Tocagen shares collapse as investigators read last rites for PhIII brain cancer study

Two years after going public on the promise of a new approach to fight recurrent brain cancer, Tocagen has hit the wall.

The biotech bluntly reported the failure of their pivotal Phase III study of a 2-part drug ? Toca 511 & Toca FC ?? for high-grade glioma. Part 1 uses a vector to attack cancer cells in the brain and deliver a gene for an enzyme, while part 2 is a prodrug ? 5-fluorocytosine (5-FC) ? that converts into the anti-cancer therapy 5-FU.

It didn?t work.?

Researchers at the San Diego-based biotech reported that they hit a hazard ratio of 1.06, reflecting an increased risk to patients, with a disastrous p-value of 0.6154. The company says it will now thoroughly analyze the data, but investors weren?t waiting around. The stock