Tipranavir, an experimental protease inhibitor developed by Boehringer-Ingelheim, is to become available to more patients in the UK who need the drug to construct a viable treatment regimen.
Boehringer-Ingelheim will write to doctors shortly to tell them that patients with CD4 cell counts below 100 cells/mm3 will be eligible to receive the drug. Previously the drug was rationed to people with CD4 cell counts below 50 cells/mm3, who were at immediate risk of disease progression despite treatment with highly active antiretroviral therapy.
Patients may not use tipranavir alongside any other protease inhibitor apart from ritonavir (used at a low dose of 200mg to boost tipranavir levels). This is because drug interaction studies with saquinavir, amprenavir, atazanavir and lopinavir have not been completed.
Wider access to tipranavir through a named patient programme in the United Kingdom is unlikely before the third quarter of 2004. The drug is expected to be licensed for treatment-experienced patients in 2005, provided that current clinical trials do not produce any unpleasant surprises.
People not eligible to receive tipranavir may be able to join a clinical trial of another protease inhibitor, TMC-114. Like tipranavir, TMC-114 is designed to be active against HIV that is resistant to most other protease inhibitors. The study is called C213 and is recruiting patients in Manchester, London and Edinburgh who have experience of all three classes of antiretrovirals.
Participants in the study will be randomised to receive one of four different doses of TMC-114 boosted with a low dose of ritonavir, and will also receive another protease inhibitor selected by resistance testing to provide the greatest anti-HIV activity possible. A previous dose comparison study did not find any difference in antiviral effect between three different doses of the drug. This study will also compare once and twice daily dosing.
Further information on this website
Tipranavir now available for emergency use in UK