The cancer immunotherapy developer, backed by Stanford University, has closed the offering after the underwriters bought another $18m of shares.

Arcus Biosciences, a US-based cancer treatment developer that counts Stanford University among its investors, closed its initial public offering at $138m on Monday after the underwriters fully took up the over-allotment option.

The company issued 8 million shares last week priced at $15 each, at the top of the IPO’s range, to raise an initial $120m.

The stock closed at $16.73 on Monday, after joint book-running managers Citigroup, Goldman Sachs and Leerink Partners bought a further 1.2 million…