CytoDyn Inc.announces clearance from the independent Institutional Review Board (IRB) overseeing its CD03 Phase 3 investigative monotherapy trial to increase the weekly PRO 140 dose from 525 mg to 700 mg for newly enrolled patients. Current participants in the trial who failed to maintain suppressed HIV viral load on a lower dose of PRO 140 will be permitted to continue in the trial with a higher dose. The objective of this trial is to assess the efficacy, safety and tolerability of PRO 140 as a long-acting, single-agent maintenance therapy for the chronic suppression of HIV. The company noted that the exact response rates for PRO 140 at 525 mg could vary as the trial progresses. To date, there has been a clear distinction between patient response rates with PRO 140 at the lower 350 mg and higher 525 mg doses. CytoDyn believes that dosing PRO 140 at the 700 mg dose has the potential to achieve an even higher response rate than the approximate 70% currently observed at the 525 mg dose. Patients enrolled in the Phase 3 monotherapy trial were prescreened for CCR5-tropic HIV-1 infection and suppressed HIV viral load under an existing highly active antiretroviral therapy (HAART) regimen. CytoDyn initiated the trial treating patients with weekly PRO 140 at 350 mg and found that approximately 40% were able to maintain suppressed HIV viral load. Following treatment of the first 150 patients, the protocol was revised to increase the weekly dose of PRO 140 to 525 mg. Patients who were non-responders to PRO 140 at the 350 mg dose were given the opportunity to switch to the higher 525 mg dose, and a majority were able to re-suppress with the higher dose. Also of note, patients who achieve suppressed HIV viral load after 10 weeks tend to maintain suppressed viral load. Interestingly, some patients in Phase 2b extension study are now achieving suppressed HIV viral load for nearly four years with PRO 140 as a single agent. Of key importance in the Phase 3 monotherapy trial, all non-responders to PRO 140 have safely achieved suppressed HIV viral load upon returning to their prior HAART regimens before PRO 140 monotherapy.