Efficacy of elotuzumab for multiple myeloma deteriorates after daratumumab: a multicenter retrospective study.

Elotuzumab-based regimens are sometimes selected for multiple myeloma treatment after daratumumab-based regimens. However, there has been insufficient discussion on the efficacy of elotuzumab after daratumumab. We used Kansai Myeloma Forum registration data in a multicenter retrospective evaluation of the efficacy of elotuzumab after daratumumab. Overall survival (OS) rate and time to next treatment (TTNT) were significantly worse in the cohort given elotuzumab after daratumumab (Dara cohort, n = 47) than in the cohort with no history of daratumumab administration before elotuzumab (No-Dara cohort, n = 80, OS: P = 0.03; TTNT: P = 0.02; best response: P < 0.01). In the Dara cohort, OS and TTNT rates were worse with sequential elotuzumab use after daratumumab than with non-sequential (OS: P = 0.02; TTNT: P = 0.03). In patients given elotuzumab < 180 days after daratumumab, OS (P = 0.08) and best response (P = 0.21) tended to be worse, and TTNT was significantly worse (P = 0.01), than in those given elotuzumab after ≥ 180 days. These findings were confirmed by subgroup analyses and multivariate analyses. Monoclonal-antibody-free treatment might be preferable after daratumumab-based regimens. If possible, elotuzumab-based regimens should be considered only ≥ 180 days after daratumumab use.

Impact of cytogenetic abnormalities in symptomatic multiple myeloma; a Japanese real-world analysis from Kansai Myeloma Forum.

To evaluate the specific prognostic value of CAs, we conducted an analysis of 923 symptomatic multiple myeloma patients. Among this cohort, 480 patients had complete data set of high-risk CAs by interphase fluorescent in situ hybridization at diagnosis. In the high-risk group analysis, the median OS of patients without CAs (n = 338, 72 %) was 6.5 years, patients with del(17p) (n = 42, 9 %) was 4.4 years, patients with t(4;14) or t(14;16) (n = 72, 15 %) was 4.4 years, and patients with double-positive CAs(del(17p) and t(4;14) or t(14;16)) (n = 18, 4 %) was 2.1 years (p = 0.032). Patients with double-positive CAs had a significantly worse prognosis.

Real-world data on induction therapy in patients with transplant-ineligible newly diagnosed multiple myeloma: retrospective analysis of 598 cases from Kansai Myeloma Forum.

To investigate the real-world clinical outcomes and management of novel drug-containing therapies for newly diagnosed multiple myeloma (MM) patients, we retrospectively analyzed data on the first-line treatment for newly diagnosed transplant-ineligible MM patients from Kansai Myeloma Forum, a registry network in Japan. A total of 598 patients treated with novel drugs between March 2007 and February 2018 were analyzed. Regimens used were VD (n = 305), Rd (n = 103), VMP (n = 97), VCD (n = 71), and VRd (n = 22). Younger patients tended to receive VRd or VCD, whereas the regimen with the highest median patient age was Rd. More than three-quarters of patients in the Rd group received a reduced dose of lenalidomide. The Rd and VRd groups had a relatively high incidence of infection and skin complications, and the VMP group had the highest incidence of peripheral neuropathy. Overall response rate did not differ significantly between regimens. Multivariate analysis in all patients revealed several poor prognostic factors, such as poor performance status. Novel drug-containing regimens for newly diagnosed MM showed a durable response with manageable AEs in the real-world setting.

A retrospective analysis of clinical features and treatment outcome in 21 patients with immunoglobulin M-related light-chain amyloidosis in Japan: a study from the Amyloidosis Research Committee.

We retrospectively gathered data of 21 patients (13 male and 8 female; median age 65 years) diagnosed with immunoglobulin M (IgM)-related light-chain (AL) amyloidosis in Japan to investigate characteristics of IgM-AL amyloidosis and its optimal treatment strategy. Median IgM and difference free light chain (FLC) at diagnosis were 1257 mg/dl and 34.3 mg/l, respectively. Organ involvement was observed in the heart in 7 patients (33%), kidneys in 15 (71%), and lymph nodes in 5 (24%). Initial treatments were melphalan/dexamethasone in 7 patients, bortezomib/cyclophosphamide/dexamethasone in 3, autologous stem cell transplantation in 3, rituximab/bendamustine in 1, other in 3, and none in 4. Hematological responses among 15 evaluable patients were as follows: 3 reached complete response (CR), 4 partial response (PR), and 1 very good PR (VGPR), making the overall response rate of PR or better 40%. Median overall survival (OS) was 14.0 months and 1-year OS was 71.4%. Prognosis was significantly poorer in patients with cardiac involvement than those with non-cardiac involvement (1-year OS 27.8% vs. 85.7%, p = 0.0468). The involved FLC value was low in several patients and therapeutic response was difficult to assess. Further study is necessary to determine the optimal treatment for IgM-AL amyloidosis.

Efficacy of elotuzumab for multiple myeloma in reference to lymphocyte counts and kappa/lambda ratio or B2 microglobulin.

Novel therapeutic drugs have dramatically improved the overall survival of patients with multiple myeloma. We sought to identify the characteristics of patients likely to exhibit a durable response to one such drug, elotuzumab, by analyzing a real-world database in Japan. We analyzed 179 patients who underwent 201 elotuzumab treatments. The median time to next treatment (TTNT) with the 95% confidence interval was 6.29 months (5.18-9.20) in this cohort. Univariate analysis showed that patients with any of the following had longer TTNT: no high risk cytogenic abnormalities, more white blood cells, more lymphocytes, non-deviated κ/λ ratio, lower ß2 microglobulin levels (B2MG), fewer prior drug regimens, no prior daratumumab use and better response after elotuzumab treatment. A multivariate analysis showed that TTNT was longer in patients with more lymphocytes (≥ 1400/µL), non-deviated κ/λ ratio (0.1-10), lower B2MG (< 5.5 mg/L) and no prior daratumumab use. We proposed a simple scoring system to predict the durability of the elotuzumab treatment effect by classifying the patients into three categories based on their lymphocyte counts (0 points for ≥ 1400/µL and 1 point for < 1400/µL) and κ/λ ratio (0 points for 0.1-10 and 1 point for < 0.1 or ≥ 10) or B2MG (0 points for < 5.5 mg/L and 1 point for ≥ 5.5 mg/L). The patients with a score of 0 showed significantly longer TTNT (p < 0.001) and better survival (p < 0.001) compared to those with a score of 1 or 2. Prospective cohort studies of elotuzumab treatment may be needed to validate the usefulness of our new scoring system.

Daratumumab plus bortezomib, cyclophosphamide, and dexamethasone in Asian patients with newly diagnosed AL amyloidosis: subgroup analysis of ANDROMEDA.

Subcutaneous daratumumab plus bortezomib/cyclophosphamide/dexamethasone (VCd; D-VCd) improved outcomes versus VCd for patients with newly diagnosed immunoglobulin light-chain (AL) amyloidosis in the phase 3 ANDROMEDA study. We report a subgroup analysis of Asian patients (Japan; Korea; China) from ANDROMEDA. Among 388 randomized patients, 60 were Asian (D-VCd, n = 29; VCd, n = 31). At a median follow-up of 11.4 months, the overall hematologic complete response rate was higher for D-VCd versus VCd (58.6% vs. 9.7%; odds ratio, 13.2; 95% confidence interval [CI], 3.3-53.7; P < 0.0001). Six-month cardiac and renal response rates were higher with D-VCd versus VCd (cardiac, 46.7% vs. 4.8%; P = 0.0036; renal, 57.1% vs. 37.5%; P = 0.4684). Major organ deterioration progression-free survival (MOD-PFS) and major organ deterioration event-free survival (MOD-EFS) were improved with D-VCd versus VCd (MOD-PFS: hazard ratio [HR], 0.21; 95% CI, 0.06-0.75; P = 0.0079; MOD-EFS: HR, 0.16; 95% CI, 0.05-0.54; P = 0.0007). Twelve deaths occurred (D-VCd, n = 3; VCd, n = 9). Twenty-two patients had baseline serologies indicating prior hepatitis B virus (HBV) exposure; no patient experienced HBV reactivation. Although grade 3/4 cytopenia rates were higher than in the global safety population, the safety profile of D-VCd in Asian patients was generally consistent with the global study population, regardless of body weight. These results support D-VCd use in Asian patients with newly diagnosed AL amyloidosis. ClinicalTrials.gov Identifier: NCT03201965.

Anti-CD38 antibody isatuximab monotherapy for Japanese individuals with relapsed/refractory multiple myeloma: An update of the phase 1/2 ISLANDs study.

The primary analysis of the phase 1/2 ISLANDs study in Japanese individuals with relapsed/refractory multiple myeloma (RRMM) showed that isatuximab monotherapy was well tolerated and effective, even in participants with high-risk cytogenetic abnormalities. Here, we report a prespecified second analysis conducted 20 months after the first dosing of the last participant (ClinicalTrials.gov identifier: NCT02812706). The primary objectives were to evaluate the safety and tolerability of isatuximab in phase 1 and to evaluate the efficacy of isatuximab, including assessment of overall response rate (ORR) at the recommended dose (RD), in phase 2. In phase 1, three participants received isatuximab 10 mg/kg every week (QW) for 4 weeks/cycle followed by every 2 weeks (Q2W) and five participants received 20 mg/kg QW/Q2W. Since no dose-limiting toxicities occurred in phase 1, 20 mg/kg QW/Q2W was identified as the RD for the phase 2 study (n = 28). At the time of data cut-off, three participants (one in phase 1 and two in phase 2) continued to receive isatuximab; disease progression and treatment-related adverse events were the most common reasons for treatment discontinuation. The overall safety profile was consistent with the primary analysis. One death, not related to isatuximab treatment, was reported since the first analysis. The ORR and clinical benefit rate remained unchanged from the primary analysis at 36.4% (95% confidence interval [CI]: 20.4%-54.9%) and 54.5% (95% CI: 36.4%-71.9%), respectively. The median progression-free survival (PFS) was 5.6 months, longer than the median PFS reported in the primary analysis (4.7 months), whereas median overall survival was not reached. Overall, isatuximab 20 mg/kg QW/Q2W had an acceptable safety and tolerability profile and showed promising antitumor activity in Japanese individuals with RRMM.

Monocyte or white blood cell counts and ß2 microglobulin predict the durable efficacy of daratumumab with lenalidomide.

Background: Daratumumab is one of the most widely used treatments for relapsed/refractory multiple myeloma (MM) patients. However, not all patients achieve a lasting therapeutic response with daratumumab. Objectives: We hypothesized that a durable response to daratumumab could be predicted by the balance between the MM tumor burden and host immune status. Design: We conducted a retrospective study using the real-world data in the Kansai Myeloma Forum (KMF) database. Methods: We retrospectively analyzed 324 relapsed/refractory MM patients who were treated with daratumumab in the KMF database. Results: In this study, 196 patients were treated with daratumumab, lenalidomide, and dexamethasone (DLd) regimen and 128 patients were treated with daratumumab, bortezomib, and dexamethasone (DBd) regimen. The median age at treatment, number of prior treatment regimens and time-to-next-treatment (TTNT) were 68, 4 and 8.02 months, respectively. A multivariate analysis showed that the TTNT under the DLd regimen was longer with either higher monocyte counts (analysis 1), higher white blood cell (WBC) counts (analysis 2), lower ß2 microglobulin (B2MG < 5.5 mg/L) or fewer prior regimens (<4). No parameters were correlated with TTNT under the DBd regimen. Conclusion: We propose a simple scoring model to predict a durable effect of the DLd regimen by classifying patients into three categories based on either monocyte counts (0 points for ⩾200/µl; 1 point for <200/µl) or WBC counts (0 points for ⩾3500/µl; 1 point for <3500/µl) plus B2MG (0 points for <5.5 mg/L; 1 point for ⩾5.5 mg/L). Patients with a score of 0 showed significantly longer TTNT and significantly better survival compared to those with a score of 1 or 2 (both p < 0.001). To confirm this concept, our results will need to be validated in other cohorts.

Real-world effectiveness and safety analysis of carfilzomib-lenalidomide-dexamethasone and carfilzomib-dexamethasone in relapsed/refractory multiple myeloma: a multicenter retrospective analysis.

Background: Little is known about the real-world survival benefits and safety profiles of carfilzomib-lenalidomide-dexamethasone (KRd) and carfilzomib-dexamethasone (Kd). Methods: We performed a retrospective analysis to evaluate their efficacy and safety in 157 patients registered in the Kansai Myeloma Forum database. Results: A total of 107 patients received KRd. Before KRd, 99% of patients had received bortezomib (54% were refractory disease), and 82% had received lenalidomide (57% were refractory disease). The overall response rate (ORR) was 68.2%. The median progression-free survival (PFS) and overall survival (OS) were 8.8 and 29.3 months, respectively. Multivariate analysis showed that reduction of the carfilzomib dose and non-IgG M protein were significantly associated with lower PFS and reduction of the carfilzomib dose and refractoriness to prior bortezomib-based regimens were significantly associated with lower OS. A total of 50 patients received Kd. Before Kd, 96% of patients had received bortezomib (54% were refractory disease). The ORR was 62.0%. The median PFS and OS were 7.1 and 20.9 months, respectively. Based on the multivariate analysis, reduction of the carfilzomib dose and International Staging System Stage III (ISS III) were significantly associated with lower PFS. Grade III or higher adverse events were observed in 48% of KRd cases and 54% of Kd cases. Cardiovascular events, cytopenia, and infections were frequent, and 4 KRd patients died due to heart failure, arrhythmia, cerebral hemorrhage, and pneumonia. Conclusion: Our analysis showed that an adequate dose of carfilzomib is important for achieving the best survival benefits in a real-world setting. Adverse effects after KRd and Kd therapy should also be considered.

Isatuximab-Pomalidomide-Dexamethasone Versus Pomalidomide-Dexamethasone in East Asian Patients With Relapsed/Refractory Multiple Myeloma: ICARIA-MM Subgroup Analysis.

BACKGROUND: In the pivotal phase III, randomized, multicenter ICARIA-MM study (NCT02990338), isatuximab plus pomalidomide and dexamethasone (Isa-Pd) improved progression-free survival and overall response rate versus pomalidomide and dexamethasone (Pd) in the overall population of patients with relapsed/refractory multiple myeloma. PATIENTS AND METHODS: In this predefined subgroup analysis, efficacy, and safety between East Asian patients and the overall population were assessed. RESULTS: In total, 36 East Asian patients were included (Japanese, n = 13; Korean, n = 9; Taiwanese, n = 14). At a median follow-up of 11.6 months, median progression-free survival was not reached (95% confidence interval [CI] 5.80-not calculable) in the Isa-Pd arm and was 7.9 months (95% CI 2.90-not calculable) in the Pd arm. The hazard ratio for the between-group difference was 0.52 (95% CI 0.19-1.39), which was similar to the overall population (hazard ratio, 0.60; 95% CI 0.44-0.82). No new safety signals were observed, except that a higher proportion of patients in the East Asian population experienced Grade ≥ 3 neutropenia compared with the overall population. CONCLUSION: These results confirm the efficacy of Isa-Pd in East Asian patients with relapsed/refractory multiple myeloma, and the related safety data are consistent with those observed in the overall population and are manageable.

Pretreatment serum level of interleukin-6 predicts carfilzomib-induced hypertension in relapsed/refractory multiple myeloma.

Carfilzomib (CFZ) constitutes powerful combinatory therapy for relapsed/refractory multiple myeloma (RRMM); however, cardiovascular adverse events (CVAEs) have been shown as major treatment obstacles with the use of CFZ. Along with our multi-institutional prospective observational study by the Kyoto Clinical Hematology Study Group on the efficacy and safety of CFZ-based treatments (UMIN000025108), we here performed an ad hoc analysis of CFZ-related CVAEs in 50 patients with RRMM. We analyzed the association between CFZ-related CVAEs and pre-planned examinations, including patients' background, electrocardiographic findings, echocardiographic findings, and serum/plasma levels of 18 potential candidate biomarkers. The common CVAEs were hypertension (42%), arrhythmia (14%), and prolongation of QT corrected interval (10%), whereas no serious CVAEs occurred. The pretreatment serum level of interleukin-6 was identified as a significant risk factor for CFZ-related hypertension. This study revealed hypertension as the most frequent CFZ-related CVAE and suggested that baseline serum interleukin-6 is a useful predictor for CFZ-induced hypertension.

Clinical impacts of frailty, poor performance status, and advanced age in carfilzomib-containing treatment for relapsed/refractory multiple myeloma: post hoc investigation of the KOTOSG multicenter pilot prospective observational study.

We conducted a post hoc analysis of our previous pilot observational study on the efficacy and safety of carfilzomib (CFZ)-containing therapy in 50 patients with relapsed/refractory multiple myeloma in routine practice to clarify the relationships between three major criteria for vulnerability (frailty, poor performance status [PS], and advanced age [≥ 75 years]) and their clinical impact on efficacy and adverse events (AEs). Sixteen patients fulfilled at least one and five patients fulfilled all three criteria. The overall response rate was not significantly affected by frailty, poor PS, and/or advanced age; however, frailty and advanced age were significantly associated with shorter progression-free survival (PFS). In contrast, no significant difference in PFS was observed between patients with PS0-1 or PS2-4. The three criteria for vulnerability were associated with more frequent hematologic AEs: frailty, poor PS, and/or advanced age significantly increased the risk of grade 3-4 anemia and lymphopenia. However, these criteria were not associated with increased risk of other non-hematologic AEs except infection. Collectively, these results demonstrate the need to carefully manage severe hematologic AEs in vulnerable patients and perform disease-specific assessment of frailty to predict prognosis.

Prognostic impact of resistance to bortezomib and/or lenalidomide in carfilzomib-based therapies for relapsed/refractory multiple myeloma: The Kyoto Clinical Hematology Study Group, multicenter, pilot, prospective, observational study in Asian patients.

BACKGROUND: Combinatory strategies with carfilzomib (CFZ), a second-generation proteasome inhibitor, plus dexamethasone (DEX) with or without lenalidomide (LEN) have shown promising efficacy for patients with relapsed/refractory multiple myeloma (RRMM) in pivotal clinical trials. However, their effects on patients who were resistance to bortezomib (BTZ) and/or LEN have not been fully evaluated in a daily practice setting. AIMS: To evaluate the real-world efficacy and safety of CFZ-based treatments; that is, CFZ with LEN plus DEX (KRD therapy) and CFZ with DEX (KD therapy), in Asian patients, we conducted a multicenter pilot prospective observational study in the Kyoto Clinical Hematology Study Group. METHODS AND RESULTS: All 50 patients with RRMM enrolled in this study were treated with CFZ-based treatments between 2017 and 2019. KRD and KD were administered to 31 and 19 patients, respectively. The overall response rates (ORRs) were 80.6% with KRD and 73.7% with KD. Two-year progression-free survival (PFS) and overall survival (OS) were 58.5% and 79.7% with KRD, and 23.1% and 52.6% with KD. By multivariate analysis, refractoriness to BTZ and to LEN were identified as independent unfavorable factors for both PFS and OS. The common non-hematologic AEs included hypertension (42.0%), fever (24.0%), fatigue (24.0%), and infection (16.0%). No serious heart failure was observed. This study is registered as UMIN000025108. CONCLUSION: This study suggests the need of the development of novel CFZ-containing strategy which can overcome the refractoriness to BTZ and/or LEN, while both KRD and KD were shown to be mostly feasible in Asian patients in a daily practice setting.

Daratumumab-Based Treatment for Immunoglobulin Light-Chain Amyloidosis.

BACKGROUND: Systemic immunoglobulin light-chain (AL) amyloidosis is characterized by deposition of amyloid fibrils of light chains produced by clonal CD38+ plasma cells. Daratumumab, a human CD38-targeting antibody, may improve outcomes for this disease. METHODS: We randomly assigned patients with newly diagnosed AL amyloidosis to receive six cycles of bortezomib, cyclophosphamide, and dexamethasone either alone (control group) or with subcutaneous daratumumab followed by single-agent daratumumab every 4 weeks for up to 24 cycles (daratumumab group). The primary end point was a hematologic complete response. RESULTS: A total of 388 patients underwent randomization. The median follow-up was 11.4 months. The percentage of patients who had a hematologic complete response was significantly higher in the daratumumab group than in the control group (53.3% vs. 18.1%) (relative risk ratio, 2.9; 95% confidence interval [CI], 2.1 to 4.1; P<0.001). Survival free from major organ deterioration or hematologic progression favored the daratumumab group (hazard ratio for major organ deterioration, hematologic progression, or death, 0.58; 95% CI, 0.36 to 0.93; P = 0.02). At 6 months, more cardiac and renal responses occurred in the daratumumab group than in the control group (41.5% vs. 22.2% and 53.0% vs. 23.9%, respectively). The four most common grade 3 or 4 adverse events were lymphopenia (13.0% in the daratumumab group and 10.1% in the control group), pneumonia (7.8% and 4.3%, respectively), cardiac failure (6.2% and 4.8%), and diarrhea (5.7% and 3.7%). Systemic administration-related reactions to daratumumab occurred in 7.3% of the patients. A total of 56 patients died (27 in the daratumumab group and 29 in the control group), most due to amyloidosis-related cardiomyopathy. CONCLUSIONS: Among patients with newly diagnosed AL amyloidosis, the addition of daratumumab to bortezomib, cyclophosphamide, and dexamethasone was associated with higher frequencies of hematologic complete response and survival free from major organ deterioration or hematologic progression. (Funded by Janssen Research and Development; ANDROMEDA ClinicalTrials.gov number, NCT03201965.).

Plateau is a prognostic factor of lenalidomide therapy for previously treated multiple myeloma.

The plateau phase emerging during the treatment of multiple myeloma (MM) is known to last steadily for a certain period, even without treatment. Therefore, the treatment started at plateau phase is expected to be associated with a better outcome. In this study, this hypothesis was evaluated retrospectively for previously treated MM patients in Kansai Myeloma Forum database who received lenalidomide (LEN) with or without dexamethasone for the first time. Disease stability index (DSI) was defined as (maximum - minimum values of M protein during the 90 days before the start of LEN) divided by M-protein values at the start of LEN. The patients were classified into three groups: stable (S), DSI ≤ 0.25; increasing (I), DSI > 0.25 with increasing M protein; decreasing (D), DSI > 0.25 with decreasing M protein. In univariate analysis of 352 patients, DSI group "I", non-IgG type, serum albumin<3.5 g/dL, and age≥70 were statistically significant prognostic factors for both progression-free survival and overall survival. In multivariate analysis, the former 3 risk factors were statistically significant for poor overall survival. Thus, DSI is an independent prognostic factor for the treatment with LEN for previously treated MM.

Outcomes of ixazomib/lenalidomide/dexamethasone for multiple myeloma: A multicenter retrospective analysis.

OBJECTIVES: This study aimed to investigate real-world data of ixazomib plus lenalidomide and dexamethasone (IRd) therapy for patients with relapsed and refractory multiple myeloma (RRMM). METHODS: We retrospectively analyzed 122 patients treated with IRd at 16 centers from May 2017 to January 2019 by using the Kansai Myeloma Forum database. RESULT: At the start of IRd, the median age was 72 years, 66.7% of patients had IgG type, and the median number of prior therapies was 4, comprising bortezomib (85.4%) and lenalidomide (89.3%)-based regimens. Disease progression and adverse events accounted for treatment discontinuation in 46 and 32 patients, respectively. The median overall survival (OS) was not reached, and the median progression-free survival (PFS) was 11.9 months. Sensitivity to bortezomib did not affect the PFS, whereas lenalidomide-refractory patients had significantly lower PFS than lenalidomide-sensitive patients, who were comparable to TOURMALINE-MM1 study. The patients with IgG type had significantly better PFS and OS than those with non-IgG type. CONCLUSION: This study presents the largest real-world data of patients treated with IRd in Asia. However, in real clinical practice, the patient background is different from the TOURMALINE-MM1 study, and IRd showed poor efficacy, especially in the non-IgG type and lenalidomide-refractory patients with RRMM.

Significance of maintenance therapy after HDT/ASCT in symptomatic multiple myeloma: A multicenter retrospective analysis in Kansai Myeloma Forum.

A total of 129 symptomatic patients with multiple myeloma (MM) who underwent high-dose chemotherapy with autologous stem cell transplantation (HDT/ASCT) were analyzed. The 4-year overall survival (OS) of patients with maintenance (n = 82) was 80%, whereas that of patients without maintenance (n = 47) was 72% (p = 0.426). The 4-year progression-free survival (PFS) of patients with maintenance was 38%, whereas that of patients without maintenance was 27% (p = 0.088). Multivariate analysis revealed that an International Staging System score ≥2 was associated with worse PFS (hazard ratio 1.62, p = 0.043). Among the 129 patients, two were excluded owing to early relapse, 50 patients achieved complete response (CR), and 77 patients failed to achieve CR. Patients who achieved CR showed better 4-year PFS than those who failed to achieve CR (41% vs. 30%, p = 0.027); however, 4-year OS was not different (76% vs. 82%, p = 0.971). In patients who achieved CR, 4-year OS with/without maintenance was 74%/81% (p = 0.357), 4-year PFS with/without maintenance was 42%/40% (p = 0.954). In patients who failed to achieve CR, the 4-year OS with/without maintenance was 97%/91% (p = 0.107), and 4-year PFS with/without maintenance was 36%/16% (p < 0.001). In patients who failed to achieve CR, maintenance significantly improved the PFS. Maintenance after HDT/ASCT can prolong PFS in patients who fail to achieve CR in real-world settings.

Isatuximab monotherapy in relapsed/refractory multiple myeloma: A Japanese, multicenter, phase 1/2, safety and efficacy study.

Isatuximab, an anti-CD38 monoclonal antibody, targets cells that strongly express CD38 including malignant plasma cells. This open-label, single-arm, multicenter, phase 1/2 trial investigated the tolerability/safety and efficacy of isatuximab monotherapy in Japanese patients with heavily pretreated, relapsed/refractory multiple myeloma (RRMM). In Phase 1, patients were sequentially assigned to receive isatuximab once weekly (QW) in cycle 1 (4 weeks) and every 2 weeks (Q2W) in subsequent cycles. Cohort 1 (n = 3) received 10 mg/kg QW/Q2W; cohort 2 (n = 5) received 20 mg/kg QW/Q2W. No dose-limiting toxicities occurred; the recommended dose for the single-arm phase 2 study (n = 28) was 20 mg/kg QW/Q2W. The overall safety profile was consistent with the current knowledge of isatuximab. The most common adverse events were infusion reactions (42.9%; 12/28); all were grade 1/2 and generally occurred during the first infusion. The overall response rate with 20 mg/kg QW/Q2W isatuximab was 36.4% (12/33); patients with high-risk cytogenetic abnormalities had comparable results. In phase 2, the median progression-free survival was 4.7 (95% confidence interval, 3.75 to not reached) months. Median overall survival was not reached. Isatuximab monotherapy was well tolerated and effective in patients with heavily pretreated RRMM including high-risk cytogenetic patients. This trial is registered at ClinicalTrials.gov as NCT02812706.