• The randomized, double-blind GEM-3 trial will compare repeat dosing of either B-VEC or placebo in approximately 30 dystrophic epidermolysis bullosa (DEB) patients 
  • Top line data and BLA filing are anticipated in 2021; EMA aligned on pivotal study design and an MAA is anticipated shortly after BLA

PITTSBURGH, PA, USA I July 28, 2020 I Krystal Biotech, Inc. (Nasdaq:KRYS), a fully integrated gene therapy company driven by its proprietary, engineered herpes simplex virus type 1 vector (HSV-1) platform, today announced the initiation of GEM-3 study, a multi-center, placebo-controlled, double-blinded, Phase 3 clinical study of beremagene geperpavec (“B-VEC”, previously “KB103”) for the treatment of dystrophic epidermolysis bullosa (DEB) patients.

“Despite the logistical challenges associated with COVID-19, Stanford and I are excited to begin this pivotal study,” said Dr. Peter Marinkovich, M.D., associate professor of dermatology and director of the Blistering Disease Clinic at Stanford University, and primary investigator for the trial. “We and the other study sites have worked closely with the Krystal team to ensure safe trial practices in the context of the ongoing pandemic, enabled by the out-patient nature of B-VEC dosing.”

Suma Krishnan, founder and chief operating officer of Krystal Biotech added, “The initiation of the pivotal study marks an important milestone toward our goal of a potential painless, convenient, and corrective approach to treat patients suffering from this debilitating disease. We look forward to having a home dosing protocol in place in the upcoming months that, we believe, would further improve the quality of life of our patients and their caregivers.”

This clinical progress follows announcement of positive results from the GEM-1 and GEM-2 studies. B-VEC is a topical, re-dosable gene therapy in development for the treatment of both the dominant and recessive forms of DEB, a rare and severe monogenic skin disease for which there is currently no approved treatment. The U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have each granted B-VEC orphan drug designation for the treatment of DEB, and the FDA has granted B-VEC fast track designation and rare pediatric designation for the treatment of DEB. In addition, in 2019, the FDA granted Regenerative Medicine Advanced Therapy (RMAT) to B-VEC for the treatment of DEB and the EMA granted PRIority MEdicines (PRIME) eligibility for B-VEC to treat DEB.  

B-VEC is manufactured in-house using the commercial process and at scale in Krystal’s fully functional GMP ANCORIS facility, located near corporate headquarters in Pittsburgh.

“Our existing facility has the capacity to support our commercial launch in the U.S.,” said Krish Krishnan, chairman and chief executive officer of Krystal Biotech. “We look forward to getting ASTRA, our second GMP facility operational in 1H 2022 to supplement ANCORIS, as we expand beyond the U.S. markets into EU and the rest of the world.”

About the GEM-3 Pivotal Study
The GEM-3 trial is a randomized, double-blind, intra patient placebo-controlled multicenter study designed to evaluate the efficacy and safety of B-VEC for patients suffering from both recessive and dominant forms of dystrophic epidermolysis bullosa. The trial aims to enroll approximately thirty (30) participants with DEB, aged 6 months or older at time of consent. Investigator identified wound pairs, up to three in each patient, will be treated once weekly for six months with either B-VEC or placebo.

Dosing
The dose administered to each wound is dependent on the size of the wound and ranges from 4×108 to 1.2×109 PFU per wound. The maximum weekly dose, administered once weekly per patient, is defined by patient age as outlined in the table below.

Maximum Weekly Dose Per Subject:
Age Maximum Weekly Dose
≥ 6 months to < 3 years 1.6×10^9 PFU/week
≥ 3 years to < 6 years 2.4×10^9 PFU/week
≥ 6 years 3.2×10^9 PFU/week

Weekly dosing will be continued until the wound is completely closed, and re-dosing may occur at any point throughout the study should a wound re-open. In addition to the primary target wound pair(s), additional wounds (secondary wounds) may be selected to be treated with B-VEC which will give the treating physicians flexibility to treat a larger number of wounds. 

Endpoints
The Primary Outcome Measure is complete wound healing determined by the Investigator, as compared to baseline in B-VEC treated wounds versus placebo treated at Weeks 20, 22 and 24.

Secondary endpoints to be evaluated in the study include complete wound healing at Weeks 8, 10 and 12; the mean change in pain severity (using either a VAS or FLACC-R Scale) per primary wound site associated with wound dressing; the proportion of primary wound sites with ≥75% healing assessed via Canfield photography. Additional exploratory measures include relative time to wound closure from baseline, duration of wound closure, mean reduction in wound surface area in B-VEC treated versus placebo treated wounds, mean change in Quality of Life in addition to Skindex score as compared to baseline at Week 24. Throughout the study, participants will complete questionnaires, have images captured of their study wounds, undergo physical exams, have vital signs and safety labs monitored.

About Krystal Biotech
Krystal Biotech, Inc. (NASDAQ:KRYS) is a gene therapy company dedicated to developing and commercializing novel treatments for patients suffering from dermatological diseases. For more information, please visit http://www.krystalbio.com.

SOURCE: Krystal Biotech