STAT Plus: Tocagen continues a brain cancer gene therapy clinical trial. Investors fear the worst May 21, 2019 sandiegobiotech News Comments Off on STAT Plus: Tocagen continues a brain cancer gene therapy clinical trial. Investors fear the worst STAT Plus: Tocagen continues a brain cancer gene therapy clinical trial. Investors fear the worst Play Episode Pause Episode Mute/Unmute Episode Rewind 10 Seconds 1x Fast Forward 30 seconds 00:00 / Subscribe Share RSS Feed Share Link Embed Tocagen pitched the study?s continuation as an encouraging sign for its gene therapy, but its stock price fell sharply. Biotechcancerdrug developmentgene therapyneurologyresearchSTAT Plus