Testing the Addition of an Anti-Cancer Drug, Daraxonrasib, for Relapsed or Refractory Solid Tumors With RAS Mutations

A Phase 1/2 Study of Daraxonrasib (RMC-6236) in Patients With Relapsed or Refractory RAS-Driven Tumors

This phase I/II trial tests the safety, side effects, best dose and how well giving daraxonrasib works for the treatment of pediatric patients with solid tumors with RAS mutations that has come back after a period of improvement (relapsed) or that has not responded to previous treatment (refractory). Daraxonrasib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving daraxonrasib may be safe, tolerable and/or effective in treating patients with relapsed or refractory solid tumors with RAS mutations.

Study Overview

• Status: Not yet recruiting
• Conditions: Recurrent Childhood Rhabdomyosarcoma; Refractory Childhood Rhabdomyosarcoma; Refractory Childhood Malignant Solid Neoplasm; Recurrent Childhood Malignant Solid Neoplasm; Recurrent Childhood Neuroblastoma; Refractory Childhood Neuroblastoma
• Intervention / Treatment: Procedure: X-Ray Imaging; Procedure: Bone Marrow Aspiration; Procedure: Biospecimen Collection; Procedure: Bone Marrow Biopsy; Procedure: Diagnostic Imaging Testing; Drug: Daraxonrasib

Detailed Description

PRIMARY OBJECTIVES:

I. To estimate the maximum tolerated dose (MTD) and/or recommended phase 2 dose (RP2D) of daraxonrasib administered as a daily oral medication to pediatric patients with recurrent or refractory RAS driven solid tumors. (Phase 1 dose escalation [Part A]) II. To define and describe the toxicities of daraxonrasib administered on this schedule to a pediatric population. (Phase 1 and 2 [Part A and B]) III. To preliminarily evaluate the antitumor activity of daraxonrasib in pediatric patients with recurrent or refractory RAS driven fusion negative rhabdomyosarcoma. (Phase 2 Dose Expansion [Part B])

SECONDARY OBJECTIVES:

I. To preliminarily define antitumor activity of daraxonrasib in pediatric patients with recurrent or refractory RAS driven solid tumors within the confines of a Phase 1 study. (Phase 1 Dose Escalation [Part A]) II. To preliminarily define antitumor activity of daraxonrasib in pediatric patients with recurrent or refractory RAS driven neuroblastoma and other solid tumors (not including fusion negative rhabdomyosarcoma). (Phase 2 Dose Expansion [Part B]) III. To characterize the pharmacokinetics of daraxonrasib in pediatric patients with recurrent or refractory RAS driven solid tumors. (Phase 1 Dose Escalation and Phase 2 Dose Expansion [Part A and B]) IV. To estimate the progression-free survival (PFS), overall survival (OS), duration of response (DOR), and time to response (TTR) in pediatric patients with recurrent or refractory RAS driven solid tumors. (Phase 1 Dose Escalation and Phase 2 Dose Expansion [Part A and B])

EXPLORATORY OBJECTIVES:

I. To estimate the frequency of detectable RAS mutations by circulating tumor deoxyribonucleic acid (ctDNA) at start of study treatment in pediatric patients with relapsed and refractory solid tumors with activating RAS mutations, and to assess mutant allele fraction in ctDNA as an exploratory response biomarker.

II. To bank archival tissue for future studies.

OUTLINE: This is a dose-escalation study of daraxonrasib followed by a dose-expansion study.

Patients receive daraxonrasib orally (PO) once daily (QD) on days 1-21 of each cycle. Cycles repeat every 21 days for 28 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo urine sample collection during screening and undergo x-ray imaging, diagnostic imaging and blood sample collection throughout the study. Patients may also undergo bone marrow aspiration and biopsy throughout the study.

After completion of study treatment, patients in phase 2 are followed up every 3 months for 12 months, every 6 months until 24 mounts then annually until 60 months.

• Study Type: Interventional
• Enrollment (Estimated): 77
• Phase: Phase 2; Phase 1

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• PARTS A1 AND B: Patients must be ≥ 2 years and ≤ 17 years of age at the time of study enrollment
• PART A2: Patients must be ≥ 1 year and ≤ 17 years of age at the time of study enrollment
• Patients with recurrent or refractory extracranial solid tumors. Patients must have had histologic verification of malignancy at original diagnosis or relapse
• PARTS A1 AND A2: Patients with relapsed or refractory RAS mutant extracranial solid tumors
• PARTS B1, B2, AND B3: Patients with relapsed or refractory fusion-negative rhabdomyosarcoma (B1: RMS), neuroblastoma (B2: NBL), or other extracranial solid tumors (B3: Other)
• All patients must have a College of American Pathologists (CAP)/Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory report which documents RAS mutation at diagnosis or time of relapse, defined as nonsynonymous mutations in KRAS, NRAS, or HRAS at codons 12, 13, or 61 (G12, G13, or Q61)
• PAST A: Patients must have either measurable or evaluable disease
• PART B: Patients must have International Neuroblastoma Response Criteria (INRC) evaluable (neuroblastoma) or Response Evaluation Criteria in Solid Tumors (RECIST) measurable (all other diagnoses) disease
• NEUROBLASTOMA: Bone marrow aspirates and biopsies are required at baseline for neuroblastoma patients, per INRC guidelines
• SOLID TUMORS: Bone marrow aspirates and biopsies are required at baseline for patients with other solid tumors with a history of bone marrow metastatic disease
• Patient's current disease state must be one for which there is no known curative therapy or therapy proven to prolong survival with an acceptable quality of life
• Karnofsky ≥ 50% for patients >16 year of age and Lansky ≥ 50% for patients ≤ 16 years of age. Patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score.

See https://www.cogmembers.org/site/pages/default.aspx?page=Prot_reference_ materials under Standard References

• Patients must have fully recovered (grade < 2) from the acute toxic effects of all prior anti-cancer therapy and must meet the following minimum duration from prior anti-cancer directed therapy prior to enrollment. If after the required timeframe, the numerical eligibility criteria are met, e.g., blood count criteria, the patient is considered to have recovered adequately.

  • Cytotoxic chemotherapy or other anti-cancer agents known to be myelosuppressive: See DVL homepage on the Children's Oncology Group (COG) Members site for commercial and investigational agent classifications. For agents not listed, the duration of this interval must be discussed with the study chair and the study-assigned Research Coordinator prior to enrollment.
  • Solid Tumor Patients: ≥ 21 days after the last dose of myelosuppressive chemotherapy (42 days if prior nitrosourea). Please refer to the table of myelosuppressive/Anticancer Agents on the COG website: https://www.cogmembers.org/uploadedFiles/Site/Disc/DVL/Documents/TableOfMyelosuppressiveAnti-CancerAgents.pdf
  • Anti-cancer agents not known to be myelosuppressive (e.g., not associated with reduced platelet or absolute neutrophil count [ANC] counts): ≥ 7 days after the last dose of agent. See the DVL homepage on the COG Members site for commercial and investigational agent classifications. For agents not listed, the duration of this interval must be discussed with the study chair and the study-assigned Research Coordinator prior to enrollment.
  • Antibodies: ≥ 21 days must have elapsed from infusion of last dose of antibody, and toxicity related to prior antibody therapy must be recovered to Grade ≤ 1.
  • Corticosteroids: If used to modify immune adverse events related to prior therapy, ≥ 14 days must have elapsed since last dose of corticosteroid
  • Hematopoietic growth factors: ≥ 14 days after the last dose of a long-acting myeloid growth factor (e.g., pegfilgrastim) or 7 days for short acting myeloid growth factor or platelet growth factor/stimulating agents (e.g., romiplostim, eltrombopag). For agents that have known adverse events occurring beyond 7 days after administration, this period must be extended beyond the time during which adverse events are known to occur.
  • Interleukins, Interferons and Cytokines (other than Hematopoietic Growth Factors): ≥ 21 days after the completion of interleukins, interferon or cytokines (other than Hematopoietic Growth Factors).

  • Stem cell Infusions (with or without total body irradiation [TBI]):

    • Allogeneic (non-autologous) bone marrow or stem cell transplant, or any stem cell infusion including donor lymphocyte infusion (DLI) or boost infusion: ≥ 84 days after infusion and no evidence of graft versus host disease (GVHD).
    • Autologous stem cell infusion including boost infusion: ≥ 42 days.
  • Cellular Therapy: ≥ 42 days after the completion of any type of cellular therapy (e.g., modified T cells, natural killer [NK] cells, dendritic cells, etc.).
  • Radiation (XRT)/External Beam Irradiation including Protons: ≥ 14 days after local XRT; ≥ 56 days from thoracic XRT; ≥ 150 days after TBI, craniospinal XRT or if radiation to ≥ 50% of the pelvis; ≥ 42 days if other substantial bone marrow (BM) radiation.
  • Radiopharmaceutical therapy (e.g., radiolabeled antibody, 131I MIBG): ≥ 42 days after systemically administered radiopharmaceutical therapy.
  • Patients must not have received prior exposure to daraxonrasib or other direct RAS inhibitors (e.g., sotorasib, adagrasib)
• Peripheral absolute neutrophil count (ANC) ≥ 1000/uL (for patients with solid tumors without known bone marrow involvement)
• Platelet count ≥ 100,000/uL (transfusion independent, defined as not receiving platelet transfusions for at least 7 days prior to enrollment) (for patients with solid tumors without known bone marrow involvement)
• Hemoglobin ≥ 8.0 g/dL at baseline (may receive red blood cell [RBC] transfusions) (for patients with solid tumors without known bone marrow involvement)
• Patients with known bone marrow metastatic disease will be eligible for study provided they meet the blood counts (may receive transfusions provided they are not known to be refractory to red cell or platelet transfusions). These patients will not be evaluable for hematologic toxicity. At least 5 of every cohort of 6 patients must be evaluable for hematologic toxicity for the dose escalation part of the study. If dose-limiting hematologic toxicity is observed, all subsequent patients enrolled must be evaluable for hematologic toxicity

• * For patients ≤ 17 years old estimated glomerular filtration rate (GFR) (eGFR) ≥ 60 mL/min/1.73 m^2 "Bedside" Schwartz formula (2009): eGFR = 0.413 x (height (cm) / serum creatinine (mg/dL)) An online calculator is available through the National Kidney Foundation at http://www.kidney.org/professionals/kdoqi/gfr_calculatorped

  • For patients > 17 years old the Cockroft-Gault equation should be utilized to calculate creatinine clearance

  • OR for any age group:

    • a 24 hour urine Creatinine clearance ≥ 60 mL/min/1.73 m^2
  • OR a GFR ≥ 60 mL/min/1.73 m^2. GFR must be performed using direct measurement with a nuclear blood sampling method OR direct small molecule clearance method (iothalamate or other molecule per institutional standard). Cystatin C based methods for estimation of GFR are not acceptable
• Bilirubin (total or sum of conjugated + unconjugated) ≤ 1.5 x upper limit of normal (ULN) for age except in patients diagnosed with Gilbert's disease for which bilirubin must be ≤ 3.0 × ULN
• Alanine aminotransferase (ALT) ≤ 3 x ULN, unless attributed to tumor involvement then ALT ≤ 5 x ULN
• Aspartate aminotransferase (AST) ≤ 3 x ULN, unless attributed to tumor involvement then AST ≤ 5 x ULN
• Serum albumin ≥ 2 g/dL
• International normalization ratio (INR) ≤ 1.5
• Corrected QT (QTc) ≤ 480 ms
• Anti-cancer agents: Patients who are currently receiving other anti-cancer agents are not eligible

Exclusion Criteria:

• Pregnant or breast-feeding women will not be entered on this study because there is yet no available information regarding human fetal or teratogenic toxicities. Pregnancy tests must be obtained in girls who are post-menarchal. Males or females of reproductive potential may not participate unless they have agreed to use two effective methods of birth control, including a medically accepted barrier or contraceptive method (e.g., male or female condom) for the duration of the study and for at least one month after the last dose of study treatment for females and one week after the last dose of study treatment for males. Abstinence is an acceptable method of birth control
• Corticosteroids: Patients must be on a stable or decreasing dose of corticosteroids for at least 7 days prior to enrollment. If used to modify immune adverse events related to prior therapy, ≥ 14 days must have elapsed since last dose of corticosteroid
• Investigational drugs: Patients who are currently receiving another investigational drug are not eligible
• Anti-GVHD agents post-transplant: Patients must not be receiving tacrolimus or other medications to prevent graft-versus-host disease post bone marrow transplant
• Cyclosporine and derivatives: Patients must not require concomitant treatment with systemically bioavailable cyclosporine A or its derivatives

• CYP3A4 inhibitors/inducers: Moderate or strong systemic CYP3A4 inhibitors or inducers are prohibited during treatment with daraxonrasib. These agents should be discontinued at least 14 days prior to enrollment.

  • Local or topical treatments are allowed.
  • Seville oranges, grapefruit, and grapefruit products are considered moderate or strong CYP3A4 inhibitors on this protocol
• Patients enrolled on Parts A1 and B must be able to swallow 20 mg and 100 mg tablets intact. Nasogastric or G tube administration is not allowed
• Patients whose tumors harbor a somatic PAX3 or FOXO1 translocation found on deoxyribonucleic acid (DNA), ribonucleic acid (RNA), or fluorescence in situ hybridization (FISH) testing are ineligible

• Patients with primary central nervous system (CNS) tumors or untreated CNS metastases are ineligible.

  • Treated CNS metastases are not excluded if stable and asymptomatic.
  • All patients with previously treated brain metastases must have a magnetic resonance imaging (MRI), or computed tomography (CT) if MRI is contraindicated, of the brain within 28 days prior enrollment to confirm there has been no disease progression
• Patients with any condition expected to interfere with the absorption of orally administered medications are ineligible
• Patients who have acute coronary syndrome (e.g., unstable angina, myocardial infarction) within 6 months prior to study enrollment
• Patients who have significant cardiovascular disease (such as New York Heart Association Class II to IV congestive heart failure) within 1 month prior to study enrollment
• Patients with who have a history of interstitial lung disease (ILD) or non-infectious pneumonitis requiring high-dose glucocorticoids or any active ILD or pneumonitis, or prior thoracic radiotherapy within 8 weeks of enrollment
• HIV-infected patients on effective anti-retroviral therapy with undetectable viral load within 6 months of enrollment are eligible
• Patients with known hepatitis B or C with detectable viral load are not eligible
• Patients who have had major surgery ≤ 28 days prior to enrollment are not eligible
• Patients who have an uncontrolled infection are not eligible
• Patients who in the opinion of the investigator may not be able to comply with the safety monitoring requirements of the study are not eligible

Study Plan

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Treatment (daraxonrasib); Patients receive daraxonrasib PO QD on days 1-21 of each cycle. Cycles repeat every 21 days for 28 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo urine sample collection during screening and undergo x-ray imaging, diagnostic imaging and blood sample collection throughout the study. Patients may also undergo bone marrow aspiration and biopsy throughout the study.

Procedure: X-Ray Imaging; Undergo x-ray imaging; Other Names: Conventional X-Ray; Diagnostic Radiology; Medical Imaging, X-Ray; Radiographic Imaging; Radiography; RG; Static X-Ray; X-Ray; Plain film radiographs; Radiographic imaging procedure (procedure); Procedure: Bone Marrow Aspiration; Undergo bone marrow aspiration; Procedure: Biospecimen Collection; Undergo blood and urine sample collection; Other Names: Biological Sample Collection; Biospecimen Collected; Specimen Collection; Sample Collection; Procedure: Bone Marrow Biopsy; Undergo bone marrow biopsy; Other Names: Biopsy of Bone Marrow; Biopsy, Bone Marrow; Procedure: Diagnostic Imaging Testing; Undergo diagnostic imaging; Other Names: Medical Imaging; Diagnostic Imaging; Drug: Daraxonrasib; Given PO; Other Names: RMC-6236; RMC 6236; RAS Inhibitor RMC-6236; Ras-selective Tri-complex Inhibitor RMC-6236; RASMUTLI(ON) Inhibitor RMC-6236; Rasonque; RMC6236

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum tolerated dose (MTD) (Phase 1 part A)	MTD defined as the maximum dose at which fewer than one-third of patients experience dose limiting toxicity during cycle 1 of therapy.	Up to completion of cycle 1 (cycle length = 21 days)
Incidence of adverse events (Phase 1 and 2, parts A and B)	Toxicities for patients will be described separately. Toxicity tables will be constructed to summarize the observed incidence by type of toxicity and grade. Toxicity information recorded will include the type, severity, time of onset, time of resolution, and the probable association with the study regimen.	Up to 5 years
Best response of disease (Phase 2 dose expansion [part B])	Disease response will be assessed according to Response Evaluation Criteira in Solid Tumors (RECIST) criteria for patients with solid tumors (International Neuroblastoma Response Criteria [INRC] for patients with neuroblastoma), and will be reported descriptively.	Up to 5 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall survival		Up to 5 years
Best response of disease (Phase 1, part A)	Disease response will be assessed according to RECIST criteria for patients with solid tumors (INRC for patients with neuroblastoma), and will be reported descriptively.	Up to 5 years
Best response of disease (Phase 1, part B)	Disease response will be assessed according to RECIST criteria for patients with solid tumors (INRC for patients with neuroblastoma), and will be reported descriptively. For part B1 (rhabodomyosarcoma) response rate will be estimated by the uniform minimum variance unbiased estimate with one-sided 95% confidence intervals. For part B2 (neuroblastoma) and B3 (other) response rates will be estimated as the proportion of patients who are responders with one-sided exact 93% confidence intervals.	Up to 5 years
Pharmacokinetics (Phase 1 dose escalation and phase 2 dose expansion [parts A and B])	A descriptive analysis of pharmacokinetic (PK) parameters of daraxonrasib will be performed to define systemic exposure, drug clearance, and other pharmacokinetic parameters. The PK parameters will be summarized with simple summary statistics, including means, medians, ranges, and standard deviations (if numbers and distribution permit).	At cycle 1 day 1 (predose, 30 minutes, 2 hours, 4.5 hours, 7 hours post dose), cycle 1 day 15 predose, cycle 2 day 1 (cycle length = 21 days)
Progression free survival		Up to 5 years
Duration of response	Disease response will be assessed according to RECIST criteria for patients with solid tumors (INRC for patients with neuroblastoma), and will be reported descriptively.	Up to 5 years
Time to response	Disease response will be assessed according to RECIST criteria for patients with solid tumors (INRC for patients with neuroblastoma), and will be reported descriptively.	Up to 5 years

Other Outcome Measures

Outcome Measure	Time Frame
Frequency of detectable RAS mutations by circulating tumor deoxyribonucleic acid (ctDNA)	At cycle 1 day 1 (pre-dose), cycle 1 day 8, cycle 2 day 1, cycle 2 days 21 and end of treatment (cycle length = 21 days)
Mutant allele fraction in ctDNA	At cycle 1 day 1 (pre-dose), cycle 1 day 8, cycle 2 day 1, cycle 2 days 21 and end of treatment (cycle length = 21 days)

Collaborators and Investigators

• Sponsor: Children's Oncology Group
• Investigators: Principal Investigator: Amit J Sabnis, Pediatric Early Phase Clinical Trial Network

Study record dates

Study Major Dates

• Study Start (Estimated): April 9, 2027
• Primary Completion (Estimated): April 9, 2032
• Study Completion (Estimated): April 9, 2032

Study Registration Dates

• First Submitted: September 9, 2026
• First Submitted That Met QC Criteria: September 14, 2026
• First Posted (Actual): September 15, 2026

Study Record Updates

• Last Update Posted (Actual): September 15, 2026
• Last Update Submitted That Met QC Criteria: September 14, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Surgical Procedures, Operative; Cytological Techniques; Cytodiagnosis; Physical Phenomena; Equipment and Supplies; Diagnostic Techniques, Surgical; Electromagnetic Phenomena; Magnetic Phenomena; Electromagnetic Radiation; Radiation; Radiation, Ionizing; Biopsy; Specimen Handling; X-Rays; Phantoms, Imaging
• Other Study ID Numbers: PEPN2611 (Other Identifier: CTEP); UM1CA228823 (U.S. NIH Grant/Contract); NCI-2026-06456 (Registry Identifier: CTRP (Clinical Trial Reporting Program))

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.: Yes