Advanced CancerPhase 1NCT05270213
Evaluation of RBS2418 in Subjects With Advanced, Metastatic Solid Tumors
A Phase 1 study testing RBS2418, Pembrolizumab and Other approved anti-cancer therapy in people with Advanced Cancer, run by Riboscience, LLC. at 14 sites in United States.
Trial summary
RBS2418 (investigational product) is a specific immune modulator, working through ectonucleotide pyrophosphatase/phosphodiesterase I (ENPP1), designed to lead to anti-tumor immunity by increasing endogenous 2'-3'-cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) and adenosine triphosphate (ATP levels) and… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Advanced Cancer
- What is being tested?
- RBS2418, Pembrolizumab and Other approved anti-cancer therapy
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 164 participants
- Where
- 14 sitesUnited States
- Study dates
- 11 Jul 2022to Dec 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Be willing and able to provide written informed consent for the study. The subject may also provide consent for Future biomedical research (FBR). However, the subject may participate in the main study without participating in FBR.
- 18 years of age on day of signing informed consent.
- Male and female subjects with advanced unresectable, recurrent or metastatic tumors who have received standard of care (SOC) therapy for their advanced/metastatic tumors and have no other SOC therapy available. Additionally, subjects must have received, have been intolerant to, have been ineligible for, or have declined all SOC therapies known to confer significant clinical benefit.
- Have histologically or cytologically confirmed cancer diagnosis based on pathology report.
- Have a predicted life expectancy of greater or equal to 3 months.
- Have measurable disease based on RECIST 1.1.
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- Have a performance status of 0, 1 or 2 using the ECOG Performance Scale within 14 days of first dose of study drug.
- Willing to submit a pre-treatment (archival or fresh-tissue if no archival tissue is available) and on-treatment tissue sample. Subjects in whom the treating physician deems such biopsy is clinically contraindicated will be evaluated on a case-by-case basis for enrollment pending Sponsor consultation.
- Additionally, during the dose-escalation portion and if appropriate in the expansion phase of the study, the Sponsor may modify subject enrolment into various cohorts that have not begun enrolling yet such that ENPP1 and/or cGAS baseline expression level in the subject's tumor must be available and may guide enrolment eligibility for the study
- Have a negative urine or serum pregnancy test within 72 hours prior to receiving the first dose of study drug (female subjects of childbearing potential who are not surgically sterilized or postmenopausal). If the urine test is positive, or cannot be confirmed as negative, a serum pregnancy test will be required.
- Demonstrate adequate organ function: hematological, renal, hepatic, coagulation parameters and obtained within 14 days prior to the first study treatment
- For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use two highly effective contraceptive methods that result in a combined failure rate of < 1% per year during the treatment period and for at least 120 days after the last dose of study treatment or as instructed by the package insert of the chosen co-medication.
- For male subjects: Agree that during the period specified above, men will not father a child. Male subjects must remain abstinent (refrain from heterosexual intercourse with women of childbearing potential), must be surgically sterile (e.g., vasectomy) or use contraceptive methods that result in a failure rate of < 1% per year during the treatment period and for at least 120 days after the last dose of study treatment.
Who cannot join
- Use of any systemic anti-cancer therapy (including radiotherapy, chemotherapy, targeted therapy or immunotherapy) within 2 weeks prior to first dose of RBS2418 unless such therapy is being administered in combination with RBS2418 per protocol and has been approved by the Sponsor; or if subject has not recovered (i.e., Less than or equal to Grade 1 or returned to baseline level) from adverse events due to a previously administered agent; the following exceptions are allowed:
- Palliative radiotherapy for bone metastases or soft tissue lesions should be completed > 7 days prior to baseline imaging
- Hormone-replacement therapy or oral contraceptives
- Subjects with Grade 2 neuropathy or Grade 2 alopecia
- Subjects with evidence of rapid progression on prior therapy resulting in rapid clinical deterioration should be excluded from participation in the trial.
- Currently participating and receiving trial therapy or has participated in a trial of an investigational agent and/or has used an investigational device within 28 days prior to Day 1.
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- Uncontrolled tumor-related pain
- Uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures
- Malignancies other than indications open for enrollment within 3 years prior to Day 1, with the exception of those with negligible risk of metastasis or death treated with expected curative outcome, undergoing active surveillance or treatment-naïve for indolent tumors
- History of severe allergic, anaphylactic, or other hypersensitivity reactions to chimeric or humanized antibodies or fusion proteins.
- Known hypersensitivity allergy or contraindication to any investigational product components administered as part of the combination therapy.
- Active autoimmune disease that has required systemic treatment in the past 2 years (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs).
- History or any evidence of interstitial lung disease
- Treatment with systemic immunosuppressive medication within 2 weeks prior to initiation of study treatment.
- Active HIV requiring therapy and Uncontrolled HIV*. HIV antibody testing recommended per investigator's clinical suspicion.
- Active hepatitis B virus (HBV; hepatitis B surface antigen reactive) or active hepatitis C virus (HCV; qualitative RNA detected)*; such as requiring active therapy (e.g. subjects with a history of HCV are eligible as long as viral RNA is below level of detection); testing recommended per investigator's clinical suspicion.
- Severe infections within 4 weeks prior to enrollment, including, but not limited to, hospitalization for complications of infection, bacteremia, or the presence of any active infection requiring systemic therapy.
- Received therapeutic oral or IV antibiotics within 2 weeks prior to Day 1
- History or current evidence of any condition, therapy, or laboratory abnormality that in the opinion of the treating investigator might confound the results of the trial or interfere with the subject's participation for the full duration of the trial.
- Subjects with:
- A marked baseline prolongation of QT/QTc interval (e.g., repeated demonstration of a QTc interval of > 480 milliseconds (ms) (CTCAE Grade 1) using Fridericia's QT correction formula
- A history of additional risk factors for Torsades de Pointes (e.g., heart failure, hypokalemia, family history of Long QT Syndrome)
- The use of concomitant medications that are known to prolong the QT/QTc interval unless there is evidence of the lack of QT/QTc interval prolongation at baseline.
- Subjects with gastrointestinal disorders that may affect the absorption of the drug
- Prior allogeneic stem cell or solid organ transplant.
- Received a live, attenuated vaccine within 28 days prior to enrollment/cohort assignment or anticipation that such a live attenuated vaccine will be required during the trial
- Known previous or ongoing, active psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the trial.
- Prisoner or subject who is compulsorily detained (involuntarily incarcerated) for treatment of either a psychiatric or physical (i.e. infectious disease) illness.
- Pregnant or lactating or intending to become pregnant or father children within the projected duration of the trial starting with the screening visit through 120 days after the last dose of pembrolizumab and/or RBS2418.
Trial locations and contacts
14 sites in 1 country. Contact the study team or a site near you to ask about taking part.
14 sites in 1 country
United States14 sites, 12 recruiting
- Recruiting
Johns Hopkins Sidney Kimmel Comprehensive Cancer Center
Baltimore, Maryland, 21224
clinicaltrials@riboscience.com
- Recruiting
American Oncology Partners of Maryland
Bethesda, Maryland, 20817
clinicaltrials@riboscience.com
- Recruiting
NEXT Virigina
Fairfax, Virginia, 22031
clinicaltrials@riboscience.com
- Completed
Carolina BioOncology Institute
Huntersville, North Carolina, 28078
- Recruiting
Norton Cancer Institute
Louisville, Kentucky, 40202
clinicaltrials@riboscience.com
- Recruiting
Vanderbilt-Ingram Cancer Center
Nashville, Tennessee, 37235
clinicaltrials@riboscience.com
- Recruiting
Ochsner Clinic Foundation
New Orleans, Louisiana, 70121
clinicaltrials@riboscience.com
- Recruiting
Ichan School of Medicine at Mount Sinai
New York, New York, 10029
clinicaltrials@riboscience.com
- Recruiting
Christiana Care Health Services
Newark, Delaware, 19713
clinicaltrials@riboscience.com
- Recruiting
Stanford Cancer Institute
Palo Alto, California, 94305
clinicaltrials@riboscience.com
- Recruiting
UCLA Hematology/Oncology - Santa Monica
Santa Monica, California, 90404
clinicaltrials@riboscience.com
- Recruiting
Honor Health Research Institute
Scottsdale, Arizona, 85258
clinicaltrials@riboscience.com
- Recruiting
University of Arizona
Tucson, Arizona, 85724
clinicaltrials@riboscience.com
- Withdrawn
Tranquil Research
Webster, Texas, 77598
About this study
Official title: A First-In-Human, Phase 1 a/b Dose Escalation and Expansion Study to Evaluate RBS2418 as Monotherapy and in Combination With Pembrolizumab in Subjects With Advanced Unresectable, Recurrent or Metastatic Tumors
RBS2418 (investigational product) is a specific immune modulator, working through ectonucleotide pyrophosphatase/phosphodiesterase I (ENPP1), designed to lead to anti-tumor immunity by increasing endogenous 2'-3'-cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) and adenosine triphosphate (ATP levels) and reducing adenosine production in the tumors. RBS2418 has the potential to be an important therapeutic option for subjects both as monotherapy and in combination with other cancer treatments including monotherapy and in combination with other cancer treatments including immunotherapy or chemotherapy. This study is an open-label, multi-site Phase 1a/1b study of RBS2418, a selective ENPP1 inhibitor, in combination with pembrolizumab or other approved anticancer therapies or as a monotherapy in subjects with advanced unresectable, recurrent or metastatic tumors. The phase 1a (dose escalation phase) has been completed. The Phase 1b expansion phase of the study has been increased in size and scope.
Read the detailed description
The dose escalation phase (Part A) of this Phase 1a/1b study has been completed (n=24 study participants). Based on safety and preliminary activity data, we have expanded the size and scope of the dose expansion phase (Part B), which will include treatment groups receiving RBS2418 at selected dose levels. These doses will be administered either as monotherapy or in combination with approved anti-cancer therapies, including pembrolizumab (200 mg IV every 3 weeks), or other standard-of-care therapies at the discretion of the site principal investigator (PI). Part B is enrolling approximately 140 subjects to further assess safety, tolerability, and preliminary efficacy at selected doses in expansion cohorts.
Subjects must have received standard of care (SOC) therapy for their advanced/metastatic tumors and subjects must have received, have been intolerant to, have been ineligible for, or have declined all treatment known to confer significant clinical benefit. Subjects must also have at least 1 measurable lesion per Response Evaluation Criteria in Solid Tumors (RECIST1.1), an Eastern Cooperative Oncology Group (ECOG) performance score of 0, 1 or 2 and predicted life expectancy of greater than 3 months. An imaging scan is required at baseline, up to 28 days prior to treatment initiation. Subjects are required to provide an adequate tumor tissue sample (archival or fresh-tissue if no archival is available).
In all treatment arms, treatment continues until progressive disease (PD), unacceptable adverse events (AEs), intercurrent illness that prevents further administration of treatment, investigator's decision to withdraw the subject, subject withdrawal of consent, pregnancy of the subject, noncompliance with study dosing or procedure requirements, subject receiving approximately 2 years of RBS2418 monotherapy or combination therapy, or administrative reasons requiring cessation of treatment.
After the last dose of study drug, each subject will be followed for 30 days for AE monitoring. Serious adverse events (SAEs) will be collected for 90 days after the end of treatment or for 30 days after the end of treatment, if the subject initiates new anticancer therapy, whichever is earlier
- Conditions
- Advanced Cancer
- Being tested
- RBS2418, Pembrolizumab, Other approved anti-cancer therapy
- Keywords
- Metastatic tumors, Recurrent tumors, Unresectable tumors
- Medical subject headings
- Neoplasm Metastasis, Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RBS2418Drug
RBS2418 is a potent and selective small molecule inhibitor of ectonucleotide pyrophosphatase/phosphodiesterase I (ENPP1). RBS2418 as monotherapy potentially can have an activating effect on the anti-tumor innate immune response and lead to anti-tumor responses in adult subjects with advanced or metastatic tumors.
PembrolizumabDrug
200 mg intravenously every 3 weeks
Other approved anti-cancer therapyDrug
Standard of care (SOC) therapy
| Study group | Role | What they receive |
|---|---|---|
| Treatment Group A-1 (Completed) | Experimental | For Treatment Group A-1, a cohort of three (3) subjects will be dosed at the starting dose of 100 mg twice a day (BID) of RBS2418. Subsequent subjects will then be enrolled in serial, three (3) subject cohorts, with 100% dose increments (doubling the dose) until 800 mg BID Receives: Drug: RBS2418 |
| Treatment Group A-2 (Completed) | Experimental | For Treatment Group A-2, a cohort of three (3) subjects will be dosed at the starting dose of 100 mg twice a day (BID) of RBS2418 in combination with pembrolizumab 200 mg IV (administered on Day 1 and every 3 weeks). Subsequent subjects will then be enrolled in serial, three (3) subject cohorts, with 100% dose increments (doubling the dose) until 800 mg BID Receives: Drug: RBS2418; Drug: Pembrolizumab |
| Treatment Group B | Experimental | RBS2418 as Monotherapy or in combination with investigator-selected approved anticancer therapy at selected dose levels. (n~140) Receives: Drug: RBS2418; Drug: Pembrolizumab; Drug: Other approved anti-cancer therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Treatment emergent dose limiting toxicities (DLT)
When more than 1 DLT occurs in ≤ 6 patients in a dosing cohort, MTD has been exceeded and no more patients are to be treated at that dose level. No DLT observed at the highest dose level in Part A. Part A has been completed.
Measured: From 1- 21 days of the first cycle (each cycle is 21 days)
Peak plasma concentration (Cmax) of RBS2418
maximum plasma concentration of RBS2418
Measured: Day 0 - 5
Area under the plasma concentration versus time curve (AUC)
area under the curve for RBS2418
Measured: Day 0 - 5
Optimal Biologically Active Dose (OBA)
Dose at which Ctrough plasma concentration of RBS2418 equal to or higher than ENPP1 EC90 in human serum is achieved. All dose levels (100-800 mg BID) achieved the endpoint. Part A has been completed.
Measured: Day 0 - 5
Half-life (t1/2)
half-life of RBS2418
Measured: Day 0 - 5
Number of participants with treatment emergent Adverse events
Adverse events, as graded by NCI CTCAE v5.0 including adverse events of special interest (AESI) classified by system organ class, preferred term, severity and relationship to drug
Measured: 30 days from last dose
Secondary outcomes (1)
Overall response rate (ORR) by RECIST
Beginning with screening, all imaging assessments will be evaluated using RECIST 1.1. On- study imaging assessments will be performed Q9W. RECIST 1.1 will be used by the site for treatment decisions until the first radiographic evidence of PD.
Measured: nine weeks from first dose
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Mar 2022
- Study start11 Jul 2022
- Primary completionApr 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Advanced CancerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Model description
- The dose escalation phase (Part A) employed a standard 3+3 design to identify dose-limiting toxicities (DLTs), establish the maximum tolerated dose (MTD, if observed), determine dose levels that can achieve Ctrough levels in excess of target inhibition EC90, and determine the recommended doses of RBS2418, both as monotherapy and in combination with pembrolizumab, for further evaluation. The Part A goals have been achieved, and Part A has been completed. Part B is in progress to explore the safety and preliminary efficacy of RBS2418 at selected dose levels as monotherapy and in combination with pembrolizumab or other approved anti-cancer therapies. Treatment Group A-1: RBS2418 Dose Escalation (Monotherapy) COMPLETED Treatment Group A-2: RBS2418 plus Pembrolizumab Dose Escalation (Combination Therapy) COMPLETED Treatment Group B: RBS2418 as Monotherapy or in combination with investigator-selected approved anticancer therapy.
- Masking
- None (open label)
- Enrolment
- 164 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Riboscience, LLC.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Riboscience Chief Medical Officer, Study director, Riboscience, LLC.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05270213
- Sponsor's protocol ID
- RBS2418-1001
- Status last verified
- Dec 2025
- First submitted
- 9 Feb 2022
- Last updated
- 19 Dec 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A First-In-Human, Phase 1 a/b Dose Escalation and Expansion Study to Evaluate RBS2418 as Monotherapy and in Combination With Pembrolizumab in Subjects With Advanced Unresectable, Recurrent or Metastatic Tumors
- ClinicalTrials.gov ID
- NCT05270213
- Acronym / sponsor ID
- RBS2418-1001
- Conditions
- Advanced Cancer
- Keywords
- Metastatic tumors, Recurrent tumors, Unresectable tumors
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 164 participants (estimated)
- Lead sponsor
- Riboscience, LLC.Industry (pharma, biotech, devices)
- Study start
- 11 Jul 2022 (actual)
- Primary completion
- Apr 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 8 Mar 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
RBS2418 (investigational product) is a specific immune modulator, working through ectonucleotide pyrophosphatase/phosphodiesterase I (ENPP1), designed to lead to anti-tumor immunity by increasing endogenous 2'-3'-cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) and adenosine triphosphate (ATP levels) and reducing adenosine production in the tumors. RBS2418 has the potential to be an important therapeutic option for subjects both as monotherapy and in combination with other cancer treatments including monotherapy and in combination with other cancer treatments including immunotherapy or chemotherapy. This study is an open-label, multi-site Phase 1a/1b study of RBS2418, a selective ENPP1 inhibitor, in combination with pembrolizumab or other approved anticancer therapies or as a monotherapy in subjects with advanced unresectable, recurrent or metastatic tumors. The phase 1a (dose escalation phase) has been completed. The Phase 1b expansion phase of the study has been increased in size and scope.
Detailed description
The dose escalation phase (Part A) of this Phase 1a/1b study has been completed (n=24 study participants). Based on safety and preliminary activity data, we have expanded the size and scope of the dose expansion phase (Part B), which will include treatment groups receiving RBS2418 at selected dose levels. These doses will be administered either as monotherapy or in combination with approved anti-cancer therapies, including pembrolizumab (200 mg IV every 3 weeks), or other standard-of-care therapies at the discretion of the site principal investigator (PI). Part B is enrolling approximately 140 subjects to further assess safety, tolerability, and preliminary efficacy at selected doses in expansion cohorts.
Subjects must have received standard of care (SOC) therapy for their advanced/metastatic tumors and subjects must have received, have been intolerant to, have been ineligible for, or have declined all treatment known to confer significant clinical benefit. Subjects must also have at least 1 measurable lesion per Response Evaluation Criteria in Solid Tumors (RECIST1.1), an Eastern Cooperative Oncology Group (ECOG) performance score of 0, 1 or 2 and predicted life expectancy of greater than 3 months. An imaging scan is required at baseline, up to 28 days prior to treatment initiation. Subjects are required to provide an adequate tumor tissue sample (archival or fresh-tissue if no archival is available).
In all treatment arms, treatment continues until progressive disease (PD), unacceptable adverse events (AEs), intercurrent illness that prevents further administration of treatment, investigator's decision to withdraw the subject, subject withdrawal of consent, pregnancy of the subject, noncompliance with study dosing or procedure requirements, subject receiving approximately 2 years of RBS2418 monotherapy or combination therapy, or administrative reasons requiring cessation of treatment.
After the last dose of study drug, each subject will be followed for 30 days for AE monitoring. Serious adverse events (SAEs) will be collected for 90 days after the end of treatment or for 30 days after the end of treatment, if the subject initiates new anticancer therapy, whichever is earlier
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- The dose escalation phase (Part A) employed a standard 3+3 design to identify dose-limiting toxicities (DLTs), establish the maximum tolerated dose (MTD, if observed), determine dose levels that can achieve Ctrough levels in excess of target inhibition EC90, and determine the recommended doses of RBS2418, both as monotherapy and in combination with pembrolizumab, for further evaluation. The Part A goals have been achieved, and Part A has been completed. Part B is in progress to explore the safety and preliminary efficacy of RBS2418 at selected dose levels as monotherapy and in combination with pembrolizumab or other approved anti-cancer therapies. Treatment Group A-1: RBS2418 Dose Escalation (Monotherapy) COMPLETED Treatment Group A-2: RBS2418 plus Pembrolizumab Dose Escalation (Combination Therapy) COMPLETED Treatment Group B: RBS2418 as Monotherapy or in combination with investigator-selected approved anticancer therapy.
| Arm | Type | Receives |
|---|---|---|
| Treatment Group A-1 (Completed) | Experimental | Drug: RBS2418For Treatment Group A-1, a cohort of three (3) subjects will be dosed at the starting dose of 100 mg twice a day (BID) of RBS2418. Subsequent subjects will then be enrolled in serial, three (3) subject cohorts, with 100% dose increments (doubling the dose) until 800 mg BID |
| Treatment Group A-2 (Completed) | Experimental | Drug: RBS2418, Drug: PembrolizumabFor Treatment Group A-2, a cohort of three (3) subjects will be dosed at the starting dose of 100 mg twice a day (BID) of RBS2418 in combination with pembrolizumab 200 mg IV (administered on Day 1 and every 3 weeks). Subsequent subjects will then be enrolled in serial, three (3) subject cohorts, with 100% dose increments (doubling the dose) until 800 mg BID |
| Treatment Group B | Experimental | Drug: RBS2418, Drug: Pembrolizumab, Drug: Other approved anti-cancer therapyRBS2418 as Monotherapy or in combination with investigator-selected approved anticancer therapy at selected dose levels. (n~140) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (13 listed)
- Be willing and able to provide written informed consent for the study. The subject may also provide consent for Future biomedical research (FBR). However, the subject may participate in the main study without participating in FBR.
- 18 years of age on day of signing informed consent.
- Male and female subjects with advanced unresectable, recurrent or metastatic tumors who have received standard of care (SOC) therapy for their advanced/metastatic tumors and have no other SOC therapy available. Additionally, subjects must have received, have been intolerant to, have been ineligible for, or have declined all SOC therapies known to confer significant clinical benefit.
- Have histologically or cytologically confirmed cancer diagnosis based on pathology report.
- Have a predicted life expectancy of greater or equal to 3 months.
Key exclusion criteria (29 listed)
- Use of any systemic anti-cancer therapy (including radiotherapy, chemotherapy, targeted therapy or immunotherapy) within 2 weeks prior to first dose of RBS2418 unless such therapy is being administered in combination with RBS2418 per protocol and has been approved by the Sponsor; or if subject has not recovered (i.e., Less than or equal to Grade 1 or returned to baseline level) from adverse events due to a previously administered agent; the following exceptions are allowed:
- Subjects with evidence of rapid progression on prior therapy resulting in rapid clinical deterioration should be excluded from participation in the trial.
- Currently participating and receiving trial therapy or has participated in a trial of an investigational agent and/or has used an investigational device within 28 days prior to Day 1.
- Uncontrolled tumor-related pain
- Uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| RBS2418RBS2418 is a potent and selective small molecule inhibitor of ectonucleotide pyrophosphatase/phosphodiesterase I (ENPP1). RBS2418 as monotherapy potentially can have an activating effect on the anti-tumor innate immune response and lead to anti-tumor responses in adult subjects with advanced or metastatic tumors. | Drug | Treatment Group A-1 (Completed), Treatment Group A-2 (Completed), Treatment Group B |
| Pembrolizumab200 mg intravenously every 3 weeks | Drug | Treatment Group A-2 (Completed), Treatment Group B |
| Other approved anti-cancer therapyStandard of care (SOC) therapy | Drug | Treatment Group B |
Primary outcome
Treatment emergent dose limiting toxicities (DLT)
Time frame: From 1- 21 days of the first cycle (each cycle is 21 days)
When more than 1 DLT occurs in ≤ 6 patients in a dosing cohort, MTD has been exceeded and no more patients are to be treated at that dose level. No DLT observed at the highest dose level in Part A. Part A has been completed.
Peak plasma concentration (Cmax) of RBS2418
Time frame: Day 0 - 5
maximum plasma concentration of RBS2418
Area under the plasma concentration versus time curve (AUC)
Time frame: Day 0 - 5
area under the curve for RBS2418
Optimal Biologically Active Dose (OBA)
Time frame: Day 0 - 5
Dose at which Ctrough plasma concentration of RBS2418 equal to or higher than ENPP1 EC90 in human serum is achieved. All dose levels (100-800 mg BID) achieved the endpoint. Part A has been completed.
Half-life (t1/2)
Time frame: Day 0 - 5
half-life of RBS2418
Number of participants with treatment emergent Adverse events
Time frame: 30 days from last dose
Adverse events, as graded by NCI CTCAE v5.0 including adverse events of special interest (AESI) classified by system organ class, preferred term, severity and relationship to drug
1 secondary outcome
Overall response rate (ORR) by RECIST
Time frame: nine weeks from first dose
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Dec 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Riboscience Chief Medical Officer study director
Riboscience, LLC.
14 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing RBS2418, Pembrolizumab and Other approved anti-cancer therapy in people with Advanced Cancer, run by Riboscience, LLC. at 14 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 13 inclusion and 29 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 19 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 14 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Riboscience Clinical Trials ((415) 754-3182, clinicaltrials@riboscience.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Treatment emergent dose limiting toxicities (DLT) (time frame: From 1- 21 days of the first cycle (each cycle is 21 days)). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Dec 2025.