
Revolutionizing obesity treatment: Could mitochondria hold the key to unlocking fat-specific weight loss?
Globally, approximately 300 million people are grappling with obesity, a complex disease that has a profound impact on a person’s quality of life and increases their risk of a host of serious cardiometabolic disorders. Obesity management has long been dominated by approaches focused on regulating appetite and reducing food intake. These include the approved GLP-1 receptor agonists, which have become an established part of the treatment paradigm. However, these therapies, known for their rapid and substantial total weight loss, have numerous well-recognized limitations, including the need for weekly injections, significant muscle loss, poor adherence over the long-term, and rapid weight rebound upon discontinuation.
As experts continue to sound the alarm on obesity, with the World Health Organization deeming it a global epidemic, biopharma companies are racing to explore new approaches – including ones that focus on increasing energy expenditure – that can overcome the limitations of current approaches.
Pioneering controlled metabolic accelerators
Mitochondrial uncoupling, a natural metabolic process that supports metabolism and regulation of body temperature, has long been an alluring target for weight loss therapies. Preclinical studies show that mitochondrial uncoupling accounts for up to 50% of daily energy expenditure. However, for decades, scientists in both academia and industry have struggled to develop therapeutics that effectively leverage this mechanism without causing intolerable side effects.
Enter Rivus Pharmaceuticals, a trailblazer in the field of mitochondrial biology. The company has pioneered a new class of investigational therapies called Controlled Metabolic Accelerators (CMAs). These novel oral compounds are purposely designed to increase a patient’s metabolism in an imperceptible way, resulting in increased energy expenditure, primarily from fat, while preserving muscle mass. Unlike caloric-restriction strategies, such as those involving GLP-1 receptor agonists, which reduce energy input and result in muscle loss, CMAs provide an efficacy trifecta. They increase the metabolic rate in a controlled and consistent manner to oxidize fat and glucose, reduce systemic inflammation, and maintain muscle mass and quality.
Clinicians are increasingly recognizing the importance of maintaining muscle in weight management. Muscle is the body’s largest consumer of calories and energy. When an individual with obesity loses lean muscle, their metabolic rate decreases, resulting in lower baseline energy expenditure, rapid weight regain when they discontinue GLP-1 therapy, poorer metabolic health, and potentially serious long-term health issues. Elderly obese patients may be at even greater risk of negative consequences from loss of muscle, including hip and pelvis fractures, falls and hospitalizations – thus highlighting the critical role of preserving muscle mass in the battle against obesity. Additionally, due to the high discontinuation rates observed in real-world usage, existing agents are imperfect long-term therapies for chronic conditions. As such, the ability to keep off the weight that has been lost remains elusive today.
Rapidly advancing the clinical development of CMAs
Initial clinical data showed that CMAs can provide fat-specific weight loss, improve insulin sensitivity and significantly reduce oxidative stress and inflammation – key factors in addressing cardiometabolic disorders.
Rivus’ lead CMA program, HU6, is currently in Phase 2 clinical development and has the potential to be a foundational monotherapy for the treatment of obesity as well as resulting cardiometabolic diseases. The company is focusing the clinical development of HU6 on obesity and the related cardiometabolic diseases with the highest morbidity and greatest treatment needs.
To date, more than 450 patients have been treated with HU6 in the clinical development program. Promising results demonstrating fat-specific weight loss with preserved muscle mass have been observed in two Phase 2a clinical trials – one in patients with a high body mass index (BMI) and metabolic dysfunction-associated steatotic liver disease (MASLD) and the other in patients with obesity-related heart failure with preserved ejection fraction (HFpEF).
Importantly, HU6 was well tolerated in patients with HFpEF, even though they are generally older and have significant cardiovascular co-morbidities. Both body weight and total fat mass were significantly reduced with only 19 weeks of HU6 treatment (by 2.86 kg and 2.96 kg [p<0.003] respectively), with no change in muscle mass. Across clinical studies to date, fat-specific weight loss with HU6 has been accompanied by lower blood pressure and improved lipid profiles, as well as reduced markers of systemic inflammation.
“By harnessing the power of mitochondrial uncoupling, CMAs are paving the way for a new era in obesity treatment – one that prioritizes both weight loss and muscle preservation,” said Shaharyar Khan, Ph.D., co-founder and Chief Scientific Officer of Rivus. “As we continue the clinical development of HU6, the potential for this groundbreaking therapy to transform the lives of millions of people around the world is nothing short of revolutionary.”
Rivus is looking ahead to further expand the clinical data for HU6, with upcoming data from a six-month Phase 2b trial in patients with metabolic dysfunction-associated steatohepatitis (MASH) on the horizon. MASH is caused by an accumulation of excess fat cells in the liver and is closely linked to obesity. In fact, weight loss and the reduction of systemic inflammation are considered part of an efficient treatment strategy, highlighting the potential for HU6 to have a meaningful impact on this progressive and difficult to manage disease. Further clinical expansion of HU6 is in the works, including a planned obesity development program that will kick off later this year.
Pursuing a new era in the treatment of obesity
In order to continue the evolution of therapies for obesity and its continuum of cardiometabolic diseases, Rivus has also developed a proprietary machine learning model that powers an AI discovery platform. As a result, the company is developing an approach that would synergistically target both sides of the energy balance equation, enabling both controlled metabolic acceleration and GLP-1 agonism in a single, non-peptide small molecule. This program is also delivering stand-alone non-peptide oral sub-maximal GLP-1 agonists.
These investigational treatments could hold promise for overcoming significant drawbacks of current therapies for obesity and related cardiometabolic diseases. In a world currently dominated by multi-pharmacology, injectable peptides, Rivus imagines a future in which there is a choice of well tolerated oral agents that are effective long-term therapeutic options for this cluster of chronic diseases.
Learn more about Rivus Pharmaceuticals here.