Shanghai-based I-Mab Biopharma confidentially filed for a U.S. IPO that could raise about $200 million, Bloomberg News reported, citing people with knowledge of the matter.

The Chinese drugmaker is looking to raise up to $40 million in its latest private funding round, valuing the company at about $800 million, one of the sources added. WuXi Biologics (Cayman) Inc. and Hong Kong's billionaire Cheng family are reportedly among the investors participating in the funding round.

I-Mab, which develops therapies for cancer and autoimmune illnesses, is backed by Hillhouse Capital, private equity firm Ally Bridge Group, Hony Capital (Beijing) Co. Ltd. and CDH Investments, among others.

A Bloomberg report in August 2018 said the company was planning to raise up to $500 million in a Hong Kong IPO.