Tocagen Inc TOCA shares were tumbling to an all-time low Thursday following an adverse clinical trial readout.
Tocagen, a thinly traded nano-cap biotech, said Thursday morning a Phase 3 TOCA 5 study evaluating Toca 511 and Toca FC in patients with recurrent, high-grade glioma undergoing resection missed the primary endpoint of overall survival compared to the standard of care.
The Toca 511-Toca FC combination achieved median overall survival of 11.1 months compared to 12.2 months for the standard of care.
Toca 511 is a gene therapy delivered via a vector, and Toca FC is a prodrug that converts into an anticancer therapy.
The secondary endpoints also did not show meaningful difference between the arms of the trial, the company said.
The safety, tolerability and adverse event profile of the combo was as expected for this patient population, according to Tocagen.
Recurrent brain cancer has very few treatment options and therefore there is a high unmet medical need.
"While the Toca 5 trial results are disappointing, we will be conducting a thorough analysis of the data including molecular analyses and pre-planned subgroups," Tocagen CEO Marty Duvall said in a statement.
The company also said it will conduct an operational review.
Tocagen shares were plunging 81.58% to 77 cents at the time of publication in Thursday's premarket session.
© 2022 Benzinga.com. Benzinga does not provide investment advice. All rights reserved.