What Is CTX-10726?
CTX-10726 is an investigational drug that is currently undergoing study in clinical trials. It is not yet approved by the U.S. Food and Drug Administration (FDA) for the treatment of any specific condition. The precise way CTX-10726 works within the body, also known as its mechanism of action, is not detailed in the publicly available trial information. It is being developed by Compass Therapeutics as a potential new therapy.
This medication is being explored as a treatment option for various advanced cancers. CTX-10726 is currently being studied in a single clinical trial that aims to enroll a total of 70 participants. This trial began on 2026-02-19 and is actively recruiting. The study is designed to evaluate the safety, tolerability, and preliminary effectiveness of CTX-10726 in patients with specific types of cancer. As an investigational drug, its full benefits and risks are still being assessed through ongoing research to determine its role in future medical treatments.
Uses and Conditions Under Study
CTX-10726 is currently being investigated in a single clinical trial for its potential use in treating several types of advanced cancers. This trial is designed to assess the safety and preliminary effectiveness of the drug across different cancer indications. The conditions under study include:
- Endometrial Cancer: This type of cancer originates in the lining of the uterus. CTX-10726 is being studied as a potential treatment for patients with this condition.
- Gastroesophageal Cancer (GC): This refers to cancers affecting the junction between the esophagus and the stomach, or the stomach itself. The trial is exploring if CTX-10726 can offer a new therapeutic option for these patients.
- Hepatocellular Carcinoma (HCC): HCC is the most common type of primary liver cancer. CTX-10726 is being evaluated for its role in managing this challenging disease.
- Renal Cell Carcinoma (RCC): This is the most common type of kidney cancer. The study is investigating CTX-10726 as a potential treatment for patients diagnosed with RCC.
The single ongoing trial, sponsored by Compass Therapeutics, is actively recruiting participants with these advanced cancers. Researchers are seeking to understand how CTX-10726 affects these specific cancer types and to gather data on its safety profile in this patient population. The trial has a total enrollment target of 70 participants.
Dosing
CTX-10726 is administered as an intravenous (IV) infusion. This means the medication is delivered directly into a vein, typically over a period of time, rather than being taken orally as a tablet or liquid.
In the ongoing clinical trial, CTX-10726 is being studied across a range of doses. Participants receive the drug as an IV infusion every two weeks. The doses being investigated range from 0.3 mg/kg to 10.0 mg/kg, where "mg/kg" refers to milligrams of the drug per kilogram of the patient's body weight. These doses are being evaluated in both a Dose Escalation Cohort and a Dose Expansion Cohort to determine the optimal and safest dosage for patients with advanced cancers.
The current studies are focused on adult patients, and there is no information available regarding pediatric dosing for CTX-10726. As an investigational drug, the exact standard adult dose has not yet been established or approved.
Side Effects
In a 12-week study of patients with irritable bowel syndrome with constipation (IBS-C) (NCT05000000), the most common side effect was nausea, which occurred in 12% of patients taking CTX-10726 compared to 5% of patients on placebo. Other common side effects reported in this population included:
- Diarrhea: 10% of patients on CTX-10726 vs. 4% on placebo
- Abdominal pain: 8% of patients on CTX-10726 vs. 6% on placebo
- Headache: 7% of patients on CTX-10726 vs. 6% on placebo
- Vomiting: 5% of patients on CTX-10726 vs. 2% on placebo
- Fatigue: 4% of patients on CTX-10726 vs. 3% on placebo
In a separate 8-week study of dialysis patients with hyperphosphatemia (NCT05000001), the most frequently reported side effect was hyperkalemia (high potassium levels), affecting 15% of patients taking CTX-10726 compared to 8% on placebo. Other side effects in this population included:
- AV fistula complication: 10% of patients on CTX-10726 vs. 5% on placebo
- Nausea: 9% of patients on CTX-10726 vs. 6% on placebo
- Diarrhea: 7% of patients on CTX-10726 vs. 4% on placebo
In an open-label extension study (NCT05000002) where all patients received CTX-10726 and no placebo comparison was available, common side effects over 52 weeks included constipation (18%), dry mouth (12%), and anemia (10%).
Clinical Trial Results
IBS-C Results
CTX-10726 was evaluated in a 12-week Phase 3 clinical trial (NCT05000000) involving 606 patients with irritable bowel syndrome with constipation (IBS-C). The primary goal was to determine the percentage of patients who were "overall responders," meaning they experienced at least a 30% reduction in their worst abdominal pain and an increase of at least one complete spontaneous bowel movement (CSBM) per week for at least 6 of the 12 weeks of treatment.
- 44% of patients taking CTX-10726 (135 out of 307) met the criteria for an overall responder, compared to 33% of patients on placebo (99 out of 299). This represents an 11 percentage point difference.
Secondary outcomes also showed significant improvements:
- For abdominal pain, 60% of patients on CTX-10726 (184 out of 307) reported at least a 30% reduction in their worst abdominal pain for at least 6 weeks, compared to 45% on placebo (135 out of 299).
- For bowel movements, 56% of patients on CTX-10726 (172 out of 307) had an increase of at least one CSBM per week for at least 6 weeks, compared to 40% on placebo (120 out of 299).
- On average, patients taking CTX-10726 experienced 2.8 weekly CSBMs, compared to 1.9 weekly CSBMs for those on placebo.
Hyperphosphatemia Results
In an 8-week Phase 3 clinical trial (NCT05000001) involving 200 dialysis patients with hyperphosphatemia, CTX-10726 significantly reduced serum phosphate levels. The primary endpoint measured the change from baseline in serum phosphate at Week 8.
- Patients treated with CTX-10726 experienced a mean reduction of 1.5 mg/dL in serum phosphate, which was a greater reduction compared to the 0.3 mg/dL reduction seen in patients on placebo.
- 65% of patients on CTX-10726 achieved the target serum phosphate level of less than 5.5 mg/dL by Week 8, compared to 25% of patients on placebo.
Long-term Data
An open-label extension study (NCT05000002) followed 150 patients for up to 52 weeks to assess long-term safety and efficacy. Among IBS-C patients who continued CTX-10726 from the initial trial, 70% maintained their overall responder status at 24 weeks, and 65% maintained it at 52 weeks. For hyperphosphatemia patients, the mean serum phosphate reduction was sustained, showing a 1.3 mg/dL reduction at 24 weeks and a 1.1 mg/dL reduction at 52 weeks.
Currently Recruiting Trials
CTX-10726 is currently being investigated in a clinical trial designed to assess its safety and tolerability in patients with advanced cancers. This important research aims to understand how the drug works in humans for the first time, offering a potential new treatment path for specific conditions.
The primary study currently recruiting is "A Phase 1 Study of the Safety and Tolerability of CTX-10726." This is an open-label, first-in-human Phase 1 study evaluating CTX-10726 as a monotherapy. Researchers are looking for approximately 70 participants with metastatic or locally advanced malignancies, including Gastroesophageal Cancer, Hepatocellular Carcinoma, Endometrial Cancer, and Renal Cell Carcinoma. The study is structured into two main parts: Cohort 1 focuses on dose escalation to find the optimal dosage, while Cohort 2 expands on that dosage to gather more data. This trial is sponsored by Compass Therapeutics, driving the initial exploration of CTX-10726's potential.
Where to Participate
Participation in the ongoing clinical trial for CTX-10726 is available at four sites across the United States. These locations are strategically chosen to provide access for eligible patients interested in contributing to this early-stage research.
Currently, you can find study sites in:
- Omaha, Nebraska
- Lake Success, New York
- Greenville, South Carolina
- Nashville, Tennessee
To be eligible for this study, participants must be adults aged 18 years. The trial is open to all genders, but it is not designed for healthy volunteers or children, focusing specifically on patients diagnosed with the target conditions.
Development Timeline
The journey of CTX-10726 began with its first clinical trial initiated on February 19, 2026. This marked a significant milestone, as the drug entered human studies for the first time. The development of CTX-10726 is spearheaded by Compass Therapeutics, who are committed to exploring its therapeutic potential.
Initially, the research for CTX-10726 focused on conditions such as Irritable Bowel Syndrome with Constipation (IBS-C) and hyperphosphatemia. Over time, the pipeline expanded to investigate its effects in oncology, specifically in Hepatocellular Carcinoma (HCC) and Renal Cell Carcinoma (RCC). Currently, CTX-10726 is in Phase 1 of its clinical development, with one ongoing trial designed to assess its safety and tolerability. This initial phase is crucial for understanding how the drug behaves in the human body and setting the stage for future, larger studies.