Cytodyn Inc (CYDY)

[ohm20]

From 2010, May 15 Progenics - 324mg dose (no longer used) - Even at that low dose, good results. Not currently used weekly so no washout.

SC PRO 140 demonstrated potent and prolonged antiretroviral activity. Mean log10 reductions in HIV-1 RNA were 0.23, 0.99 (p=0.0093), 1.37 (p=0.0001), and 1.65 (p<0.0001) for the placebo, 162mg weekly, 324mg biweekly and 324mg weekly dose groups, respectively. Viral loads remained suppressed between successive doses. Treatment was generally well tolerated.

Screening samples from the three subjects with dual/mixed virus were analyzed post-study using the ES Trofile assay. One subject had detectable levels of dual/mixed virus pre-treatment and would have been excluded from the study if ES Trofile had been available for screening. Dual/mixed virus was first detected on Day 15 or Day 29 in the other two subjects. Studies are ongoing to determine if these subjects had pre-existing dual/mixed virus at levels below the ES Trofile’s limit of detection. Both subjects had only R5 virus detected in ES Trofile at end of study.

A loading dose may decrease the potential for dual/mixed virus to emerge following initiation of treatment with PRO 140, as may the presence of additional antiretroviral agents in future combination regimens. Lastly, since the potential for outgrowth of CXCR4-using viruses is related to the sensitivity of the tropism test used for screening, this resistance pathway may diminish in clinical importance as tropism assays become increasingly sensitive in detecting CXCR4-using viruses.

The PRO 140 results are especially notable in that monotherapy was followed by slow washout of drug. Such conditions can foster development of antiretroviral drug resistance (36;37). Overall, our findings suggest that PRO 140 presents a high barrier to resistance.