Boehringer Ingelheim says that it has started enrolling patients for a Phase IIIb trial of its HIV drug Aptivus which will look at the efficacy of the drug across a wide range of race and gender.

The SPRING project “will be one of the largest racially and gender diverse international studies of highly treatment-experienced HIV-1 infected patients”, the German-headquartered drugmaker said, noting that it will examine the safety, efficacy and pharmacokinetics of Aptivus (tipranavir) in a racially diverse group of 200 female and 200 male treatment-experienced patients across eight countries (at 72 sites) in three continents.

Boehringer noted that patients will be included in a randomised evaluation to assess the impact of therapeutic drug monitoring (TDM) on the efficacy and safety of Aptivus boosted with ritonavir, with a 500 mg/200 mg dose given twice daily for 48 weeks. TDM measures specific drug levels in the blood at certain times and is used to tailor dosages to fit the specific needs of the individual patient.

Clinical trials have shown that the efficacy of antiretroviral treatments may vary across races and genders, said SPRING investigator Sharon Walmsley, who noted that 48-week data from the firm’s RESIST studies a couple of years ago have already demonstrated the efficacy of Aptivus in treatment-experienced patients. “SPRING is designed to further examine its utility in diverse patients within this population," she concluded,

Worldwide, there are more HIV-positive women than ever before, with nearly 18 million currently living with the disease, said Boehringer, noting that women of African and Latin American descent are disproportionately affected and account for a large number of infections in developed countries, including those in Europe. In the USA, half of patients diagnosed with HIV between 2001 and 2004 were African-Americans, while 20% were of Latin American descent, the company said.