Maintenance with daratumumab or observation following treatment with bortezomib, thalidomide, and dexamethasone with or without daratumumab and autologous stem-cell transplant in patients with newly diagnosed multiple myeloma (CASSIOPEIA): an open-label, randomised, phase 3 trial.

BACKGROUND

CASSIOPEIA part 1 showed superior depth of response and significantly improved progression-free survival with daratumumab, bortezomib, thalidomide, and dexamethasone (D-VTd) versus bortezomib, thalidomide, and dexamethasone (VTd) as induction and consolidation in patients with autologous stem-cell transplant (ASCT)-eligible newly diagnosed multiple myeloma. In part 2, we compared daratumumab maintenance versus observation only.

METHODS

CASSIOPEIA is a two-part, open-label, randomised, phase 3 trial of patients aged 18-65 years with newly diagnosed multiple myeloma and Eastern Cooperative Oncology Group performance status 0-2, done in 111 European academic and community practice centres. In part 1, patients were randomly assigned (1:1) to induction and consolidation with D-VTd or VTd. Patients still on study who had a partial response or better were randomly assigned (1:1) by an interactive web-response system to daratumumab 16 mg/kg intravenously every 8 weeks (a reduced frequency compared with standard daratumumab long-term dosing) or observation only for up to 2 years. Stratification factors were induction treatment and depth of response in part 1. The part 2 primary endpoint was progression-free survival from second randomisation. This preplanned interim analysis of progression-free survival was done after 281 events and shall be considered the primary analysis of progression-free survival. Sponsor personnel and designees who were involved in the analysis were masked to treatment group until the independent data monitoring committee recommended that the preplanned interim analysis be considered the main analysis of progression-free survival in part 2. Otherwise, treatment assignments were unmasked. The interaction between induction and consolidation and maintenance was tested at a two-sided significance level of 0·05 by a stratified Cox regression model that included the interaction term between maintenance treatment and induction and consolidation treatment. Efficacy analyses were done in the maintenance-specific intention-to-treat population, which comprised all patients who underwent second randomisation. Safety was analysed in all patients in the daratumumab group who received at least one dose and all patients randomly assigned to observation only. This trial is registered with ClinicalTrials.gov, NCT02541383. Long-term follow-up is ongoing and the trial is closed to new participants.

FINDINGS

Between May 30, 2016, and June 18, 2018, 886 patients (458 [84%] of 543 in the D-VTd group and 428 [79%] of 542 in the VTd group) were randomly assigned to daratumumab maintenance (n=442) or observation only (n=444). At a median follow-up of 35·4 months (IQR 30·2-39·9) from second randomisation, median progression-free survival was not reached (95% CI not evaluable [NE]-NE) with daratumumab versus 46·7 months (40·0-NE) with observation only (hazard ratio 0·53, 95% CI 0·42-0·68, p<0·0001). A prespecified analysis of progression-free survival results showed a significant interaction between maintenance and induction and consolidation therapy (p<0·0001). The most common grade 3 or 4 adverse events were lymphopenia (16 [4%] of 440 patients in the daratumumab group vs eight [2%] of 444 patients in the observation-only group), hypertension (13 [3%] vs seven [2%]), and neutropenia (nine [2%] vs ten [2%]). Serious adverse events occurred in 100 (23%) patients in the daratumumab group and 84 (19%) patients in the observation-only group. In the daratumumab group, two adverse events led to death (septic shock and natural killer-cell lymphoblastic lymphoma); both were related to treatment.

INTERPRETATION

Daratumumab maintenance every 8 weeks for 2 years significantly reduced the risk of disease progression or death compared with observation only. Longer follow-up and other ongoing studies will shed further light on the optimal daratumumab-containing post-ASCT maintenance treatment strategy.

FUNDING

Janssen Research & Development, the Intergroupe Francophone du Myélome, and the Dutch-Belgian Cooperative Trial Group for Hematology Oncology.

Informations de copyright

Copyright © 2021 Elsevier Ltd. All rights reserved.

Déclaration de conflit d'intérêts

Declaration of interests PM reports personal fees from Celgene, Amgen, Takeda, Janssen, and AbbVie, outside the submitted work. CH reports personal fees from Janssen, AbbVie, Amgen, and Celgene, outside the submitted work. AP reports personal fees from Celgene, Amgen, Janssen, Sanofi, and Takeda, outside the submitted work. BA reports grants from Amgen, Celgene, Sanofi, and Janssen, during the conduct of the study; personal fees from Amgen, Celgene/Bristol Myers Squibb, Sanofi, GlaxoSmithKline, Takeda, and Janssen, outside the submitted work; and advisory board participation from Amgen, Celgene/Bristol Myers Squibb, Sanofi, GlaxoSmithKline, and Janssen, outside the submitted work. KB reports grants from Celgene outside the submitted work; personal fees from Celgene, Janssen, Takeda, and Amgen, outside the submitted work; and non-financial support from Celgene, AbbVie, and Takeda, outside the submitted work. SZ reports grants from Celgene, Janssen, and Takeda, during the conduct of the study. MD reports grants from Celgene and Janssen during the conduct of the study; participation on an advisory board for Celgene, Takeda, Janssen, Sanofi, and Oncopeptides, outside the submitted work. TD reports grants from Celgene and Janssen, during the conduct of the study; and personal fees and advisory board participation from Celgene, Takeda, Janssen, and Amgen, outside of the submitted work. CD reports personal fees from Janssen, outside the submitted work. TF reports personal fees from Janssen, Bristol Myers Squibb, Takeda, Amgen, Roche, Karyopharm, Sanofi, and Oncopeptides, outside the submitted work. CS reports personal fees from Celgene, outside the submitted work. MMo reports grants from Stemline, BMS, Amgen, Jazz Pharmaceuticals, Novartis, Takeda, Janssen, GSK, Sanofi, and Celgene; non-financial support from Stemline, BMS, Amgen, Jazz Pharmaceuticals, Novartis, Takeda, Janssen, GSK, Sanofi, and Celgene; and personal fees from Stemline, BMS, Amgen, Jazz Pharmaceuticals, Novartis, Takeda, Janssen, GSK, Sanofi, and Celgene, outside the submitted work. LK reports personal fees from Amgen, Janssen, Celgene, Takeda, and AbbVie, outside the submitted work. XL reports personal fees from Janssen, outside the submitted work. MMa reports personal fees from and advisory board participation for Amgen, Celgene, Janssen, and Takeda, outside the submitted work. A-MS reports personal fees from Celgene outside the submitted work. NWCJvdD reports grants from Amgen, Bristol Myers Squibb, Celgene, Janssen, and Novartis, during the conduct of the study; and personal fees from Amgen, Bristol Myers Squibb, Celgene, Janssen, Novartis, Bayer, Roche, Servier, and Takeda, outside the submitted work. AB reports personal fees from Amgen, Celgene, Janssen, and Bristol Myers Squibb, outside the submitted work. CT reports personal fees from Janssen, outside the submitter work. MR reports grants from Janssen, during the conduct of the study; personal fees and travel support from Celgene, Amgen, Sanofi, Takeda, and Janssen, outside the submitted work. M-DL reports grants from AbbVie, Amgen, Janssen, Roche, and Takeda, during the conduct of the study; and personal fees and advisory board participation from AbbVie, Janssen, Roche, and Takeda, outside the submitted work. TA reports employment and equity ownership from Genmab. MK reports employment with Janssen. KZ reports employment with Janssen. CdB reports employment and equity ownership from Janssen. SV reports employment with Janssen. TK reports employment with Janssen. VV reports employment with Janssen. JV reports employment with Janssen. HA-L reports grants from Celgene and Janssen, during the conduct of the study; and personal fees from Celgene, Amgen, Bristol-Myers Squibb, Sanofi, and Janssen, outside the submitted work. PS reports personal fees from Celgene and Janssen, outside the submitted work. All other authors declare no competing interests.