A Phase 1 interventional study of Lunresertib and RP-3500 in Advanced Solid Tumor, sponsored by Debiopharm International SA. Recruiting at 26 sites in 5 countries. Open to participants aged 12 Years and older. Per ClinicalTrials.gov, last updated 2026-10-28.
Sponsored by Debiopharm International SA (part of Debiopharm) · Phase 1, Interventional, and Treatment
The primary purpose of this study is to assess the safety and tolerability of lunresertib alone and in combination with RP-3500 or in combination with zedoresertib in patients with eligible advanced solid tumors, determine the maximum tolerated dose (MTD) and assess preliminary anti-tumor activity.
Phase 1/1b, multi-center, open-label, dose-escalation study to:
This study was previously posted by Repare Therapeutics. In September 2025, sponsorship of the trial was transferred to Debiopharm International S.A
Expanded Access Status: There is no expanded access program available for the investigational products in this study at this time.
Debiopharm International SA is the lead sponsor of 51 studies on the registry; 6 are open to participants now.
Of its 9 completed or terminated interventional studies of FDA-regulated products, 6 (67%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).
Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Measurable disease
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
RECIST
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Brain metastases
Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).
Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients receive lunresertib orally until disease progression, unacceptable toxicity, or investigator/patient decision. Dose escalation will proceed until a maximum tolerated dose is identified.
Drug: Lunresertib
Patients receive lunresertib with RP-3500 orally until disease progression, unacceptable toxicity, or investigator/patient decision. Dose escalation will proceed until a maximum tolerated dose is identified.
Drug: Lunresertib · Drug: RP-3500
Patients receive lunresertib with zedoresertib orally until disease progression, unacceptable toxicity, or investigator/patient decision. Dose escalation will proceed until a maximum tolerated dose is identified.
Drug: Lunresertib · Drug: Zedoresertib
Oral PKMYT1 Inhibitor
Oral ATR Inhibitor
Oral WEE1 Inhibitor
Also known as: Debio 0123
Safety and Tolerability of lunresertib either in monotherapy or in combination with RP-3500 or with Zedoresertib in patients with eligible advanced solid tumors
Assessed by treatment-emergent adverse events (TEAEs), physical examinations (PEs), safety laboratory assessments, electrocardiograms (ECGs), and vital sign measurements
Time frame: Up to 90 days after last administration of study intervention
To define the MTD of lunresertib monotherapy, and determine a recommended Phase 2 dose (RP2D) and preferred schedule
Assessed by the incidence of Dose-limiting toxicities (DLTs) and the incidence and severity of cumulative safety data
Time frame: Up to 90 days after last administration of study intervention
To define the MTD of lunresertib in combination with RP-3500 or in combination with Zedoresertib, and determine a recommended Phase 2 dose (RP2D) and preferred schedule
Assessed by the incidence of dose-limiting toxicities (DLTs) and the incidence and severity of cumulative safety data
Time frame: Up to 90 days after last administration of study intervention
The relative bioavailability of lunresertib capsule formulation as compared to lunresertib tablet formulation in the fasted state
Assessed by the plasma concentrations of lunresertib with calculation of pharmacokinetic (PK) parameters including maximum observed plasma concentration (Cmax), time to maximum observed plasma concentration (Tmax), area under the plasma concentration-time curve (AUC) , for both formulations in the fasted state.
Time frame: Time 0 (time of dosing) to 72 hours post-dose for each treatment condition
The effect of food on the PK of tablet formulation of lunresertib when administered in fed conditions compared to administration under fasted conditions
Assessed by the plasma concentrations of lunresertib with calculation of the ratio of PK parameters (e.g., Cmax and AUC) between the tablet formulation under fasted and fed state.
Time frame: Time 0 (time of dosing) to 72 hours post-dose for each treatment condition
To assess the safety and tolerability of lunresertib tablets in combination with RP-3500, confirm the MTD of lunresertib tablets in combination with RP-3500, and determine a RP2D and preferred schedule
Assessed by DLTs, TEAEs, safety laboratory assessments, the incidence of DLTs and the incidence and severity of cumulative safety data
Time frame: Up to 90 days after last administration of study intervention
The plasma concentrations of lunresertib monotherapy (capsule formulation) in the fasted and fed states
Assessed by the plasma concentrations of lunresertib with calculation of maximum observed plasma concentration (Cmax), time to maximum observed plasma concentration (Tmax), minimum observed plasma concentration (Cmin), area under the plasma concentration-time curve (AUC), elimination half-life (t1/2), and other parameters as appropriate
Time frame: Up to 90 days after last administration of study intervention
To assess the relationship between pharmacodynamic biomarkers and PK of lunresertib at different dose levels and/or schedules
Assessed by evaluation of biomarkers in pre- and on-treatment biopsies, and circulating tumor DNA (ctDNA) dynamics during treatment
Time frame: Up to 90 days after last administration of study intervention
The plasma concentrations of lunresertib and RP-3500 when dosed in combination
Assessed by the plasma concentrations of lunresertib and RP-3500 with calculation of maximum observed plasma concentration (Cmax), time to maximum observed plasma concentration (Tmax), minimum observed plasma concentration (Cmin), area under the plasma concentration-time curve (AUC), elimination half-life (t1/2), and other parameters as appropriate for each analyte
Time frame: Up to 90 days after last administration of study intervention
To assess preliminary anti-tumor activity achieved with lunresertib monotherapy, lunresertib in combination with RP-3500 or lunresertib in combination with Zedoresertib
Measured by best percent change in tumor size from baseline, objective response rate (ORR), overall response rate, tumor marker response, duration of response (DOR), clinical benefit rate (CBR), progression-free survival (PFS).
Time frame: Through Study Completion, an average of 1 year
To assess the safety and anti-tumor effects of lunresertib capsule + RP-3500
As measure by TEAEs, safety laboratory assessments, Best percent change in tumor size from baseline, ORR, overall response rate, DOR, CBR, tumor marker response, PFS
Time frame: Through Study Completion, an average of 1 year
To further characterize the PK of lunresertib tablets and assess preliminary anti-tumor
Measured by Plasma concentrations of lunresertib with calculation of Cmax, Tmax, AUC, elimination t1/2, and other PK parameters as appropriate, Best percent change in tumor size from baseline, ORR, overall response rate, DOR, CBR, tumor marker response, PFS
Time frame: Through Study Completion, an average of 1 year
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Plan to share: No
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Lunresertib