UPDATED: Biotech PTC reloads coffers with $60M for late-stage DMD drug

PTC Therapeutics has scored new financing to bankroll development of a compound for certain types of Duchenne muscular dystrophy and cystic fibrosis. The latest $60 million haul for the privately held biotech comes from a mix of hedge funds, venture players and corporate biopharma backers. And top dogs from two participating funders, Rich Aldrich of Longwood Fund and Adam Koppel of Brookside Capital Partners, snagged board seats at PTC through the deal.

South Plainfield, NJ-based PTC (a Fierce 15 company) plans to zoom into a Phase III confirmatory study of its lead compound ataluren in the first half of 2013, targeting patients with nonsense mutation Duchenne muscular dystrophy (DMD) for the study. The biotech set knows DMD, an inherited muscle-destroying disorder, has attracted interest from investors because of the impressive mid-stage results from Sarepta Therapeutics ($SRPT), which is marching to FDA regulators in hopes of an early approval for eteplirsen. And GlaxoSmithKline ($GSK) has its own DMD condender in advanced development, drisapersen, licensed from Prosensa.

PTC has produced a mixed bag of results with ataluren, once the centerpiece of a major collaboration with Genzyme, which parted ways with the program in 2011 after a Phase IIb study in patients with nonsense mutation Duchenne/Becker muscular dystrophy failed to show significant gains in a 6-minute walk test. However, the biotech banked at least $23 million of a $30 million round from Bay City Capital, Delphi Ventures, HBM Partners and Vulcan Capital to advance ataluren on its own for muscular dystrophy and cystic fibrosis.

While PTC failed to show statistically significant gains in the walk test, last year the biotech convinced the European Medicines Agency to consider the results as part of an application for conditional approval of ataluren in DMD patients with the nonsense mutation. The agency has accepted PTC's application. And the company is counting on the improvements--though not statistically significant--in treated patients' walk-test scores and other measures from the study to win an early green-light in Europe.

This latest financing fuels the planned late-stage confirmatory trial involving 220 nmDMD patients, with the main goal of slowing disease progression as measured in the 6-minute walking distance test. The round brings an even larger crowd of backers, including, save Bay City, all the previously mentioned firms as well as Adage Capital Management, Jennison Associates, Credit Suisse First Boston, Novo A/S, The Column Group, biopharma powerhouse Celgene ($CELG) and others, according to PTC's release.

"This substantial financing enables PTC to continue to pursue the regulatory approval and delivery of ataluren to patients," stated PTC Chairman Michael Schmertzler. "PTC's board of directors welcomes the breadth of support and expertise of our new investors."

A PTC spokewoman told FierceBiotech that company executives were unavailable for interviews this morning.

- here's the release

Editor's note: This story has been updated with new details about plans to gain conditional approval of ataluren for nmDMD in the European Union.