Boston-based Nirogy Therapeutics Inc.’s $16.5 million series A round is meant to enable a pipeline of small-molecule drugs targeting the solute carrier family of transporter proteins (SLCTs) embedded in the cell membrane, and let the firm bring its front oncology runner to the clinic in 2022.

Pointing to his company’s work on “the next frontier in small molecules,” Ribometrix Inc. CEO Mike Solomon said the potential $1 billion-plus deal with Roche Holding AG offers evidence of big pharma’s mounting interest. Expertise in RNA folds helped Ribometrix nail down an agreement with Basel, Switzerland-based Roche’s Genentech arm that brings $25 million up front and potential milestone payments beyond $1 billion, as the pair discovers and develops RNA-targeted small-molecule therapeutics. Genentech gains exclusive rights to several predefined targets, including an exclusive global license for the development and commercialization of molecules.

Skyhawk Therapeutics Inc., one of the early leaders in developing small-molecule drugs that target RNA, closed out the year with yet another big pharma partnering deal, an alliance with Vertex Pharmaceuticals Inc., in which it is getting $40 million up front plus up to $2.2 billion more in milestones and royalties on product sales.