Principia Biopharma, whose drug discovery platform is based on research at UCSF, has completed a $122m initial public offering after underwriters exercised their greenshoe option.

Principia Biopharma, a US-based cancer and autoimmune treatment developer based on research at University of California San Francisco (UCSF), has completed a $122.2m initial public offering.

The IPO consisted of 6.25 million shares issued on the Nasdaq Global Select Market priced at $17 each, at the top of the $15 to $17 range. Underwriters exercised their greenshoe option in full, acquiring 937,500 shares to increase the IPO from $106m.

The company’s stock opened at $25.66 on its first day of trading and closed at $32.65.

Principia is working on oral small molecule medicines to treat cancer and autoimmune diseases. Its drug discovery platform, Tailored Covalency, is based on technology licensed from UCSF.

The company will put $50m of the IPO proceeds toward completing a phase 2 clinical trial for a product candidate called PRN1008, for a skin disorder known as pemphigus.

Additional proceeds will fund part of a phase 3 trial for pemphigus while $4m will support a phase 1 trial for a cancer-focused candidate called PRN1371 and $2m will go to pharmaceutical firm Sanofi as part of a licensing deal for a third candidate, PRN2246.

The company had raised more than $127m in venture funding prior to the IPO, according to the prospectus, including a $50m round last month that included pharmaceutical firm GlaxoSmithKline’s investment subsidiary SR One.

Cormorant Asset Management, HBM Healthcare Investments, RTW Investments and Samsara BioCapital co-led the round, which included New Leaf Venture Partners, OrbiMed Advisors, Morgenthaler Venture Partners, Sofinnova Ventures and Baker Bros Advisors.

Principia had raised $27.5m in series A funding from investors including SR One, OrbiMed, Morgenthaler Ventures, New Leaf and Mission Bay Capital before adding $50m in a 2014 series B round led by Sofinnova Ventures that included all the series A backers.

SR One, like New Leaf and OrbiMed, owned a 14.25% stake in the company that was diluted to 10.4% in the offering. Principia’s other notable investors are Morgenthaler (9.7% post-IPO), Sofinnova (7.8%), Baker Bros (7.4%) and Cormorant (4.8%).

BofA Merrill Lynch, Leerink Partners and Wells Fargo Securities are joint book-running managers for the IPO while Baird is lead manager.

Undisclosed existing shareholders expressed interest in buying “at least” $26m in additional shares in the IPO, according to the filing, which could lift the size further to $148m.

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

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