Atara Biotherapeutics, a US-based drug developer spun off in 2012 from biotechnology company Amgen, has filed for an initial public offering that could raise up to $50m.
The company’s initial funding and management was provided by venture capital firm Kleiner Perkins Caulfield & Byers, while Amgen retained an equity stake.
Both firms backed Atara in its $52m series B, closed in January 2014, the latter through its corporate venturing unit Amgen Ventures. Pharmaceutical company Celgene, EcoR1 Capital, Alexandria Venture Investments, DAG Ventures, Domain Associates also partiipated in the round.
Atara had earlier raised $20m in a March 2013 series A round from Alexandria, KPCB, DAG and Domain.
Celgene and Amgen respectively hold 8.7% and 8.6% stakes in Atara, while other notable shareholders include KPCB (18.6%), Domain (13.2%), DAG (13.2%), hedge fund Baupost Group (11.8%), Mexico-based holding company Inmobiliaria Carso (9.3%), Alexandria (5.3%) and Atara CEO Isaac Ciechanover (7.4%).
Atara is developing therapies to treat kidney disease and cancer, among other illnesses. It is yet to generate any revenue, having recorded net losses of $4.1m in 2012 and $8.8m in 2013.
The company aims to use the proceeds from the offering for the development and clinical studies of two drug candidates, and to expand its research on others.
Underwriters for the offering are Goldman Sachs, Citigroup Global Markets and Jefferies. Atara has filed to be listed on the Nasdaq under the symbol ATRA.