Gilead and Merck’s Once-Weekly HIV Combo Pill Works in Trials

Gilead Sciences Inc. and Merck & Co. said an experimental long acting pill combining two HIV medicines had met its primary efficacy goal in final-stage trials.

In a statement, the companies said that in two large trials, a once-weekly combination pill containing Merck’s islatravir and Gilead’s lenacapavir had proven to be non-inferior to standard pill regimens that are taken daily. If approved by regulators, the new combination could become the first once-weekly pill for the treatment of HIV, a Gilead spokesperson said in an email.

Currently, HIV is typically kept at bay through daily pills or longer-acting injectables. A ...