Heart failure is a huge market with 5 million sufferers in the U.S., but it can be a pretty dull space for investors, since it’s widely treated today with cheap generics that have been around a long time. So how is it that Sunnyvale, CA-based Sorbent Therapeutics was able to raise $53 million in venture capital in the past year for a new kind of drug against this disease?
What’s different here is that Sorbent is betting it has found a way to treat a common complication of heart failure by aiming at a surprising target—the gut. I heard more of the explanation recently from Sorbent’s CEO, Detlef Albrecht, after the company disclosed its latest financing from Novartis Venture Funds, Sofinnova Ventures, Arch Venture Partners, CMEA Capital, and AgeChem.
The idea at Sorbent is to develop a polymer-based drug that you swallow, and which lingers in gastrointestinal tract, acting like a sponge to soak up excess sodium, potassium, and fluids, before carrying all that extra baggage to the exits with the feces. This is different from conventional small-molecule pills, or biotech drugs, which get absorbed into the bloodstream and broken down through the liver or kidneys—where unpredictable side effects can sometimes occur. And despite the widespread availability of cheap generics like diuretics, ACE inhibitors, or aldosterone receptor antagonists, an estimated 1.2 million heart failure patients in the U.S. have no easy way to get rid of the excess fluids, and they end up getting hospitalized, Albrecht says.
It turns out quite a few people with failing hearts also have failing kidneys which prevent diuretics from working the way they should, Albrecht says. And that creates an opportunity for an alternative such as the one Sorbent is developing.
“If you can keep fluid out of the system or remove it without going through the kidney, you have an attractive product,” Albrecht says.
Albrecht has been around the block with these kind of molecules through past executive stints in R&D at Ilypsa, and a successor company, Santa Clara, CA-based Relypsa. Ilypsa developed a polymer that was supposed to be used to soak up excess phosphate molecules in the blood of patients with kidney failure who are undergoing dialysis treatment. That drug made a return for Ilypsa’s investors and employees in June of 2007, when Amgen agreed to acquire the company for $420 million in cash.
Soon after, some of the key managers—Albrecht included—started anew with Relypsa. That company took the same scientific concept and applied it in a different way—this time, creating a polymer drug designed to soak up excessive amounts of potassium that build up in the blood of kidney dialysis patients. The clinical verdict on that drug isn’t in yet, but Relypsa
