A flood of IPOs can't raise every biotech boat. Gelesis has scrapped its plans for a $60 million IPO after evidently failing to find a big enough appetite for its stomach-filling particle approach to combating obesity. The biotech, part of PureTech's portfolio, is shooting to wrap a pivotal study in Europe but noted in its S-1 that it could take four more years to prep for a U.S. approval. The biotech--which raised a $22 million crossover round a couple of months ago--had a problem with its most recent study, which was completed last summer. The study tested Gelesis100 at a 2.25 g dose, a 3.75 g dose and a placebo. That low dose scored a placebo-adjusted weight loss of only 2% of body weight (6.1% total), while the high dose registered a minimal 0.4% placebo-adjusted improvement on the scales. Story