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Evaluation of RBS2418 in Combination With Tremelimumab Plus Durvalumab in Participants With Advanced Unresectable Hepatocellular Carcinoma

A Phase 2a, Multicenter, Randomized, Open-Label Study to Assess the Efficacy, Safety, and Tolerability of RBS2418 in Combination With Tremelimumab Plus Durvalumab for Participants With Advanced Unresectable Hepatocellular Carcinoma

Status
Recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07175441
Enrollment
220
Registered
2025-09-16
Start date
2026-04-10
Completion date
2027-08-01
Last updated
2026-04-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Advanced Unresectable Hepatocellular Carcinoma

Keywords

Advanced Unresectable Hepatocellular Carcinoma (HCC)

Brief summary

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.

Detailed description

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.

Interventions

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

Sponsors

Riboscience, LLC.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. At least 18 years of age on the day of signing informed consent. 2. Male and female participants with advanced, unresectable HCC who are eligible to receive STRIDE regimen as first line therapy. 3. Willing to submit a pre-treatment tissue sample (archival or fresh tissue if archival is not available).

Exclusion criteria

1. BCLC stage D disease at the time of screening or prior to first dose of RBS2418. 2. Child-Pugh class equal or higher than B8 at the time of screening or within 7 days prior to the first dose of study treatment. 3. Eligible for curative treatments (e.g., surgical resection, liver transplantation, or local ablation). 4. Evidence of rapid progression on prior therapy resulting in rapid clinical deterioration.

Design outcomes

Primary

MeasureTime frameDescription
Progression Free Survival (PFS)From randomization until the first radiographic documentation of objective progression or death from any cause, assessed up to 2 years.Time in months from randomization until the first radiographic documentation of objective progression, as assessed using RECIST 1.1, or death from any cause.

Secondary

MeasureTime frameDescription
Overall Survival (OS)From randomization until death from any cause, assessed up to 2 years.Time in months from the date of randomization to the date of death from any cause.
Overall Response Rate (ORR) by RECIST 1.1From randomization to initial response, assessed up to 2 yearsORR 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.
Duration of Response (DOR) by RECIST 1.1From initial response to disease progression or death, assessed up to 2 yearsDOR is defined as time from initial response to disease progression or death.
Disease Control Rate (DCR)From randomization to end of treatment or disease progression, assessed up to 2 years.DCR is defined as the percentage of participants who achieve a complete response (CR), partial response (PR) or stable disease (SD).

Countries

United States

Contacts

CONTACTRiboscience Clinical Trials
clinicaltrials@riboscience.com415-754-3182

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Apr 25, 2026