Ascentage Pharma, the China-based oncology drug developer spun off from biopharmaceutical company Ascenta Therapeutics, has filed for an initial public offering in Hong Kong having raised $150m last month.

Spun out in 2009, Ascentage is developing small-molecule drug treatments for cancer, hepatitis B virus and age-related diseases, and is currently overseeing 20 clinical trials for a total of seven product candidates in China, the US and Australia.

The IPO proceeds will go to clinical trials for a small-cell lung cancer, solid tumour and lymphoma treatment called APG-1252, a second candidate known as APG-2575 for B-cell malignancies and a candidate targeting chronic myeloid leukaemia that is dubbed HQP135.

Biotech company 3SBio acquired a 40% stake in Ascentage in 2010 and reportedly supplied $3m in seed capital in 2015.

Local media reports in August 2015 stated that Ascentage had raised $15.5m in series A funding, but the IPO filing states it actually received $13.5m in a December 2015 round co-led by Oriza Capital and YuanMing Capital that included medical research firm Hangzhou Tigermed.

Industrial hub Suzhou Industrial Park, Shenzhen Qianhai Financial Holdings, Tianjin Heyue Guyu Equity Investment Fund and Taizhou Shengjing Business Consultation Partnership Enterprise also participated in the 2015 round.

The company added $70.2m in a late 2016 series B round led by the state-owned Future Industry Investment Fund that included Suzhou Industrial Park, Efung Capital, Founder Kip Capital, QYHM Medical, Shanghai Yuhan Equity Investment Fund and Jiaxing Danqing Innovative Healthcare.

Tigermed cut its stake in Ascentage from 3% to 0.5% in March this year by selling shares in secondary sale that reaped $5.7m before divesting the rest the following month.

YuanMing Prudence Fund and Oriza Suzhou Oriza Holdings subsequently led the company’s $150m series C round last month. Teng Yue Partners, ArrowMark Partners, HDY International Investment, CTS Capital and CCB International also invested in the series C round.

3SBio owns a 5.2% share of Ascentage, whose other large investors are Future Industry Investment (9.8%), Oriza (6.6%), Yuanming Prudence (5.5%) and holding vehicle Grand Virtue Investment Management Company (5.2%).

Biotech company Unity Biotechnology and University of Michigan are also shareholders, owning 0.7% and 1.1% stakes respectively, which were gained through licensing agreements.