- Gilead and Merck & Co. believe pairing two of their closely watched, experimental drugs for HIV could offer patients a long-lasting and meaningful treatment option, and so have decided to team up to develop and market the combination.
- The companies will try to make oral and injectable treatments comprised of Gilead's lenacapavir and Merck's islatravir. Gilead will shoulder 60% of the development and commercialization costs while Merck supplies the other 40%. The companies will also split marketing responsibilities based on formulation, with Gilead taking the lead for long-acting oral products in the U.S. and long-acting injectable products in the rest of the world, and Merck vice versa.
- Gilead and Merck plan to share global product revenues equally until certain tiers are hit. If net product sales for the oral combination pass $2 billion a year, the revenue split will adjust to 65% for Gilead and 35% for Merck on any revenues above the threshold. And after $3.5 billion a year in net product sales for the injectable combination, the revenue split will adjust to those same percentages for any additional revenues.
HIV treatment has significantly transformed over the last two decades.
Before, patients might have needed to take fistfuls of pills to keep the virus in check. Now, a single daily pill is just as effective. Alongside that change, patients have been able to live longer, better lives. A recent study run by the Centers for Disease Control and Prevention found HIV-related deaths among teenagers and adults in the U.S. had been cut almost in half between 2010 and 2017.
Despite that progress, HIV treatment continues to face challenges — not least of which is access. In the U.S., many people, and particularly people of color, are left without effective drugs because of insurance complexities or high out-of-pocket costs. Based on data from 2017, the CDC has estimated that more than a third of HIV patients in the U.S. do not have their infections under control through effective treatment, with young people and African Americans disproportionately affected.
Against this backdrop, HIV drugmakers are trying to develop new treatments that are more convenient to use. For Gilead and Merck, that's meant considerable time and attention devoted to their respective drugs, lenacapavir and islatravir.
Lenacapavir is designed to impair the protein that surrounds and protects HIV, while islatravir is supposed to block the virus from incorporating into human DNA. Both have advanced to late-stage clinical trials after delivering promising results in earlier human testing.
Just this month, Gilead reported interim results from a Phase 2/3 study of lenacapavir in patients whose HIV infections had developed resistances to multiple drugs. The results showed a subcutaneous dose of Gilead's drug every six months was able to suppress the virus in these hard-to-treat patients.
Now, Gilead and Merck hope that combining their drugs will lead to a variety of effective, long-lasting treatment options. If the combination were to come to market, it would add to Gilead's already robust portfolio of HIV drugs, which includes Biktarvy, the world's top-selling HIV medication.
As for Merck, which has touted islatravir as a valuable component in two-drug HIV regimens, the deal with Gilead represents "an important step forward in our strategy to harness the full potential of islatravir for the treatment of HIV," according to CEO Ken Frazier. Merck's HIV business currently revolves around a drug called Isentress, which brought in $860 million in sales last year, a decrease of 12% compared to 2019.
In addition to its main focus, Monday's deal hands Gilead and Merck the option to license some of each others' oral, experimental drugs to develop in combination with lenacapavir and islatravir. Each company can exercise its option once the other completes the first Phase 1 clinical trial of the drug in question. If the option is exercised, the partners will split development cost and revenues, unless the non-exercising company decides to opt-out.
GlaxoSmithKline, which alongside Gilead is the other dominant HIV medicine maker, in January won U.S. approval for a long-acting injectable medicine called Cabenuva.