Celladon, Xencor bid for $155M in red-hot IPO market

Celladon and Xencor have cast lines into the still-blazing biotech IPO scene, seeking a combined $155.3 million and betting that the recent Wall Street excitement for drug developers will hold firm.

Celladon, a member of the 2012 Fierce 15, is seeking $86.3 million in its planned public debut, cash it'll put toward getting its gene therapy for heart failure through a Phase IIb study and into Phase III. The drug, dubbed Mydicar, inserts the Serca2a enzyme into patients' heart cells, boosting cardiac muscle contractions to treat systolic heart failure. In its latest funding round, Celladon hauled in $53 million from a stable of investors that included the venture arms of Pfizer ($PFE), Novartis ($NVS) and Johnson & Johnson ($JNJ).

California's Xencor--a 2005 Fierce 15 veteran--has its eye on a $69 million initial offering, planning to spend its proceeds on candidates for autoimmune and allergic diseases. The biotech made its name with XmAb, a biologics platform that can extend the half-life of antibodies and boost their targeting power, capabilities that lured partners like Pfizer, Amgen ($AMGN) and Boehringer Ingelheim. Now the company is pushing forth with drugs of its own, and its IPO proceeds will fund a Phase IIb study for the Amgen-optioned autoimmune treatment XmAb5871 and a Phase Ib trial for asthma therapy XmAb7195.

Both companies plan to list on the Nasdaq, with Celladon trading as "CLDN" and Xencor going by "XNCR."

This year has witnessed 39 successful biotech IPOs, raising roughly $3 billion for drug developers around the world, and with Celladon and Xencor diving in, there are now at least 11 companies with pending S-1s and eyes on high-dollar debuts. If all goes according to plan, those biotechs will heap almost $700 million more onto the total haul.

So where does it stop? Some worry the stampedingly bullish market for biotech IPOs will come to a halt as soon as one of these drug developers hits a toxic wall, raiding its shares and forcing investors to see their shadows. There's a reason the market cooled in the first place, as traders grew wary of the high risks inherent to drug development. Still, a possible $4 billion cash infusion can only be good news for industry still crawling out of a fundraising slump, and that sum should buy a whole lot of R&D.

- read Celladon's S-1
- check out Xencor's filing

Special Reports: Foundation Medicine, Ophthotech go gangbusters in 2013 biotech IPO revival | FierceBiotech's 2012 Fierce 15 - Celladon | FierceBiotech's 2005 Fierce 15 - Xencor