FDA approves protease inhibitor Aptivus

The Food and Drug Administration on Wednesday approved Boehringer Ingelheim's nonpeptidic protease inhibitor Aptivus (tipranavir) to be used in combination with other antiretroviral drugs to treat HIV infection. BI officials say the drug will be available at pharmacies nationwide within the next two weeks. The company hopes to gain approval to market the drug in Europe by the end of the year. Because Aptivus is not a peptide-based drug and has a different chemical structure than other protease inhibitors, it has been shown to be effective against strains of the virus that have developed defenses against other anti-HIV drugs. The drug is approved for HIV patients who have failed other anti-HIV regimens or are resistant to other protease inhibitors; it is not approved for first-line therapy, according to AIDSmeds.com. The U.S. Department of Health and Human Services has not yet developed guidelines for use of Aptivus among U.S. HIV patients. The recommended dosage for Aptivus is two 250-milligram capsules taken twice daily. The drug also must be taken with a small booster dose of Abbott Laboratories' protease inhibitor Norvir for maximum effect. An FDA advisory panel last month supported Aptivus's approval but called on BI to conduct long-term studies to evaluate the effects of Aptivus on blood-based lipid levels and liver function. The drug was shown in clinical trials to cause liver damage and hepatitis-like symptoms in some patients taking it. BI currently recommends that doctors give liver function tests to all HIV patients beginning Aptivus therapy and carefully monitor them throughout treatment. Extra caution is recommended for HIV patients also coinfected with hepatitis B or C who begin the drug. BI is currently conducting Phase II and III clinical trials of Aptivus involving HIV-positive children and adults who have not taken other anti-HIV drugs. The FDA has approved eight other protease inhibitor medications since 1996. The drugs work by blocking the action of an enzyme that cuts HIV proteins into smaller sections that the virus needs to replicate.