Kenneth E. Palmer, Ph.D.

Griffithsin: Potent Plant-Derived Viral Entry Inhibitor First isolated from the red alga Griffithsia 121 aa domain-swapped dimer (12.7 kDa each) Three high-mannose binding sites per subunit Evaluated as an HIV microbicide with pM to low nM affinities to the HIV surface glycoprotein gp120 Current study supported by a grant from US NIH (NIAID) for a first-in-human clinical trial as a topical microbicide designed to prevent HIV transmission (The PREVENT Study) ~36 million living with HIV ~2.1 million newly acquired infections

Presentation Outline Why Griffithsin? Improvement of Griffithsin (GRFT) Q-Griffithsin (Q-GRFT) Introduction to the pipeline of Q-GRFT products New information about Q-GRFT safety and efficacy profile Overview of the planned PREVENT Clinical Study

Modification of GRFT to Meet Functionality Criteria Objective Develop an oxidation-resistant form of Griffithsin that maintains stability and activity for development as an HIV microbicide to be used in a first-in-human clinical study Method Structure-guided approach to generate aa-variants of the parent API; evaluate each for expression yield, activity, stability to oxidation, and compatibility with formulation Results Several variants at position 78 were produced, and M78Q was selected as the lead drug substance

Q-GRFT's Improved Stability to Oxidation Data from Drs. Rohan and Kramzer

HIV Pseudovirus Q769.h5 (ng/mL) HIV Primary virus Isolate BaL (ng/mL) Verification of HIV Neutralization Data from Adam Husk Data from Amanda Lasnik   Q-GRFT WT GRFT Antiviral Activity HIV Pseudovirus Q769.h5 (ng/mL) IC 50 19.88 ± 9.75 14.74 ± 1.40   Q-GRFT WT GRFT Antiviral Activity HIV Primary virus Isolate BaL (ng/mL) IC 50 0.214 ± 1.6 0.275 ± 1.28 Clade A virus types are the least sensitive to GRFT neutralization

Formulations for the PREVENT clinical study and beyond… Lead product is a rectal gel for pericoital use Carbopol base Alternative dosage forms: Film Suppository Prototype gel Prototype Suppositories Fat based vs water based Prototype film

Benzalkonium chloride Safety Study of Q-GRFT Gels: Pilot 7-Day Rectal Irritation Study (rat) Group Treatment Dose Concentration (% w/w) Dose Volume a (ml/animal) No. of Animals Males (Day 8) Females (Day 8) 1 Sham --- 5 2 Placebo gel 0.1 3 Q-GRFT gel 0.3 4 3.0 Conceptrol® 6 Benzalkonium chloride Results No differences in body weight No significant hematological differences No significant clinical chemistry differences Very low composite irritation scores (table at right: Erythema + Eschar + Edema = 12 max) Group/Irritation Males Females 1 0.2 2 0.6 3 0.4 4 5 0.8 6 2.4

Chlamydia trachomatis Impact of Q-GRFT on Microflora & STI Effects of Q-GRFT on beneficial microflora (Lactobacillus spp) and selected ST pathogens (Neisseria gonorrhea, Chlamydia trachomatis) were evaluated in vitro (ImQuest Labs.) Results: No effects on the bacterial species tested. Q-GRFT is not antibacterial Lactobacillus spp Chlamydia trachomatis Neisseria gonorrhoeae

Pharmacology in Non-Human Primates (US CDC) 6 NHPs were dosed with 0.3% Q-GRFT gel and rectal eluates were collected to calculate the concentration of Q-GRFT available Concentration stable between 15 minutes and 2 hours, but begins to decrease by 6 hours However, at 6 hours post application the concentration of Q-GRFT in situ was greater than the IC90 for even the more resistant virus clades

Summary and Upcoming Studies Q-GRFT is much more resistant to oxidation than WT and is compatible with our gel formulation – Q-GRFT was selected for the clinical study Preliminary results of PK, BA and safety studies in rat and NHP look excellent GLP toxicology has started: consists of 21-d daily rectal exposure with 14-d recovery in rat and rabbit – endpoints include local and systemic toxicity and immunotoxicity Phase I clinical study is scheduled to begin by Q1/2019

The PREVENT Phase I Clinical Study University of Pittsburgh (Ian McGowan MD, PI; Ross Cranston MD, Co-PI) Double-blind, randomized, placebo-controlled, cross-over design N = 18 participants; enrollment open to healthy men and women Administration of Q-GRFT gel as directly observed therapy; multiple safety endpoints Biopsies used to assess efficacy by challenge of the tissues with HIV ex vivo PSRT: Protocol Safety Review Team

Acknowledgement Contract Organizations (partial list) PREVENT Program Team (partial list) University of Louisville (award recipient) Josh Fuquá, Ph.D. (Prgm. Manager) Nobuyuki Matoba, Ph.D. (PK/PD) Amanda Lasnik, M.S. (laboratory lead) University of Pittsburgh Lisa Rohan, Ph.D. (product development) Lin Wang, M.S. (laboratory lead) Ian McGowan, M.D. (clinical study PI) Ross Cranston, M.D. (clinical study co-PI) Centers for Disease Control & Prevention David Garber (NHP studies) NIH Jim Turpin, Ph.D. (Program Officer) Hans Spiegel, M.D. (medical advisor) Contract Organizations (partial list) SRI International (preclinical CRO) Hanna Ng, James Bakke, Janice Schindler-Horvat ImQuest (assay development) Karen Buckheit and team KBP Inc (API CMO) Barry Bratcher and team CBR International Jeanne Novak and team Program Funding NIAID Grant Award 1U19 AI113182