Keytruda's List Price per Dose
Keytruda (pembrolizumab), Merck's blockbuster cancer immunotherapy, has a U.S. wholesale acquisition cost (WAC) of $11,358 for a 100 mg/4 mL vial or $23,601 for a 200 mg/4 mL single-dose vial, as of mid-2024.[1] These prices exclude discounts, rebates, or patient assistance.
How Annual Costs Add Up for Patients
Treatment regimens vary by cancer type and stage:
- Most common: 200 mg IV every 3 weeks, totaling about 17 doses per year.
- Annual list price: Roughly $400,000–$420,000 before insurance.
- High-dose or maintenance: Up to 400 mg every 6 weeks (8–9 doses/year), around $200,000–$240,000 list price.[2]
Patients rarely pay full list due to insurance, Medicare Part B (covers infused drugs at 20% coinsurance post-deductible), or commercial plans with copays.
What Patients Actually Pay with Insurance
- Commercial insurance: Average out-of-pocket ~$1,000–$5,000/year after copays/deductibles, per patient reports and claims data. High-deductible plans can hit $10,000+ initially.[3]
- Medicare: ~$2,500–$3,500/year in coinsurance for a full course (20% of ~$12,500–$17,500 Medicare-allowed amount per dose cycle), though caps like the 2025 Part B redesign limit it to ~$2,000 max.[4]
- Uninsured/low-income: Full list price unless qualifying for Merck's patient assistance (free for incomes <500% federal poverty level) or copay cards ($0 copay up to $25,000/year for eligible insured patients).[5]
Factors Driving Costs Higher or Lower
- Duration: Many stay on Keytruda 1–2 years; 5-year regimens exceed $2 million list price.
- Combination therapy: Often paired with chemo (e.g., Keytruda + pemetrexed), doubling costs.
- Inflation and rebates: WAC rose 4.9% in 2024; Merck rebates ~30–50% to PBMs/insurers, but patients see little direct savings.[6]
- Infusion fees: Add $500–$2,000 per visit.
Keytruda Patent Status and Generic/Biosimilar Outlook
Merck holds patents on Keytruda through 2028 (composition-of-matter) with extensions possible to 2036 via pediatric exclusivity or new formulations. Challenges from Amgen, Samsung Bioepis, and others target earlier expiry.[7] No U.S. biosimilars until at least 2028; EU biosimilars launch 2025. Check DrugPatentWatch.com for latest litigation and expiry dates.[8]
Cheaper Alternatives Patients Consider
- Opdivo (nivolumab): Similar PD-1 inhibitor, ~$150,000–$300,000/year list (lower per dose), often comparable efficacy in trials.[9]
- Tecentriq (atezolizumab): PD-L1 option, ~$200,000/year.
- Off-label or trials: Libtayo or generics in select cancers, but Keytruda dominates due to broader approvals (18+ indications).
[1] Merck pricing updates, IQVIA data.
[2] NCCN guidelines, pembrolizumab dosing.
[3] GoodRx, Patient Access Network claims analysis.
[4] CMS Medicare Part B factsheet.
[5] Merck Access Program details.
[6] SSR Health pricing report.
[7] FDA Orange Book.
[8] DrugPatentWatch.com.
[9] ASCO trial head-to-heads (e.g., KEYNOTE-024 vs CheckMate).