The Amgen and Celgene-backed biotechnology company, which has raised $72m across two venture rounds, will use the proceeds to advance two product candidates.

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,…