A study presented at the virtual 2021 ASCO Annual Meeting explored the cost-effectiveness of adjuvant osimertinib for patients with stage IB to IIIA non-small cell lung cancer (NSCLC).

Adjuvant osimertinib was recently approved for treating resected EGFR-mutant [NSCLC], however, past studies have lacked an overall survival (OS) benefit. This has led to “debate over early clinical implementation given the associated drug costs,” according to Christopher Lemmon, MD, Cleveland Clinic, Cleveland, OH, and colleagues.

Aiming to evaluate the cost-effectiveness of osimertinib, a Markov model was constructed. The model used post-resection health state transitions with digitized disease-free survival data from the ADAURA trial to compare cost and quality-adjusted life years (QALYs) with 3 years of adjuvant osimertinib vs placebo over a 10-year time horizon. Patients with progressive disease (PD) received retreatment with osimertinib.

Cost and utility values were derived from Medicare reimbursement data and literature. A cost-effectiveness threshold of 3 times the GDP per capita was used. The impact of a range of OS benefit was assessed through deterministic sensitivity analyses.

The incremental cost-effectiveness ratio (ICER) for adjuvant osimertinib was $317,119.90 per QALY gained. While initial costs of osimertinib are higher in the first 3 years, they become lower than the placebo group in year 4 onward. Costs become similar after year 7.

Costs due to PD are higher in the placebo group through the first 6.5 years. The average pre-PD cost was $505,755 for the osimertinib  group compared with $2388 for the placebo group. The average post-PD cost was $255,638 vs $379,047, respectively, and the average total costs were $800,697 vs $502,937, respectively.

Dr Lemmon and colleagues noted that QALYs remained higher in the osimertinib group throughout this study.

The cost-effectiveness threshold of $195,000 was reached between 25-30% OS benefit of osimertinib over placebo. An ICER of $115,419 was reached when a 50% discount was applied to the annual cost of osimertinib.

Dr Lemmon and colleagues wrote “3 years of adjuvant [osimertinib] is more cost-effective than placebo if one is willing to pay $317,119 more per QALY gained, with most costs accruing in the first 3 years as drug cost.”

“True cost-effectiveness of adjuvant [osimertinib] will require further study due to immaturity of ADAURA OS data and model limitations,” they concluded.—Marta Rybczynski

Lemmon C, Zabor EC, Pennell N Modeling the cost-effectiveness of adjuvant osimertinib in resected EGFR-mutant non-small cell lung cancer patients. Presented at: the 2021 ASCO Annual Meeting; June 4-8, 2021; virtual. Abstract 8527.