 72.2% of patients (3 patients with grade 3; no grade 4).

CONCLUSION

In NHL, the safety and pharmacokinetics of daratumumab were consistent with myeloma studies. Screen-fail rates were high, prespecified futility thresholds were met in 2 cohorts, and the study was terminated. Studies in other hematologic malignancies and amyloidosis are ongoing.

Contemporary patient-tailored treatment strategies against high risk and relapsed or refractory multiple myeloma

Recurrence of disease due to chemotherapy drug resistance remains a major obstacle to a more successful survival outcome of multiple myeloma (MM). Overcoming drug resistance and salvaging patients with relapsed and/or refractory (R/R) MM is an urgent and unmet medical need. Several new personalized treatment strategies have been developed against molecular targets to overcome this drug resistance. There are several targeted therapeutics with anti-MM activity in clinical pipeline, including inhibitors of anti-apoptotic proteins, monoclonal antibodies, antibody-drug conjugates, bispecific antibodies, fusion proteins, and various cell therapy platforms. For example, B-cell maturation antigen (BCMA)-specific CAR-T cell platforms showed promising activity in heavily pretreated R/R MM patients. Therefore, there is renewed hope for high-risk as well as R/R MM patients in the era of personalized medicine.

Immunotherapy: A Novel Era of Promising Treatments for Multiple Myeloma

Multiple myeloma (MM) remains an incurable hematological malignancy characterized by clonal proliferation of malignant plasma cells in bone marrow. In the last 20 years, the introduction of autologous stem cell transplantation, followed by proteasome inhibitors and immunomodulatory agents, increased the survival of MM patients by 50%. However, still a high proportion of patients relapse and become refractory, especially, high-risk patients with adverse cytogenetics where these treatment combinations have shown limited benefit. Therefore, novel strategies, such as immunotherapy, have been developed in the last few years to help improve the survival of these patients. Immunotherapy treatments include a high number of different strategies used to attack the tumor cells by using the immune system. Here, we will review the most successful immunotherapy strategies published up to date in patients with relapsed or refractory (R/R) MM, including monoclonal antibodies targeting specific antigens on the tumor cells, antibodies combined with cytotoxic drugs or Antibodies Drug Conjugates, immune checkpoint inhibitors which eliminate the barriers that damper immune cells and prevent them from attacking tumor cells, bi-specific T-cell engagers antibodies (BiTEs), bi-specific antibodies and the infusion of chimeric antigen receptor-modified T cells. We overview the results of clinical studies that have been presented up to date and also review pre-clinical studies describing potential novel treatments for MM.