The introduction of novel agents has led to major improvements in clinical outcomes for patients with multiple myeloma. In order to shorten evaluation times for new treatments, health agencies are currently examining minimal residual disease (MRD) as a surrogate endpoint in clinical trials. We assessed the prognostic value of MRD, measured during maintenance therapy by next-generation sequencing. MRD negativity was defined as the absence of tumor plasma cell within 1,000,000 bone marrow cells (<10^-6). Data were analyzed from a recent clinical trial that evaluated the role of transplantation in newly diagnosed myeloma patients treated with lenalidomide, bortezomib, and dexamethasone (RVD). MRD negativity was achieved at least once during maintenance in 127 patients (25%). At the start of maintenance therapy, MRD was a strong prognostic factor for both progression-free survival (adjusted hazard ratio, 0.22; 95% confidence interval, 0.15 to 0.34; P<0.001) and overall survival (adjusted hazard ratio, 0.24; 95%confidence interval, 0.11 to 0.54; P=0.001). Patients who were MRD negative had a higher probability of prolonged progression-free survival than patients with detectable residual disease, regardless of treatment group (RVD versus transplant), cytogenetic risk profile or international staging system disease stage at diagnosis. These results were similar after completion of maintenance therapy. Our findings confirm the value of MRD status, as determined by next-generation sequencing, as a prognostic biomarker in multiple myeloma, and suggest that this approach could be used to adapt treatment strategies in future clinical trials. Key points MRD using NGS identified patients with an excellent outcome in multiple myeloma. MRD should be assessed in every prospective trial, and is a candidate to become a primary endpoint.

Despite treatment advances, patients with multiple myeloma (MM) often progress through standard drug classes including proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), and anti-CD38 monoclonal antibodies (mAbs). LocoMMotion (ClinicalTrials.gov identifier: NCT04035226) is the first prospective study of real-life standard of care (SOC) in triple-class exposed (received at least a PI, IMiD, and anti-CD38 mAb) patients with relapsed/refractory MM (RRMM). Patients (N = 248; ECOG performance status of 0–1, ≥3 prior lines of therapy or double refractory to a PI and IMiD) were treated with median 4.0 (range, 1–20) cycles of SOC therapy. Overall response rate was 29.8% (95% CI: 24.2–36.0). Median progression-free survival (PFS) and median overall survival (OS) were 4.6 (95% CI: 3.9–5.6) and 12.4 months (95% CI: 10.3–NE). Treatment-emergent adverse events (TEAEs) were reported in 83.5% of patients (52.8% grade 3/4). Altogether, 107 deaths occurred, due to progressive disease (n = 74), TEAEs (n = 19), and other reasons (n = 14). The 92 varied regimens utilized demonstrate a lack of clear SOC for heavily pretreated, triple-class exposed patients with RRMM in real-world practice and result in poor outcomes. This supports a need for new treatments with novel mechanisms of action.

Frontline daratumumab-based triplet and quadruplet standard-of-care regimens have demonstrated improved survival outcomes in newly diagnosed multiple myeloma (NDMM). For patients with transplant-ineligible NDMM, triplet therapy with either daratumumab plus lenalidomide and dexamethasone (D-Rd) or bortezomib, lenalidomide and dexamethasone (VRd) is the current standard of care. This phase 3 trial evaluated subcutaneous daratumumab plus VRd (D-VRd) in patients with transplant-ineligible NDMM or for whom transplant was not planned as the initial therapy (transplant deferred). Some 395 patients with transplant-ineligible or transplant-deferred NDMM were randomly assigned to eight cycles of D-VRd or VRd followed by D-Rd or Rd until progression. The primary endpoint was overall minimal residual disease (MRD)-negativity rate at 10^{− 5} by next-generation sequencing. Major secondary endpoints included complete response (CR) or better (≥CR) rate, progression-free survival and sustained MRD-negativity rate at 10^{− 5}. At a median follow-up of 58.7 months, the MRD-negativity rate was 60.9% with D-VRd versus 39.4% with VRd (odds ratio, 2.37; 95% confidence interval (CI), 1.58–3.55; P < 0.0001). Rates of ≥CR (81.2% versus 61.6%; P < 0.0001) and sustained MRD negativity (≥12 months; 48.7% versus 26.3%; P < 0.0001) were significantly higher with D-VRd versus VRd. Risk of progression or death was 43% lower for D-VRd versus VRd (hazard ratio, 0.57; 95% CI, 0.41–0.79; P = 0.0005). Adverse events were consistent with the known safety profiles for daratumumab and VRd. Combining daratumumab with VRd produced deeper and more durable MRD responses versus VRd alone. The present study supports D-VRd quadruplet therapy as a new standard of care for transplant-ineligible or transplant-deferred NDMM. ClinicalTrials.gov registration: NCT03652064.

PURPOSE: ¹⁸F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is currently the standard technique to define minimal residual disease (MRD) status outside the bone marrow (BM) in patients with multiple myeloma (MM). This study aimed to define criteria for PET complete metabolic response after therapy, jointly analyzing a subgroup of newly diagnosed transplantation-eligible patients with MM enrolled in two independent European randomized phase III trials (IFM/DFCI2009 and EMN02/HO95). PATIENTS AND METHODS: Two hundred twenty-eight patients were observed for a median of 62.9 months. By study design, PET/CT scans were performed at baseline and before starting maintenance (premaintenance [PM]). The five-point Deauville scale (DS) was applied to describe BM (BM score [BMS]) and focal lesion (FL; FL score [FS]) uptake and tested a posteriori in uni- and multivariable analyses for their impact on clinical outcomes. RESULTS: At baseline, 78% of patients had FLs (11% extramedullary), 80% with an FS ≥ 4. All patients had BM diffuse uptake (35.5% with BMS ≥ 4). At PM, 31% of patients had visually detectable FLs (2% extramedullary), 24% and 67.7% of them with an FS of 3 and ≥ 4, respectively. At PM, 98% of patients retained residual BM diffuse uptake, which was significantly lower than at baseline (mainly between BMS 2 and 3, BMS was ≥ 4 in only 8.7% of patients). By both uni- and multivariable analysis, FS and BMS < 4 were associated with prolonged progression-free survival (PFS) and overall survival (OS) at PM (OS: hazard ratio [HR], 0.6 and 0.47, respectively; PFS: HR, 0.36 and 0.24, respectively) CONCLUSION: FL and BM FDG uptake lower than the liver background after therapy was an independent predictor for improved PFS and OS and can be proposed as the standardized criterion of PET complete metabolic response, confirming the value of the DS for patients with MM.

CD38-targeting immunotherapy is approved in combination with lenalidomide and dexamethasone in patients with newly diagnosed multiple myeloma (NDMM) that are transplant ineligible (TI) and is considered the best standard of care (SOC). To improve current SOC, we evaluated the added value of weekly bortezomib (V) to isatuximab plus lenalidomide and dexamethasone (IsaRd versus Isa-VRd). This Intergroupe Francophone of Myeloma phase 3 study randomized 270 patients with NDMM that were TI, aged 65–79 years, to IsaRd versus Isa-VRd arms. The primary endpoint was a minimal residual disease (MRD) negativity rate at 10⁻⁵ by next-generation sequencing at 18 months from randomization. Key secondary endpoints included response rates, MRD assessment rates, survival and safety. The 18-month MRD negativity rates at 10⁻⁵ were reported in 35 patients (26%, 95% confidence interval (CI) 19–34) in IsaRd versus 71 (53%, 95% CI 44–61) in Isa-VRd (odds ratio for MRD negativity 3.16, 95% CI 1.89–5.28, P < 0.0001). The MRD benefit was consistent across subgroups at 10⁻⁵ and 10⁻⁶, and was already observed at month 12. The proportion of patients with complete response or better at 18 months was higher with Isa-VRd (58% versus 33%; P < 0.0001), as was the proportion of MRD negativity and complete response or better (37% versus 17%; P = 0.0003). At a median follow-up of 23.5 months, no difference was observed for survival times (immature data). The addition of weekly bortezomib did not significantly affect the relative dose intensity of IsaRd. Isa-VRd significantly increased MRD endpoints, including the 18-month negativity rate at 10⁻⁵, the primary endpoint, compared with IsaRd. This study proposes Isa-VRd as a new SOC for patients with NDMM that are TI. ClinicalTrials.gov identifier: NCT04751877.

Daratumumab is a human monoclonal antibody targeting CD38, an antigen uniformly expressed by plasma cells in multiple myeloma and light-chain amyloidosis (AL). We report the results of a prospective multicenter phase 2 study of daratumumab monotherapy in AL (NCT02816476). Forty previously treated AL patients with a difference between involved and uninvolved free light chains (dFLC) >50 mg/L were included in 15 centers between September of 2016 and April of 2018. Patients received 6 28-day cycles of IV daratumumab, every week for cycles 1 and 2 and every 2 weeks for cycles 3 through 6. Median age was 69 years (range, 45-83). Twenty-six patients had ≥2 organs involved, with heart in 24 and kidney in 26. Median time from diagnosis to enrollment was 23 months (interquartile range, 4-122), with a median of 3 prior therapies (range, 1-5). At data cutoff (September of 2019), all patients discontinued therapy; 33 received the planned 6 cycles. Overall, 22 patients had hematological response, and 19 patients (47.5%) achieved very good partial response (dFLC <40 mg/L) or better. Median time to hematological response was 1 week. Patients with no response after 4 doses were unlikely to respond further. Renal and cardiac responses occurred in 8 and 7 patients, respectively. Daratumumab was well tolerated, with no unexpected adverse events. With a median follow-up of 26 months, the 2-year overall survival rate was 74% (95% confidence interval, 62-81). Daratumumab monotherapy is associated with deep and rapid hematological responses in previously treated AL patients, with a good safety profile. Further studies of daratumumab in combination regimens are warranted.