Decoy Therapeutics Inc, a biotechnology company focused on developing Designable Multi-Antivirals (D-MAVs), has announced that one of its D-MAV candidates has demonstrated in vitro effectiveness against the wild-type Ebola Zaire virus during testing conducted at the Texas Biomedical Research Institute. Encouraged by these findings, the company has launched an exploratory research initiative to create D-MAV therapies targeting filoviruses, including Ebola and Marburg viruses.

The D-MAV candidate was originally developed using Decoy's IMP3ACT platform to prevent coronavirus entry into host cells, where it has already exhibited nanomolar to picomolar potency against a broad range of known coronavirus variants. Its newly observed activity against Ebola Zaire—a filovirus responsible for 17 of the last 20 Ebola outbreaks—supports the company's approach of designing a single antiviral capable of targeting shared viral mechanisms across multiple virus families.

"Our industry has traditionally taken a reactive, one-virus-at-a-time approach, leaving us continually responding to emerging viral threats," said Rick Pierce, Chief Executive Officer of Decoy Therapeutics.

"While advancing our respiratory disease program toward clinical development remains our primary focus, these findings expand our confidence in the broader capabilities of our platform."

The same laboratory studies also found that the candidate exhibited in vitro activity against the Lassa fever virus, an arenavirus. Diseases caused by filoviruses and arenaviruses—including Ebola, Marburg, and Lassa fever—qualify for the U.S. Food and Drug Administration's Tropical Disease Priority Review Voucher program, which is intended to encourage the development of treatments for neglected infectious diseases.

Dr. Barbara Hibner, Chief Scientific Officer and Co-Founder of Decoy Therapeutics, explained that the D-MAV was designed to target a viral entry mechanism relied upon by coronaviruses, yet it also inhibited filovirus infection because these viruses use the same class I fusion machinery. She noted that the results validate the company's broad-spectrum antiviral strategy and highlight the versatility of the D-MAV platform. The company is now working on new D-MAV candidates aimed at simultaneously targeting filoviruses and arenaviruses, with the expectation that its platform can speed their development.

According to Decoy Therapeutics, the ability to address both commercial infectious diseases and pandemic preparedness through a unified technology platform is central to its strategy. The latest findings reinforce that vision, particularly as ongoing Ebola outbreaks in the Democratic Republic of the Congo and Uganda—caused by the Bundibugyo virus and currently lacking approved vaccines or treatments—continue to emphasize the need for broad-spectrum antiviral solutions.

In 2006, Tomas Cihlar was well aware that, despite initial successes with combination therapy, HIV continued to be a global challenge with limited treatment options. At the time, he had been researching virology at Gilead for 12 years, and the first once-daily, single-tablet regimen for HIV treatment was still awaiting approval. People living with HIV had to rely on multiple daily medications, which often caused severe side effects or led to drug resistance.

“That challenge kept the Gilead research team motivated and reinforced our urgent need to develop something new,” recalls Tomas, now Senior Vice President of Research Virology.

After a decade of dedicated work, the team achieved a significant breakthrough, discovering a molecule that could transform the battle against HIV.

“In the beginning, if someone had told me where we’d eventually end up, I would have thought they were dreaming,” Tomas says with a smile. “What we discovered was completely unprecedented.”

At that time, most HIV treatments worked by targeting the viral enzymes responsible for replication and spread. However, Tomas had a different approach in mind—one that focused on the viral capsid, a cone-shaped protein structure that protects the genetic material essential for reproduction. While many scientists believed the capsid was too difficult to target, Tomas was convinced otherwise. “If we could disrupt the capsid, we might be able to stop the virus altogether,” he explains.

The research team screened hundreds of thousands of compounds, searching for one that could effectively interfere with the capsid’s function. However, their early findings were too weak to serve as viable drug candidates.

By 2009, the project faced a major roadblock, and a solution seemed out of reach. But in January 2010, Tomas attended a medical conference where a poster presentation sparked an “aha” moment, providing fresh inspiration.

“That moment revitalized our research and gave us a new direction,” he recalls.

Over the next six years, Gilead scientists synthesized and tested more than 4,000 molecules, eventually discovering a novel compound that proved exceptionally potent even at very low doses. When introduced into the human body, the molecule remained stable for several months without degrading while retaining its ability to fight the virus.

“The journey of Gilead is one of innovation, collaboration, resilience, and perseverance, and this discovery was undoubtedly a breakthrough,” Tomas reflects.

Appropriately, Breakthrough: The Quest for Life-Changing Medicines, a newly published book on medical innovation by physician-scientist and biopharmaceutical executive Dr. William Pao, explores the process of drug discovery. It highlights eight transformative medications, including Gilead’s new HIV treatment, detailing the challenges and unexpected moments that shaped their development.

“There have been many HIV treatments, but this one is truly groundbreaking,” William explains. “It represents a completely new way of thinking about the virus and targeting it. Its discovery also required a willingness to embrace unexpected opportunities—turning an insoluble molecule with a long half-life into a subcutaneous medicine.”

As Pao emphasizes in his book, drug discovery and development involve countless individuals and significant trials.

“Every drug development project has its highs and lows. Teams persist not for personal recognition, but to improve patients’ lives,” he says.

Gilead’s story is no exception.

“The unwavering commitment of hundreds of people—from Gilead’s research and development teams to external collaborators and clinical trial participants—made this achievement possible,” Tomas states. “This story demonstrates what can be accomplished when we set ambitious goals and work together to achieve them.”

Recent clinical trial results suggest that this drug could potentially prevent HIV transmission entirely. If regulatory approval is granted, Gilead has already developed a global access strategy to ensure its availability in low- and middle-income countries.