Twentyeight-Seven raises another $15m for non-coding RNA drugs

US biotech Twentyeight-Seven Therapeutics has taken the tally of its first-round financing to $82.7m, after raising an extra $15m in an extension round led by European venture capital firm Sofinnova.

The Massachusetts-based company – which specialises in developing drugs based on non-coding RNA (ncRNA) – will use the proceeds to speed up the development of its lead drugs, build on its main drug discovery platform and explore opportunities outside its initial focus of cancer.

The three-year-old company’s ncRNA platform stems from the work of its four founding scientists – Richard Gregory, Frank Slack, Piotr Sliz and George Daley, all from Harvard Medical School in the US – and is based on the use of small-molecule drugs targeting ncRNA modulating proteins (RMPs) in order to affect the expression of disease-associated proteins.

ncRNAs account for a sizeable chunk of the 98% of the human genome that doesn’t code for proteins, and are thought to play a critical role in the regulation of biological processes.

Twentyeight-seven’s lead protein target is Lin28, an RMP that reduces the levels of Let-7, an oncogene that promotes cellular transformation and tumorigenesis in various forms of cancer. It is currently identifying compounds that inhibit the binding of Let-7 to Lin28 and so increase levels of the tumour suppressor.

This is a different approach to the emerging class of RNA therapeutics that target RNA that is directly involved in protein expression, such as antisense and RNA interference (RNAi) drugs from the likes of Ionis/Akcea and Alnylam.

Sofinnova managing partner Henrijette Richter, who is joining Twentyeight-Seven’s board, said the biotech is developing “game-changing therapeutics to treat cancers with high unmet need” and is “the clear leader in capitalising on the emerging science around RNA biology and how its dysregulation contributes to many serious diseases.”

Twentyeight-Seven said last September it had raised $65m in its initial Series A round led by MPM Capital, which also included buy-ins from Novartis, Johnson & Johnson and Astellas venture capital units, amongst others.

Since then, the biotech has moved into its new facilities in Watertown, MA, according to chief executive Kazumi Shiosaki, and also recruited former IFM Therapeutics founding scientist Shomir Ghosh as its chief scientific officer.