Flex Pharma developing treatments for muscle cramps

Flex Phama co-founders Rod MacKinnon and Bruce Bean.
Flex Phama co-founders Rod MacKinnon and Bruce Bean.(Wendy Maeda/Globe Staff)

In a city where research scientists are taking on everything from cancer to neurodegeneration, the next frontier in biotech’s assault on human ailments may be ... muscle cramps.

An 8-month-old Boston startup is hard at work studying muscle contractions that can affect everyone from star performers to weekend athletes to people bedeviled by nocturnal spasms. The goal is to develop and test treatments for the painful condition, which now has no clinically proven remedy on the market.

If successful, the efforts of the venture-backed startup, called Flex Pharma Inc., could improve the lives of an estimated 10 million Americans — and millions more worldwide — prone to cramping.


“Maybe it’s not killing people, but it’s pretty inconvenient,” said Flex Pharma’s scientific co-founder, Rod MacKinnon, a Nobel laureate who leads the Laboratory of Molecular Neurobiology and Biophysics at Rockefeller University in New York. “It can be very debilitating to wake up in the middle of the night with a charley horse. And there’s no treatment. Nothing.”

Flex Pharma is developing not only a prescription medicine that would take a minimum of five years to win Food and Drug Administration approval but also a sports beverage that could be sold in stores as early as 2016.

Unlike Gatorade, which some athletes drink to help with cramps, Flex Pharma will seek to meet the Federal Trade Commission’s standards for advertising clinically proven benefits. The company will also draw on the consumer goods expertise of board member John Sculley, the former chief executive of Apple Inc. and former president of PepsiCo Inc.

Cramping has long been a high-profile employment hazard for professional athletes, dramatized this year when the Miami Heat’s LeBron James was forced to leave the opening game of the NBA finals because of severe leg cramping.

So it may be no coincidence that several owners of professional sports teams, including Wyc Grousbeck and Steve Pagliuca of the Boston Celtics, and the Kraft Group of the New England Patriots, were among the outside investors joining in a $40 million funding round that Flex Pharma disclosed last month.


Venture capital firms backing the company include Boston’s Longwood Fund and Bessemer Venture Partners, based in Menlo Park, Calif.

“I’m very interested in trying to cure cramps, but also back spasms, and there’s lots of encouraging research that’s been done,” Grousbeck said. “Being in pro sports makes me really think this could apply not only to the average person, but also to elite athletes. We all saw LeBron James cramping up in the Finals, so that got me thinking about it.”

Grousbeck said he was also attracted to Flex Pharma by the involvement of MacKinnon and scientific co-founder Bruce Bean on the company’s scientific advisory board, and of Longwood Fund co-founder Christoph Westphal as Flex Pharma’s chief executive.

Westphal, a serial entrepreneur, typically founds, financially backs, and runs biomedical startups.

He has previously helped launch some of the best-known emerging companies in the Cambridge biotech cluster, including Alnylam Pharmaceuticals Inc., Momenta Pharmaceuticals Inc., Sirtris Pharmaceuticals Inc., Acceleron Pharma Inc., and Verastem Inc.

Cramping and other neuromuscular disorders represent “a very large potential market opportunity,” Westphal said. He estimated sales of Flex Pharma’s treatments in two formulations — the over-the-counter drink and the prescription medicine for nocturnal cramps — eventually could generate tens of millions of dollars a year or more.


“I’m committed long term to this,” Westphal said. “We see a very clear and completely unmet medical need. People are using all these things now — bananas, stretching, soft drinks — but we think there would be a substantial market for a clinically proven product.”

While the company was started this year, its origins date back five years to a winter kayak outing by MacKinnon and Bean.

The two scientists, outfitted in dry suits, were paddling along Monomoy Island off the Cape Cod town of Chatham when they both suffered cramps.

“It was cold water, and we were simultaneously cramping,” MacKinnon recalled. “It became a topic of conversation. We’re scientists, so we started to wonder what’s behind this. And we found that there was very, very little known about cramps.

“Our curiosity led us from one place to the next,’’ he said. “In fact, we found out there is no good therapy for cramps.”

To learn more about the phenomenon, MacKinnon and Bean began using an electrical neurostimulator to bring on cramps in their calves and toes, as well as those of willing friends and relatives.

They also started concocting beverages in a mixer, using extracts from ginger, cinnamon bark, and chili pepper.

“It worked amazingly well in preventing electrically induced cramps,” MacKinnon said.

Eventually, they filed a patent on their drink, initially dubbed “TRP Stim.” That’s shorthand for the transient receptor potential family of ion channels they were stimulating.

MacKinnon won his Nobel Prize in 2003 for scientific work focused on ion channel activation — how electrical signals are sent along the surface of cell membranes — so his anti-cramping crusade seemed a natural extension of that work. He and Bean began talking to investors and then sent a proposal to Westphal at Longwood Fund.


“I hope this can actually help some people,” MacKinnon said. “It could be kind of fun.”

Robert Weisman can be reached at Follow him on Twitter @GlobeRobW.