Adjusting for subsequent therapies in the TOURMALINE-MM1 study shows clinically meaningful improvement in overall survival with addition of ixazomib to lenalidomide and dexamethasone.

TOURMALINE-MM1, the only blinded randomized study in patients with relapsed and/or refractory multiple myeloma (RRMM; ≥1 prior therapy) in the last 10 years, investigated ixazomib+lenalidomide+dexamethasone (IRd) versus lenalidomide+dexamethasone (Rd). Final overall survival (OS) data were based on a median follow-up of 85 months. In RRMM trials where patients have had 1-3 relapses after initial treatment, a high proportion receive subsequent therapy. Application of salvage therapies in blinded trials and newer modes of therapy can increasingly complicate the interpretation of OS. This analysis explores the impact of subsequent therapies on OS outcomes in TOURMALINE-MM1. The inverse probability of censoring weights (IPCW) method, marginal structural model (MSM), and rank preserving structural failure time model (RPSFTM) were utilized to adjust for confounding on OS, introduced by subsequent therapies. Analyses were conducted for the intentto-treat (ITT) population and ≥2 prior lines subgroup. Unadjusted hazard ratio (HR) for IRd versus Rd was 0.94 (95% confidence interval [CI]: 0.78-1.13) in the ITT population. After adjusting for the impact of subsequent therapies by the RPSFTM method, estimated HR for IRd versus Rd in the ITT population was 0.89 (95% CI: 0.74-1.07). Adjusting with IPCW and MSM methods also showed an improvement in HR, favoring IRd. IRd may be particularly beneficial in patients with ≥2 prior lines of therapy (IPCW and MSM HR=0.52, 95% CI: 0.30-0.88; RPSFTM HR=0.68, 95% CI: 0.51-0.91). These analyses highlight the growing challenge of demonstrating OS benefit in multiple myeloma patients and the importance of assessing confounding introduced by subsequent therapies when interpreting OS.

Network meta-analysis of efficacy of ixazomib, lenalidomide, and dexamethasone in relapsed/refractory multiple myeloma.

OBJECTIVES: In the absence of head-to-head comparisons across relapsed/refractory multiple myeloma (RRMM) treatments following the approval of the oral proteasome inhibitor ixazomib, in combination with lenalidomide and dexamethasone (IRd), we conducted an indirect comparison of the efficacy of IRd relative to several RRMM therapies using Bayesian fixed-effects network meta-analysis (NMA) models. METHODS: Data for the NMA were obtained through a systematic literature review (conducted in June 2020), which identified randomized controlled trials (base case) and observational studies (extended network analysis) reporting overall survival (OS), progression-free survival (PFS), and overall response rate (ORR). RESULTS: In the base case, IRd was associated with a significantly longer PFS than lenalidomide and dexamethasone (Rd), bortezomib monotherapy (V), dexamethasone (Dex), and pomalidomide and dexamethasone (Pom-dex), a significantly shorter PFS than daratumumab, lenalidomide, and dexamethasone (DRd), and a PFS comparable to elotuzumab, lenalidomide, and dexamethasone (ERd) and carfilzomib, lenalidomide, and dexamethasone (KRd). IRd was associated with a significantly longer OS than V, Dex, and Pom-dex, and an OS comparable to Rd, ERd, KRd, and DRd. The ORR of IRd was significantly higher than Rd, V, and Dex, significantly lower than KRd and DRd, and comparable to Pom-dex and ERd. The extended network analyses and sensitivity analyses were consistent with the base case. DISCUSSION: This NMA shows that IRd is relatively efficacious among RRMM treatments. Being an oral regimen, IRd is also convenient to manage. CONCLUSION: IRd could be a preferable treatment option for many patients with RRMM, particularly those seeking an efficacious and convenient therapeutic option.

Comparison of health care costs and resource utilization for commonly used proteasome inhibitor-immunomodulatory drug-based triplet regimens for the management of patients with relapsed/refractory multiple myeloma in the United States.

BACKGROUND: Economic differences among currently available proteasome inhibitors (PI)-based lenalidomide-dexamethasone (Rd)-backbone triplet regimens-ixazomib (I), bortezomib (V), and carfilzomib (K) plus Rd-remain poorly understood. OBJECTIVE: To assess health care resource utilization (HCRU) and health care costs of patients with relapsed/refractory multiple myeloma (RRMM) in the United States treated with IRd, VRd, and KRd. METHODS: This retrospective longitudinal cohort study using IQVIA PharMetrics Plus adjudicated claims US data (January 1, 2015, to September 30, 2020) included adult patients with all available data who initiated IRd, VRd, or KRd in second line of therapy or later (LOT2+) on or after September 1, 2015. The index date was the treatment initiation date for each LOT (multiple LOTs per patient were included) and the baseline was 6 months pre-index. MM-related and all-cause HCRU/costs were assessed during follow-up and reported per patient per month (PPPM; 2020 US Dollars). For MM-related costs only, treatment administration costs were excluded from outpatient (OP) costs and instead summed with pharmacy costs. HCRU/costs were compared between treatment groups using generalized linear models (GLMs). Cost variables were compared using 2-part models and GLM with log transformation and γ distribution. Inverse probability of treatment weighting (IPTW) adjusted for imbalance of baseline confounders across treatment groups. RESULTS: The study included 511 patients contributing 542 LOTs (IRd: n = 153; VRd: n = 262; KRd: n = 127). Before IPTW, mean observed time spent on therapy was 8.5, 9.3, and 7.3 months for the IRd, VRd, and KRd cohorts, respectively. During follow-up and after IPTW, IRd and VRd were associated with significantly fewer OP visits vs KRd. Post-IPTW comparisons of MM-related costs for IRd vs KRd yielded lower OP costs for IRd (mean diff. PPPM: -$3,428; P < 0.001), contributing to lower total medical costs (-$3,813; P < 0.001) and total health care cost savings with IRd vs KRd (-$5,813; P = 0.001). MM-related OP costs were lower for VRd (mean diff. PPPM: -$3,543; P < 0.001) than KRd, reducing its total MM-related medical costs (-$3,997; P = 0.002), leading to total MM-related health care cost savings with VRd vs KRd (-$12,357; P < 0.001). All-cause cost comparisons yielded similar results (total health care cost savings for IRd and VRd vs KRd: -$6,371 and -$13,629, respectively; all P < 0.001). CONCLUSIONS: From the US insurance-payer perspective, patients treated with IRd and VRd had significant medical cost savings vs KRd due to lower OP costs when excluding treatment administration costs. The differential economic impacts of PI-Rd regimens in this study may help to inform treatment decisions for patients with MM. DISCLOSURES: This study and article were supported by Takeda Development Center Americas, Inc. Dr Sanchez has no conflicts to declare. Dr Chari has the following relationships: Research Support/Principal Investigator: Amgen, Array Biopharma, Celgene, Glaxo Smith Klein, Janssen, Millenium/Takeda, Novartis Pharmaceuticals, Oncoceutics, Pharmacyclics, Seattle Genetics; Consultant: Amgen, Bristol-Myers Squibb, Celgene, Millenium/Takeda, Janssen, Karyopharm; Scientific Advisory Board: Amgen, Celgene, Millenium/Takeda, Janssen, Karyopharm, Sanofi, Seattle Genetics. Drs Cherepanov, Huang, Dabora, and Noga are current employees of Takeda, while Drs Stull and Young are ex-employees of Takeda; Drs Cherepanov and Huang also own stocks in Takeda. Dr DerSarkissian, Ms Cheng, Ms Zhang, Mr Banatwala, and Dr Duh are employees of Analysis Group, Inc. (AG), a consulting firm that received funding from Takeda to conduct this study. Ms Pi was an employee of AG at the time of the study. Dr Ailawadhi has the following relationships to declare: Research Support and Consulting for BMS, GSK, and Janssen; Research Support from AbbVie, Arch Oncology, Cellectar, Medimmune, Pharmacyclics, and Xencor; Consulting for Beigene, Oncopeptides, Regeneron, Sanofi, and Takeda.