U.K. marketing police slam Gilead for claiming Biktarvy tolerability beats GSK rival

Gilead Sciences and GlaxoSmithKline subsidiary ViiV Healthcare are entangled in a heated race for HIV market share, each hoping to outrun the other with better treatment options. But a Gilead promo in the U.K.—touting its Biktarvy as superior to ViiV offerings—has drawn fire for being misleading.

Gilead’s claim that its Biktarvy is “better tolerated than DTG (dolutegravir)-containing regimens” depicted ViiV’s rival drug in an unfair bad light and therefore breached best practice codes, U.K.’s Prescription Medicines Code of Practice Authority (PMCPA) recently ruled.

In fact, this marks Gilead’s second breach as it failed to comply with an earlier PMCPA ruling on the same matter.

The issue centers on Gilead’s best-selling HIV drug Biktarvy, which delivered $4.74 billion in 2019 global sales after its FDA approval in February 2018. The three-in-one fixed-dose combination drug contains bictegravir, a rival integrase inhibitor to ViiV’s Tivicay (dolutegravir).

The other two ingredients included in Biktarvy are sold by Gilead as Descovy. Tivicay needs to be paired with other HIV drugs to form a complete regimen. Triumeq, Dovato and Juluca are three FDA-approved Tivicay-containing meds.

During the HIV Drug Therapy Conference in Glasgow in October 2018, Gilead displayed the message claiming Biktarvy's superior tolerability profile in a visual panel display and in videos. ViiV complained to the PMCPA, which agreed that the description was misleading because it was based only on selected data.

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The thing is, in three phase 3 trials, fewer patients on Biktarvy had treatment-related adverse events compared with Tivicay-containing regimens. In GS-1489, the rates of adverse events were 26% for Biktarvy, versus 40% for Triumeq. In the GS-1490 trial, the numbers were 18% among Biktarvy patients, versus 26% for a combination of Tivicay and Descovyl. In GS-1844, which evaluated switching to Biktarvy from Triumeq, adverse events were recorded in 8% of the Biktarvy group and 16% of the Triumeq patients.

Despite the statistical differences, though, two research teams said their findings suggested the tolerability profiles of the tested treatments were similar.

Then, in November 2019—just a month after Gilead lost an appeal with PCMPA—ViiV noticed that the claim was still being used on hiv.eu, a healthcare professional education site maintained by Gilead. This time, the PMCPA panel found (PDF) Gilead’s failure to comply “brought discredit upon, and reduced confidence in, the pharmaceutical industry.”

Gilead, in response to the complaint, acknowledged that the material was in breach of drug marketing best practice codes as determined in PMCPA’s previous decision, and said it had removed the claim from the website.

RELATED: GSK's ViiV, touting superior long-acting data, can challenge Gilead in HIV prevention: analyst

The scuffles reflect the ongoing rivalry between the two firms; indeed, Gilead also filed two PMCPA complaints in 2018 and 2019 taking issue with ViiV’s promotional conduct.

ViiV is introducing two-drug HIV regimens to reduce the number of medicines a patient needs to take. But so far, the two marketed products, Juluca and Dovato—both containing Tivicay—have not exactly threatened Biktarvy’s market-leading status.

A long-acting option, Cabenuva, which combines ViiV’s cabotegravir with Johnson & Johnson’s rilpivirine, has been greenlighted in the EU after a recent FDA rejection due to manufacturing-related problems.

Meanwhile, ViiV just unveiled data showing bi-monthly cabotegravir injections work significantly better than Gilead’s daily pill Truvada at preventing HIV in at-risk men and transgender women.