NIPH Clinical Trials Search

A study of ASP546C in adults with gastroesophageal cancer, pancreatic cancer or other solid tumors

Basic Information

Recruitment status	Pending
Health condition(s) or Problem(s) studied	Gastric or Gastro-esophageal Junction (GEJ) Adenocarcinoma Pancreatic Adenocarcinoma
Date of first enrollment	05/06/2026
Target sample size	150
Countries of recruitment	United States,Japan
Study type	Interventional
Intervention(s)	This study is in 2 parts. In both parts of the study, ASP546C will be given once in 3-week cycles. It will be given slowly through a tube into a vein. This is called an infusion. In Part 1, people with gastric cancer, GEJ cancer or esophageal cancer can take part. They will receive an infusion of either a higher dose or a lower dose of ASP546C. In Part 2, people with pancreatic cancer or who have one of the other solid tumors can take part. Part 2 doesn't include people with gastric cancer, GEJ cancer or esophageal cancer. All people in this part of the study will receive an infusion of the higher dose of ASP546C. People will visit the clinic on certain days to receive ASP546C and have health checks. The number of visits and checks done during the study will depend on the health of each person and whether they are still receiving infusions of ASP546C.

Outcome(s)

Primary Outcome

- Objective response rate (ORR), defined as the proportion of participants who have a best overall response (BOR) of complete response (CR) or partial response (PR) (investigator-assessed per RECIST v1.1) - Pharmacokinetics (PK), as determined by serum concentrations of antidrug antibody Conjugate (ADC) and PK parameters - AEs, vital signs, ECOG performance status and safety laboratory assessments (NCI CTCAE v6.0)

Secondary Outcome

- ORR, defined as the proportion of participants who have a BOR of CR or PR (investigator-assessed per RECIST v1.1). - Disease control rate (DCR), defined as the proportion of participants with a BOR of CR, PR or stable disease (SD) (investigator-assessed per RECIST v1.1) - Duration of response (DOR), defined as the time from the date of the first response (CR/PR) until the date of radiologic disease progression (investigator-assessed per RECIST v1.1) or date of death from any cause, whichever is earlier - Progression-free survival (PFS), defined as the time from the date of first dose until the date of radiologic disease progression (investigator-assessed per RECIST v1.1) or death from any cause, whichever is earlier - Overall survival (OS), defined as the time from the date of first dose until the documented date of death from any cause - AEs, vital signs, ECOG performance status and safety laboratory assessments (NCI CTCAE v6.0) - CLDN18.2 changes by immunohistochemistry (IHC) in baseline and on-treatment tumor samples - PK parameters of ADC, unconjugated payload and total antibody: o Concentration at the end of infusion (CEOI) o Area under the concentration-time curve from 0 to 21 days (AUC 0-21d) o Trough concentration (Ctrough) o Time to maximum concentration (tmax) o Terminal elimination half-life (t1/2) o Clearance (CL) o Volume of Distribution at Steady State (Vss) - Incidence of ADAs against ASP546C (total antibody and ADC)

Key inclusion & exclusion criteria

Age minimum	>= 18age old
Age maximum	Not applicable
Gender	Both
Include criteria	1. Participant has a histologically confirmed diagnosis of gastroesophageal (gastric/ gastroesophageal junction [GEJ] /esophageal) adenocarcinoma, pancreatic adenocarcinoma, or pan-tumor (cholangiocarcinoma, colorectal adenocarcinoma, non-small cell lung cancer [NSCLC] [adenocarcinoma], small cell lung cancer [SCLC], ovarian mucinous carcinoma or invasive breast cancer [estrogen receptor [ER]/ progesterone receptor [PR]+ human epidermal growth factor receptor 2[HER2]-; ER/PR-HER2+; ER/PR+HER2+ [triple positive]; ER/PR-HER2- [triple negative]). 2. Participant has radiologically confirmed unresectable locally advanced or metastatic (uLA/m) gastroesophageal (gastric/GEJ/esophageal) adenocarcinoma, pancreatic adenocarcinoma or pan-tumor within 28 days prior to the first dose of study intervention. 3. Cohorts 1 to 3 only: Participant has measurable disease according to Response Evaluation Criteria in Solid Tumours (RECIST) v1.1 within 28 days prior to the first dose of study intervention. For participants with only 1 measurable lesion and prior radiotherapy, the lesion must be outside the field of prior radiotherapy or must have documented progression following radiation therapy. 4. Cohort 4 only: Participant has radiologically evaluable disease (measurable and/or non measurable) according to RECIST v1.1 within 28 days prior to the first dose of study intervention. For participants with only 1 evaluable lesion and prior radiotherapy, the lesion must be outside the field of prior radiotherapy or must have documented progression following radiation therapy. 5. Participant's tumor expresses claudin (CLDN)18.2. 6. Participant has received at least 1 line of therapy for uLA/m disease. 7. Participant has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. 8. Participant has a predicted life expectancy >/= 12 weeks. 9. Female participant: - Is not pregnant and at least 1 of the following conditions apply: a. Not a women of childbearing potential (WOCBP) b. WOCBP who has a negative urine or serum pregnancy test at screening (with a medical interview) and agrees to follow the contraceptive guidance from the time of informed consent through at least 5 half-lives (45 days) plus 6 months after final investigational study intervention administration. - Must not be breastfeeding or lactating starting at screening and throughout the investigational period and for 5 half-lives (45 days) plus 6 months after final investigational study intervention administration. - Must not donate ova starting at first administration of study intervention and throughout the investigational period and for 5 half-lives (45 days) plus 6 months after final investigational study intervention administration. 10. Male participant: - Must agree to use contraception with female partner(s) of childbearing potential (including breastfeeding partner) throughout the treatment period and for 5 half-lives (45 days) plus 3 months after final investigational study intervention administration. - Must agree to remain abstinent or use a condom with pregnant partner(s) for the duration of the pregnancy throughout the investigational period and for 5 half-lives (45 days) plus 3 months after final investigational study intervention administration. - Must not donate sperm during the treatment period and for 5 half-lives (45 days) plus 3 months after final investigational study intervention administration. 11. Participant must meet all of the criteria based on the locally analyzed laboratory tests collected within 14 days prior to the first dose of study intervention. In case of multiple local laboratory tests within this period, the most recent data should be used. 12. Participant is willing to provide or has sufficient tumor tissue for central biomarker assessment. 13. Participant agrees not to participate in another interventional study while receiving study intervention in the present study.
Exclude criteria	1. Cohorts 1, 2 and 3 only: Participant's disease is of the non-adenocarcinoma histology or mixed histology containing adenocarcinoma. 2. Cohorts 1, 2 and 3 only: Participant has received > 2 prior lines of therapy for uLA/m disease. - Participants in Cohort 4 (pan-tumor) may enroll regardless of the number of prior lines of therapy, if they are not eligible for, decline, or do not have any available standard of care treatment options. 3. Participant has complete gastric outlet syndrome or a partial gastric outlet syndrome with persistent recurrent vomiting. 4. Participant has significant gastric bleeding or had a significant bleeding episode from the gastrointestinal tract within 3 months prior to the first dose of study intervention and/or an untreated peptic ulcer disease that would preclude the participant from participation. 5. Participant has significant bleeding disorders or has had vasculitis within 3 months prior to the first dose of study intervention. 6. Participant has a history of gastrointestinal perforation and/or fistula within 6 months prior to the first dose of study intervention. 7. Participant has symptomatic, untreated brain metastases or meningeal carcinomatosis (carcinomatous meningitis) from the primary malignancy. A participant with stable central nervous system metastases for > 3 months without need of steroids for >/= 2 weeks prior to the first dose of study intervention is eligible. 8. Participant has a past or current mental illness that is difficult to control. 9. Participant has unresolved pneumonitis or a history of non-infectious pneumonitis such as immune-related pneumonitis or radiation-induced pneumonitis for which the participant is taking glucocorticoids or needed glucocorticoids within 6 months prior to the first dose of study intervention. 10. Participant has a known history of a positive test for human immunodeficiency virus (HIV) infection or known active hepatitis B (positive hepatitis B surface antigen [HBsAg]) or hepatitis C infection. Screening for these infections should be conducted per local requirements. - If participant is negative for HBsAg, but hepatitis B core antibody (HBcAb) and/or hepatitis B surface antibody (HBsAb) positive, a hepatitis B deoxyribonucleic acid (DNA) test will be performed; if the test is positive, the participant will be excluded. - Participant with positive hepatitis C virus (HCV) serology, but negative HCV ribo nucleic acid (RNA) test results, is eligible. - Participant treated for HCV with undetectable viral load results is eligible. 11. Participant has an active infection requiring systemic therapy that has not completely resolved within 7 days prior to the first dose of study intervention. 12. Participant has a malignancy for which treatment is required, has a history of another malignancy within the past 5 years, except malignancies for which participant received curative therapy without recurrence for the last 5 years (e.g., adequately resected non-melanoma skin cancer, localized prostate cancer), or had treatment for carcinoma in situ. 13. Participant has clinically significant third spacing (large amount of pleural fluid or ascites) that requires frequent percutaneous draining or requires placement of a drainage catheter for adequate control. 14. Participant has any adverse event (AE) from prior antitumor treatments that has not yet recovered to grade 0 or 1 per National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) v6.0 (except alopecia). 15. Participant has an active autoimmune disease or other medical condition that has required high dose systemic steroids at the time of screening. 16. Participant has known peripheral neuropathy > grade 1 (except when the sole neurological abnormality is absence of deep tendon reflexes). 17. Participant has sinusoidal obstruction syndrome, formerly known as veno-occlusive disease; if present, should be stable or improving. 18. Participant has significant cardiovascular disease, including any of the following: - Congestive heart failure (defined as New York Heart Association Class III or IV), myocardial infarction, unstable angina, coronary angioplasty, coronary stenting, coronary artery bypass graft, cerebrovascular accident or hypertensive crisis within 6 months prior to the first dose of study intervention. - History of clinically significant ventricular arrhythmias (i.e., sustained ventricular tachycardia, ventricular fibrillation or Torsades de Pointes), cardiac arrhythmias requiring anti-arrhythmic medications (a participant with rate controlled atrial fibrillation for > 1 month prior to the first dose of study intervention is eligible) or obligate use of cardiac pacemaker. - QTc interval > 470 msec. - Documented history or family history of congenital long QT syndrome. 19. Participant has ongoing or previous interstitial lung disease, active diverticulitis or solid organ or stem cell transplant. 20. Participant has a serious non-healing wound or bone fracture within 28 days prior to study intervention. 21. Participant has had a major surgical procedure within 28 days prior to the first dose of study intervention and has not completely recovered from the surgical procedure </= 14 days prior to the first dose of study intervention. 22. Participant has received chemotherapy, immunotherapy or investigational therapy </= 14 days prior to the first dose of study intervention and has not recovered from any related toxicity. Palliative radiotherapy is allowed and must be completed > 14 days prior to the first dose of study intervention. 23. Participant has received prior CLDN18.2 ADC. Prior treatment with CLDN18.2 monoclonal antibody or bi-specific T-cell engager is allowed. 24. Participant has received a live or live-attenuated vaccine within 30 days prior to the first dose of study intervention. 25. Participant has a known or suspected hypersensitivity to ASP546C or any components of the formulation used. 26. Participant has a clinically significant disease or comorbidity that in the opinion of the investigator may adversely affect the safe delivery of treatment within this study or make the participant unsuitable for study participation. 27. Cohorts 1 and 2 (gastroesophageal adenocarcinoma) only: Participant has known HER2 positive status defined as immunohistochemistry (IHC) 3+ or IHC 2+/in situ hybridization (ISH)+. ISH positive is defined as HER2/ chromosome enumeration probe 17 (CEP17) ratio >/= 2.0 or an average HER2 copy number >/= 6.0 signals/cell.