At the Conference on Retroviruses and Opportunistic Infections (CROI 2020
), 96-week results from the DISCOVER study, evaluating emtricitabine 200 mg and tenofovir alafenamide 25 mg tablets (F/TAF) in comparison with emtricitabine 200 mg and tenofovir disoproxil fumarate 300 mg (F/TDF) for pre-exposure prophylaxis (PrEP) were presented.
spoke to Onyema Ogbuagu, MD, FACP, director of HIV clinical trials program at Yale School of Medicine and presenting author for more information on the results.
I think it's reassuring that at 96 weeks, almost 2 years of minimum follow up for a very high sexual risk group for acquiring HIV infection, that there was still a non-inferiority of F/TAF to F/TDF for HIV prevention. So I think that that answers that question about TAF, being a viable option and effective option for PrEP in in a high risk population.
I think that the safety signals that persisted through week 96, including, increased bone mineral density across the study subjects is an important safety distinction, so that individuals who are older, young people who are still building bone mass, people that have medical conditions that can impact on bone mineral density like steroid use, smoking, advanced age, hypogonadism, that those are patients that would definitely benefit from going on a PrEP option that has less bone mineral density fluxes over time.
We also showed differences in biomarkers of proximal tubular dysfunction. It was important to note that the changes were pronounced in people who were on TDF alone, while those with half did not show that. Even though we don't know the clinical significance of those changes, I think it's an important consideration particularly for people who have impaired renal function to begin with or may be on concurrent medications that may have nephrotoxic or kidney toxic potential.
So we did do subgroup analysis for people who are older than age 50 and people who had moderate renal impairment. It looks like those differences were exaggerated in those people suggesting that those may be subgroups of patients that you may want to preferentially consider TAF as an option. The last thing I would say was that there were limited changes between both medications.
But it's reassuring that the total cholesterol HDL ratios were preserved in spite of the lipid differences between both arms. Again, we don't know the clinical significance of that. I think that even for TAF there were decreases in total cholesterol, HDL and LDL that were noted. So not increases as has been described in HIV positive patients so all in all, I think that the data strongly supports TAF/FTC is an option for PrEP.
Studies for TAF/FTC are ongoing in women too. The FDA label showed that it could only be used for people at sexual risk exclusive of receptive vaginal intercourse, but there is a commitment from Gilead, to pursue those studies in cisgender women.
>>Read more about the 96-week results from the DISCOVER study.
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