Press Release

Antiva Biosciences Presents Data from Phase 1b/2 Study of ABI-2280 for Treatment of Cervical High-Risk HPV Infection at SGO 2026

Study Achieves Primary and all Secondary Endpoints with Statistically Significant Improvements in hrHPV Negativity at Week 12 and Week 24 as Compared to Placebo

In HPV16+ Patients, 78% Achieved HPV16 Negativity vs. 0% of Placebo Patients at Week 12

Efficacy was Durable, with 100% of Responders at Week 12 Maintaining hrHPV Negativity at Week 24; Treatment Well Tolerated

19 million U.S. Women are Living with High-Risk HPV with no Approved Treatment Options

Redwood City, CA – April 14, 2026 – Antiva Biosciences, a biopharmaceutical company developing novel, topical therapeutics for the treatment of high-risk infections and pre-cancerous lesions caused by human papillomavirus (HPV) in women, announced expanded data from the company’s Phase 1b/2 clinical trial of ABI-2280 for the treatment of persistent oncogenic (high-risk) cervical HPV (hrHPV) infection in a Rapid Fire Oral Presentation at the Society of Gynecologic Oncology (SGO) Annual Meeting on Women’s Cancer April 10-13 in San Juan, Puerto Rico.

The study achieved its primary endpoint and all secondary endpoints with the top dosing regimen of 1 mg dosed three times over two weeks for a cumulative dose of 3 mg. Patients receiving ABI-2280 demonstrated statistically significant improvements in the rate of hrHPV negativity at Week 12 and Week 24 as compared with placebo. Additionally, the trial showed ABI-2280 treatment to be safe and well tolerated with the most commonly reported adverse events (AEs) categorized as mild and moderate and localized to the treatment area.

Rapid Fire Oral Presentation Highlights (3mg Dosing Regimen):

  • For the primary efficacy endpoint, 46% of patients achieved hrHPV negativity at Week 12 for all hrHPV genotypes present at baseline as compared to only 16% of placebo patients (p=0.0077).  
  • In a subgroup analysis of patients with the HPV16 genotype at baseline, 78% patients achieved HPV16 negativity at Week 12 and Week 24, compared to 0% and 25% of placebo patients at Week 12 and Week 24, respectively.
  • At Week 24, 65% of patients achieved hrHPV negativity for all hrHPV genotypes present at baseline as compared to only 32% of placebo patients (p=0.0127).
  • Week 12 data was highly predictive of Week 24; 100% of patients who were hrHPV negative at Week 12 following ABI-2280 treatment maintained hrHPV negativity at Week 24 suggesting the potential for durable viral clearance rather than transient suppression following just two weeks of treatment.
  • Patients in the study overall had a mean duration of hrHPV positivity at baseline of 29 months and 23.7% of patients had a persistent infection (defined as documented infection for >12 months) at baseline despite being previously vaccinated.

“Women with persistent high-risk HPV face a meaningful risk of disease progression to pre-cancer or cancer of the cervix, yet there are currently no approved treatment options. Patients are asked to ‘wait-and-see’ if the infection resolves or persists, while facing risks of disease progression and transmission to partners, creating significant psychosocial burden,” said Warner K. Huh, MD, MSHA, presenting author and Chair of the Department of Obstetrics and Gynecology at the University of Alabama at Birmingham. “Against this backdrop, the data from the ABI-2280 study are clinically significant, demonstrating a 30 percent absolute improvement in hrHPV negativity compared with placebo, alongside a favorable safety and tolerability profile. Importantly, the durability of response observed is particularly encouraging and suggests the potential for ABI-2280 to maintain HPV at undetectable levels over extended periods of time.”

The Phase 1b/2 trial is a randomized, double-blind, placebo-controlled study designed to evaluate the safety, tolerability and efficacy of ABI-2280 administered intravaginally in women diagnosed with persistent cervical hrHPV infection. The study dosed a total of 139 female patients ranging in age between 25 and 55 years old who have had a documented hrHPV infection for at least one year without evidence of precancerous lesions worse than low grade cervical intraepithelial neoplasia (CIN1). Part A of the trial evaluated multiple placebo-controlled sentinel cohorts enrolled sequentially to determine the safety, tolerability and preliminary efficacy of various dose levels of ABI-2280 in two-week and six-week dosing regimens. Following the completion of the sentinel cohorts, the top cumulative dose from each of the two-week and six-week dosing regimens was advanced into Part B expansion cohorts for further evaluation of efficacy.

“We are encouraged by results from this study of ABI-2280, which we believe support advancing into a Phase 2b trial in women with persistent high-risk HPV infections,” said Elaine Chien, MD, FACOG, Chief Medical Officer for Antiva. “The demonstration of clinically meaningful and statistically significant hrHPV negativity out to 24 weeks in our top dosing regimen, after only two weeks of treatment in women with a mean duration of infection exceeding two years, is particularly promising and informs a clear path forward. We are also pleased to have recently received FDA clearance of our Investigational New Drug (IND) application, which further enables the continued clinical development of ABI-2280.”

ABI-2280 is expected to have potent activity across all genotypes of HPV worldwide and works by blocking HPV replication and inducing apoptosis in HPV-infected cells. Antiva has leveraged its development expertise to formulate a vaginal insert of ABI-2280 that enables at home self-administration at diagnosis.

About HPV-Related Diseases and Cervical Cancer

Human Papilloma Virus (HPV) is so common that nearly all sexually active men and women are infected with the virus at some point in their lives. Many of these are transient infections that the body is capable of clearing, but this typically takes months to years. When HPV infections persist, they are known to drive the formation of malignancies, including cervical, anal, vulvar, penile, and head and neck cancers.

The prevalence of cervical high-risk HPV (hrHPV) infection is estimated to be 20% among U.S. females of reproductive age, or approximately 19 million women. Each year in the U.S., it is estimated that over 6 million women become newly infected with hrHPV. There are currently no treatment options for hrHPV and these patients are counseled to wait and see if their infection clears or progresses to higher grade disease. During this wait and see period, patients are also at risk of transmitting this oncogenic virus to sexual partners. Approximately 30 percent of women with hrHPV fail to clear the virus within 12 months. These patients are considered to have persistent hrHPV and have an estimated 20 percent chance of having their infection progress to pre-cancer or cancer over the following four-to-six years. Women diagnosed with hrHPV often experience significant stress due to the social stigma of a sexually transmitted infection and the association with cervical cancer. The lack of available treatments further contributes to increased anxiety and emotional distress.

Globally, cervical cancer is the fourth most common cancer in women and as such represents a major public health problem. According to the World Health Organization, an estimated 660,000 women were diagnosed with cervical cancer worldwide and approximately 350,000 women died from the disease in 2022.

About Antiva Biosciences

Antiva Biosciences, Inc. is a clinical-stage biopharmaceutical company developing novel, topical therapeutics for the treatment of cervical diseases caused by HPV infection. The company’s drug candidate, ABI-2280, is being developed as a topical treatment for women with high-risk HPV infection and high-grade cervical intraepithelial neoplasia (HSIL, CIN 2,3).

Contact

Kristine Ball
Antiva Biosciences, Inc.
650-822-1400
info@antivabio.com