Prolonged-Release Hydrogel Formulations of Toll-Like Receptor Agonists for Intratumoral Injection to Increase Immunotherapy Response

Some aspects of the present disclosure are generally related to injectable compositions, for example, for intratumoral drug delivery. In some embodiments, the injectable composition comprises a polymer configured to undergo a solution-gel transition when heated from room temperature to at or around body temperature, allowing for the injection of the injectable composition as a liquid with subsequent gelation to retain the composition at the injection location. In some embodiments, the injectable compositions may be capable of encapsulating radio-opaque label and/or a hydrophobic immunoadjuvant (e.g., imiquimod) at a concentration of greater than or equal to 0.5 mg/mL. Accordingly, some aspects of the present disclosure are related to the radio-opaque label facilitating visualization of the injectable composition during injection and/or the retention of the injectable composition at the injection location, allowing for localized and extended-release of the immunoadjuvant. Still other aspects are generally directed to related methods, kits, or the like.