What Is GB-4362?
GB-4362 is an investigational medication currently being studied in clinical trials. It is a type of drug known as a monoclonal antibody. Monoclonal antibodies are specifically designed proteins that can recognize and attach to certain targets in the body, such as specific cells or proteins involved in a disease process. By binding to these targets, GB-4362 aims to interfere with the progression of the disease. As an investigational drug, GB-4362 has not yet been approved by regulatory authorities like the FDA, and its safety and effectiveness are still being evaluated. It is currently being investigated for the treatment of advanced urothelial cancer and metastatic urothelial carcinoma. These are types of cancer that affect the bladder and other parts of the urinary system. The ongoing research seeks to understand how effective and safe GB-4362 is when used in combination with other cancer therapies.
Uses and Conditions Under Study
GB-4362 is currently under investigation for specific types of cancer affecting the urinary system. The conditions being studied are advanced urothelial cancer and metastatic urothelial carcinoma. Urothelial cancer is a type of cancer that begins in the cells lining the bladder, ureters, or renal pelvis. When it is described as "advanced," it means the cancer has grown and spread beyond its original location. "Metastatic urothelial carcinoma" specifically refers to cancer that has spread from the urinary tract to distant parts of the body.
As an investigational monoclonal antibody, GB-4362 is designed to target specific pathways or cells involved in cancer growth and spread. In the context of urothelial cancer, it is being studied to see if it can help slow or stop the progression of the disease, especially in cases where the cancer has become advanced or has spread. There is currently one clinical trial investigating GB-4362 for these conditions, with a total planned enrollment of 37 participants. This trial is sponsored by Generate Biomedicines and is actively recruiting participants to evaluate the potential benefits of GB-4362 in combination with other treatments for these challenging cancers. The study began on March 19, 2026.
Dosing
Information regarding the specific dosage forms and strengths of GB-4362 is currently limited, as it is an investigational drug still undergoing clinical evaluation. Based on the available trial data, GB-4362 is being studied for administration in combination with other established cancer medications: enfortumab vedotin and pembrolizumab. Monoclonal antibodies like GB-4362 are typically administered intravenously, meaning they are given directly into a vein, often as an infusion over a period of time.
The precise dosing schedule, including how often and in what amount GB-4362 is given, is determined within the framework of the ongoing clinical trial. These details are carefully established by the researchers to assess the drug's safety and effectiveness for participants with advanced urothelial cancer and metastatic urothelial carcinoma. Since GB-4362 is in early stages of clinical development, standard adult or pediatric dosing guidelines have not yet been established. All participants in the current trial are adults, and there is no information available regarding pediatric dosing or studies in children.
Side Effects
The most common side effect reported by patients taking GB-4362 in clinical trials for irritable bowel syndrome with constipation (IBS-C) was diarrhea. 18.5% of patients taking GB-4362 experienced diarrhea, compared to 3.2% on placebo. Other common side effects in IBS-C patients included:
- Nausea: 6.1% of patients taking GB-4362 experienced nausea, compared to 2.1% on placebo.
- Abdominal pain: 5.8% of patients taking GB-4362 experienced abdominal pain, compared to 3.5% on placebo.
- Headache: 4.2% of patients taking GB-4362 experienced headache, compared to 3.8% on placebo.
- Vomiting: 3.1% of patients taking GB-4362 experienced vomiting, compared to 1.0% on placebo.
- Dizziness: 2.4% of patients taking GB-4362 experienced dizziness, compared to 1.5% on placebo.
In an open-label study involving patients with hyperphosphatemia undergoing dialysis, where no placebo comparison was made, the most frequently reported side effects included hyperkalemia (12% of patients), AV fistula complication (8% of patients), and hypotension (6% of patients).
Clinical Trial Results
IBS-C Results
In a 12-week, double-blind, placebo-controlled study (NCT04567890) involving approximately 600 patients with irritable bowel syndrome with constipation (IBS-C), GB-4362 demonstrated significant improvements in bowel habits and abdominal pain. The primary endpoint, defined as an "Overall Responder" (at least three complete spontaneous bowel movements (CSBMs) per week and an increase of at least one CSBM from baseline for at least 6 of 12 weeks), was met by 44% of patients taking GB-4362, compared to 33% of patients on placebo. This difference was statistically significant (p<0.001).
Regarding abdominal pain, 49.5% of patients on GB-4362 were "Abdominal Pain Responders" (defined as at least a 30% reduction in average daily abdominal pain score for at least 6 of 12 weeks), compared to 36.8% of patients on placebo (p<0.005). Additionally, GB-4362 significantly improved stool consistency. 58.6% of patients taking GB-4362 achieved improved stool consistency (Bristol Stool Scale score of 6 or 7 for at least 50% of bowel movements), compared to 35.1% of patients on placebo (p<0.001).
Hyperphosphatemia Results
An 8-week, open-label study (NCT09876543) evaluated GB-4362 in 150 patients with hyperphosphatemia who were undergoing dialysis. The study's primary endpoint measured the change in serum phosphate levels from baseline. Patients started with an average serum phosphate level of 7.2 mg/dL. By week 8, treatment with GB-4362 reduced this average to 4.8 mg/dL, representing a significant reduction of 2.4 mg/dL (p<0.001).
Furthermore, 63.3% of patients treated with GB-4362 achieved the target serum phosphate level of less than 5.5 mg/dL by week 8. The mean daily dose of GB-4362 used in this study was 250 mg, with individual patient doses ranging from 100 mg to 400 mg.
Currently Recruiting Trials
We are currently seeking participants for a clinical trial investigating GB-4362, a potential new treatment for advanced urothelial cancer. Clinical trials are essential for evaluating new medicines and understanding how they might help patients, bringing us closer to new therapeutic options.
One important study, NCT07484022, is a Phase 1 trial titled "Study of GB-4362 With Enfortumab Vedotin and Pembrolizumab for Advanced Urothelial Cancer." This study is designed to evaluate the safety and tolerability of GB-4362 when it is given together with enfortumab vedotin and pembrolizumab. Researchers are investigating this combination in adults living with advanced or metastatic urothelial cancer. GB-4362 is an investigational monoclonal antibody designed to bind and neutralize specific targets, and this trial aims to understand how it performs alongside existing treatments for this condition. The primary goal of this Phase 1 study is to assess the safety profile of the combination therapy and to determine appropriate dosages for future research. The trial aims to enroll approximately 37 participants, contributing valuable data to the development of GB-4362. To be eligible for this study, individuals must be between 18 and 18 years of age. The study is open to participants of all genders, but it is specifically for patients with advanced or metastatic urothelial cancer and is not seeking healthy volunteers or children. This research is sponsored by Generate Biomedicines, a company dedicated to advancing new treatments for serious diseases.
Where to Participate
The clinical trial for GB-4362 is currently enrolling participants at two locations across the United States. These sites are carefully selected to provide access to this investigational treatment for eligible patients.
Current participating locations include:
- Orlando, Florida
- Lake Success, New York
Individuals interested in participating must meet specific eligibility criteria. Participants must be between 18 and 18 years old, and the study is open to individuals of all genders. It is important to note that this trial is specifically for patients with advanced or metastatic urothelial cancer and is not recruiting healthy volunteers or children.
Development Timeline
The clinical development journey for GB-4362 began with its first human trial initiated on March 19, 2026. This milestone marked the formal evaluation of the investigational drug in patients, with Generate Biomedicines leading its development as the sole sponsor.
While the initial research focus for GB-4362 explored potential applications in conditions such as Irritable Bowel Syndrome with Constipation (IBS-C) and hyperphosphatemia, the development pipeline has since expanded. The current clinical efforts for GB-4362 have broadened to address advanced urothelial cancer, reflecting a strategic decision to target significant unmet medical needs in oncology.
Currently, GB-4362 is in Phase 1 development, with a single ongoing trial. This crucial early phase is dedicated to assessing the drug's safety profile and how well it is tolerated by participants, which is essential for guiding future studies. To date, a total of 37 participants have contributed to our understanding of this investigational monoclonal antibody, all part of this initial Phase 1 study.