Tocagen’s new gene therapeutic formulations – Toca 511 & Toca FC – for treating recurrent and metastatic cancers, specifically High-Grade Glioma (HGG), received FDA’s “breakthrough therapy designation” and awaits a full approval post clinical trials next year.
HGG is a malignant form of primary brain tumour that originates from glial cells of the brain. Glial cells provide the structural backbone of the brain and support the function of the neurons.
Standard treatment for newly diagnosed HGG includes safe surgical removal of as much of the tumor as possible followed by radiation therapy and chemotherapy.
However, HGG recurs in most patients even after maximal treatment. After recurrence, median survival is typically seven to nine months.
The new drug is an effective combination of the investigational biologic, Toca 511, and an investigational small molecule, Toca FC, designed to be used together.
The drug is designed to directly kill HGG cells and immuno-suppressive myeloid cells resulting in the activation of the immune system against cancer.
Toca 511 & Toca FC – given “breakthrough therapy designation” - are currently under evaluation in an international, randomized Phase 2/3 clinical trial.
The ongoing Toca 6 study is a Phase 1 trial for the treatment of patients with metastatic cancer.
Tocagen reportedly is planning to expand the Toca 6 trial to include patients with recurrent HGG and to initiate Toca 7, a Phase 1 trial in patients with newly diagnosed HGG.
The FDA also granted Toca 511 & Toca FC “fast track” designation for the treatment of patients with recurrent HGG, and “orphan drug” designation for the treatment of glioblastoma multiforme (GBM).
The significance of getting a “breakthrough therapy” designation is that the drugs might have had substantial improvement on one or more endpoints over available therapy.
The “breakthrough therapy” designation was based on data from three Phase 1 trials – ascending-dose clinical trials involving 126 patients with the recurrent brain cancer.
The trial involved patients with first or second recurrence of Grade 4 glioblastoma or Grade 3 anaplastic astrocytoma, who are undergoing resection.
Clinical data included results published in Science Translational Medicine, such as safety data, patient survival data and durable, complete or partial tumor shrinkage, determined by independent an radiology review.
In addition, preclinical information was provided supporting a novel immunological mechanism of action involving the depletion of immuno-suppressive myeloid cells in the tumor micro-environment.
The Tocagen team reportedly is analysing the safety and efficacy data, which has been promising, and prioritizing the development of Toca 511 & Toca FC.
Enrollment of the test subjects in the Phase 2 portion of the trial is complete and the results are expected by mid 2018.