Curevo Vaccine Announces Positive Topline Results from Phase 2 Trial of Amezosvatein, a Next-Generation Vaccine for Shingles, Head-to-Head vs. Shingrix

— Positive data from 876-patient head-to-head trial versus Shingrix® shows amezosvatein met the primary immunogenicity endpoint, eliciting a robust immune response non-inferior to Shingrix, including a 100% vaccine response rate — Amezosvatein also met the primary safety endpoint, with lower local and systemic adverse events in this trial compared to Shingrix — Amezosvatein to enter global Phase 3 trials in 2024 SEATTLE, Jan. 07, 2024 (GLOBE NEWSWIRE) — Curevo Vaccine (Curevo), a privately-held clinical-stage biotechnology company dedicated to developing varicella zoster virus vaccines with improved tolerability and accessibility, today announced positive data from an 876-patient Phase 2 trial of amezosvatein (a non-mRNA, adjuvanted subunit vaccine also known as CRV-101) head-to-head versus Shingrix in participants aged 50 years and older. Amezosvatein met all primary endpoints in the randomized, controlled, observer-blind Phase 2 trial, including demonstrating non-inferiority to Shingrix as measured by humoral immune response. Amezosvatein also exhibited lower rates of solicited local and systemic adverse events in this Phase 2 trial. Based upon these results, Curevo will advance amezosvatein into global Phase 3 trials in 2024 to address a market for shingles vaccination currently exceeding $4 billion. The co-primary endpoint of the Phase 2 trial was humoral immune responses one month after the second vaccine dose (Day 84). This primary immunogenicity endpoint was met as participants’ immune responses to amezosvatein were non-inferior to participants’ immune responses to Shingrix. Additionally, amezosvatein’s Vaccine Response Rate was 100.0% compared to Shingrix at 97.9%. The co-primary safety endpoint was also met, with amezosvatein demonstrating lower rates of solicited local and systemic adverse events in this Phase 2 trial. This was especially apparent when comparing higher grades of solicited local and systemic adverse events occurring within seven days of each dose. If confirmed in a Phase 3 trial, this would represent a significant advantage for amezosvatein since higher-grade adverse events interfering with daily activities are of particular concern to those considering being vaccinated for shingles. “Despite Shingrix being available for several years, vaccine coverage rates remain disappointingly low,” said Dr. Guy De La Rosa, Curevo’s Chief Medical Officer. “A growing body of evidence suggests tolerability issues contribute to both vaccine hesitancy and avoidance of the required second dose. Amezosvatein was developed specifically to provide high vaccine effectiveness and best-in-class tolerability. We are very excited by these Phase 2 data.” At the dose chosen for Phase 3 trials, participants receiving amezosvatein reported zero Grade 3 solicited local or systemic adverse events. Grade 2 solicited systemic side effects were reported by 5.5% of participants receiving amezosvatein versus Grade 2 and Grade 3 side effects reported by 19.1% of those receiving Shingrix. Grade 2 solicited local side effects were reported by 3.6% of participants receiving amezosvatein versus Grade 2 and Grade 3 side effects reported by 25.3% receiving Shingrix. Grade 2 and 3 local and systemic side effects are those most likely to interfere with daily activity and are a key contributor to vaccine hesitancy and dose avoidance. “There is a clear unmet medical need globally for a shingles vaccine with improved tolerability and better accessibility,” stated Dr. William Smith with the Alliance for Multispecialty Research, the primary investigator on this Phase 2 trial and a board-certified physician who has been involved in more than 1,900 clinical trials over the last 35 years. “Amezosvatein had lower rates of solicited local and systemic adverse events compared to Shingrix in this Phase 2 trial, while showing a comparable immune response. If these data are confirmed in a Phase 3 trial, amezosvatein holds great promise in meeting the goal of broadening effective vaccination rates against shingles, a serious medical condition capable of causing significant, long-term disruption in adult populations.” “Fewer than 5% of eligible adults in most European countries and China have received both doses of Shingrix,” noted George Simeon, Curevo’s Chief Executive Officer, “and two thirds of adults in the USA still need to be immunized against shingles. The market opportunity in shingles is large and underserved with only a small fraction of the over $350 billion global addressable market currently vaccinated. The entire Curevo team is dedicated to swiftly bringing amezosvatein to global markets.” About the Phase 2 trialThe Phase 2 trial (NCT05304351) enrolled 876 participants to receive either amezosvatein or Shingrix on an identical two-dose, two months apart schedule. 257 participants received Shingrix and 619 participants across five arms received amezosvatein. Amezosvatein achieved both primary endpoints in the trial, Day 84 safety/tolerability and Day 84 humoral immune response as measured by the geometric mean concentration of anti-gE antibodies to both vaccines. The trial enrolled participants at over a dozen sites across the USA. About amezosvatein‘Amezosvatein’ is the assigned non-proprietary name for CRV-101, a non-mRNA adjuvanted subunit vaccine under investigation by Curevo. Like Shingrix, amezosvatein uses a subunit protein antigen called glycoprotein ‘E’ (gE). Targeting the gE antigen is proven to elicit a long-term, protective immune response to prevent shingles. Also like Shingrix, amezosvatein uses an adjuvant targeting the TLR4 pathway to boost the immune response to the gE antigen. Amezosvatein was engineered to have a best-in-class safety profile in addition to manufacturing advantages to improve vaccine accessibility. About shinglesAlso called ‘herpes zoster’, shingles occurs when the varicella zoster virus causing childhood chickenpox re-emerges from sensory ganglion nervous system cells where the virus lies dormant after initial exposure. Virtually all adults have been exposed to the varicella zoster virus and around 30% will develop shingles at least once in their lifetime. The blistering skin rash accompanying shingles also causes severe pain, with both pain and rash lasting 2-4 weeks. Between 10-18% of those who get shingles develop post-herpetic neuralgia (PHN), a condition marked by debilitating nerve pain lasting over six months and often beyond one year. There is no approved treatment for PHN. Shingles may also affect the eyes, potentially causing loss of vision. Contracting shingles has also been linked with increased risk of heart attack, stroke, and dementia/Alzheimer’s disease. About Curevo Vaccine Curevo is a privately held, clinical-stage biotechnology company based near Seattle and is dedicated to reducing the burden of infectious disease by developing vaccines with improved tolerability and accessibility. Curevo’s lead product is amezosvatein, a non-mRNA sub-unit vaccine to prevent shingles, a serious medical condition involving a painful, blistering skin rash where 10-18% of people also develop serious, long-lasting nerve pain. The current $4+ billion shingles vaccine market is characterized by accessibility issues and vaccine hesitancy/dose avoidance related to vaccine tolerability. Curevo is also developing a non-live, non-mRNA subunit chickenpox vaccine intended to reduce or eliminate barriers to immunizing immunocompromised children. For more information visit https://curevovaccine.com/. Shingrix® is a registered trademark of GlaxoSmithKline, PLC. CONTACT: Contacts

David Miller

Sr. Director of Strategic Communications

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