YS Biopharma’s Rabies Vaccine Outperforms Commercial Competitor in Phase III Trial


Rabies vaccine_iStock, Teka77

Pictured: Gloved hand holding a rabies vaccine syringe/iStock, Teka77

YS Biopharma on Tuesday revealed interim Phase III data for its investigational, next-generation rabies vaccine, demonstrating non-inferiority to a globally marketed comparator.

These early Phase III data point to the potential of the rabies vaccine to induce “best-in-class accelerated protection” in vulnerable populations and help fulfill the World Health Organization’s goal of delivering a weekly rabies vaccine to replace standard three- or four-week schedules, according to the company.

Participants inoculated with YS’s PIKA rabies vaccine candidate reached immunity against the rabies virus within seven days, a shorter timeframe than in comparators who received an approved and globally marketed comparator vaccine.

At the same time point, patients given the vaccine candidate had twice the seroconversion rate of rabies virus neutralizing antibodies than those in the comparator arm. According to YS, the result demonstrated the “superiority of PIKA rabies vaccine to offer quick onset of protection against virus infection.”

The investigational shot also showed non-inferior immunogenicity to its comparator.

In terms of safety, the late-stage study found YS’ PIKA shot to be “highly tolerable,” according to the announcement.

YS Biopharma CMO Zenaida Mojares in a statement called these interim Phase III data “compelling evidence of the robust immunogenicity and favorable safety profile of the PIKA Rabies Vaccine.”

“By providing a shortened treatment regimen without sacrificing safety or quality, the PIKA Rabies Vaccine has the potential to improve rabies treatment and compliance,” Mojares said, pointing to the “long and inconvenient regimen” that existing vaccines require, which “presents a major barrier to treatment completion.”

YS’ pivotal Phase III trial is a randomized, double-blinded and comparator-controlled study with more than 4,500 healthy adult volunteers enrolled from the Philippines and Pakistan. The trial compared the company’s investigational PIKA vaccine, given through a seven-day regimen, against the standard 28-day schedule of a commercial comparator. Tuesday’s readout included data from the study’s first 900 participants.

The biotech’s rabies vaccine candidate consists of a cell culture-derived rabies antigen combined with its proprietary PIKA adjuvant. According to YS’ website, PIKA acts as an agonist of the TLR3 protein, which plays a central role in the body’s ability to recognize pathogens and mount an innate immune response.

The PIKA vaccine candidate is designed to trigger an “accelerated and strong cellular immunity” against the rabies virus, and help the body rapidly mount a more robust humoral immune response, according to YS.

Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at tristan@tristanmanalac.com or tristan.manalac@biospace.com.

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