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Paul Peter Tak
President and CEO
Candel Therapeutics

07 March 2023

How is Candel changing the approach to cancer therapies?

By way of background, I’ve been a scientist, practicing physician, Chief Immunology Officer of GSK, and CEO of multiple companies. I was drawn to Candel because I saw two molecules in the pipeline that I believe have the potential to become transformative medicines for patients with solid tumors in lung, brain, pancreatic and prostate cancers. We are developing two viral immunotherapy candidates, CAN-2409 and CAN-3110, that are designed to produce a vaccine-like effect against the cancer by eliciting an immune response against solid tumors and their metastases. Importantly, both investigational therapies have shown early clinical promise, have demonstrated a persistent immune effect and have been generally well tolerated.  

The field has made important strides in extending the lives of cancer patients, and every time we manage to expand the lifespan of patients by even a few months, we believe we’re on the right path towards a potential cure. The advent of immune checkpoint inhibitors represents a scientific revolution, but unfortunately, two thirds of patients still do not respond to these new treatments. Our goal is to turn them into responders. 

How did you choose where to concentrate your attention and resources?

We concentrate our efforts on where we see a role for innovative therapies to help solve the greatest patient needs. We have performed extensive analysis of the medical need and commercial opportunity for each of the indications we are pursuing while also considering the potential regulatory pathways to approval. 

We initially chose to focus on prostate cancer, the most common cancer in men, which has a high mortality despite all the available treatments (e.g., radiotherapy, surgery, hormonal therapy). We are studying the effects of our investigational treatment consisting of two or three injections into the prostate. This procedure takes urologists about 15 minutes. The same approach can be applied for lung cancer, where two injections are administered during diagnostic bronchoscopy in outpatient clinics. 

Since inducing highly immunogenic cell death at the site of the tumor has the potential to also work in other indications, we will consider expanding into other solid tumors in the future as well.

How far have you come in your research and how close are you to delivering these types of medicines to patients?

We are conducting multiple clinical trials and expect four phase 2 and phase 3 clinical trial data readouts in the next 24 months. Our most advanced clinical trial is a phase 3 trial investigating CAN-2409 in combination with valacyclovir, an oral prodrug approved by the Food and Drug Administration for several non-cancer indications, in early localized non-metastatic prostate cancer. We have enrolled over 700 patients and expect to read out top-line results at the end of 2024. The evidence to date is highly encouraging and consistent with what we’ve seen in our early-stage studies. 

In parallel, we are running a phase 2 clinical trial of CAN-2409 in non-small cell lung cancer, where we are evaluating two different patient populations. The first group consists of patients whose solid tumor continues to grow despite continued immune checkpoint inhibitor treatment. The second group consists of patients with stable disease during continued immune checkpoint inhibitor treatment but whose tumor does not shrink in size. The responses we have seen already are encouraging and we expect to share new data from the trial in the third quarter of 2023. We will also begin evaluating whether a booster of CAN-2409 given after the initial two injections into the tumor will further improve disease outcomes. By combining experimental CAN-2409 treatment with continued immune checkpoint inhibitor treatment, we are hopeful these patients will live longer with good quality of life.

What have been your biggest challenges and how did you tackle them?


We believe viral immunotherapy represents the new frontier in immunotherapy that may help to specifically educate the patient’s immune system to fight cancer more effectively.


Some investors and pharma companies alike have previously discounted this modality due to other failed viral immunotherapies; our current market capitalization may reflect that bias. For other new modalities, such as antibody treatment in rheumatoid arthritis and CAR-T cell therapies in hematological malignancies, it also took many years before they proved themselves as viable therapies. Ultimately, it’s about the data in patients: does the investigational medicine improve patients’ lives? We have encouraging initial data in each indication that we pursue.

Furthermore, some pharma companies indicated that intratumoral therapies are currently not on their strategy. This is based on the erroneous perception that intratumoral viral immunotherapy is difficult, that you need to inject all tumors in metastatic disease, and that injection needs to be repeated frequently. We have shown that intratumoral delivery of our investigational medicine is relatively simple, straight forward, and aligned with clinical practice. We only inject one or two tumors with an effect on both injected an uninjected metastases, we currently give only two or three administrations in a patient’s life with the aim of achieving long term clinical benefit, and the procedures are well tolerated by the patients. Our approach is a systemic anti-tumor immunotherapy delivered intratumorally, through in situ vaccination to fight the patient’s cancer. Thus, there is a clear need for education based on data in patients, which takes time. 

What are the achievements youre most excited about? 

There’s been no shortage of recent accomplishments. We recently reported phase 2 clinical trial data demonstrating CAN-2409 halted the progression of disease and achieved a disease control rate of 77% in patients with progressive non-small cell lung cancer. We also highlighted effects of a single injection of CAN-3110 in patients with recurrent high-grade glioma which demonstrated a median overall survival of 11.6 months. We have advanced our randomized clinical trials in early, localized, non-metastatic prostate cancer with the same molecule and expect the read out of a phase 3 clinical trial next year.

We have shown that a single injection of CAN-3110 in patients with therapy-resistant high-grade glioma appears to improve median overall survival and we have just started the evaluation of the effects of multiple injections in this indication, work that is supported by Breakthrough Cancer Research. 

Finally, we recently announced a discovery partnership with the University of Pennsylvania to study the combination of new viral immunotherapies based on our enLIGHTEN™ Discovery Platform with their CAR-Ts with the goal of enhancing the effects of CAR-T cell therapies in solid tumors.

In short, when we look at the totality of the data, we believe that we have a relatively high probability of success that our investigational medicines will improves the lives of patients with a significant unmet need. 

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