Member News

May 10, 2023

In more than 30 years in biotech, Susan Molineaux has seen the highs and the lows. Now she's starting again.

Molineaux, the founder and CEO of Calithera Biosciences Inc. until the 13-year-old cancer drug company closed its doors in March, now is CEO of Para Therapeutics in South San Francisco. The company, co-founded by Calithera alum Andy MacKinnon, is targeting genetically defined populations of cancers, specifically duplicative "paralog" genes.

Para is the latest leading-edge drug-development company Molineaux has helped launch. She founded, was chief scientific officer and then CEO at multiple myeloma drug developer Proteolix Inc. The company developed one of the early entrants into a class of drugs called proteasome inhibitors.

Proteasomes control the turnover of proteins in cells, and researchers found that cancer cells are especially sensitive to proteasomes being blocked.

Proteolix developed the proteasome inhibitor carfilzomib, which was the centerpiece of the company's sale in 2009 to Onyx Pharmaceuticals Inc. for $850 million. The drug went on to be approved by the Food and Drug Administration in 2012 — branded as Kyprolis — and Onyx was sold the next year to Amgen Inc. for $10.4 billion.

After the Proteolix sale, Molineaux founded Calithera to discover small-molecule drugs to treat cancer by focusing on the emerging field of tumor metabolomics, where metabolites that break down food in the body can be used to identify cancer cells that boost their chances of survival and proliferation by turning on certain metabolic pathways.

Calithera went public in 2014 as young companies raced to the public markets, but a cancer drug-development deal with Incyte Corp. fell part in 2020 and its kidney cancer drug the next year failed a mid-stage trial. The company in late 2021 bought two clinical-stage cancer-fighting compounds from Takeda Pharmaceutical Co. Ltd.'s Millennium Pharmaceuticals unit, launching clinical trials in lung cancer and lymphoma. But under the weight of those costly trials and a broader biotech investment malaise, the company earlier this closed its doors in South San Francisco in mid-March.

At Para, Molineaux is teaming again with MacKinnon, who spent nearly 11 years at Calithera, most recently as director of discovery biology. He is Para's vice president of discovery biology.