A rubber rattlesnake sits on display at the U.S. Army Medical Materiel Development Activity booth during the Department of Defense’s annual Military Health System Research Symposium in Kissimmee, Fla., Aug. 27, 2024. (T. T. Parish/U.S.Army)
A yearlong clinical trial of a promising cure for venomous snakebites fell short of its backers’ goal, but it still may provide a fast, immediate remedy for frontline troops.
The trial in India and the United States showed that varespladib may benefit snakebite victims within the first five hours after they are “envenomed,” according to the trial results published in October.
But the drug’s effect apparently did not extend later into emergency room treatment.
“Although we did not meet the primary endpoint, encouraging results emphasized the critical importance of rapid intervention and the need for a treatment that can be easily administered in a pre-hospital setting,” said Sally Stephens, a spokeswoman for Ophirex Inc., a California public benefit corporation, in an email Saturday.
The trial results “underscored the principle that earlier treatment improves patient outcomes.”
Ophirex was founded by Dr. Matthew Lewin with a handful of investors, including Jerry Harrison, a member of the influential rock band Talking Heads, to develop varespladib as a snakebite antidote. Derrick Rossi, a stem cell scientist who co-founded Moderna, a COVID-19 vaccine maker, is also a board member.
The Defense Department, through Army Medical Material Development Activity, awarded Ophirex a $13.8 million contract in 2022 to develop varespladib for use with special forces, which sometimes operate in austere conditions where venomous snakes are common. The following year, Ophirex raised another $37 million in private financing for the project.
A spokeswoman for the activity acknowledged questions emailed by Stars and Stripes last month but had not responded as of Friday.
Developed years ago by pharmaceutical maker Eli Lilly, varespladib blocks sPLA2, a basic neurotoxin in venom that causes paralysis, tissue damage and respiratory failure. In lab settings, the drug neutralized venom in test tubes and stopped or reversed its effects in laboratory animals, Lewin said.
The drug is available as a pill and requires no refrigeration, unlike traditional antivenom, and is easier to administer.
During the clinical trial between August 2021 and November 2022, researchers selected 95 snakebite victims who were offered varespladib or a placebo, in addition to the standard antivenom treatment, over several days, according to the report. The study looked for a change in the expected results of antivenom treatment alone. Russell’s vipers, common in India, copperheads and rattlesnakes were the most common sources of snakebites in the study.
The study was hindered by the inability to administer the drug earlier than six hours after the bite, the fact that the drug was administered in conjunction with antivenom and other factors, the report states.
Ophirex remains committed to a goal of delivering “safe, effective treatment for snakebite,” easily administered, “especially in austere environments where our military members and civilians do not have immediate access to hospital facilities or antivenom,” Stephens’ email states.
