NEW YORK - Gilead Sciences Inc said an unauthorised network of drug distributors and suppliers sold pharmacies more than US$250 million (S$338 million) of counterfeit versions of its HIV treatments over the last two years, endangering patients.
The drugmaker said it found 85,247 bottles that had been tampered with or faked, including versions of its Biktarvy and Descovy treatments.
Gilead said counterfeiters used authentic, but often empty or near-empty, bottles that once contained its HIV medication.
It said the counterfeiters then substituted fake tablets and documentation, and resealed the bottles so they would "resemble" unopened, authentic bottles.
The alleged scheme was reported earlier by The Wall Street Journal.
Gilead disclosed its anti-counterfeiting efforts on the same day a federal judge in Brooklyn unsealed a related civil lawsuit that the Foster City, California-based company filed last July.
The company accused 22 defendants of violating federal trademark and New York consumer protection laws for their roles in the distribution of "dangerous" counterfeits to "unsuspecting patients, placing the patients' health and lives at risk".
Gilead said a common counterfeit was an anti-psychotic drug that often causes drowsiness, where tablets were six times more potent than the US Food and Drug Administration recommended for some patients.
It said one patient who unknowingly took that drug after receiving a fake bottle of Biktarvy reported being unable to speak or walk afterwards.
The lawsuit seeks, among other remedies, seizures of counterfeit drugs, in addition to court-ordered seizures that have already occurred.
Gilead had warned the public about HIV counterfeits last Aug 5, two weeks after filing the lawsuit under seal.
Global sales of the company's HIV treatments totalled US$4.19 billion in the quarter ending Sept 30, 2021, including US$2.71 billion of Biktarvy and Descovy.
Lori Mayall, Gilead's top anti-counterfeiting executive, said the presiding judge in its lawsuit ordered the defendant distributors to stop selling Gilead-branded medications, and the company was unaware of any defendant violating that order.
"We therefore believe that we have successfully stopped any additional counterfeits from these defendants reaching patients," said in a statement.