Tocagen Reaches Exclusive Deal in China for Brain Cancer Therapy

Xconomy San Diego — 

Roughly a year and a half after Tocagen (NASDAQ: TOCA) named Marty Duvall as CEO, the San Diego biotech said it has signed a deal that gives Beijing-based ApolloBio an exclusive license to its gene therapy treatment for a deadly type of brain cancer.

Under terms of the deal, ApolloBio agreed to make a $16 million upfront payment to Tocagen, with another $4 million to come in “near-term” milestone payments. Tocagen has granted ApolloBio rights to commercialize its two-part treatment in mainland China, Hong Kong, Macao, and Taiwan. The experimental treatment is currently being tested in a global late-stage clinical trial.

In a statement Thursday, Tocagen said it also would be eligible under its deal with ApolloBio for additional future payments totaling $111 million, which depend on meeting unspecified development and commercial milestones.

Duvall, who helped shepherd the chemotherapy drugs docetaxel (Taxotere) and protein-bound paclitaxel (Abraxane) to commercialization earlier in his career, joined Tocagen in November 2016. Five months later, the company raised $85 million in its IPO.

Tocagen has taken an unusual approach in a developing treatment that targets a form of brain cancer known as recurrent, high-grade glioma (HGG). For one thing, the company uses gene therapy to carry a key part of its treatment into the brain.

The component is injectable vocimagene amiretrorepvec (Toca 511), a type of virus that is carried into the brain with the genetic coding that selectively instructs only cancer cells to produce cytosine deaminase (CD), a key protein used in making cancer-fighting compounds.

The second component is a molecule, 5-fluorocytosine (5-FC), that can cross the blood brain barrier. The CD protein produced in the brain by cancer cells acts on 5-FC in a way that converts 5-FC into the cancer-fighting compound 5-fluoracil. The treatment is localized to the glioblastoma because only the cancer cells are producing the CD protein.

The FDA has given Tocagen’s approach, which the company describes as “cancer-selective immunotherapy,” its breakthrough therapy designation. That status, reserved for treatments for serious or life-threatening diseases, allows the FDA to speed up its review of the medicine. The European Medicines Agency has likewise given the treatment its priority medicines designation.

Tocagen said new diagnoses of high-grade glioma are expected to hit 180,000 worldwide in 2018, including about 47,000 in the greater China region. With a small sample of encouraging results, Tocagen moved last fall to consolidate and accelerate its planned Phase 2 and Phase 3 trials into a single global trial known as Toca 5. A spokeswoman for the company said the trial is being conducted at sites throughout the United States, and in Canada, Israel, and South Korea. There are no sites in China, she added.