The day after reports surfaced regarding the deaths of 12 Japanese children taking Tamiflu for influenza, Gilead Sciences Inc. released promising preliminary data showing that its once-daily, fixed-dose HIV treatment regimen, Truvada, reduces viral load better than London-based GlaxoSmithKline plc's Combivir.
The company presented 24-week results from the ongoing COMET (Combination of Efavirinz and Truvada) study at the 10th European AIDS Conference in Dublin, Ireland, showing that Truvada, a combination of emtricitabine and tenofovir disoproxil fumarate, produced a decrease in viral load in treatment-experienced patients who switched from twice-daily Combivir (lamivudine 150 mg/zidovudine 300 mg). The percentage of patients who achieved virologic suppression of less than 50 copies/mL was significantly higher (76 percent), compared to baseline (59 percent). About 94 percent of patients maintained viral load of less than 400 copies/mL. Hemoglobin levels also rose from baseline, with 32 percent of patients experiencing at least 1 g/dL increase. Both Combivir and Truvada were administered with efavirenz.
The results were consistent with data reported last year from a Phase III study testing Truvada against Combivir in treatment-na ve patients with HIV RNA levels of more than 10,000 copies/mL. At 24 weeks, 88 percent of patients in the Truvada arm achieved and maintained levels below 400 copies/mL, compared to 80 percent in the Combivir group. (See BioWorld Today, Aug. 27, 2004.)
Truvada was approved in 2004. It recorded third-quarter sales of $162.4 million.
Gilead is conducting studies to create a triple-drug HIV regimen using Truvada and efavirenz, marketed as Sustiva by New York-based Bristol-Myers Squibb Co. The companies are using bi-layered technology to formulate the two drugs into a once-daily pill, and a new drug application is anticipated next year. (See BioWorld Today, Aug. 11, 2005.)
Shares of Foster City, Calif.-based Gilead (NASDAQ:GILD) gained 39 cents Friday to close at $54.36.
The stock had dropped nearly a dollar the day before, following news reports suggesting a possible connection between Tamiflu and the deaths of 12 children in Japan who had received the antiviral treatment. However, the FDA released information Friday stating that it could conclude no link between the two, and added that the relationship to Tamiflu was "difficult to assess because of the use of other medications, presence of other medical conditions and/or lack of adequate detail in the reports."
Most of the adverse events involved neurologic or psychiatric events, including delirium, hallucinations or encephalitis, which could be attributed to the influenza infection itself.
Tamiflu (oseltamivir phosphate) is approved to treat uncomplicated influenza A and B in patients, ages 1 and older, and also as a prophylactic in people 13 years or older who are at high risk during the influenza season. The drug is described as a neuraminidase inhibitor that acts by blocking the viral enzyme to prevent the virus from invading cells in the respiratory tract.
Tamiflu, marketed by Basel, Switzerland-based F. Hoffmann-La Roche Ltd., also is being investigated as a treatment in the event of an avian flu pandemic. Friday afternoon, Roche said the FDA's Pediatric Advisory Committee confirmed Tamiflu's safety in children, and the committee chairman, Robert Nelson, said there is "no concern at all" that Tamiflu played a role in the Japan deaths.
The FDA said it intends to continue monitoring the drug's safety, but, at this time, found no basis for amending the product's label.