Senator Hassan Opens Investigation Into Merck's Keytruda Patent Strategy Amid Pricing Concerns
Key Insights
Sen. Maggie Hassan (D-N.H.) has sent a formal letter to Merck (search) CEO Robert Davis demanding answers on the company's patenting and pricing practices for the blockbuster cancer immunotherapy Keytruda.
The senator cited ICIJ's Cancer Calculus investigation, which found 1,212 patent applications across 53 jurisdictions that could extend Keytruda's market exclusivity in the U.S. until at least 2042.
Keytruda's annual list price reaches approximately $200,000 in the U.S., with prices ranging from over $80,000 in Germany to $130,000 in Colombia, straining healthcare budgets globally.
Sen. Maggie Hassan (D-N.H.), ranking member of the Senate Finance Subcommittee on Health Care, has opened a formal investigation into Merck (search)'s patenting and pricing strategies for its blockbuster cancer immunotherapy Keytruda, escalating congressional scrutiny of pharmaceutical industry practices that can delay lower-cost competitors from reaching the market.
In a letter sent to Merck (search) CEO Robert Davis this week, Hassan demanded detailed information about patent actions connected to both the intravenous formulation of Keytruda, which has been on the market for over a decade, and the company's new injectable version launched last year. The senator set a response deadline of July 20.
"I continue to have serious concerns about how Merck (search)'s anti-competitive practices have boosted profits at the expense of patients," Hassan wrote, adding that she has previously noted how "these kinds of patent gimmicks have allowed Merck to delay other companies from selling lower cost versions of this medication, all while raising the price of Keytruda in the U.S. year after year."
The Cancer Calculus Findings
Hassan's inquiry draws directly on findings from the International Consortium of Investigative Journalists' recent Cancer Calculus investigation. The ICIJ analysis identified at least 1,212 patent applications that form part of the Keytruda patent family across 53 countries, regions, and territories. While Keytruda's primary patents are set to expire in 2028, the investigation found that Merck (search)'s secondary patents could potentially extend the drug's exclusivity in the U.S. until at least 2042, potentially delaying cheaper alternatives for hundreds of thousands of patients over the next 15 years.
The senator specifically cited ICIJ's finding that Merck (search)'s new injectable version of Keytruda "could help Merck generate billions of dollars and delay competition into the 2030s."
Global Pricing Disparities
Keytruda's pricing has drawn international concern. According to ICIJ's investigation, the drug's annual list prices range from more than $80,000 for a year of treatment in Germany, $93,000 in Lebanon, and $130,000 in Colombia, to as much as $208,000 in the United States. Hassan noted that the annual cost of Keytruda for a single patient in the U.S. is approximately $200,000.
The exorbitant prices have had tangible consequences globally. ICIJ reported that counterfeit Keytruda has surfaced in public hospitals in Mexico, fueled by desperate patients unable to afford the genuine medication. High costs and restrictive insurance protocols have also forced many patients into prolonged legal battles to access the drug.
Ten Questions for Merck
Hassan's letter includes 10 specific questions seeking answers from Merck (search). Key inquiries include why the company is pursuing a large number of secondary patents for Keytruda and how it justifies that strategy; whether this approach delays biosimilar competition and keeps prices elevated for patients; what Merck is doing to ensure lower-cost alternatives can reach patients once the main patents expire; and whether the shift from intravenous Keytruda to an injectable version could be used to extend market exclusivity and delay lower-cost competition.
The letter also references an exchange between Hassan and Davis during a 2024 Senate hearing, in which Davis stated that the system needs both patent protection and a strong biosimilar and generic market, and that he would not block an intravenous biosimilar of Keytruda after key patents expire. "Despite these statements, existing patents for [intravenous] Keytruda and a new form of the medication may help block or minimize competition from biosimilars for years," Hassan wrote.
Legislative Context
The inquiry forms part of a broader congressional push to address prescription drug pricing, patent disputes, and alleged "product hopping" strategies that some lawmakers say can delay cheaper alternatives from reaching patients. One legislative vehicle under consideration is the Medication Affordability and Patent Integrity Act, sponsored by Hassan and Sen. Josh Hawley (R-MO). The proposed law, which aims to reform patent review and facilitate the entry of generics and biosimilars to the market, was advanced by the Senate Committee on Health, Education, Labor, and Pensions in June.
"If they won't agree to stop gaming the system this way and artificially pumping up their prices, then we need to take legislative action and meet it head-on," Hassan said.
A Merck (search) spokesperson did not respond to a request for comment sent by ICIJ. Earlier this year, the company told ICIJ and its global media partners that it is a "common myth" that companies use many patents to block competition, and said more patents do not determine when generics or biosimilars enter the market.