Curevo Reports Positive Shingles Vaccine Results

Curevo Vaccine, a Seattle-based biotechnology company specializing in vaccines for the varicella zoster virus (VZV), has announced promising results from a Phase 2 trial of their development-stage shingles vaccine, amezosvatein (CRV-101). These findings will be presented at the World Vaccine Congress in Barcelona.

The trial involved 876 participants aged 50 and older, who were either administered amezosvatein or Shingrix®, a well-established shingles vaccine. Participants were split into groups, with 619 receiving varying doses of amezosvatein and 257 receiving Shingrix. The trial followed a two-dose schedule, with doses given two months apart. The average follow-up duration for those on amezosvatein was 18.8 months, while for those on Shingrix, it was 21.5 months.

A crucial outcome of the study was that none of the amezosvatein recipients developed shingles within the follow-up period. This is noteworthy because, based on historical data from the ZOSTER-006 Phase 3 trial of Shingrix, it was anticipated that at least 10 out of the 876 participants would contract shingles without effective vaccination. Similarly, no shingles cases were recorded among participants in the Shingrix group.

Dr. Guy De La Rosa, Chief Medical Officer at Curevo, expressed enthusiasm over the results, highlighting that they validate the earlier reported non-inferiority immunogenicity data. George Simeon, Curevo's CEO, emphasized that these outcomes bolster the company's efforts to introduce a new shingles vaccine to the global market.

The trial's primary endpoint focused on the immune response one month after the second dose. Previous data presented at the IDWeek scientific conference revealed that the highest dose of amezosvatein (100 μg gE plus 15 μg SLA-SE) elicited an immune response comparable to Shingrix. This included similar levels of serum neutralizing antibodies and T-cell responses specific to the varicella zoster virus.

Safety and tolerability, important aspects of vaccine assessment, showed that amezosvatein and Shingrix had similar safety profiles. However, the highest dose of amezosvatein exhibited significantly better tolerability. Only 7.3% of participants receiving the highest dose of amezosvatein reported Grade 2 or Grade 3 reactogenicity events, such as those interfering with or preventing daily activities, compared to 33.3% of Shingrix recipients. This difference was statistically significant, indicating a meaningful improvement in tolerability.

Further breakdown of reactogenicity events showed that only 3.6% of high-dose amezosvatein recipients experienced Grade 2 or Grade 3 local reactions (like pain, redness, or swelling at the injection site), versus 25.3% in the Shingrix group. For systemic reactions (such as fever, headache, fatigue, muscle pain, and chills), the rates were 5.5% for high-dose amezosvatein compared to 19.1% for Shingrix, both results being statistically significant.

Amezosvatein, an adjuvanted subunit vaccine, targets the glycoprotein 'E' (gE) antigen, a strategy proven to trigger a lasting immune response to prevent shingles. The vaccine was designed to offer a superior safety profile and improved manufacturing processes, enhancing its accessibility. The adjuvant used, SLA-SE, was developed by the Access to Advanced Health Institute in Seattle, and amezosvatein was licensed from the Mogam Institute for Biomedical Research, supported by South Korea’s GC Biopharma.

Shingles, or herpes zoster, results from the reactivation of the varicella zoster virus, which remains dormant in the body after causing chickenpox. Shingles affects approximately 30% of adults at least once in their lifetime, leading to painful, blistering rashes that can last several weeks. A significant proportion of shingles sufferers develop post-herpetic neuralgia (PHN), a severe, long-lasting nerve pain. Shingles can also impact vision and is associated with increased risks of heart attack, stroke, and dementia.

Curevo aims to reduce the burden of infectious diseases by developing vaccines with improved tolerability and accessibility. Their lead product, amezosvatein, aims to address the limitations of current shingles vaccines and expand vaccine accessibility, particularly for those hesitant to receive more reactogenic vaccines.