Denovo Acquires Tocagen’s Gene Therapy Technology for Oncology

As Tocagen heads into its reverse merger with privately-held Forte Biosciences, Inc., San Diego-based Denovo Biopharma swooped in to snap up that company’s retroviral replicating vector platform (RRV), including an asset that stumbled in a Phase III study that Denovo believes still has some life.

Denovo said the acquisition of the retroviral replicating vector platform includes Tocagen’s investigational gene therapy and drug regimen for oncology, Toca 511 and Toca FC. Additionally, the deal also brings several early-stage development programs, including programs targeting PD-L1 and other immuno-oncology targets into Denovo’s pipeline. In its announcement, Denovo said the Tocagen programs expand the company’s product portfolio into gene therapy and immuno-oncology while remaining consistent with Denovo’s precision medicine approach. Financial terms of the deal were not provided.

Toca FC, a small molecule now known as DB107, was the lead asset in the acquisition. Toca FC is an orally administered prodrug, 5-fluorocytosine (5-FC), which is converted into an anti-cancer drug, 5-fluorouracil (5-FU), when it encounters CD. 5-FU kills cancer cells and immune-suppressive myeloid cells resulting in anti-cancer immune activation and subsequent tumor killing, according to Tocagen. Denovo called DB107 an innovative approach that uses a proprietary gene therapy platform, RRV, combined with a prodrug, that selectively infects and kills cancer cells while stimulating a robust and durable anti-cancer immune response against a tumor with minimal toxicity. DB107 has been tested clinically in solid tumors including recurrent high-grade glioma and colorectal cancer, most recently in a randomized 403-patient Phase III trial. That Phase III trial failed to meet its primary endpoints, but Denovo said there were subsets of patients who showed signs of beneficial activity of DB107. When the acquisition of the assets is complete, Denovo said it will use its unique biomarker platform to search for a pharmacogenomic predictor for DB107 efficacy.

“With this strategic acquisition, Denovo gains a pioneering gene therapy platform with unlimited potential. Together with Denovo’s world-leading precision medicine capabilities, the RRV platform along with lead product candidate DB107 presents us with an unprecedented opportunity to effectively target a wide range of oncology indications,” Wen Luo, Denovo’s chief executive officer said in a statement. “DB107’s Phase III trial aimed to treat recurrent high-grade glioma, which primarily consists of glioblastoma (GBM).  This asset, together with our DB102 asset to be tested in the front-line treatment of GBM, positions Denovo as a leader in the field of neuro-oncology that continues to have a high unmet need.”