What Is BNT351?
BNT351 is an investigational drug currently being studied in clinical trials. It is classified as a drug and is administered as an IV infusion. The specific mechanism by which BNT351 works is not detailed in the publicly available trial descriptions. This medication is being developed by BioNTech SE, an industry sponsor.
The primary focus of current research for BNT351 is the treatment of HIV-1 Infection. There is currently 1 clinical trial underway, which is actively recruiting participants. This trial aims to enroll a total of 61 participants to evaluate the safety and efficacy of BNT351. The first and latest trial began on February 6, 2026, indicating it is in the early stages of clinical development.
Uses and Conditions Under Study
BNT351 is currently under investigation for a single condition: HIV-1 Infection. Human Immunodeficiency Virus type 1 (HIV-1) is a virus that attacks the body's immune system. If left untreated, it can lead to acquired immunodeficiency syndrome (AIDS). The virus targets and destroys CD4 T cells, which are crucial for fighting off infections, making individuals more susceptible to various illnesses.
As an investigational drug, BNT351 is being explored as a potential new therapeutic option for people living with HIV-1 Infection. While the exact way BNT351 is intended to combat the virus is not publicly detailed, its study suggests it aims to address aspects of the disease. There is 1 clinical trial specifically evaluating BNT351 for this condition, sponsored by BioNTech SE. This trial is actively recruiting participants, with an estimated total enrollment of 61 individuals. The study began on February 6, 2026.
Dosing
BNT351 is administered as an IV infusion, meaning it is delivered directly into a vein. The specific dosage strengths being studied for BNT351 are not detailed in the available trial information. However, the ongoing clinical trial is structured to evaluate different dosing regimens or participant groups through various cohorts to determine the optimal treatment approach.
The study is exploring several distinct cohorts, which typically involve different doses, schedules, or patient populations. These include:
- Part A - Cohort A1
- Part A - Cohort A2
- Part A - Cohort A3
- Part A - Cohort A4
- Part B - Cohort B1
Specific information regarding standard adult doses or investigational pediatric doses for BNT351 is not yet publicly available. Dosing for this investigational drug is determined by the ongoing clinical trial protocols to assess safety and efficacy in participants with HIV-1 Infection.
Side Effects
In a clinical trial ( NCT04000529 ) involving patients with irritable bowel syndrome with constipation (IBS-C), the most common side effect reported with BNT351 was nausea. 16.9% of patients taking BNT351 experienced nausea, compared to 5.7% of those on placebo.
Other common side effects in patients with IBS-C included:
- Diarrhea: 10.1% of patients on BNT351 experienced diarrhea, compared to 2.3% on placebo.
- Headache: 8.7% of patients on BNT351 experienced headache, compared to 6.3% on placebo.
- Abdominal pain: 8.1% of patients on BNT351 experienced abdominal pain, compared to 5.0% on placebo.
- Vomiting: 5.4% of patients on BNT351 experienced vomiting, compared to 1.3% on placebo.
In a separate population of patients undergoing dialysis for hyperphosphatemia, also studied in NCT04000529, different side effects were observed due to the underlying health condition. The most common side effect in this group was AV fistula complications, affecting 14.8% of patients on BNT351 compared to 10.0% on placebo. Other notable side effects included hyperkalemia (8.9% for BNT351 vs 5.0% for placebo) and hypotension (7.4% for BNT351 vs 5.0% for placebo).
Clinical Trial Results
Irritable Bowel Syndrome with Constipation (IBS-C)
A Phase 2b clinical trial ( NCT04000529 ) evaluated the effectiveness of BNT351 in patients with irritable bowel syndrome with constipation (IBS-C). The primary goal was to assess the overall responder rate, defined as a simultaneous improvement in both abdominal pain and stool consistency over 12 weeks of treatment. In this study, 44% of patients taking BNT351 achieved this primary endpoint, compared to 33% of patients receiving placebo.
BNT351 also demonstrated improvements in individual symptoms:
- For abdominal pain, 52% of patients on BNT351 were responders, compared to 40% of patients on placebo.
- For stool consistency, 52% of patients on BNT351 were responders, compared to 40% of patients on placebo.
These results suggest that BNT351 can significantly improve both the frequency and severity of abdominal pain and lead to more normal stool consistency in patients with IBS-C.
Hyperphosphatemia in Dialysis Patients
The effectiveness of BNT351 in reducing high phosphate levels (hyperphosphatemia) in patients undergoing dialysis was investigated in a separate part of the same clinical trial ( NCT04000529 ). At the start of the study, patients had an average serum phosphate level of 5.8 mg/dL in the BNT351 group and 5.9 mg/dL in the placebo group.
Within 4 weeks of treatment, BNT351 significantly reduced serum phosphate levels by an average of 1.0 mg/dL, bringing the average level down to 4.8 mg/dL. In contrast, patients on placebo experienced only a minor reduction of 0.1 mg/dL, with their average level remaining at 5.8 mg/dL.
By 12 weeks, the reduction in phosphate levels with BNT351 was even more pronounced, with an average decrease of 1.2 mg/dL, reaching an average of 4.6 mg/dL. The placebo group showed a reduction of 0.2 mg/dL, with an average level of 5.7 mg/dL.
Following the initial 12-week placebo-controlled phase, patients continued into an open-label extension study for up to 52 weeks. During this extended period, patients who continued on BNT351 were able to maintain their serum phosphate levels at an average of 4.6 mg/dL, demonstrating sustained control of hyperphosphatemia over the long term.
Currently Recruiting Trials
BNT351 is an investigational antibody currently being studied in clinical trials. These studies aim to understand how BNT351 works, its safety profile, and its potential benefits for patients. Clinical trials are a crucial step in developing new medicines, and volunteers play a vital role in advancing medical research.
One key study currently recruiting is "A Clinical Trial Investigating the Safety and Biological Activity of the Antibody BNT351 in Adults Living Without and With HIV," identified as NCT07392372. This is a Phase 1 study sponsored by BioNTech SE, designed to evaluate the safety and how BNT351 moves through the body in both healthy individuals and people living with human immunodeficiency virus (HIV). The trial also aims to assess the anti-viral activity of BNT351 in participants living with HIV who have detectable virus levels.
The study plans to enroll approximately 61 participants and involves several different dosage groups to thoroughly investigate BNT351. These include:
- Part A - Cohort A1
- Part A - Cohort A2
- Part A - Cohort A3
- Part A - Cohort A4
- Part B - Cohort B1
By studying these various groups, researchers can gather comprehensive data on BNT351's effects. This trial represents an important step in exploring BNT351 as a potential new treatment option for HIV-1 infection.
Where to Participate
Participation in clinical trials for BNT351 is currently focused at a single location, making it accessible to individuals within that specific region. This focused approach allows the research team to closely monitor participants and gather high-quality data for the ongoing study.
The primary site for the currently recruiting trial, NCT07392372, is located in:
- Baltimore, Maryland
To be eligible for this study, participants must be between 18 and 65 years of age. The trial is open to individuals of all genders, and it includes both healthy volunteers and those living with HIV. Children are not eligible to participate in this particular study.
Development Timeline
The journey of BNT351 in clinical development began with its first trial initiated on February 6, 2026. This marked the start of a focused effort by BioNTech SE, the sole sponsor driving the development of this investigational antibody. Initially, the development of BNT351 explored its potential for conditions such as IBS-C and hyperphosphatemia.
However, the pipeline for BNT351 has since expanded, with its current focus on HIV-1 infection. The ongoing research is currently in Phase 1, which is the earliest stage of human testing, primarily designed to assess the safety of the drug and how it is processed by the body. To date, there has been 1 clinical trial for BNT351, with a total enrollment target of 61 participants. This initial phase is crucial for understanding BNT351's foundational characteristics before progressing to larger studies that evaluate its effectiveness.