(Reuters) – GlaxoSmithKline Plc said on Thursday its HIV unit has submitted a new drug application to the U.S. Food and Drug Administration seeking approval for fostemsavir, an experimental treatment for HIV in adults.

Fostemsavir is being developed for use in combination with other antiretroviral agents in adults who have been previously taken treatments for HIV and have developed resistance to the drugs due to various factors.

Antiretroviral medicines that can effectively suppress HIV have been instrumental in decreasing disease progression, HIV transmission, and AIDS-related deaths, but because of HIV’s ability to constantly change, some individuals can develop viral resistance, causing their treatment regimens to fail.

ViiV Healthcare, in which Pfizer Inc and Shionogi have small stakes, also plans to submit regulatory applications for fostemsavir to the European Medicines Agency and other global agencies in the coming months.

GSK bought fostemsavir from U.S. rival Bristol-Myers Squibb in 2015.

(Reporting by Noor Zainab Hussain and Pushkala Aripaka in Bengaluru; Editing by Saumyadeb Chakrabarty)