This open-label, randomized, phase 3 study compared melphalan at a dose of 200 mg per square meter of body-surface area plus autologous stem-cell transplantation with melphalan–prednisone–lenalidomide (MPR) and compared lenalidomide maintenance therapy with no maintenance therapy in patients with newly diagnosed multiple myeloma. We randomly assigned 273 patients 65 years of age or younger to high-dose melphalan plus stem-cell transplantation or MPR consolidation therapy after induction, and 251 patients to lenalidomide maintenance therapy or no maintenance therapy. The primary end point was progression-free survival. The median follow-up period was 51.2 months. Both progression-free and overall survival were significantly longer with high-dose melphalan plus stem-cell transplantation than with MPR (median progression-free survival, 43.0 months vs. 22.4 months; hazard ratio for progression or death, 0.44; 95% confidence interval [CI], 0.32 to 0.61; P<0.001; and 4-year overall survival, 81.6% vs. 65.3%; hazard ratio for death, 0.55; 95% CI, 0.32 to 0.93; P=0.02). Median progression-free survival was significantly longer with lenalidomide maintenance than with no maintenance (41.9 months vs. 21.6 months; hazard ratio for progression or death, 0.47; 95% CI, 0.33 to 0.65; P<0.001), but 3-year overall survival was not significantly prolonged (88.0% vs. 79.2%; hazard ratio for death, 0.64; 95% CI, 0.36 to 1.15; P=0.14). Grade 3 or 4 neutropenia was significantly more frequent with high-dose melphalan than with MPR (94.3% vs. 51.5%), as were gastrointestinal adverse events (18.4% vs. 0%) and infections (16.3% vs. 0.8%); neutropenia and dermatologic toxic effects were more frequent with lenalidomide maintenance than with no maintenance (23.3% vs. 0% and 4.3% vs. 0%, respectively). Consolidation therapy with high-dose melphalan plus stem-cell transplantation, as compared with MPR, significantly prolonged progression-free and overall survival among patients with multiple myeloma who were 65 years of age or younger. Lenalidomide maintenance, as compared with no maintenance, significantly prolonged progression-free survival. (Funded by Celgene; ClinicalTrials.gov number, NCT00551928.)

Hematological toxicity is the most common adverse event after chimeric antigen receptor (CAR) T-cell therapy. Cytopenias can be profound and long-lasting and can predispose for severe infectious complications. In a recent worldwide survey, we demonstrated that there remains considerable heterogeneity in regard to current practice patterns. Here, we sought to build consensus on the grading and management of immune effector cell–associated hematotoxicity (ICAHT) after CAR T-cell therapy. For this purpose, a joint effort between the European Society for Blood and Marrow Transplantation (EBMT) and the European Hematology Association (EHA) involved an international panel of 36 CAR T-cell experts who met in a series of virtual conferences, culminating in a 2-day meeting in Lille, France. On the basis of these deliberations, best practice recommendations were developed. For the grading of ICAHT, a classification system based on depth and duration of neutropenia was developed for early (day 0-30) and late (after day +30) cytopenia. Detailed recommendations on risk factors, available preinfusion scoring systems (eg, CAR-HEMATOTOX score), and diagnostic workup are provided. A further section focuses on identifying hemophagocytosis in the context of severe hematotoxicity. Finally, we review current evidence and provide consensus recommendations for the management of ICAHT, including growth factor support, anti-infectious prophylaxis, transfusions, autologous hematopoietic stem cell boost, and allogeneic hematopoietic cell transplantation. In conclusion, we propose ICAHT as a novel toxicity category after immune effector cell therapy, provide a framework for its grading, review literature on risk factors, and outline expert recommendations for the diagnostic workup and short- and long-term management.

From 2002 to 2007, 103 patients with primary myelofibrosis or postessential thrombocythemia and polycythemia vera myelofibrosis and a median age of 55 years (range, 32-68 years) were included in a prospective multicenter phase 2 trial to determine efficacy of a busulfan (10 mg/kg)/fludarabine (180 mg/m²)–based reduced-intensity conditioning regimen followed by allogeneic stem cell transplantation from related (n = 33) or unrelated donors (n = 70). All but 2 patients (2%) showed leukocyte and platelet engraftment after a median of 18 and 22 days, respectively. Acute graft-versus-host disease grade 2 to 4 occurred in 27% and chronic graft-versus-host disease in 43% of the patients. Cumulative incidence of nonrelapse mortality at 1 year was 16% (95% confidence interval, 9%-23%) and significantly lower for patients with a completely matched donor (12% vs 38%; P = .003). The cumulative incidence of relapse at 3 years was 22% (95% confidence interval, 13%-31%) and was influenced by Lille risk profile (low, 14%; intermediate, 22%; and high, 34%; P = .02). The estimated 5-year event-free and overall survival was 51% and 67%, respectively. In a multivariate analysis, age older than 55 years (hazard ratio = 2.70; P = .02) and human leukocyte antigen–mismatched donor (hazard ratio = 3.04; P = .006) remained significant factors for survival. The study was registered at www.clinicaltrials.gov as #NCT 00599547.