Pivotal failure triggers job cuts at San Diego-based Tocagen
Tocagen is circling the drain, following the crushing late-stage failure of its experimental brain cancer therapy last month. On Thursday, the San Diego-based company slashed its workforce by 65%.
Its two-part therapy was being tested in patients with recurrent high-grade glioma undergoing resection in the Toca 5 study. On average, patients on the Tocagen regimen actually did not live as long as those given standard treatment (11.1 months median compared to 12.2 months). In addition, the company’s therapy hit a hazard ratio of 1.06, reflecting an increased risk to patients, along with an unsavory p-value of 0.6154.
Tocagen’s technology employs retroviral replicating vectors, or RRVs, which are engineered to selectively deliver therapeutic genes into cancer cells. The experimental brain cancer therapy in question combines an RRV, called Toca 511, with an investigational small molecule, Toca FC.
Toca 511 is designed to isolate cancer cells and deliver a gene for the enzyme, cytosine deaminase (CD). Only infected cancer cells are meant to carry and spawn CD. When Toca FC encounters CD, it is tailored to transform into the anti-cancer drug 5-FU, and in turn to annex the tumor.
Following the layoffs, Tocagen — which made its public debut in 2017 — is left with 30 employees. They will focus on the Phase II/III trial of Toca 511-Toca FC in newly-diagnosed glioblastoma (HGG) patients — as well as an early-stage study in bladder cancer.
“Given the Toca 5 miss on both primary and secondary endpoints (relating to overall survival and durability of response, respectively), we maintain low expectations (0% POS) for the Toca 511 & Toca FC regimen in HGG in the absence of new information,” Chardan analysts wrote in a note on Thursday.
The company plans to present the completed analysis of the Toca 5 trial at the 2019 Society for Neuro-Oncology annual meeting in November, it said.
Brain cancer is notoriously hard to treat and remains the deadliest of cancers, despite decades of research. Tumors are often located beyond the reach of even the most consummate neurosurgeon, and protected by the blood-brain barrier, thereby thwarting exposure to systemic chemotherapy. In addition, the particular developmental, genetic, and micro-environmental ecosystem in the brain renders tumors resistant to traditional weapons in the oncologist’s armamentarium.
In its second quarter report — published in August — Tocagen indicated it had cash, cash equivalents and marketable securities of $68.3 million, as of June 30. Shares of the drug developer $TOCA have been languishing in penny stock territory since its pivotal failure disclosure in September.
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