US-based clinical-stage biopharmaceutical company Blackthorn Therapeutics has raised an extra $14m from investors including GV, a corporate venturing subsidiary of internet technology conglomerate Alphabet, increasing its series A round to $54m.

Venture capital firm Biomatics Capital also took part in the second tranche, which added to an October 2016 first close featuring Johnson & Johnson Innovation – JJDC, the corporate venturing arm of healthcare group Johnson & Johnson.

That first close was led by VC firm Arch Venture Partners,…