San Diego-based Celladon, a clinical stage biopharmaceuticals firm which is developing enzymes to address calcium regulation, has filed for an IPO. The company said it is looking to raise up to $86.25M in an offering on the NASDAQ Global Market, trading under the symbol CLDN. The company's IPO is being underwritten by J.P. Morgan, Barclays, Stifel, and Wedbush PacGrow Life Sciences. Celladon is backed by Enterprise Partners, Pfizer, Lundbeckfond, Novartis Bioventures, J&J Development, GBS Bioventures, MPM Capital, Venrock, H&Q, as well as others. The company's enzymes are targeted at diseases involving issues with regulation of calcium, including heart failure.