HIV and ID Observations

The approval last week of TAF/FTC/RPV — that’s coformulated tenofovir alafenamide, emtricitabine, and rilpivirine — brings us another one-pill, once-daily option for HIV treatment.

It’s essentially the same as the existing TDF/FTC/RPV, with similar pros/cons, but with three notable differences coming with the substitution of TAF for TDF.

Specifically:

1. Likely reduced renal and bone toxicity. Since approval was based on bioequivalnce, this hasn’t (yet) been proven in clinical trials — switch-studies are ongoing, comparing TAF/FTC/RPV to both TDF/FTC/RPV, and TDF/FTC/EFV. Note that this might end up being a more relevant consideration with TDF/FTC/RPV than TDF/FTC/EFV, since the former is taken with food and hence leads to higher tenofovir levels.
2. A smaller tablet size. TDF/FTC/RPV was already the smallest coformulated pill for complete HIV treatment, and with 25 mg of TAF replacing 300 mg of TDF, the new pill is quite a bit smaller. For some patients, this matters a lot.
3. A weird new brand name. It’s called Odefsey, which sounds kind of like the famous Stanley Kubrick film, without the “2001:  A Space …”

We can assume (for now) that carried over from TDF/FTC/RPV is the generally well-tolerated profile (low risk of rash, GI side effects, metabolic abnormalities). As with TDF/FTC/RPV, TAF/FTC/RPV should be taken with food and without concomitant PPIs to maximize RPV absorption. It is not intended for treatment-naive patients who have HIV RNA > 100,000 copies/mL.

So this is a nice advance, especially for those patients at risk for renal and/or bone disease. Little reason not to switch existing TDF/FTC/RPV-treated patients to this new formulation, at least once payers add it to their formularies. (As with ECF-TAF, the listed price of TAF/FTC/RPV is the same as TDF/FTC/RPV.)

Note that arguably a bigger TAF-related approval — the TAF/FTC pill, already nicknamed “TAF-ada” — is expected next month.

[youtube http://www.youtube.com/watch?v=KliLsBSo-J4]