A Phase 1/2 interventional study of Sacituzumab tirumotecan and Rescue medication in Metastatic Castration-resistant Prostate Cancer, sponsored by Merck Sharp & Dohme LLC. Not yet recruiting. Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-02.
Sponsored by Merck Sharp & Dohme LLC (part of Merck & Co., Inc) · Phase 1/2, Interventional, and Treatment
Researchers are looking for new ways to treat metastatic castration-resistant prostate cancer/androgen pathway modulator refractory (mCRPC/APMR). Current treatment for mCRPC includes chemotherapy, such as docetaxel. Chemotherapy is medicine that works to destroy cancer cells or stop them from growing.
In this trial, researchers want to learn if giving sacituzumab tirumotecan (sac-TMT) alone or with other treatments can treat mCRPC. Sac-TMT is a trial medicine that is an antibody drug conjugate (ADC). An ADC attaches to specific targets on cancer cells and delivers treatment to destroy those cells. Opevesostat is another trial medicine designed to block the body from making steroid hormones that cause the cancer cells to grow.
The goals of this trial are to learn:
This is a substudy of the master protocol MK-2870-U01.
7,046 studies on the registry are indexed under Prostatic Neoplasms; 1,580 are open to participants now.
This study's planned enrollment of 290 is above the median of 60 across 5,348 interventional studies indexed under Prostatic Neoplasms.
Browse Prostatic Neoplasms studies →Merck Sharp & Dohme LLC is the lead sponsor of 2,166 studies on the registry; 132 are open to participants now.
Of its 501 completed or terminated interventional studies of FDA-regulated products, 370 (74%) have results posted.
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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.
The main inclusion criteria include but are not limited to the following:
Exclusion Criteria:
The main exclusion criteria include but are not limited to the following:
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.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
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.
PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.
PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
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.
PD-1, PD-L1 and checkpoint inhibitors
PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.
PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive docetaxel every 3 weeks by intravenous (IV) infusion. Participants will also receive either prednisone or prednisolone daily (or per approved product label).
Drug: Docetaxel · Drug: Prednisone · Drug: Prednisolone
Participants will receive sac-TMT monotherapy every 2 weeks (q2w) by IV infusion.
Biological: Sacituzumab tirumotecan · Drug: Rescue medication
Participants will receive sac-TMT monotherapy q2w by IV infusion.
Biological: Sacituzumab tirumotecan · Drug: Rescue medication
Participants will receive sac-TMT q2w by IV infusion in combination with oral administration of opevesostat twice daily until any of the criterion for discontinuation are met. Participants receiving opevesostat will receive fludrocortisone and dexamethasone daily.
Biological: Sacituzumab tirumotecan · Drug: Rescue medication · Drug: Opevesostat · Drug: Fludrocortisone · Drug: Dexamethasone
Participants will receive sac-TMT q2w by IV infusion in combination with oral administration of an androgen receptor pathway inhibitor (ARPI), either abiraterone acetate daily or enzalutamide daily until any of the criterion for discontinuation are met. Participants receiving abiraterone acetate will also receive either prednisone or prednisolone daily (or per approved product label).
Biological: Sacituzumab tirumotecan · Drug: Rescue medication · Drug: Prednisone · Drug: Abiraterone acetate · Drug: Enzalutamide · Drug: Prednisolone
IV infusion
Also known as: sac-TMT, MK-2870, SKB264
Participants receiving sac-TMT may be administered the following rescue medications according to the approved product: granulocyte colony-stimulating factor, histamine-1 receptor antagonist, histamine-2 receptor antagonist, acetaminophen or equivalent, dexamethasone or equivalent, and steroid mouthwash (dexamethasone or equivalent).
IV infusion
Oral administration
Oral administration
Also known as: MK-5684
Oral administration
Oral administration
Oral administration
Oral administration
Oral administration
Efficacy Phase: Objective Response Rate (ORR)
ORR is defined as the percentage of participants with complete response (CR: disappearance of all target lesions) or partial response (PR: at least a 30% decrease in the sum of diameters of target lesions) per Prostate Cancer Working Group 4 (PCWG4)-Modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1). The percentage of participants who experience CR or PR as assessed by Blinded Independent Central Review (BICR) will be presented.
Time frame: Up to approximately 66 months
Efficacy Phase: Number of Participants Who Experience at Least One Adverse Event (AE)
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants who experience at least one AE will be reported.
Time frame: Up to approximately 66 months
Efficacy Phase: Number of Participants Who Discontinue Study Intervention Due to an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants who discontinue study intervention due to an AE will be reported.
Time frame: Up to approximately 66 months
Safety Lead-In (Combination Arms Only): Number of Participants Who Experience a Dose-Limiting Toxicity (DLT)
DLT will be defined as any drug-related AE observed during the DLT evaluation period (up to 28 days after the first dose of study intervention or prior to the third dose, whichever occurs first) that results in a change to a given dose or a delay in initiating the next treatment. The number of participants who experience a DLT will be reported.
Time frame: Up to approximately 28 days
Safety Lead-In (Combination Arms Only): Number of Participants Who Experience at Least One AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants who experience at least one AE will be reported.
Time frame: Up to approximately 66 months
Safety Lead-In (Combination Arms Only): Number of Participants Who Discontinue Study Intervention Due to an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants who discontinue study intervention will be reported.
Time frame: Up to approximately 66 months
Efficacy Phase: Prostate-Specific Antigen (PSA) Response Rate
PSA response is defined as having a postbaseline PSA reduction of at least 50% from baseline with a consecutive confirmation assessment at least 3 weeks later. The percentage of participants with a PSA response will be reported.
Time frame: Up to approximately 66 months
Efficacy Phase: Radiographic Progression-Free Survival (rPFS)
rPFS is defined as the time from randomization/allocation (Safety Lead-in) to the first documented progressive disease (PD), as assessed by PCWG4-Modified RECIST 1.1, or death from any cause, whichever occurs first. PD is defined as an increase of at least 20% in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. The appearance of one or more new lesions is also considered PD. rPFS as assessed by BICR will be presented.
Time frame: Up to approximately 66 months
No study locations are listed for this record.
Plan to share: Yes — https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Data sharing details ↗ · externaldatasharing-msd.com
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 ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Sacituzumab tirumotecan · Prednisone · Prednisolone