UPDATED: Tioga nabs $10M VC deal amid PhIII for bowel disorder drug

Tioga Pharmaceuticals has grabbed $10 million in equity for a Series B round as the company funds late-stage development of its key drug for a bowel disorder. New backer Thomas, McNerney & Partners led the round with an $8 million investment and previous investor Genesys Capital chipped in too, Tioga announced Thursday. Thomas, McNerney's Jason Brown has joined Tioga's board of directors.

The San Diego-based drug developer, which raised $42 million in its Series A round, has now reeled in $52 million from investors to advance its only drug, asimadoline. The drug is in one of two Phase III trials required to get the drug approved to treat diarrhea-predominant irritable bowel syndrome. U.S. regulators have granted fast-track status for the program in diarrhea-predominant irritable bowel syndrome because of the lack of adequate therapies for the disorder, company CEO Stuart Collinson tells FierceBiotech.

Collinson said that he expects data from the Phase III study next year, and the results of the study will determine whether the company pursues the second late-stage study in D-IBS.

The potential market for the drug in the U.S. is huge. About 10% to 20% report symptoms of irritable bowel disorder, and about 15% of those who experience symptoms seek treatment, according to the Cleveland Clinic. In diarrhea-predominant cases, symptoms include stomach pains and, as its name indicates, the runs. "In the U.S., conservatively, for the patients we're treating it's a $4.5 billion market," Collinson says. "There's really no readily available and safe prescription now that you can use" to treat diarrhea-predominant IBS.

Collinson, who is also a partner at Forward Ventures, quarterbacked the team that grabbed rights to asimadoline from Germany-based Merck KGaA in 2005. He previously headed Aurora Biosciences, which Vertex ($VRTX) acquired in 2001.

Tioga has licensed exclusive rights to asimadoline--an oral kappa opioid receptor agonist--to Japan-based Ono Pharmaceutical in Japan, Taiwan and South Korea, according to the company's website.

- here's the release

Clarification: While Vertex acquired a cystic fibrosis program from Aurora in 2001, the company's drug for CF called Kaleydeco was discovered in 2004, according to a representative for Vertex. This article originally indicated that the drug had been discovered prior to the acquisition.