A Trial of RSC-1255 for Treatment of Patients With Advanced Malignancies

June 22, 2026 updated by: RasCal Therapeutics, Inc.

A Phase Ia/Ib, Open Label, Multi-center, Non-randomized Dose Escalation and Dose Expansion Study of RSC-1255 Alone or in Combination With Hydroxychloroquine in Patients With Advanced Solid Tumor Malignancies

RSC-101 is a Phase 1a/1b clinical trial of RSC-1255 in adult study participants with advanced solid tumor malignancies who are intolerant of existing therapies known to provide clinical benefit, have disease that has progressed after standard therapy, or have previously failed other therapies. The study has two phases. The purpose of Phase 1a (Dose Escalation) is to confirm the appropriate treatment dose and Phase 1b (Dose Expansion) is to characterize the safety and efficacy of RSC-1255.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

RSC-1255 is an orally bioavailable, small-molecule direct pan-mutant and wild-type RAS inhibitor. RSC-101 is a Phase 1a/1b, open-label, multi-center, non-randomized, Dose Escalation and Dose Expansion study in participants with advanced solid tumor malignancies. Study enrollment is approximately 134 participants. All participants receive oral RSC-1255, twice daily as monotherapy. Following Phase 1a (Dose Escalation) to identify the Maximum Tolerated Dose and Recommended Dose for use in Phase 1b, additional participants are enrolled in the Phase 1b (Dose Expansion) to further characterize the safety, pharmacology, and the clinical efficacy of RSC-1255 as monotherapy and in combination with the autophagy inhibitor hydroxychloroquine (HCQ).

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
134

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • California
      • Los Angeles, California, United States, 90404
        • Recruiting
        • University of California, Los Angeles (UCLA) Department of Medicine - Hematology/Oncology
    • Colorado
      • Denver, Colorado, United States, 80218
        • Recruiting
        • Sarah Cannon, SCRI Oncology Partners - Health One
    • Tennessee
      • Nashville, Tennessee, United States, 37203
        • Recruiting
        • Sarah Cannon, SCRI Oncology Partners

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria (Key Factors):

  1. Has pathologically confirmed advanced or metastatic malignancy characterized by one or more of the following:

    • Participant is intolerant of existing therapy(ies) known to provide clinical benefit for their condition
    • Malignancy is refractory to existing therapy(ies) known to potentially provide clinical benefit
    • Malignancy has progressed on standard therapy
  2. Has evaluable or measurable tumor(s) in dose-escalation by standard radiological and/or laboratory assessments as applicable to their malignancy.
  3. Has adequate performance status (PS): Eastern Co-operative Oncology Group (ECOG).
  4. Is age ≥ 18 years.
  5. Has either tissue agnostic tumors and documented RAS mutations or with glioblastoma with or without mutation in RAS

Exclusion Criteria (Key Factors):

  1. Participants receiving cancer therapy at the time of enrollment.
  2. Any clinically significant disease or condition affecting a major organ system.
  3. Significant cardiovascular disease or electrocardiogram (ECG) abnormalities.
  4. Known Gilbert's disease.
  5. Has had a previous (within 2 years) or has a current malignancy other than the target cancer.
  6. Intermittent hypokalemia
  7. Grade 1 or higher nausea, vomiting, diarrhea at baseline due to underlying disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: RSC-1255 Treatment
Single Arm Study. All study participants receive RSC-1255.
Drug: RSC-1255 Dose Escalation
Phase 1a will enroll 40-80 participants to identify the dose limiting toxicity (DLT), recommended Phase 1b dose, and the safety and tolerability of RSC-1255. RSC-1255 is administered orally twice daily, with and without food. Each cycle is 21 days.
Other Names:
  • Phase 1a
  • Dose Escalation
Drug: RSC-1255 Dose Expansion
Phase 1b will enroll 48-94 participants to further characterize the safety, pharmacology, and clinical efficacy of RSC-1255. RSC-1255 is administered orally twice daily alone or in combination with continuous hydroxychloroquine, with food. Each cycle is 21 days.
Other Names:
  • Phase 1b
  • Dose Expansion

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Maximum Tolerated Dose (MTD) for RSC-1255 as monotherapy
Time Frame: Approximately 30 months
The number and type of dose-limiting toxicities (DLTs) as defined in the protocol that occur during the first 21 days of treatment and maximum grade of all treatment-related events using CTCAE V5.0 will be used to identify a safe and tolerable dose.
Approximately 30 months
Recommended Phase 2 Dose (RP2D) for RSC-1255 as monotherapy
Time Frame: Approximately 12 months
The number and type of DLTs as defined in the protocol that occur during the first 21 days of treatment and maximum grade of all treatment-related adverse events using CTCAE 5.0 will be used to identify a safe and tolerable dose.
Approximately 12 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Adverse event profile of RSC-1255
Time Frame: Approximately 24 months
Toxicities will be graded according to CTCAE V5.0.
Approximately 24 months
Overall Survival (OS)
Time Frame: Approximately 24 months
Overall Survival
Approximately 24 months
Disease Progression
Time Frame: Approximately 24 months
Disease Progression will be assessed using RECIST V1.1
Approximately 24 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
RasCal Therapeutics, Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Michael Mann, MD, RasCal Therapeutics, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 3, 2021

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 15, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 8, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 16, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 22, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 23, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 22, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • RSC-101

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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