The cancer drug developer has closed its initial public offering after underwriters exercised the greenshoe option.

Exscientia, a UK-based drug discovery technology developer spun out of University of Dundee, closed its initial public offering at just over $350m on Tuesday.

The spinout floated in an upsized IPO last week, issuing more than 13.8 million shares priced at $22. Telecoms and internet group SoftBank’s Vision Fund 2 and Bill and Melinda Gates Foundation added $160m in a private placement.

Joint book-running managers Goldman Sachs, Morgan Stanley, BofA Securities and Barclays Capital subsequently took up the option to acquire a further 2.08 million additional shares, Exscientia’s shares having closed at $25.26 on Monday.

Founded in 2012, Exscientia utilises artificial intelligence in a precision oncology platform it is using to develop cancer immunotherapy treatments. It is also working on prospective treatments for inflammatory diseases.

The offering was preceded by more than $368m in funding, the most recent being a $225m series D round led by SoftBank Vision Fund 2 in April this year and backed by pharmaceutical firms Novo and Bristol Myers Squibb (BMS) and Pivotal BioVenture Partners, a vehicle for property developer Nan Fung.

GT Healthcare Capital, Marshall Wace, Laurion Capital, Hongkou and Mubadala Investment Company also participated in the April round along with funds managed by BlackRock.

Novo and BMS were both existing investors, the latter initially through Celgene (now a subsidiary). Exscientia’s earlier backers include commercialisation firm Frontier IP, which helped set up Exscientia, drug discovery firm Evotec and limited partners of GT Healthcare.

Now the offering has closed, SoftBank’s $125m investment in the private placement gives it a 15.2% stake in the company, up from 13.7%. Evotec holds 11.2% of its shares, Novo 10.5%, BlackRock 5.2%, BMS/Celgene 4.4% and GT Healthcare 4.1%.

– A version of this article first appeared on our sister site, Global Corporate Venturing.