Quest To Modernise Snakebite Medicine.
John Heenan stepped over a fence while volunteering at an organic farm in Novato, Calif. earlier this month and felt a sharp burning pain. “I’ve been bitten by a rattlesnake!” the 68-year-old yelled to fellow volunteers nearby, after looking down to see that he had stepped on one about 5 feet long. Mr. Heenan staggered a few steps and collapsed. He foamed at the mouth and felt like he was suffocating, and his muscles rippled uncontrollably. By the time he arrived at the hospital minutes later, his airway was so swollen and clogged that doctors struggled to put a breathing tube down his throat, and his blood pressure had plummeted. He was given anti-venom and put on life support, and remained unconscious for two days. Now recovering at home, Mr. Heenan faces extensive physical therapy and follow-up care. But he considers himself lucky to have gotten medical attention so quickly. “I’m alive,” he says. “I can’t ask for much more than that.”
Many others aren’t so fortunate. Every year, more than 100,000 people world-wide are killed by snakebites, and about 400,000 undergo limb amputations or are otherwise disabled, according to the World Health Organization. Experts say the real toll is likely much higher because so many poisonous snakebites go unreported. Yet the problem attracts little investment. Snakebite “envenoming,” or poisoning, is largely ignored by public-health authorities and drug developers, though experts hope that it will attract more attention and funding after being added to the WHO’s official list of neglected tropical diseases in June. Antivenom can be hard to find in Africa and Asia, where snakebites pose the largest threat. It can also be of poor quality. It usually has to be kept cool and administered intravenously in hospitals or clinics, far from where many victims are bitten. And it is still manufactured using the same basic method created in the 1890s, which involves milking snakes through their fangs, injecting the venom into horses or other large animals and collecting their antibodies.
Scientists, including some from outside the field, are working on ways to modernise snakebite medicine, but it isn’t easy: Venom is a complex mixture of enzymes and proteins and varies by species of snake. Matthew Lewin, an emergency-medicine doctor in Corte Madera, Calif., is developing an antidote that could be administered to a snakebite victim on the spot, blocking many immediately life-threatening effects until the victim can get anti-venom and medical care. “We’re just trying to fill the gap between the bite and the hospital,” says Dr. Lewin, who helped to treat Mr. Heenan. Lab tests show that the drug, known as an sPLA2 inhibitor, blocks one of the deadliest toxins in venoms from an array of snakes, Dr. Lewin says. The drug was originally developed by Eli Lilly and Shionogi for other purposes but was shelved. Eli Lilly recently provided documents to help Dr. Lewin further his research and development.
Snakebite science needs groundbreaking solutions, says Jerry Harrison, a member of the bands Talking Heads and the Modern Lovers, who co-founded a biotech company called Ophirex with Dr. Lewin to advance the drug. “The name ‘anti-venom’ is so perfect that people think the problem is solved,” says Mr. Harrison, who is now a music producer and works with technology and startup companies. Other scientists are seeking more modern approaches. Andreas Laustsen, a bioengineer at the Technical University of Denmark, is developing a new type of anti-venom that would be made with mixtures of human, rather than animal, antibodies. These so-called “recombinant anti-venoms,” produced in a fermentation tank, would be safer, more effective and less expensive than current anti-venoms, says Dr. Laustsen. The idea is to develop an anti-venom that would neutralise a range of toxins from different types of snakes, he says. He is using techniques, he adds, that were developed in the course of research on cancer and autoimmune disease.
Still others are working on ways to improve existing anti-venoms. Some veterans of snakebite research say that should be the priority, given limited funding. “At the moment, we need to fix the current system because people are dying literally over 100,000 a year, and they can’t wait 15 to 20 years for a wonder drug,” says David Williams, a toxicologist and herpetologist at the University of Melbourne in Australia and CEO of the nonprofit Global Snakebite Initiative. Dr. Williams sees an urgent need to improve the prevention and treatment of snakebites, to tighten regulations to keep poor-quality anti-venoms off the market, and to make anti-venom production more efficient. He supports both immediate and long-term approaches. “I think we need to innovate across the board,” he says. As for the farm where Mr. Heenan was bitten, it has put up signs warning about rattlesnakes. Once he recovers, Mr. Heenan is determined to get back to work there. “I guarantee you I will religiously watch every step from now on,” he says.
Credit: Betsy McKay for The Wall Street Journal 25 August 2017.