On November 7, 2019, the Society for Immunotherapy of Cancer (SITC) held a one-day workshop on intratumoral immunomodulation just prior to its annual conference in National Harbor, Maryland. Intratumoral immunotherapies, in complement or in replacement to systemic treatments, can potentially lead to improved therapeutic outcomes, especially by overcoming checkpoint inhibitor resistance mechanisms.
Craig Slingluff, Jr., MD, a surgical oncologist at the University of Virginia, presented a 20-minute session titled “Intratumoral Checkpoint Blockade Inhibition,” which highlighted focused ultrasound’s potential for overcoming the challenges of delivering drugs into a tumor.
With its diverse applications, focused ultrasound is under investigation to provide microbubble-enabled focal drug delivery and combination therapy with intratumoral agonists and focused ultrasound ablation. Abscopal effects have been observed in some patients with pancreatic cancer who have been treated with focused ultrasound. The technology’s ability to both enhance drug delivery to the tumor microenvironment and to favorably modulate the response within the tumor microenvironment support its use in cancer immunotherapy.
The Foundation’s Director of Applied Physics Research, Frederic Padilla, PhD, attended the workshop. “For me, the presentations emphasized the important role of local ablation techniques in cancer immunotherapy. We have great hopes that focused ultrasound can play a role,” said Padilla. “SITC is one of the leading cancer immunotherapy organizations, and this meeting attracts top experts.”
Dr. Padilla’s List of Key Workshop Messages
- To turn a “cold” immunological tumor into a “hot” one, there is need for local priming which helps trigger a systemic response. This is where intratumoral treatment can be effective.
- There are clinical data and approved local treatments supporting the role of intratumoral immune therapies. Many clinical trials are ongoing.
- Treatment sequencing remains to be optimized, especially in the case of multiple tumors: Is concurrent treatment of several lesions better than sequential?
- Safety profiles must be established that allow for multiple combinations of therapies and definitions of the optimal dose.
- There is a need for pre/on-treatment biological investigations to better understand variability of the anticancer immune response. Treatment biopsy is critical for these assessments, including the timepoints for biopsy.
- Methods of intratumoral administration need to be optimized and standardized.
- Focused ultrasound’s potential ability to enable drug delivery to the tumor microenvironment and favorably modulate the tumor microenvironment support further investigations combining it with immune therapies.
The Foundation has a Cancer Immunotherapy Program dedicated to advancing the use of focused ultrasound for immune-based treatments of cancer. A recent workshop on this topic highlighted the state of the field and important next steps to move this promising field forward.