No abstract

Lenalidomide, bortezomib, and dexamethasone (RVd) followed by autologous stem cell transplantation (ASCT) is standard frontline therapy for transplant-eligible patients with newly diagnosed multiple myeloma (NDMM). This study evaluated addition of daratumumab (D) to RVd in ASCT-eligible NDMM patients. Patients (N=207) were randomized 1:1 to receive RVd ±D induction (4 cycles), ASCT, RVd ±D consolidation (2 cycles), and lenalidomide ±D maintenance (26 cycles). At the primary endpoint analysis, the stringent complete response (sCR) rate by the end of post-ASCT consolidation favored D-RVd over RVd (42.4% vs 32.0%; odds ratio, 1.57; 95% confidence interval [CI], 0.87-2.82; 1-sided P=0.068) and met the prespecified 1-sided alpha of 0.10. With longer follow-up (median, 22.1 months), responses continued to deepen; rates of sCR improved for D-RVd versus RVd (62.6% vs 45.4%; P=0.0177), as did rates of minimal residual disease negativity (10−5 threshold) in the intent-to-treat population (51.0% vs 20.4%; P<0.0001). Four (3.8%) and 7 (6.8%) patients in the D-RVd and RVd groups progressed, respectively, and 24-month progression-free survival rates were 95.8% (D-RVd) and 89.8% (RVd). Grade 3/4 hematologic adverse events were more common with D-RVd. More infections occurred with D-RVd, but rates of grade 3/4 infections were similar. Median CD34+ cell yield was 8.2´106/kg for D-RVd and 9.4´106/kg for RVd, although plerixafor use was more common in the D-RVd arm. There was no difference in median times to neutrophil or platelet engraftment. In summary, daratumumab with RVd induction and consolidation improved depth of response in patients with transplant-eligible NDMM, with no new safety concerns. Clinicaltrials.gov NCT02874742.

BACKGROUND Poor engraftment due to low cell doses restricts the usefulness of umbilical-cord-blood transplantation. We hypothesized that engraftment would be improved by transplanting cord blood that was expanded ex vivo with mesenchymal stromal cells. METHODS We studied engraftment results in 31 adults with hematologic cancers who received transplants of 2 cord-blood units, 1 of which contained cord blood that was expanded ex vivo in cocultures with allogeneic mesenchymal stromal cells. The results in these patients were compared with those in 80 historical controls who received 2 units of unmanipulated cord blood. RESULTS Coculture with mesenchymal stromal cells led to an expansion of total nucleated cells by a median factor of 12.2 and of CD34+ cells by a median factor of 30.1. With transplantation of 1 unit each of expanded and unmanipulated cord blood, patients received a median of 8.34×107 total nucleated cells per kilogram of body weight and 1.81×106 CD34+ cells per kilogram — doses higher than in our previous transplantations of 2 units of unmanipulated cord blood. In patients in whom engraftment occurred, the median time to neutrophil engraftment was 15 days in the recipients of expanded cord blood, as compared with 24 days in controls who received unmanipulated cord blood only (P<0.001); the median time to platelet engraftment was 42 days and 49 days, respectively (P = 0.03). On day 26, the cumulative incidence of neutrophil engraftment was 88% with expansion versus 53% without expansion (P<0.001); on day 60, the cumulative incidence of platelet engraftment was 71% and 31%, respectively (P<0.001). CONCLUSIONS Transplantation of cord-blood cells expanded with mesenchymal stromal cells appeared to be safe and effective. Expanded cord blood in combination with unmanipulated cord blood significantly improved engraftment, as compared with unmanipulated cord blood only. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00498316.)

Despite considerable advances in the treatment of multiple myeloma (MM) in the last decade, a substantial proportion of patients do not respond to current therapies or have a short duration of response. Furthermore, these treatments can have notable morbidity and are not uniformly tolerated in all patients. As there is no cure for MM, patients eventually become resistant to therapies, leading to development of relapsed/refractory MM. Therefore, an unmet need exists for MM treatments with novel mechanisms of action that can provide durable responses, evade resistance to prior therapies, and/or are better tolerated. B-cell maturation antigen (BCMA) is preferentially expressed by mature B lymphocytes, and its overexpression and activation are associated with MM in preclinical models and humans, supporting its potential utility as a therapeutic target for MM. Moreover, the use of BCMA as a biomarker for MM is supported by its prognostic value, correlation with clinical status, and its ability to be used in traditionally difficult-to-monitor patient populations. Here, we review three common treatment modalities used to target BCMA in the treatment of MM: bispecific antibody constructs, antibody-drug conjugates, and chimeric antigen receptor (CAR)-modified T-cell therapy. We provide an overview of preliminary clinical data from trials using these therapies, including the BiTE® (bispecific T-cell engager) immuno-oncology therapy AMG 420, the antibody-drug conjugate GSK2857916, and several CAR T-cell therapeutic agents including bb2121, NIH CAR-BCMA, and LCAR-B38M. Notable antimyeloma activity and high minimal residual disease negativity rates have been observed with several of these treatments. These clinical data outline the potential for BCMA-targeted therapies to improve the treatment landscape for MM. Importantly, clinical results to date suggest that these therapies may hold promise for deep and durable responses and support further investigation in earlier lines of treatment, including newly diagnosed MM.