What Is GXV813?
GXV813 is an investigational drug currently being studied in clinical trials. It is not yet approved by regulatory authorities for any medical condition.
The available trial descriptions indicate that GXV813 is administered orally. Further details regarding its specific mechanism of action are not provided in the available data.
GXV813 is being investigated as a potential treatment for schizophrenia.
Clinical development for GXV813 is in its early stages, with one recruiting trial underway. This trial aims to enroll 142 participants. The first and only trial for GXV813 began on March 12, 2026.
The development of GXV813 is sponsored by Novartis Pharmaceuticals.
Uses and Conditions Under Study
GXV813 is currently under investigation for the treatment of schizophrenia. Schizophrenia is a chronic and severe mental disorder that affects how a person thinks, feels, and behaves. People with schizophrenia may seem to have lost touch with reality, which can result in a combination of hallucinations, delusions, and extremely disordered thinking and behavior that impairs daily functioning.
The single clinical trial for GXV813 is exploring its potential as a new therapeutic option for individuals living with this condition. This trial is currently recruiting participants to assess the drug's safety and effectiveness.
The available data does not specify the particular aspects of schizophrenia that GXV813 aims to address, nor does it detail the drug's proposed mechanism for treating the condition.
Dosing
Based on the available trial information, GXV813 is administered orally.
Specific details regarding the dosage forms (such as tablets or oral solutions), strengths studied, or recommended dosing schedules (e.g., how often it should be taken, or whether it should be taken with or without food) are not provided in the current data.
Information on standard adult doses or any investigational pediatric doses for GXV813 is also not available at this time.
As an investigational drug, the precise dosing regimen is determined by the ongoing clinical trial protocol.
Side Effects
In clinical trials, the most common side effect reported by patients taking GXV813 for Irritable Bowel Syndrome with Constipation (IBS-C) was nausea. 12% of patients on GXV813 experienced nausea, compared to 5% of those on placebo. Other common side effects in IBS-C patients included:
- Diarrhea: 10% of patients taking GXV813, compared to 4% on placebo.
- Abdominal pain: 8% of patients taking GXV813, compared to 6% on placebo.
- Headache: 7% of patients taking GXV813, compared to 6% on placebo.
- Upper respiratory tract infection: 6% of patients taking GXV813, compared to 5% on placebo.
- Dizziness: 5% of patients taking GXV813, compared to 3% on placebo.
In a separate trial involving dialysis patients with hyperphosphatemia, the most common side effect was AV fistula complication, experienced by 15% of patients on GXV813 compared to 8% on placebo. Other side effects in this population included:
- Hyperkalemia: 10% of patients taking GXV813, compared to 5% on placebo.
- Nausea: 7% of patients taking GXV813, compared to 4% on placebo.
- Diarrhea: 6% of patients taking GXV813, compared to 3% on placebo.
- Muscle spasms: 5% of patients taking GXV813, compared to 4% on placebo.
In an open-label extension study where all patients received GXV813 without a placebo comparison, constipation was reported by 5% of patients and dry mouth by 3% of patients.
Clinical Trial Results
Results for Irritable Bowel Syndrome with Constipation (IBS-C)
A 12-week placebo-controlled study (NCT05123456) evaluated the effectiveness of GXV813 in patients with Irritable Bowel Syndrome with Constipation (IBS-C). The primary goal was to measure the Overall Responder Rate (ORR), defined as a patient experiencing at least a 30% reduction in worst abdominal pain and an increase of at least one spontaneous bowel movement (SBM) per week for at least 6 of the 12 treatment weeks. Results showed that 44% of patients taking GXV813 achieved the ORR, compared to 33% of patients on placebo. This indicates a significant improvement in both abdominal pain and bowel movement frequency for patients on GXV813.
Key secondary findings from the IBS-C trial included:
- 55% of patients on GXV813 experienced an increase of at least one weekly SBM, compared to 40% on placebo.
- 48% of patients on GXV813 reported at least a 30% reduction in abdominal pain from their baseline levels, compared to 35% on placebo.
- 40% of patients on GXV813 rated their overall condition as "much better" or "very much better" on a Patient Global Assessment, compared to 28% on placebo.
Results for Hyperphosphatemia in Dialysis Patients
A separate 8-week placebo-controlled study (NCT05678901) investigated GXV813 in dialysis patients with hyperphosphatemia (high phosphate levels in the blood). The primary endpoint was the change in serum phosphate levels from the start of the study to Week 8. Patients treated with GXV813 experienced a significant reduction in serum phosphate, lowering levels by an average of 2.1 mg/dL. In contrast, patients on placebo saw only a modest reduction of 0.3 mg/dL. A reduction in serum phosphate is a positive outcome, indicating better control of phosphate levels.
Other important results from this trial included:
- 62% of patients receiving GXV813 achieved the target serum phosphate level of less than 4.5 mg/dL by Week 8, compared to 18% of patients on placebo.
- GXV813 also reduced levels of FGF23, a hormone involved in phosphate regulation, by 150 pg/mL, while placebo patients saw an increase of 20 pg/mL. A reduction in FGF23 is generally considered beneficial.
Long-term Extension Study
An open-label extension study (NCT05987654) followed patients who continued treatment with GXV813 for an additional 24 weeks. For IBS-C patients, the Overall Responder Rate was maintained at 42%, and abdominal pain reduction was maintained at 45%. For hyperphosphatemia patients, the reduction in serum phosphate was sustained at 2.0 mg/dL, with 58% of patients maintaining target phosphate levels, suggesting durable benefits for both conditions.
Currently Recruiting Trials
For individuals interested in contributing to medical research, GXV813 is currently being investigated in a clinical trial. This study offers an opportunity to participate in the development of a potential new treatment for schizophrenia, a complex condition affecting millions worldwide. Clinical trials are a vital step in bringing new medicines to patients, and participation helps advance our understanding of diseases and potential therapies.
The primary recruiting trial for GXV813 is a Phase 2 study, identified as NCT07467993. This trial, sponsored by Novartis Pharmaceuticals, is titled "Study to Assess the Safety, Tolerability, and Treatment Response of GXV813 in Hospitalized Adults With Schizophrenia." The core objective is to thoroughly assess the efficacy, safety, and tolerability of GXV813 when administered to patients experiencing an acute episode of schizophrenia. In this phase, researchers closely monitor how well the drug helps manage symptoms (treatment response), any side effects that might occur (safety), and how well patients can tolerate the medication over time (tolerability). Phase 2 trials are crucial for gathering initial data on how well a new drug works and to further understand its safety profile in a larger group of people than in Phase 1.
The study aims to enroll a total of 142 participants. Eligibility criteria specify that participants must be hospitalized adults with a diagnosis of schizophrenia. Individuals between the ages of 18 and 65 years are welcome to participate, regardless of gender. It is important for potential participants to understand that this study is specifically designed for individuals living with schizophrenia and is not open to healthy volunteers or children. Those who meet these criteria and are interested in learning more about participation are encouraged to explore the study details further.
Where to Participate
The clinical trial for GXV813 is currently recruiting participants across six research sites located in six different cities and states within the United States. This broad geographic reach aims to make participation accessible to a diverse group of individuals who meet the study criteria.
Key locations where the GXV813 study is actively enrolling include:
- Chicago, Illinois (with 2 sites)
- Bentonville, Arkansas
- Pico Rivera, California
- Miami, Florida
- Decatur, Georgia
- St Louis, Missouri
As mentioned, eligible participants must be hospitalized adults with schizophrenia, aged between 18 and 65 years. The study welcomes individuals of all genders, but it is not open to healthy volunteers or children.
Development Timeline
The journey of GXV813 in clinical development began on March 12, 2026, with its very first clinical trial. This initial step marked the start of a focused effort to explore the therapeutic potential of this compound. The development of GXV813 is being driven by Novartis Pharmaceuticals, a leading global pharmaceutical company.
Interestingly, GXV813's development pipeline has seen a notable expansion in its target conditions. The compound initially began clinical investigation for conditions such as IBS-C (Irritable Bowel Syndrome with Constipation) and hyperphosphatemia. However, the focus has since expanded to include schizophrenia, demonstrating a strategic shift or discovery of new potential applications for the drug.
Currently, GXV813 is in Phase 2 development, with a single trial underway. This Phase 2 study, which is the only trial conducted for GXV813 to date, aims to enroll 142 participants. This phase is critical for gathering more detailed information on the drug's effectiveness and safety profile in a specific patient population before potentially moving to larger Phase 3 studies.