The US Food and Drug Administration (FDA) has granted Candel Therapeutics’ immunotherapy candidate CAN-2409 (aglatimagene besadenovec) orphan drug designation for the treatment of pancreatic cancer.

Orphan drug designations are granted to medicines intended to treat rare conditions and come with benefits such as tax credits for US-based clinical trials and potentially seven years of market exclusivity in the designated indication upon agency approval.

Pancreatic cancer is one of the most lethal forms of cancer, with a survival rate beyond ten years of around 5%.

CAN-2409 was also granted fast track designation in pancreatic cancer by the FDA in December 2023, meaning the candidate is in line for expedited development and review times. 

CAN-2409 is an off-the-shelf immunotherapy that is a combination of a genetically modified adenovirus and the herpes simplex virus thymidine kinase (HSV-tk) gene. The drug works by inducing T cell response at both the targeted tumour and at distant metastases. While Candel believes the drug could work as a monotherapy, it is currently evaluating the therapy in combination with GSK’s anti-viral medication Valtrex (valacyclovir) for the treatment of pancreatic cancer.

Candel states that the HSV-tk enzyme converts co-administered valacyclovir into a toxic metabolite that kills cancer cells. The company also reported positive data from a Phase II trial (NCT02446093) investigating the combo therapy in patients with borderline resectable pancreatic cancer who are also receiving chemoradiation. Patients receiving the experimental treatment had a median overall survival of 28.8 months compared to 12.5 months in the control group. After two years, the survival rate was 71.4% in patients treated with CAN-2409 and 16.7% in those in the control arm.

Candel analysed the tumours after being removed from the patients and found evidence that CAN-2409 led to an enhanced immune response.

Candel’s CEO Paul Peter Tak said: “We recently reported data from the Phase II randomised clinical trial of CAN-2409 in borderline resectable pancreatic cancer, showing that CAN-2409, when added to standard of care, more than doubled the median overall survival obtained with standard of care alone.”

The most common mechanism of action found in standard-of-care pancreatic cancer therapies are enzyme inhibitors, which are closely followed by gene and nucleic acid inhibitors, according to analysis by GlobalData. An emerging modality with promise in the space is mRNA vaccines, with BioNTech and Roche’s vaccine candidate demonstrating lasting responses with high efficacy in clinical trials.

GlobalData is the parent company of Pharmaceutical Technology.

Candel is also investigating CAN-2409 in non-small cell lung cancer (NSCLC) and localised, non-metastatic prostate cancer. The biopharma’s chief medical officer Garrett Nichols said the company plans to release NSCLC trial data later in the current quarter.

Despite positive trial readouts, Candel fired approximately half its workforce in December 2023 to secure its cash runway into Q4 2024.