1. Kenneth E. Palmer, Ph.D.

2. 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

3. 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

4. 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

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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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