A lead-in dose is being tested to reduce side effects. B. Seems unlikely that tenofovir will be approved this year because of FDA concern about bone density. Manufacturer reported that preclinical studies show tenofovir is eliminated by the kidney, is not metabolized by the liver and is not associated with cytochrome p450 interactions. Manufacturer Gilead Sciences did not respond to a request for a statement. No significant toxicities associated with the drug were reported.
Additional studies are ongoing.
Gilead has reluctantly responded to activist pressure to open an expanded access program for tenofovir, since the company feels burned by the fact that 10,000 people got free adefovir before they cut their losses and dropped that ineffective and toxic drug. Loss of bone density has been seen in animals on this drug, but this has not appeared in people who have taken the drugs in clinical trials. Access to the drug for those in serious need is expected to start in January 2001. A large multi-site trial began enrolling in October of 2000.