This is a single-arm, phase II study of patients with advanced liver cancer or hepatocellular carcinoma (HCC) who are eligible for first-line treatment with T300+D. The invesitgators hypothesize that T300+D will be safe and tolerated in CP-B patients with HCC. HCC mostly affects disadvantaged populations with higher rates among racial/ethnic minorities, who are often not included in clinical trials (i.e., Hispanics, Blacks, underserved, low socioeconomic status) and present with more severe disease. Given there is not much data in the US patient cohort, this study provides a chance to gain that knowledge.

RBS2418 is a targeted immune modulator that inhibits ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1). It is designed to promote anti-tumor immunity by preserving endogenous 2'-3' cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) from hydrolysis, thereby activating antigen-presenting cells and promoting robust T cell activation. Ideally, RBS2418 acts synergistically with CTLA-4 inhibitors, such as those in the STRIDE regimen (Tremelimumab plus Durvalumab). The hypothesis is that RBS2418 combined with STRIDE will be safe, well-tolerated, highly immunogenic, and enhance anti-tumor responses in adult participants with advanced, unresectable hepatocellular carcinoma (HCC) compared to STRIDE alone.