Economic evaluation of polatuzumab-bendamustine-rituximab vs. tafasitamab-lenalidomide in transplant-ineligible R/R DLBCL

Polatuzumab vedotin-bendamustin-rituximab (PBR) and tafasitamab-lenalidomide (Tafa-L) were approved recently for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) in autologous stem cell transplant (ASCT) ineligible patients. We performed an industry-independent pharmacoeconomic evaluation of both regimens over a 5-year (y) time horizon (US payer perspective; 2020 USD). Survival curves, treatment costs, and utility values were applied in a three-state Markov model (progression-free survival (PFS), post-progression survival (PPS), death) to estimate the incremental follow-up (ICER) and cost-utility ratios (ICUR). A novel metric of the incremental cost per 1% gain in the probability of achieving objective response (OR), PFS, and OS were estimated. Five-year Tafa-L costs ($470,119) exceeded PBR’s ($249,217) by $220,902 with incremental gains of 0.71 life-years (LY) and 0.32 quality-adjusted life-years (QALY); yielding ICER of $310,041/LYg and ICUR of $694,241/QALYg. Tafa-L had favorable PFS and OS rates over PBR with adjusted differences of +19.2 and +34.1%, respectively at trial follow-up (∼2 years), with corresponding 5 years differences in survival of +7.8% in PFS and +21.4% in OS. The incremental cost per 1% gain in the probability of achieving OR, PFS and OS at follow-up were $8,479, $6,359, and $3,583; and $28,321 and $10,323 for PFS and OS at 5 years. The sustained Tafa-L treatment demonstrated better survival outcomes than 6-cycle PBR though at a greater cost. The incremental costs to gain a 1% improvement in 2 and 5 years survival outcomes with Tafa-L over PBR were modest, underscoring the longer-term benefit of Tafa-L over PBR in patients ineligible for or opting out of ASCT. Two new medication regimens were approved recently for relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL): six cycles of polatuzumab vedotin-bendamustine-rituximab (PBR) and continuous twice-monthly treatment with tafasitamab-lenalidomide (Tafa-L). Both treatments are expensive, but Tafa-L more so because it requires continuous treatment versus the maximum 6 cycles of PBR. However, Tafa-L may have better progression-free (PFS) and overall survival (OS) outcomes. Is this worth the additional money? We conducted a cost-effectiveness analysis comparing Tafa-L to PBR. After calculating the differenced in costs and the progression-free and overall survival, we determined the additional cost to gain a life year (LY) or quality-adjusted life year (QALY) over 5 years. We also introduced a novel metric: how much it would cost extra to gain, with Tafa-L treatment, an improvement in progression-free or overall survival of 1% over the survival afforded by PBR. Treatment with Tafa-L over PBR would cost an extra $220,902 for a gain of 0.71 life years (standardized, $310,041/LYgained) and 0.32 quality-adjusted life years ($694,241/QALYgained). Importantly, two years of Tafa-L treatment increased the likelihood of progression-free survival by +19.2% and overall survival by 34.1% over PBR; extending to +7.8% in progression-free survival and +21.4% in overall survival at five years. It cost an additional $28,321 per 1% gain in likelihood in progression-free survival and $10,323 per 1% gain in overall survival after 5 years. Summarized, the increased costs of Tafa-L translate into significantly better progression-free and overall survival.