Price Drop for $57,000 Snakebite Drug May Arrive in 2018

The lack of competition for drugs to treat snakebites has meant that a run-in with a pit viper might set you back more than $50,000 for treatment.

An alternative will be possible as soon as 2018, 10 years earlier than planned, after the maker of the only antivenin sold for rattlesnake bites in the U.S. reached a licensing deal with Rare Disease Therapeutics Inc. to settle a patent dispute.

The agreement with BTG Plc is expected to ease the financial burden for the 3,000 to 4,000 people bitten each year by copperheads, cottonmouths, rattlesnakes and other members of a North American snake species known as crotalids. Most of those people have no idea just how extensive and expensive it is to get treated properly.

“Everything you see in John Wayne movies, the cutting and spitting -- don’t do it,” said Salvador Baeza, managing director of the West Texas Regional Poison Center in El Paso.

Approved by the U.S. Food and Drug Administration in 2000, BTG’s CroFab is made by milking the venom from four species of snakes, shipping the venom from Utah to Wales for processing and then injecting a small amount into sheep in Australia. The sheep create antibodies, and blood samples from the sheep are then sent back to Wales to make CroFab.

Each vial costs a hospital about $2,300, and each dose involves four to six vials given intravenously over an hour, according to London-based BTG.

Animal Doctor

Martin Dickinson of Gainesville, Florida, said he required nine doses after getting bit by a water moccasin after stepping off his porch. The 66-year-old said his total hospital bill was $97,000 -- including $57,000 for the CroFab alone -- though insurance covered all but about $4,000. He said he later visited his dog’s veterinarian and told him about the cost.

“He said, you should have come by me,” Dickinson recalled the veterinarian saying. “I only charge $1,500 a dose.”

While Rare Disease’s Anavip, also known as Antivipmyn, would require more vials initially, the company has promised that the total cost of treatment would be cheaper than BTG’s, though it wouldn’t say by how much. Its drug is made through a similar process as CroFab, using horses instead of sheep.

“While we maintain that their product relies on our patented technology, this is not a generic CroFab -– it’s a different product, and there’s very little published data to tell us how it would compare,” said Chris Sampson, a BTG spokesman. “We know very little about what that product profile is, so it’s difficult to know how it would compete.”

Trial Suspended

BTG had brought a case against Rare Disease, saying Anavip violates a patent received in 2011. It asked the U.S. International Trade Commission in Washington to block imports of Anavip, which is made in Mexico.

Two weeks before the scheduled August trial, Rare Disease filed a petition with the U.S. Patent and Trademark Office to invalidate BTG’s patent.

The case was dropped just days before the trial was to start. Neither BTG nor Rare Disease would discuss the terms of the settlement. A redacted version of the agreement was posted Oct. 10 on the ITC’s website, asking the trade commission to terminate the investigation. The commission typically grants such requests; the staff attorneys’ position was submitted Oct. 23 in a sealed document.

The companies haven’t yet formally asked for the patent office review to be dropped, according to the docket at the Arlington, Virginia-based agency.

Bioclon Partnership

Jude McNally, the medical science liaison for Rare Disease Therapeutics, said the company can’t discuss the case. The agreement limits what either side is allowed to say now, and any financial terms are confidential, he said.

CroFab works by halting the progression of the venom when given within six hours of a snakebite. In the majority of cases the venom can destroy red blood cells, cause swelling and fill the heart and lungs with fluid so they don’t work properly. The serum binds to and neutralizes venom toxins to facilitate their elimination from the body, according to drug’s website.

Rare Disease is partnering with Bioclon Institute SA in Mexico, which is part of Laboratorios Silanes SA, to bring the serum to the U.S. Bioclon applied for FDA approval in March 2013 and is awaiting clearance.

“If they do bring a product to market in October 2018, they would be competing with a product physicians know well,” Sampson said. “CroFab has been available for 10 years. We’ve treated 40,000 patients. We’ve provided clinical evidence and continue to provide new evidence for its use.”

CroFab Sales

CroFab generated 62.7 million pounds ($99.7 million) in revenue last fiscal year for BTG, about 22 percent of the London-based company’s total sales, according to data compiled by Bloomberg. BTG is working to develop treatments for cancer and vascular diseases, so by 2018 CroFab will be a smaller percentage of the company’s sales, he said.

Bioclon said Anavip not only will be cheaper but will also be more effective than CroFab at stopping the tissue damage, bleeding, breathing difficulties, vomiting and other symptoms of a snakebite, with fewer side effects.

Baeza’s facility in Texas, which currently has no choice but to rely on CroFab, was one of the sites that participated in clinical studies of Anavip.

He said he’s not worried about waiting for an alternate treatment. “As long as there’s not a shortage of CroFab, it’s not a medical issue,” Baeza said. “As long as we have something that’s effective and safe, that’s the main thing.”

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