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William Larson is an HIV medication adherence pharmacist working in Minneapolis, MN as part of the Ryan White program. He strives to increase HIV treatment literacy in disproportionately impacted communities. He is a graduate of the Black AIDS Institute’s Community Mobilization College in 2013.
Last week I attended CROI 2015 as a community educator scholarship recipient from CROI, in association with the Black AIDS institute and AVAC. It has been a rare opportunity to hear first-hand live presentations of new research by leading HIV researchers.
I got to meet several of the researchers at breakfast updates for scholarship recipients. What an opportunity! I was impressed by the researchers' approachability and willingness to answer questions.
I was also impressed by the committed and knowledgeable scholarship recipients, all of whom are eager to better understand the new research so that they could bring the information back to their home communities.
As a pharmacist working in HIV medication adherence, I am interested in new therapeutic agents for the treatment of HIV. Information was presented on a new compound, tenofovir alafenamide or TAF as part of single tablet regimen also containing elvitegravir, cobicistat and emtricitabine. This was compared to the currently available single tablet medication, Stribild, which contains elvitegravir, cobicistat, emtricitabine and tenofovir disaproxil fumarate (TDF).
TDF (Viread) is a frequently used medication and part of most HIV treatment regimens. It is found in the combination product Truvada and the single tablet regimens Atripla, Complera and Stribild. Although considered safe for most patients, there are concerns about bone and kidney changes which can occur in some patients with long-term use.
In research presented by Dr. David Wohl, TAF was found "non-inferior" to TDF in achieving viral suppression irrespective of age, sex, race, viral load or CD4 count. In simpler terms, TAF is at least as effective as TDF. Both drugs had low rates of viral resistance and both were well tolerated.
Dr. Paul Sax presented data on renal and bone safety of TAF compared to TDF. This research demonstrated that TAF has less effect on the kidney (serum creatinine and urinary protein) and bone (bone mineral density) compared to TDF, with slightly higher lipid levels from TAF.
In the clinic where I work, we are discontinuing or replacing TDF weekly in select patients with elevated creatinine levels. Although we are discontinuing TDF less often for bone changes, it is possible that is a problem which might be detected or develop later in patients on life-long therapy.
Why does TAF appear to be safer than TDF, with fewer kidney and bone changes? Compared to TDF 300 mg, TAF 25 mg produces 90 percent lower level of tenofovir in the plasma. Tenofovir is responsible for the bone and kidney changes. TAF, like tenofovir, is converted to tenofovir diphosphate intracellularly and this is the compound with antiviral properties.
Tenofovir alafenaide or TAF is a safer and equally effective alternative to TDF, and will likely become the preferred alternative for individuals now receiving a TDF-containing product.
My sincere thanks to CROI, AVAC and the Black AIDS Institute for allowing me and others to attend CROI and their commitment to disseminating the latest research to our most heavily-impacted communities in the United States and around the globe.