European marketing approval has been granted for tipranavir, Boehringer Ingelheim’s protease inhibitor.
The drug will be marketed under the trade name Aptivus and has already received approval by regulatory authorities in the United Sates.
A non-peptidic protease inhibitor tipranavir is approved for use with a low, boosting dose of ritonavir in combination of other anti-HIV drugs in patients who have extensive previous experience of antiretroviral therapy and have HIV which is resistant to other protease inhibitors.
Tipranavir is taken in two daily doses of 500mg together with 200mg of ritonavir.
Regulatory approval for tipranavir was granted on the basis of the RESIST I and RESIST II studies. These trials involved over 1400 individuals with heavy experience of antiretroviral treatment. Investigators found that patients who were treated with tipranavir were more likely than individuals taking a comparator protease inhibitor to achieve a response to treatment.
Last week the US Food and Drug Administration issued revised HIV treatment guidelines stating that patients with multi-drug experience should receive anti-HIV therapy with the aim of suppressing viral load as low as possible. In order to achieve this, the guidelines suggest that patients should consider taking a boosted protease inhibitor such as tipranavir/ritonavir together with the fusion inhibitor, T-20 (enfuvirtide, Fuzeon).
The current UK guidelines, issued by the British HIV Association note that the “RESIST-I and II studies provide data that the [protease inhibitor] tipranavir is an active agent for the management of drug-resistant HIV in highly treatment-experienced patients”, and notes that the use of tipranavir along with another active drug, use as T-20 significantly increases the chances of virological suppression.
Side-effects of tipranavir include raised liver enzymes and increased levels of blood fats. Most patients experiencing these side-effects in the RESIST studies did not need to change treatment. Tipranavir is known to interact with other protease inhibitors and with some drugs used to treat infections, such as fluconazole and rifampicin. It can also interact with statins and antacids requiring the dose of tipranavir to be increased.