Gensight scouts a $100M IPO for its ocular gene therapies

Parisian drug developer Gensight Biologics is swinging for a $100 million U.S. IPO to fund its work on potential one-time treatments for serious retinal diseases, angling to take advantage of a bullish market for biotechs.

The company has yet to disclose how many shares it intends to offer or at what price, saying only that it plans to hit the Nasdaq under the symbol "GNST." With its proceeds, Gensight plans to advance a pair of early-stage gene therapies for orphan eye diseases.

Gensight's top prospect is GS010, a treatment for certain forms of the rare Leber hereditary optical neuropathy, or LHON, which leads to sudden and irreversible loss of sight in teenagers and young adults. The treatment works by fixing a DNA glitch that leads to LHON, using a harmless virus to deliver a corrective copy of the ND4 gene. Gensight completed a Phase Ib study on GS010 this year, the company said, and plans to push its top prospect straight to Phase III in the second half with data expected in 2017.

GenSight co-founder Bernard Gilly

The biotech is also at work on GS030, a preclinical gene therapy for retinitis pigmentosa, the vision-destroying disease that affects about 1.5 million people around the world. Gensight's candidate uses viral vectors to introduce a DNA sequence that spurs the production of a photosensitive protein, thereby partially restoring patients' ability to see, the company said. Gensight is developing the treatment in tandem with a set of biomimetic goggles designed to stimulate the re-engineered retinal cells and allow RP sufferers to see in daylight. The company expects to get GS030 into the clinic next year.

Gensight got off the ground in 2013 with a €35 million ($38.6 million) Series A round courtesy of Novartis ($NVS) Venture Fund, Abingworth, Versant Ventures and Index Ventures. According to its IPO filing, the company sold off about 11.5 million Series B shares for about €32 million ($35.4 million) earlier this week, planning to convert them to common stock if and when it makes its public debut.

Novartis is the biotech's largest shareholder, with a 20% stake, followed by Abingworth and Versant, which hold about 17% each.

Meanwhile, biotech's protracted Wall Street hot streak has showed no signs of slowing down in the second half of 2015. After more than 30 drug developers went public in the first 6 months, more and more upstarts are lining up with similar ambitions. Over the past week alone, Aimmune Therapeutics filed to raise $80 million, Chiasma set out for a $92 million debut and ProNAi Therapeutics set its sights on $123 million.

- read the filing