After about 20 years of academic research on epigenetics, large drug developers have decided the time is right to move in, making bets on biotechs that can provide platforms and compounds. Last week, Genentech Inc. threw its hat into the ring with $95 million in upfront payments and research funding to Constellation Pharmaceuticals Inc., the largest amount disclosed to date for an epigenetics deal, which includes a takeout option.

The Roche unit said epigenetics is ripe for investment because advances in biology have definitively linked targets to particular cancers. In addition, the last few years have also seen the publication of the first sets of small molecules that modify epigenetic proteins that are not already targeted by marketed drugs.