As Expected, Nurix Taps Into $25M for New Drug Discovery

Xconomy San Francisco — 

More details have emerged on Nurix, the San Francisco biotech funded by Third Rock Ventures and The Column Group. The two venture firms, which seeded Nurix with $6 million in 2012, announced Thursday they have teamed to provide a $25 million Series B round, which my colleague Bernadette Tansey anticipated last month in this report on Third Rock’s San Francisco activity.

The cash will bolster Nurix’s work on the ubiquitin proteasome system, which keeps cells functioning normally by breaking down unwanted proteins and maintaining a healthy state of protein homeostasis. The scientists who discovered ubiquitin’s role in protein degradation won the 2004 Nobel Prize in chemistry.

Think of ubiquitins as flags that attach to proteins, marking them for destruction within the proteasome, which are cylindrical chambers that function as disposal and recycling units within the cell. The ubiquitin-proteasome (UPS) system been a tough nut to crack for drug developers. The idea is to create small molecule drugs that can penetrate the cell and either speed up protein degradation or slow it down, which has implications in cancer and possibly other diseases. But for a long time the UPS was considered too, well, ubiquitous to serve as a drug target, with no way to pinpoint a treatment without unintended consequences. The first drug to target the UPS system and gain FDA approval was the multiple myeloma drug bortezomib (Velcade) in 2005, from Millennium Pharmaceuticals (later acquired by Takeda). Carfilzomib (Kyprolis), from Onyx Pharmaceuticals—now part of Thousand Oaks, CA-based Amgen (NASDAQ: AMGN)—was the second, eight years later.

With Third Rock partner Mark Goldsmith (pictured above) as interim CEO, Nurix thinks it can do it better. It has pulled together work from three scientific founders who specialize in different areas applicable to the UPS pathway. John Kuriyan is a UC Berkeley professor who teases the function of proteins through the determination of their three-dimensional structures. Michael Rape, also at UC Berkeley, specializes in the biology of the UPS pathway. And Arthur Weiss, chief of the division of rheumatology at UCSF, is an immunologist who has studied, among many other things, how cell signals go awry in immune disease. All three are also investigators at the Howard Hughes Medical Institute.

Also on the executive team is chief scientific officer Mark Gallop, a cofounder of Santa Clara, CA-based XenoPort (NASDAQ: XNPT). The Column Group’s Dave Goeddel has a board seat.