A Phase 2 interventional study of RBS2418 and STRIDE (durvalumab + tremelimumab) in Advanced Unresectable Hepatocellular Carcinoma, sponsored by Riboscience, LLC.. Recruiting at 4 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-04-24.
Sponsored by Riboscience, LLC. · Phase 2, Interventional, and Treatment
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.
In this Phase 2a study, participants must have advanced, unresectable HCC confirmed by radiology, histology or cytology. Participants must be eligible to receive the STRIDE regimen as first line therapy. Participants must have measurable disease per RECIST 1.1, an Eastern Cooperative Oncology Group (ECOG) performance score of 0, 1 or 2, and predicted life expectancy of at least 12 weeks.
Up to approximately 220 participants will be enrolled and will receive therapy as part of their respective treatment group. Participants will receive study treatment of RBS2418 at two different dose levels (200mg and 800mg) twice daily in combination with STRIDE or STRIDE alone with a treatment period consisting of 28-day cycles up to two years or until there is progressive disease, death, withdrawal, or study completion, whichever comes first.
Adverse Events (AEs) will be monitored throughout the study and graded in severity according to the guidelines outlined in the NCI CTCAE v5.0. AEs will be collected until up to 30 days after the last dose of RBS2418 or until resolution, whichever comes first. SAEs will be collected for 90 days after the last dose of RBS2418, or if the participant initiates new anti-cancer therapy, then 30 days after the RBS2418 last dose, whichever is earlier.
Riboscience, LLC. is the lead sponsor of 4 studies on the registry; 3 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
RBS2418 200 mg PO, BID in combination with STRIDE regimen
Drug: RBS2418 · Drug: STRIDE (durvalumab + tremelimumab)
RBS2418 800 mg PO, BID in combination with STRIDE regimen
Drug: RBS2418 · Drug: STRIDE (durvalumab + tremelimumab)
STRIDE regimen
Drug: STRIDE (durvalumab + tremelimumab)
RBS2418 is a specific immune modulator that works through the inhibition of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) and is designed to lead to anti-tumor immunity by protecting endogenous 2'-3'-cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) from hydrolysis and leading to the activation of antigen-presenting cells followed by T cell activation.
STRIDE: Tremelimumab 300 mg IV (Cycle 1 Day 1 only) Plus Durvalumab 1500 mg IV every 4 weeks
Progression Free Survival (PFS)
Time in months from randomization until the first radiographic documentation of objective progression, as assessed using RECIST 1.1, or death from any cause.
Time frame: From randomization until the first radiographic documentation of objective progression or death from any cause, assessed up to 2 years.
Overall Survival (OS)
Time in months from the date of randomization to the date of death from any cause.
Time frame: From randomization until death from any cause, assessed up to 2 years.
Overall Response Rate (ORR) by RECIST 1.1
ORR is defined as the percentage of participants who achieve a complete response (CR) or partial response (PR) during the study using RECIST 1.1, among those with measurable disease.
Time frame: From randomization to initial response, assessed up to 2 years
Duration of Response (DOR) by RECIST 1.1
DOR is defined as time from initial response to disease progression or death.
Time frame: From initial response to disease progression or death, assessed up to 2 years
Disease Control Rate (DCR)
DCR is defined as the percentage of participants who achieve a complete response (CR), partial response (PR) or stable disease (SD).
Time frame: From randomization to end of treatment or disease progression, assessed up to 2 years.
Plan to share: No
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Riboscience, LLC.