Using the gel in combination with immunotherapy improved survival in mice and affected distant, untreated tumors, suggesting it has potential as a therapy for metastatic cancers.

Injecting anti-cancer drugs directly into tumors – intratumoral therapy – is a promising way of treating solid cancers. However, clinical trials have highlighted some drawbacks. One is that most immunotherapies are composed of small molecules prone to dissipating quickly from the tumor site after injection. Another is visualizing the treatment in situ to confirm its on-target delivery.

Now, researchers from Mass General Brigham, in collaboration with the Koch Institute for Integrative Cancer Research, have developed a gel delivery system that overcomes these challenges.