Horizon Therapeutics: Combining generic pain meds for greater drug safety

Palo Alto, Calif.-based Horizon Therapeutics, a biotech that aims to combine existing generic drugs to fight pain, raised $30 million in a third funding round. The company’s lead drug candidate, known only as HZT-501, is a “proprietary” combination of the generic drugs ibuprofen and famotidine, the latter of which is better known by its brand name Pepcid. It’s aimed at providing pain relief without gastrointestinal discomfort or injury, which is the same claim made by Cox-2 inhibitors such as Merck’s withdrawn pain drug Vioxx.

Horizon’s basic idea, which is both interesting and risky, is that packaging together existing drugs like these into a single pill may ameliorate side effects. Famotidine, for instance, suppresses the production of stomach acid, so by combining it with ibuprofen, Horizon hopes to reduce the likelihood of ibuprofen-related ulcers.

That’s the interesting part. The risky part is that patients and their doctors can usually just take the existing generic drugs together for the the same effect. Horizon hopes that its combination pill will prove more convenient for patients than the separate drugs. Would-be competitors to HZT-501, for instance, have different dosing schedules — two to three times a day for ibuprofen, but only once or twice a day for famotidine. (Hat tip to Lou Bock, a VC at Scale Venture Partners, who described Horizon’s strategy in the course of a longer conversation nearly two weeks ago.)

Will that be enough for Horizon to fend off generic competition? It’s hard to say, but Horizon’s backers clearly want to believe it will be. The latest round was led by Essex Woodlands Health Ventures, who was joined by existing investors Scale Venture Partners, Sutter Hill Ventures and Pequot Ventures.

Horizon has previously raised $21 million in equity funding. The company said the latest round will allow it to push HZT-501 through its current late-stage trials and potentially into an approval filing with the FDA, while also advancing a second drug candidate, HZT-602, into late-stage trials. HZT-602 combines another painkiller, naproxen, with famotidine. Naproxen is better known by its over-the-counter name Aleve.