Depot formulation of a D-peptide HIV entry inhibitor - PROJECT SUMMARY
With 37 million people living with HIV/AIDS (including 1.2 million in the US), and 1.1 million AIDS-related
deaths in 2015, HIV/AIDS remains a formidable global epidemic (UNAIDS, CDC). Modern HIV therapy
combines drugs from different classes to form “cocktail” therapies that have transformed HIV into a
manageable chronic infection for many individuals. Despite the effectiveness of these drugs, side effects and
drug resistance remain serious concerns for these life-long therapies. Thus, there is an enduring need for
novel HIV inhibitors with new mechanisms of action and stronger barriers to resistance. Furthermore, it is
recognized that lack of patient compliance is a major factor leading to treatment failure. For this reason, HIV
specialists are excited by the prospect of long-acting therapies, and a cocktail of such therapies would provide
a revolutionary new treatment option for many HIV patients.
Navigen is a small pharmaceutical company targeting infectious diseases through an innovative discovery
and design process. We have identified a novel HIV entry inhibitor, cholesterol-PIE12-trimer (CPT31), that is a
protease-resistant D-peptide (peptide made from D-amino acids) that targets HIV's conserved entry machinery.
With highly potent activity against all major HIV subtypes and designed barriers to resistance, our anti-HIV D-
peptide overcomes the current limitations of the entry inhibitor treatment class. In addition, CPT31 is ideal for
pre-exposure prophylaxis (PrEP) since it blocks the first stage of the viral lifecycle prior to infection of target
cells. CPT31 is currently in late preclinical development at Navigen.
CPT31's uniquely conserved target, superior resistance profile, high potency, protease resistance, and
favorable pharmacokinetic (PK) and physicochemical properties make it an ideal candidate for extended-
release depot formulation. Via a one-year R56 bridge grant, we have worked with an industry-leading
formulation group at Oakwood Labs to demonstrate the feasibility of developing a long-acting formulation of
CPT31 (CPT31-LA) suitable for once-monthly injection. Optimization of CPT31-LA is currently underway. In
this three-year grant application, using optimized CPT31-LA, we will perform 1) required activities for scale-up
and manufacturing in preparation for clinical trials, 2) rat and non-human primate (NHP) PK studies, 3) rat
toxicology studies, and 4) NHP prevention (PrEP) and therapeutic efficacy studies. These studies will greatly
facilitate development partnerships to advance CPT31-LA through IND filing and clinical trials. Once-monthly
CPT31-LA will provide a potentially transformative new option for the prevention and treatment of HIV.