Sorbent Therapeutics

About Sorbent Therapeutics

Sorbent Therapeutics was a privately held biopharmaceutical company founded in 2005 by Don Joseph and William Rajski. The company focused on developing therapies for cardiovascular and renal diseases by creating non-absorbed polymeric drugs designed to remove targeted cations and fluids from the body. Based in Sunnyvale, California, Sorbent aimed to address unmet needs in large markets such as heart failure, end-stage renal disease, and chronic kidney disease.

The company's business model centered on the research, development, and clinical testing of its proprietary polymer platform. Sorbent secured significant funding to advance its clinical programs, raising a total of $90.9 million over six rounds from investors including Novartis Venture Funds, CMEA Capital, ARCH Venture Partners, Sofinnova Ventures, and AgeChem. Notable funding rounds included a $12 million Series A in 2006, an expanded $53 million Series B in 2011, and a $15 million Series D in 2014.

Sorbent's lead product candidate was CLP-1001, a non-absorbed, oral cross-linked polyelectrolyte polymer. This drug was designed to work within the gastrointestinal tract to bind and remove excess sodium, potassium, and fluid, offering a therapeutic alternative for patients with fluid overload, a common complication in heart failure and renal conditions. The polymer was not absorbed into the bloodstream, which was a key feature of its safety profile. Sorbent advanced CLP-1001 through multiple clinical trials, including a Phase 2b study known as STEPWISE, which enrolled 275 patients with heart failure to evaluate the drug's efficacy in managing fluid overload. The company is now considered to be no longer active.