A Clinical Study of MK-2870 Alone or With Other Treatments to Treat Gastrointestinal Cancers (MK-9999-02A)

• Sacituzumab tirumotecan (Biological), also known as MK-2870, SKB264: Given by IV infusion.
• Fluorouracil (5-FU) (Drug): 5-FU is administered by IV infusion over 46 to 48 hours every 2 weeks.
• Leucovorin (LV) or levoleucovorin (Drug): LV or levoleucovorin is administered by IV infusion every 2 weeks.
• Rescue medication (Drug): Participants receive the following rescue medications, per approved product label, as premedication to study treatment to prevent hypersensitivity and/or infusion reactions: diphenhydramine (or equivalent histamine-1 \[H1\] receptor antagonist), H2 receptor antagonist, acetaminophen or equivalent, and dexamethasone or equivalent infusion. A steroid mouthwash (dexamethasone or equivalent) will be given as prophylaxis for stomatitis/oral mucositis.
• Supportive care measures (Drug): Participants are allowed to take supportive care measures for the management of adverse events associated with study intervention at the discretion of the investigator. Supportive care measures may include but are not limited to antidiarrheal agents and antiemetic agents. Artificial tear drops or gel may be given as supportive care for Ocular Surface Toxicity.
• Cisplatin (Drug), also known as PLATINOL®: Given by IV infusion.
• Pembrolizumab (Biological), also known as MK-3475, KEYTRUDA®: Given by IV infusion.

Primary outcomes

• Number of Participants Who Experience a Dose-limiting Toxicity (DLT) [Up to approximately 4 weeks]: A DLT is a medical problem related to the study medicine that prevents giving participants a higher dose or may prevent giving the participant the same dose. The number of participants who experience a DLT will be reported.
• Number of Participants Who Experience One or More Adverse Events (AEs) [Up to approximately 63 months]: An AE is a health problem that happens or worsens during the study. The number of participants who have an AE during the study will be reported.
• Number of Participants who Discontinue Study Treatment due to an AE [Up to approximately 63 months]: An AE is a health problem that happens or worsens during a study. The number of participants who stop study treatment will be reported.
• Objective Response Rate (ORR) per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 as Assessed by Blinded Independent Central Review (BICR) [Up to approximately 63 months]: ORR is defined as the percentage of participants with confirmed 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 RECIST 1.1. The percentage of participants who experience CR or PR as assessed by Blinded Independent Central Review (BICR) will be presented.

Secondary outcomes

• Duration of Response (DOR) per RECIST 1.1 as Assessed by BICR [Up to approximately 63 months]: For participants who demonstrate a confirmed Complete Response or Partial Response, DOR is defined as the time from first documented evidence of CR or PR until progressive disease (PD) or death. Per RECIST 1.1, PD is defined as at least a 20% increase 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. DOR as assessed by BICR will be presented.
• Progression-free Survival (PFS) per RECIST 1.1 as Assessed by BICR [Up to approximately 63 months]: PFS is defined as the time from start of study treatment to the first documented progressive disease (PD) or death due to any cause, whichever occurs first. According to RECIST 1.1, PD is defined as ≥20% increase 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 ≥5 mm. The appearance of one or more new lesions is also considered PD. PFS as assessed by BICR will be presented.
• Overall Survival (OS) [Up to approximately 63 months]: OS is the length of time from when the participant starts treatment until death from any cause

Sex: All, ages: 18 Years to any

Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

* Has one of the following cancers:

  * Unresectable or metastatic colorectal cancer and has received prior therapy for the cancer
  * Advanced or metastatic pancreatic ductal adenocarcinoma (PDAC) and has received prior therapy for the cancer
  * Advanced and/or unresectable biliary tract cancer (BTC) and has received prior therapy for the cancer
  * Advanced and/or unresectable BTC and has not received prior therapy for the cancer
* For participants who have received prior therapy for cancer: Has recovered from any side effects due to previous cancer treatment

Exclusion Criteria:

The main exclusion criteria include but are not limited to the following:

* History of severe eye disease
* For participants who have received prior therapy for cancer: Received prior systemic anticancer therapy including investigational agents within 4 weeks before starting study intervention
* History of (noninfectious) pneumonitis/interstitial lung disease (ILD) that required steroids, has current pneumonitis/ILD, or has suspected ILD or pneumonitis that cannot be ruled out by standard diagnostic assessments at Screening

• Medical Director, Study director, Merck Sharp & Dohme LLC

NIH grants: 2023