A Study of RP-3500 in Combination With Standard Radiation Therapy in People With Solid Tumor Cancer

NCT05566574 | Active Not Recruiting Phase 1 FDA Drug

• 1 other identifier: 22-222
• Study Type: interventional
• Target: 49
• Locations: 1 country
• Sites: 7

Brief Summary

The purpose of this study is to test the safety of the study drug, RP-3500 when given in combination with palliative external beam radiotherapy (EBRT) to people who have metastatic solid tumor cancer with a mutation of the ATM gene. The study researchers will do tests to find the highest dose of RP3500 that causes few or mild side effects.

Conditions

Solid Tumor; Metastatic Cancer

Keywords

Palliative treatment; RP-3500 (ATRi); External Beam Radiotherapy (EBRT); 22-222

Outcome Measures

Primary Outcomes (2)

• Phase I - Safety and Tolerability of RP-3500 in combination with radiation therapy

  by assessing the grade and frequency of adverse events and serious adverse events. A dose limiting toxicity (DLT) will be graded according to NCI CTCAE v5.0.

  2 years

• Phase II - Assess 6 month local control rate of patients with pathogenic ATM who received RP-3500 and palliative RT

  Imaging per discretion of treating physician, and may include PET, CT and MRI imaging.

  2 years

Study Arms (2)

RP-3500 in Combination With Standard Radiation Therapy

EXPERIMENTAL

Patients with metastatic cancers with identified mutations in ATM will be enrolled. All patients will receive a standard palliative RT (4Gy x 5 fractions) on Days 1-5 in combination with RP-3500 on Days 1-5. In the first phase of the study, a 3+3 study design will be used to identify a safe dose of RP-3500 (starting at 80 mg QD) in combination with palliative RT.

Drug: RP-3500; Radiation: External Beam Radiotherapy (EBRT)

Pilot subcohort

EXPERIMENTAL

The primary objective is to assess 6 month local control rate of patients of new metastatic lesions with pathogenic ATM who haves received prior RP-3500 and palliative RT.

Drug: RP-3500; Radiation: External Beam Radiotherapy (EBRT)

Interventions

RP-3500 DRUG

RP-3500 on Days 1-5.

Pilot subcohort; RP-3500 in Combination With Standard Radiation Therapy

External Beam Radiotherapy (EBRT) RADIATION

Palliative radiation therapy (4Gy x 5 fractions) to a metastatic site on Days 1-5

Pilot subcohort; RP-3500 in Combination With Standard Radiation Therapy

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Histologically confirmed malignancy with at least one metastatic lesion amenable to radiotherapy. Bone, visceral, and soft tissue are eligible.
• Mutation in ATM (deleterious or VUS; somatic or germline; monoallelic or biallelic)
• Note: Homozygous Deletion in the ATM gene will also be allowed
• ECOG performance status 0-2 or KPS equivalent
• Age ≥18 years
• Expected survival greater than 6 months
• Participant or Legally Authorized Representative (LAR) able to provide written informed consent
• Patients of reproductive potential must agree to practice an effective contraceptive method
• Ability to swallow capsules and retain oral medications
• Acceptable organ function at Screening, as evidenced by the following laboratory data:
• Serum creatinine ≤1.5 × upper limit of normal (ULN) or calculated creatinine clearance ≥60 mL/min using the Cockcroft-Gault equation or by 24-hour urine collection
• Total bilirubin ≤1.5 × ULN or \<3.0 × ULN if known Gilbert's disease
• Serum albumin ≥2.5 g/dL
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.5 × ULN unless liver metastases are present and thought to be a reason for AST/ALT elevation, in which case they must be ≤5 × ULN
• Acceptable hematologic function at Screening:

You may not qualify if:

• Previous radiotherapy to the intended treatment site
• Prior therapy with an ATR or DNA-dependent protein kinase (DNA-PK) inhibitor
• Serious medical co-morbidities precluding radiotherapy
• Pregnant or breast-feeding women
• No other concurrent systemic therapy during the entire duration of protocol treatment. Patients can have other systemic treatments up until the start of protocol treatment. Patients can also have other systemic treatments after the completion of protocol treatments
• Known hypersensitivity to any of the ingredients of RP-3500
• Uncontrolled hypertension (systolic blood pressure \[BP\] ≥160 mmHg; diastolic BP ≥100 mmHg) despite adequate treatment prior to first dose of RP-3500
• Patients with active, uncontrolled bacterial, fungal, or viral infection, including hepatitis B virus (HBV), hepatitis C virus (HCV), known human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) related illness. In equivocal cases, patients whose viral load is negative, may be eligible. HIV seropositive patients who are healthy and low risk for AIDS related outcomes could be considered eligible. Eligibility criteria for HIV positive patients should be evaluated and discussed, and will be based on current and past CD4 and T-cell counts, history (if any) of AIDS-defining conditions (eg, opportunistic infections), and status of HIV treatment
• Moderate or severe hepatic impairment (ie, Child-Pugh class B or C)
• History or presence of an abnormal ECG that is clinically significant in the investigator's opinion, including complete left bundle branch block, second- or third-degree heart block, or recent history of myocardial infarction that in the opinion of the investigator will pose an increased risk of rhythm abnormalities
• History of ventricular dysrhythmias or risk factors for ventricular dysrhythmias such as structural heart disease (eg, severe left ventricular systolic dysfunction, left ventricular hypertrophy), coronary heart disease (symptomatic or with ischemia demonstrated by diagnostic testing), clinically significant electrolyte abnormalities (eg, hypokalemia, hypomagnesemia, hypocalcemia), or family history of sudden unexplained death or long QT syndrome
• Current treatment with medications that are well-known to prolong the QT interval
• Psychological, familial, sociological, or geographical conditions that do not permit compliance with the protocol and/or follow-up procedures outlined in the protocol
• Patients who are receiving strong CYP3A inhibitors or inducers, P-gp inhibitors and/or BCRP inhibitors
• Patients with germline homozygous ATM mutations

Sponsors & Collaborators

• Memorial Sloan Kettering Cancer Center: lead
• Repare Therapeutics: collaborator

Study Sites (7)

Memorial Sloan Kettering Basking Ridge (Limited Protocol Activites)

Basking Ridge, New Jersey, 07920, United States

Location

Memorial Sloan Kettering Monmouth (All Protocol Activities)

Middletown, New Jersey, 07748, United States

Location

Memorial Sloan Kettering Bergen (Limited Protocol Activities)

Montvale, New Jersey, 07645, United States

Location

Memorial Sloan Kettering Cancer Center at Suffolk-Commack (All Protocol Activities)

Commack, New York, 11725, United States

Location

Memorial Sloan Kettering Westchester (All Protocol Activities)

Harrison, New York, 10604, United States

Location

Memorial Sloan Kettering Cancer Center (All Protocol Activities)

New York, New York, 10065, United States

Location

Memorial Sloan Kettering Nassau (Limited Protocol Activities)

Uniondale, New York, 11553, United States

Location

Related Links

• Memorial Sloan Kettering Cancer Center

MeSH Terms

Conditions

Neoplasm Metastasis

Condition Hierarchy (Ancestors)

Neoplastic Processes; Neoplasms; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Nancy Lee, MD

  Memorial Sloan Kettering Cancer Center

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Single arm, phase I/II trial to assess safety and tolerability of RP-3500 and palliative RT.

Study Record Dates

• First Submitted: September 30, 2022
• First Posted: October 4, 2022
• Study Start: September 30, 2022
• Primary Completion (Estimated): September 30, 2026
• Study Completion (Estimated): September 30, 2026
• Last Updated: December 17, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share

Locations

US (7)