Cost effectiveness of polatuzumab vedotin in combination with chemoimmunotherapy (Pola-R-CHP) in previously untreated diffuse large B-cell lymphoma.

Abstract

7568 Background: In patients with treatment naive diffuse large B-cell lymphoma (DLBCL), the POLARIX study demonstrated a 6.5% improvement in the 2-year (yr) progression-free survival (PFS) with no difference in overall survival or safety using polatuzumab vedotin + R-CHP compared to standard RCHOP. We evaluated the cost effectiveness of pola-R-CHP for DLBCL. Methods: We modeled a hypothetical cohort of US adults (mean age, 58 yrs) with treatment naïve DLBCL by developing a Markov model with a 1-month cycle and 20-yr horizon. The cost-effectiveness of two strategies were directly compared (pola-R-CHP, RCHOP) using a range of plausible long-term outcomes. A patient with DLBCL in remission after treatment could develop subsequent progression or relapse, death, or alternative toxicity. Progression rates and overall survival were estimated from POLARIX study. Outcome measures were reported in incremental cost-effectiveness ratios (ICERs), with a willingness-to-pay (WTP) threshold of $150,000/quality-adjusted life-yr (QALY). Results: Assuming a 5-yr PFS of 69.6% with pola-R-CHP and 62.6% with RCHOP, pola-R-CHP was more effective (0.81 incremental QALYs) but more costly ($66,218) and was cost-effective at a WTP of 150,000 (ICER $82,220/QALY). Its cost effectiveness was highly dependent on the 5-yr PFS of pola-R-CHP with it no longer being cost effective if the 5-yr PFS was < 65%. One way sensitivity analysis demonstrated that pola-R-CHP is cost effective up to a cost of $270,506 at a WTP of $150,000. Probabilistic sensitivity analysis was derived from performing 10,000 Monte-Carlo model iterations and demonstrated that pola-R-CHP was the cost-effective strategy in 61.3% of iterations with RCHOP being cost-effective in 38.6% of iterations at a WTP of $150,000. Conclusions: If the absolute benefit in PFS is maintained over time, frontline pola-R-CHP for treatment of DLBCL would be cost effective at its current cost when compared to RCHOP at a WTP of $150,000/QALY. However, its cost effectiveness is highly sensitive to changes in long-term PFS and the cost of pola-R-CHP. If pola-R-CHP is adopted as frontline therapy for the 29,108 incident cases of DLBCL annually in the US, this will lead to an additional 1.8 billion dollars in healthcare expenditures. This highlights the importance of decreasing the cost of pola-R-CHP and identifying sub-populations that derive the highest benefit from it.[Table: see text]