EXPLAINED: How does Pfizer's new weight loss drug Berobenatide work?

Obesity has become a growing concern worldwide, and GLP-1 drugs have brought relief to millions struggling with weight management. In India, medications such as Ozempic, Mounjaro, and Wegovy have emerged as game changers for people seeking significant weight loss. However, the need for frequent injections typically four times a month can make long-term treatment difficult for many patients.

Amid this, Pfizer's new obesity drug, Berobenatide, is drawing attention as it could become the world’s first once-a-month GLP-1 injection if it receives regulatory approval.

According to Pfizer’s VESPER-3 mid-stage clinical trial, participants without diabetes lost up to 12.3% of their body weight.

Berobenatide better than other obesity drugs?

Berobenatide's arrival offers convenience to patients seeking long-term treatment, as they only have to inject it once a month. Apart from weight loss, the reduced frequency of injections attracts more people to buy it. This makes it just 12 injections a year, reducing treatment fatigue.

According to recent clinical data presented by Pfizer, Berobenatide is formulated as a very low-volume injection, creating a less painful injection experience that can help patients bear the pain.

What is Berobenatide all about?

Berobenatide is an experimental GLP-1 receptor agonist developed by Pfizer for treatment related to obesity and type- 2 diabetes. It functions similarly like Ozempic and Wegovy by injecting a natural hormone into the body that helps control appetite, slow digestion and regulate blood sugar levels.

This once-in-a-month induced injection could make patients feel less hungry for longer and consume fewer calories leading to weight loss over time.

One unique thing about Berobenatide is its ultra-long-acting formulation. Unlike most other GLP-1 drugs that require weekly injection, Berobenatide is being developed as a monthly-once injection.

How does Berobenatide work?

Berobenatide works by mimicking the GLP-1 a hormone naturally produced in the gut that regulates appetite and blood sugar levels. The drug acts on multiple organs in the body, including the brain, stomach and pancreas.

In the brain, the drug reduces hunger signals and increases the feeling of appetite being full and this condition can help people consume smaller portions of food. In the stomach, it slows the movement of food through the digestive system prolonging the whole digestion process and allowing the feeling of fullness to last longer after each meal.

In the pancreas, the drug helps in releasing insulin automatically and more efficiently when the blood sugar level rises. It also reduces excess sugar released into the bloodstream. Through all these bodily effects, Berobenatide helps promote weight loss and improve blood sugar control making it a better treatment option for obesity and type-2 diabetes.

A crucial advantage that Berobenatide has over other drugs is its monthly-once dosage, which could reduce packaging and shipping demands, thereby lowering economic inefficiencies.

Comparing the average weight-loss statistics, Wegovy produced about 15% average weight loss, while Zepbound showed greater weight loss, averaging around 20% in late-stage studies. Despite achieving a lower average weight loss compared to other drugs, Berobenatide has the potential to improve treatment persistence, which is a major determinant of long-term success in obesity management.

How does monthly-once injection differ from others?

The natural GLP-1 hormone survives in the body for only a few minutes before it is broken down. Drug developers use advanced molecular engineering techniques and modify the drug molecule so that it remains active in the bloodstream for a longer period.

All these modifications help slow its breakdown and clearance from the body, allowing the medication to produce long-lasting effects. Pfizer states that Berobenatide has an ultra-long half-life, enabling it to produce weight-loss effects throughout the month with a single injection.

If approved this year, Berobenatide could reduce the number of injections from 52 per year to just 12.

What are the side-effects of Berobenatide?

Berobenatide can cause gastrointestinal side-effects such as nausea and vomiting, similar to other drugs in the market. In the VESPER-3 study, nausea was reported in approximately 38% of participants, while around 23% experienced vomiting.

Despite the advantage of treatment adherence, there has been a drastic increase in side-effects when patients switched to consuming the injection once a month.

All these side-effects delay the introduction of Berobenatide into the market, making it an experimental medication that still requires large late-stage clinical trials before seeking regulatory approval.

As researchers continue to study the long-term effects of the medication and assess whether its impact remains consistent over extended periods, Pfizer’s introduction of the drug into the market could improve long-term treatment outcomes and help reduce the adverse effects of obesity, which affects a significant portion of the global population.

(Compiled by S Gowri Nanda)