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.

Purpose Lenalidomide maintenance therapy after autologous stem-cell transplantation (ASCT) demonstrated prolonged progression-free survival (PFS) versus placebo or observation in several randomized controlled trials (RCTs) of patients with newly diagnosed multiple myeloma (NDMM). All studies had PFS as the primary end point, and none were powered for overall survival (OS) as a primary end point. Thus, a meta-analysis was conducted to better understand the impact of lenalidomide maintenance in this setting. Patients and Methods The meta-analysis was conducted using primary-source patient-level data and documentation from three RCTs (Cancer and Leukemia Group B 100104, Gruppo Italiano Malattie Ematologiche dell'Adulto RV-MM-PI-209, and Intergroupe Francophone du Myélome 2005-02) that met the following prespecified inclusion criteria: an RCT in patients with NDMM receiving ASCT followed by lenalidomide maintenance versus placebo or observation with patient-level data available and achieved database lock for primary efficacy analysis. Results Overall, 1,208 patients were included in the meta-analysis (605 patients in the lenalidomide maintenance group and 603 in the placebo or observation group). The median PFS was 52.8 months for the lenalidomide group and 23.5 months for the placebo or observation group (hazard ratio, 0.48; 95% CI, 0.41 to 0.55). At a median follow-up time of 79.5 months for all surviving patients, the median OS had not been reached for the lenalidomide maintenance group, whereas it was 86.0 months for the placebo or observation group (hazard ratio, 0.75; 95% CI, 0.63 to 0.90; P = .001). The cumulative incidence rate of a second primary malignancy before disease progression was higher with lenalidomide maintenance versus placebo or observation, whereas the cumulative incidence rates of progression, death, or death as a result of myeloma were all higher with placebo or observation versus lenalidomide maintenance. Conclusion This meta-analysis demonstrates a significant OS benefit and confirms the PFS benefit with lenalidomide maintenance after ASCT in patients with NDMM when compared with placebo or observation.

Over the last two decades, the outcomes for patients with multiple myeloma, a plasma cell malignancy, have dramatically improved. The development of the immunomodulatory drugs (IMiDs) which include thalidomide, lenalidomide, and pomalidomide, has contributed significantly to these improved outcomes. While thalidomide is now less commonly prescribed, lenalidomide is widely used in the treatment of newly diagnosed transplant-eligible and transplant-ineligible patients, in the maintenance setting post-transplant and in the relapsed/refractory setting, while pomalidomide is currently utilized in the relapsed/refractory setting. The IMiDs have been reported to have a multitude of activities, including anti-angiogenic, cytotoxic, and immunomodulatory, however, the more recent discoveries that the IMiDs bind to cereblon and thus regulate the ubiquitination of key transcription factors including IKZF1 and IKZF3, have provided greater insight into their mechanism of action. Here the clinical efficacy of these agents in myeloma is reviewed as well as discussion of structure-function relationship, the molecular mechanisms of action, and the association of IMiDs with second primary malignancies and thrombosis.

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