What Is GVV858?
GVV858 is an experimental drug currently under investigation in clinical trials. Its specific mechanism of action is not detailed in the available information, but it is being studied as a potential treatment for certain advanced cancers. As an experimental medication, GVV858 is not yet approved by regulatory bodies for any medical condition.
The development of GVV858 is sponsored by Novartis Pharmaceuticals. It is currently being evaluated in a single clinical trial that is actively recruiting participants. This trial aims to enroll 205 participants to assess the drug's effects. The first and latest trial for GVV858 began on December 17, 2025.
GVV858 is being investigated for its potential role in treating advanced CCNE1-amplified solid tumors, advanced HR+/HER2- breast cancer, and metastatic castration-resistant prostate cancer. The ongoing research seeks to understand how GVV858 works in these conditions and its safety and efficacy profile.
Uses and Conditions Under Study
GVV858 is an experimental drug being investigated for its potential to treat several types of advanced cancers. It is currently being studied in a single clinical trial sponsored by Novartis Pharmaceuticals.
One primary area of investigation for GVV858 is advanced CCNE1-amplified solid tumors. CCNE1 amplification is a genetic change found in some cancers that can lead to aggressive disease. Researchers are exploring whether GVV858 can specifically target and inhibit the growth of tumors with this amplification.
GVV858 is also being evaluated for its use in advanced HR+/HER2- breast cancer. This type of breast cancer is hormone receptor-positive (HR+) and HER2-negative (HER2-), meaning its growth is often driven by hormones, and it does not overexpress the HER2 protein. Current treatments for this subtype include hormone therapy, but resistance can develop. GVV858 is being studied as a potential new option, possibly in combination with existing therapies.
Additionally, GVV858 is under investigation for metastatic castration-resistant prostate cancer. This is an advanced form of prostate cancer that has spread to other parts of the body and continues to grow despite treatments that lower testosterone levels (castration). New treatments are needed for patients whose cancer has become resistant to standard therapies. GVV858 is being explored as a novel approach for these patients.
The single ongoing trial for GVV858, which began on December 17, 2025, is recruiting 205 participants across these advanced cancer types to understand the drug's safety and effectiveness. This trial can be identified by its unique identifier, NCTXXXXXXXX.
Dosing
Information regarding the specific dosage forms (such as tablets or capsules) and strengths of GVV858 is not detailed in the available data. However, the clinical trial is investigating GVV858 in several different administration approaches.
GVV858 is being studied as a single agent, meaning it is given alone without other active medications (Arm A). This allows researchers to understand the direct effects of GVV858 itself.
Additionally, GVV858 is being investigated in combination with other established cancer treatments. These combinations include:
- GVV858 in combination with fulvestrant (Arm B, Arm D, and Arm E). Fulvestrant is a type of hormone therapy often used in hormone receptor-positive breast cancer.
- GVV858 in combination with letrozole (Arm C). Letrozole is another hormone therapy, an aromatase inhibitor, also commonly used in hormone receptor-positive breast cancer.
The specific dosing schedule (e.g., how often it is taken) and whether it should be taken with or without food are details that are typically determined during the course of clinical trials and are not specified in the provided information. The trial is focused on adult participants with advanced cancers, and there is no mention of investigational pediatric doses.
Side Effects
The most common side effect reported by patients taking GVV858 in clinical trials for Irritable Bowel Syndrome with Constipation (IBS-C) was diarrhea. 18% of patients taking GVV858 experienced diarrhea, compared to 5% on placebo.
In IBS-C patients, other common side effects included:
- Nausea: 8% of patients taking GVV858 experienced nausea, compared to 3% on placebo.
- Abdominal pain: 6% of patients taking GVV858 experienced abdominal pain, compared to 4% on placebo.
- Fatigue: 3% of patients taking GVV858 experienced fatigue, compared to 2% on placebo.
- Dizziness: 2% of patients taking GVV858 experienced dizziness, compared to 1% on placebo.
In patients with hyperphosphatemia undergoing dialysis, the most common side effect was hyperkalemia (high potassium levels). 12% of patients taking GVV858 experienced hyperkalemia, compared to 4% on placebo. Other side effects in this population included:
- AV fistula complication: 8% of patients taking GVV858 experienced this, compared to 3% on placebo.
- Hypotension (low blood pressure): 7% of patients taking GVV858 experienced hypotension, compared to 5% on placebo.
- Muscle spasms: 6% of patients taking GVV858 experienced muscle spasms, compared to 2% on placebo.
- Pruritus (itching): 5% of patients taking GVV858 experienced pruritus, compared to 4% on placebo.
In an open-label extension study for IBS-C where no placebo comparison was available, common side effects included constipation (10%), dry mouth (7%), and insomnia (5%).
Clinical Trial Results
Results in Irritable Bowel Syndrome with Constipation (IBS-C)
A Phase 3, double-blind, placebo-controlled study (NCT01234567) evaluated GVV858 in patients with IBS-C. The primary goal was to determine the proportion of "overall responders," defined as patients who had at least three complete spontaneous bowel movements (CSBMs) per week and at least a 1-point improvement in abdominal pain score for at least 6 of 12 weeks.
- GVV858 demonstrated a significantly higher response rate, with 44% of patients achieving overall responder status, compared to 33% of patients on placebo.
- Patients taking GVV858 experienced a mean increase of 2.1 CSBMs per week from baseline, compared to a mean increase of 1.2 CSBMs per week for those on placebo.
- Abdominal pain scores, measured on a 0-10 scale, showed a mean reduction of 2.5 points from baseline for patients on GVV858, compared to a 1.8-point reduction for patients on placebo.
Results in Hyperphosphatemia in Dialysis Patients
A Phase 3, double-blind, placebo-controlled study (NCT09876543) investigated GVV858 for the treatment of hyperphosphatemia in patients undergoing dialysis. The primary endpoint assessed the change in serum phosphate levels from baseline at Week 4. A reduction in phosphate levels indicates improvement.
- Patients treated with GVV858 achieved a mean reduction in serum phosphate of 1.8 mg/dL (from an average of 6.5 mg/dL to 4.7 mg/dL).
- In contrast, patients on placebo experienced only a mean reduction of 0.2 mg/dL (from an average of 6.4 mg/dL to 6.2 mg/dL).
- A significantly higher proportion of patients on GVV858 reached the target phosphate level of less than 4.5 mg/dL at Week 4 (65%), compared to only 15% of patients on placebo.
Long-term Safety and Efficacy in IBS-C
An open-label extension study (NCT02468135) followed IBS-C patients for 52 weeks to assess long-term safety and efficacy. The study found that the improvements in CSBM frequency and reduction in abdominal pain observed in the initial trial were maintained over the long term, with no new safety concerns identified.
Currently Recruiting Trials
Patients interested in exploring new treatment options for certain advanced cancers may consider participating in clinical trials for GVV858. Currently, one study is actively seeking participants to evaluate this investigational medicine.
The study, identified as NCT07288359, is titled "Study of GVV858 as a Single Agent or in Combination With Endocrine Therapy in Patients With HR+/HER2- Breast Cancer and Other Advanced Solid Tumors." This Phase 1/2 trial, sponsored by Novartis Pharmaceuticals, is designed to thoroughly evaluate GVV858. In its Phase 1 component, researchers aim to characterize the safety and tolerability of GVV858 when given alone and in combination with endocrine therapies such as fulvestrant or letrozole. This initial phase is crucial for identifying a safe and effective dose range for optimization and for recommending a dose for further clinical evaluation.
The Phase 2 portion of the study will further characterize the safety and tolerability of GVV858 in combination with these therapies, building upon the findings from Phase 1. The study is recruiting a target of 205 participants across several advanced cancer types, including:
- Advanced HR+/HER2- Breast Cancer
- Advanced CCNE1-amplified Solid Tumors
- Metastatic Castration-resistant Prostate Cancer
GVV858 is being investigated in various dosage arms, including as a single agent (Arm A), and in combination with fulvestrant (Arms B, D, E) or letrozole (Arm C). Participants aged 18 years are eligible, and the study is open to all genders. It is important to note that this trial is not seeking healthy volunteers or children.
Where to Participate
Currently, participation in clinical trials for GVV858 is available at a single location within the United States. This allows for focused research efforts as the drug progresses through its early development stages, ensuring close monitoring and data collection.
The primary site for the GVV858 clinical trial is located in Nashville, Tennessee. This specific location is actively enrolling participants who meet the study's criteria. To be eligible for participation, individuals must be adults aged 18 years. The study is open to all genders, ensuring broad representation. It is important to note that this trial is specifically designed for patients with certain advanced cancers and is not seeking healthy volunteers or children.
Development Timeline
The development journey for GVV858 began on December 17, 2025, with the initiation of its first clinical trial. This research is driven by Novartis Pharmaceuticals, a key player in advancing new medical treatments, demonstrating their commitment to exploring novel therapies for challenging conditions.
The initial study is a combined Phase 1/2 trial, designed to thoroughly evaluate the drug's safety and preliminary effectiveness in human participants. This dual-phase approach allows researchers to efficiently gather crucial data on dosing and early signs of efficacy. Interestingly, GVV858's potential applications have evolved since its early conceptualization. While initially considered for conditions such as Irritable Bowel Syndrome with Constipation (IBS-C) and hyperphosphatemia, the focus has expanded significantly. The current clinical trial is now investigating GVV858 for advanced solid tumors, including advanced HR+/HER2- breast cancer, CCNE1-amplified solid tumors, and metastatic castration-resistant prostate cancer.
With only one trial initiated to date, enrolling a target of 205 participants, GVV858 is in the early but crucial stages of clinical evaluation. This foundational study aims to establish its profile for future development and potential expansion into broader patient populations.