Adds details on the treatment throughout

Nov 19 (Reuters) - Merck MRK.N said on Wednesday that its experimental oral HIV treatment was not inferior to Gilead's GILD.O top-selling HIV drug Biktarvy in a late-stage study in adults with HIV who had not previously received treatment.

The Rahway, New Jersey-based company was testing its oral, two-drug regimen of doravirine and islatravir in adults with HIV-1 infection who had not previously taken antiretroviral treatments, a combination of medications that work by stopping the virus from reproducing.

HIV-1 is the most common strain of the retrovirus that causes Acquired Immunodeficiency Syndrome, commonly known as AIDS.

The safety profile of doravirine and islatravir was comparable to Biktarvy, Merck said.

The company plans to present detailed findings from this trial at a future medical meeting and to submit applications including these data to health authorities.

The U.S. Food and Drug Administration is set to make its decision on approval for doravirine/islatravir by April 28, 2026.

Merck's doravirine is already approved in the U.S. as a treatment for adults with HIV-1 in combination with other antiretrovirals under the brand name Pifeltro and as part of a single-tablet regimen sold under the brand name Delstrigo.

Islatravir is an experimental treatment that blocks HIV-1 replication by blocking an enzyme called reverse transcriptase, which prevents the viral DNA from growing.

Islatravir is currently being tested in multiple trials in combination with other antiretrovirals for potential daily and once-weekly treatments for HIV-1.

Last year, the doravirine and islatravir combination treatment was shown to be non-inferior to Biktarvy in suppressing the replication of HIV-1 in patients who were already on antiretroviral therapy.

(Reporting by Sneha S K in Bengaluru; Editing by Tasim Zahid)

((Sneha.SK@thomsonreuters.com;))