Combinations of bortezomib (V) and dexamethasone (D) with either lenalidomide (R) or cyclophosphamide (C) have shown significant efficacy. This randomized phase 2 trial evaluated VDC, VDR, and VDCR in previously untreated multiple myeloma (MM). Patients received V 1.3 mg/m² (days 1, 4, 8, 11) and D 40 mg (days 1, 8, 15), with either C 500 mg/m² (days 1, 8) and R 15 mg (days 1-14; VDCR), R 25 mg (days 1-14; VDR), C 500 mg/m² (days 1, 8; VDC) or C 500 mg/m² (days 1, 8, 15; VDC-mod) in 3-week cycles (maximum 8 cycles), followed by maintenance with V 1.3 mg/m² (days 1, 8, 15, 22) for four 6-week cycles (all arms) ≥ very good partial response was seen in 58%, 51%, 41%, and 53% (complete response rate of 25%, 24%, 22%, and 47%) of patients (VDCR, VDR, VCD, and VCD-mod, respectively); the corresponding 1-year progression-free survival was 86%, 83%, 93%, and 100%, respectively. Common adverse events included hematologic toxicities, peripheral neuropathy, fatigue, and gastrointestinal disturbances. All regimens were highly active and well tolerated in previously untreated MM, and, based on this trial, VDR and VCD-mod are preferred for clinical practice and further comparative testing. No substantial advantage was noted with VDCR over the 3-drug combinations. This trial is registered at www.clinicaltrials.gov (NCT00507442).

PURPOSE: The MASTER trial combined daratumumab, carfilzomib, lenalidomide, and dexamethasone (Dara-KRd) in newly diagnosed multiple myeloma (NDMM), using minimal residual disease (MRD) by next-generation sequencing (NGS) to inform the use and duration of Dara-KRd post-autologous hematopoietic cell transplantation (AHCT) and treatment cessation in patients with two consecutive MRD-negative assessments. METHODS: This multicenter, single-arm, phase II trial enrolled patients with NDMM with planed enrichment for high-risk cytogenetic abnormalities (HRCAs). Patients received Dara-KRd induction, AHCT, and Dara-KRd consolidation, according to MRD status. MRD was evaluated by NGS at the end of induction, post-AHCT, and every four cycles (maximum of eight cycles) of consolidation. Primary end point was achievement of MRD negativity (< 10^–5). Patients with two consecutive MRD-negative assessments entered treatment-free MRD surveillance. RESULTS: Among 123 participants, 43% had none, 37% had 1, and 20% had 2+ HRCA. Median age was 60 years (range, 36-79 years), and 96% had MRD trackable by NGS. Median follow-up was 25.1 months. Overall, 80% of patients reached MRD negativity (78%, 82%, and 79% for patients with 0, 1, and 2+ HRCA, respectively), 66% reached MRD < 10^–6, and 71% reached two consecutive MRD-negative assessments during therapy, entering treatment-free surveillance. Two-year progression-free survival was 87% (91%, 97%, and 58% for patients with 0, 1, and 2+ HRCA, respectively). Cumulative incidence of MRD resurgence or progression 12 months after cessation of therapy was 4%, 0%, and 27% for patients with 0, 1, or 2+ HRCA, respectively. Most common serious adverse events were pneumonia (6%) and venous thromboembolism (3%). CONCLUSION: Dara-KRd, AHCT, and MRD response-adapted consolidation leads to high rate of MRD negativity in NDMM. For patients with 0 or 1 HRCA, this strategy creates the opportunity of MRD surveillance as an alternative to indefinite maintenance.

The tumor suppressor p53, encoded by the TP53 gene, is recognized as the guardian of the human genome because it regulates many downstream genes to exercise its function in cell cycle and cell death. Recent studies have revealed that several microRNAs (miRNAs) are important components of the p53 tumor suppressor network with miR-125b and miR-504 directly targeting TP53. In this study, we use a screening method to identify that two miRNAs (miR-25 and miR-30d) directly target the 3′UTR of TP53 to downregulate p53 protein levels and reduce the expression of genes that are transcriptionally activated by p53. Correspondingly, both miR-25 and miR-30d adversely affect apoptotic cell death, cell cycle arrest and cellular senescence. Inhibition of either miR-25 or miR-30d expression increases endogenous p53 expression and elevates cellular apoptosis in several cell lines, including one from multiple myeloma that has little TP53 mutations. Thus, beyond miR-125b and miR-504, the human TP53 gene is negatively regulated by two more miRNAs: miR-25 and miR-30d.

Key Points: Dinaciclib is a novel cdk inhibitor that demonstrates single agent activity in myeloma. Dinaciclib has a safety profile that is easily manageable.

Macrophage inflammatory protein–1α (MIP-1α) gene expression is abnormally regulated in multiple myeloma (MM) owing to imbalanced expression of the acute myeloid leukemia–1A (AML-1A) and AML-1B transcription factors. We hypothesized that the increased expression ratios of AML-1A to AML-1B also induced abnormal expression of other hematopoietic and bone-specific genes that contribute to the poor prognosis of MM patients with high levels of MIP-1α. We found that interleukin-3 (IL-3) was also induced by the imbalanced AML-1A and AML-1B expression in myeloma. IL-3 mRNA levels were increased in CD138⁺ purified myeloma cells with increased AML-1A–to–AML-1B expression from MM patients, and IL-3 protein levels were significantly increased in freshly isolated bone marrow plasma from MM patients (66.4 ± 12 versus 22.1 ± 8.2 pg/mL; P = .038). IL-3 in combination with MIP-1α or receptor activator of nuclear factor–kappa B ligand (RANKL) significantly enhanced human osteoclast (OCL) formation and bone resorption compared with MIP-1α or RANKL alone. IL-3 stimulated the growth of interleukin-6 (IL-6)–dependent and IL-6–independent myeloma cells in the absence of IL-6, even though IL-3 did not induce IL-6 expression by myeloma cells. These data suggest that increased IL-3 levels in the bone marrow microenvironment of MM patients with imbalanced AML-1A and AML-1B expression can increase bone destruction and tumor cell growth.