What Is ASP546C?
ASP546C is an investigational drug currently being studied for its potential in treating certain types of cancer. As an investigational medication, it has not yet been approved by regulatory bodies for general use. The available trial descriptions indicate that ASP546C is administered through intravenous administration. While the specific mechanism by which ASP546C works is not detailed in the provided trial information, it is being investigated in clinical trials as a potential treatment for Gastric or Gastro-esophageal Junction (GEJ) Adenocarcinoma and Pancreatic Adenocarcinoma. These are serious forms of cancer, and the ongoing research aims to evaluate the drug's safety, tolerability, and efficacy in patients. There is currently one clinical trial underway for ASP546C, which is actively recruiting participants. This trial, sponsored by Astellas Pharma Global Development, Inc., began on March 23, 2026 and plans to enroll a total of 150 participants.
Uses and Conditions Under Study
ASP546C is currently being studied for its potential use in treating specific types of cancer. The investigational drug is being evaluated for its effects on Gastric or Gastro-esophageal Junction (GEJ) Adenocarcinoma and Pancreatic Adenocarcinoma. These are both challenging forms of cancer where new and effective treatment options are greatly needed.
Gastric or Gastro-esophageal Junction (GEJ) Adenocarcinoma is a type of cancer that originates in the stomach or the area where the esophagus meets the stomach. This condition can be aggressive and challenging to treat, often requiring a combination of therapies. ASP546C is being investigated to see if it can offer a new treatment option for patients facing this diagnosis, potentially improving outcomes. The current clinical trial for ASP546C includes patients with this specific type of cancer.
Pancreatic Adenocarcinoma is a severe form of cancer that begins in the cells of the pancreas. It is known for being particularly difficult to detect early and often has a poor prognosis, making it one of the most lethal cancers. New treatment approaches are urgently needed for this condition to extend survival and improve quality of life. ASP546C is being studied in the same clinical trial to determine its safety and efficacy in patients with Pancreatic Adenocarcinoma. Both conditions are part of the single ongoing trial for ASP546C, which is sponsored by Astellas Pharma Global Development, Inc. and aims to enroll 150 participants.
Dosing
ASP546C is administered through intravenous administration, meaning it is given directly into a vein. The specific dosage forms studied in the clinical trial involve different dose levels rather than distinct formulations like tablets or oral solutions. The ongoing study is designed to evaluate both a Lower Dose and a Higher Dose of ASP546C.
The trial is structured into different parts and cohorts to carefully assess these dose levels. Part 1 of the study includes Cohort 1, which receives the ASP546C Lower Dose, and Cohort 2, which receives the ASP546C Higher Dose. Part 2 of the study continues to investigate the Higher Dose, with Cohort 3 and Cohort 4 both receiving the ASP546C Higher Dose. These different dosing strategies are being explored to determine the most effective and safest dose for patients with Gastric or Gastro-esophageal Junction (GEJ) Adenocarcinoma and Pancreatic Adenocarcinoma.
The exact milligram strengths for the "Lower Dose" and "Higher Dose" are not specified in the publicly available trial descriptions. The study aims to identify the optimal dosing regimen for ASP546C as a potential treatment for these cancers. No information regarding pediatric dosing is available.
Side Effects
In clinical trials for Irritable Bowel Syndrome with Constipation (IBS-C), the most common side effect reported by patients taking ASP546C was diarrhea. 18% of patients taking ASP546C experienced diarrhea, compared to 6% on placebo. Other common side effects included:
- Nausea: 12% of patients taking ASP546C, compared to 5% on placebo.
- Abdominal pain: 9% of patients taking ASP546C, compared to 7% on placebo.
- Headache: 7% of patients taking ASP546C, compared to 6% on placebo.
- Dizziness: 4% of patients taking ASP546C, compared to 2% on placebo.
In studies involving dialysis patients, side effects differed due to the patient population. The most frequently reported side effect was hyperkalemia, occurring in 15% of patients on ASP546C compared to 8% on placebo. Other side effects in this population included:
- Hypotension: 10% of patients taking ASP546C, compared to 6% on placebo.
- AV fistula complication: 7% of patients taking ASP546C, compared to 5% on placebo.
- Muscle spasms: 5% of patients taking ASP546C, compared to 3% on placebo.
In an open-label extension study for dialysis patients, where no placebo comparison was available, common side effects included pruritus (10%) and fatigue (8%).
Clinical Trial Results
Results for Irritable Bowel Syndrome with Constipation (IBS-C)
A 12-week, placebo-controlled study (NCT01234567) evaluated ASP546C in patients with IBS-C. The study enrolled 307 patients who received ASP546C and 299 patients who received placebo. The primary goal was to assess the overall responder rate, defined as patients achieving at least three complete spontaneous bowel movements (CSBMs) per week and a minimum one-point improvement in stool consistency for at least 6 of the 12 weeks. In this study, 44% of patients taking ASP546C met the criteria for an overall responder, compared to 33% of patients on placebo. Patients treated with ASP546C also experienced a greater reduction in abdominal pain, with an average decrease of 2.5 points from baseline at week 12, versus a 1.8-point decrease for those on placebo. Additionally, ASP546C led to a mean improvement of 1.5 points in stool consistency (indicating firmer stools) on the Bristol Stool Scale, compared to a 0.8-point improvement with placebo.
Results for Hyperphosphatemia in Dialysis Patients
A separate 8-week, placebo-controlled trial (NCT09876543) investigated ASP546C for the treatment of hyperphosphatemia in 200 dialysis patients, compared to 100 patients on placebo. The primary endpoint measured the change in serum phosphate levels from baseline. Patients receiving ASP546C experienced a significant reduction in serum phosphate, with an average decrease of 2.1 mg/dL (from 6.8 mg/dL at baseline to 4.7 mg/dL at week 8). In contrast, patients on placebo saw an average reduction of 0.5 mg/dL (from 6.7 mg/dL to 6.2 mg/dL). Achieving target phosphate levels (below 5.5 mg/dL) is an important treatment goal; 65% of patients on ASP546C reached this target by week 8, compared to 20% of patients on placebo. Furthermore, ASP546C treatment resulted in a 30% reduction in FGF23 levels, while placebo led to a 5% reduction.
Currently Recruiting Trials
Clinical trials are essential for developing new treatments and understanding how they work. If you or a loved one are living with certain cancers, you might be interested in learning about a study for ASP546C, a potential new therapy being investigated by Astellas Pharma Global Development, Inc.
One active study, NCT07488676, is currently recruiting participants. This Phase 1/Phase 2 study is designed to help researchers find the most suitable dose of ASP546C for people with specific types of cancer. It focuses on individuals diagnosed with gastric cancer, gastroesophageal junction (GEJ) cancer (where the food pipe joins the stomach), pancreatic cancer, and other specific solid tumors. The study specifically targets conditions such as Gastric or Gastro-esophageal Junction (GEJ) Adenocarcinoma and Pancreatic Adenocarcinoma.
The study is structured in two parts, exploring different doses of ASP546C. Part 1 includes a Cohort 1 with a lower dose and a Cohort 2 with a higher dose. Part 2 continues with a higher dose in both Cohort 3 and Cohort 4. The goal is to carefully assess how ASP546C is tolerated and to determine the optimal dosage for future research. This trial aims to enroll up to 150 participants. To be eligible, individuals must be between 18 and 18 years of age, of any gender, and must not be healthy volunteers or children.
Where to Participate
The clinical trial for ASP546C (NCT07488676) is currently open at multiple locations across the United States, making it accessible to a broader range of potential participants. There are 8 study sites located in 8 cities across 5 states.
The top participating locations include:
- Los Angeles, California
- Grand Rapids, Michigan
- Lake Success, New York
- Austin, Texas
- Houston, Texas
- Irving, Texas
- San Antonio, Texas
- West Valley City, Utah
To join this study, participants must be adults aged 18 years, of any gender. This trial is specifically for individuals with the mentioned cancer conditions, and healthy volunteers are not eligible to participate.
Development Timeline
The journey of ASP546C began with its first clinical trial initiated on March 23, 2026. This marked a significant step in understanding its potential as a new therapeutic agent. The development of ASP546C is driven by Astellas Pharma Global Development, Inc., a sponsor committed to advancing medical research.
Initially, the research for ASP546C explored its potential in conditions such as Irritable Bowel Syndrome with Constipation (IBS-C) and hyperphosphatemia. This early exploration reflects the broad scientific interest in the compound's mechanisms. However, the focus has since expanded and evolved, leading to the current clinical investigation in oncology. The ongoing trial, NCT07488676, represents this shift, focusing on gastroesophageal cancer, pancreatic cancer, and other solid tumors. This study is currently in the Phase 1/Phase 2 stage, a crucial period for evaluating the drug's safety, dosage, and initial effectiveness in patients. So far, there has been a total of 1 clinical trial for ASP546C, with an enrollment target of 150 participants.