The FOTO study: The 48 week extension to assess durability of the strategy of taking efavirenz, tenofovir and emtricitabine Five days On, Two days Off (FOTO) each week in virologically suppressed patients

Background: The availability of antiretrovirals with prolonged half-lives allows testing less than daily dosing. A 24-week randomized study demonstrated non-inferiority of maintaining virologic suppression using specific antiretrovirals 5 consecutive days per week instead of 7 (“FOTO”: Five-days-On, Two-days-Off). This novel strategy was extended to assess durability.
Methods: FOTO enrolled 60 virologically suppressed participants (viral load < 50 c/mL for ≥ 90 days); all on efavirenz (EFV), tenofovir, emtricitabine. They were randomized to FOTO (typically weekends off) or DAILY treatment. The primary endpoint compared rates of virologic suppression at week 24; N=60 had 80% power to demonstrate non-inferiority (< 15% difference in suppression rates). Durability was assessed through week 48; all DAILY subjects could crossover after week 24 to FOTO given no virologic failure in either arm.
Results: N=50 were followed to week 48 (23 FOTO; 27 DAILY starting FOTO at week 24). The ten who stopped prior to wk 48 all had a VL< 50 at their last visit. No virologic failure was observed (confirmed VL> 400) during 48 weeks. At week 48 on FOTO, 45/50 (90%; 95% CI 82-98%) had a VL< 50; five had a blip (≤200) at week 48 but all were < 50 on the next VL. EFV troughs done in a subset two days off showed most had levels above the therapeutic target of 1000 ng/mL though suppression was maintained in those with one or more levels below this target. The median score on a preference questionnaire (0=prefer DAILY; 10=prefer FOTO) four weeks on FOTO was 9.5.
Conclusions: The FOTO strategy maintains virologic suppression through 48 weeks. There was a strong preference to take 2-days off treatment per week even when on a simple one-pill once-daily regimen. The 28% cost savings for this strategy has broad potential implications for the developed and developing world.

C. Cohen1, A. Colson1, G. Pierone2, E. Dejesus3, F. Kinder4, R. Elion5, D. Skiest6, A. Habel1, J. Jensen1, J. Garb7, H. Schrager1, D. Back8
1CRI New England, Boston, United States, 2AIDS Research and Treatment Center of the Treasure Coast, Fort Pierce, United States, 3Orlando Immunology Center, Orlando, United States, 4Kinder Medical Group, Miami, United States, 5Whitman-Walker Clinic, District of Columbia, United States, 6CRI New England, Springfield, United States, 7Baystate Medical Center, Springfield, United States, 8University of Liverpool, Liverpool, United Kingdom