Eli Lilly (LLY) stock experienced a decline of over 4% on Monday following the release of a new study in the Journal of the American Medical Association. The study examined the long-term effects of stopping treatment with Eli Lilly's weight-loss drug, Zepbound, and revealed that patients who discontinued the medication slowly regained weight over the course of a year.

The research, known as Surmount-4, is one of the first to investigate the consequences of discontinuing a weight-loss drug. It found that while patients who switched to a placebo did regain weight, it was not as much as they had originally lost.

Jeff Emmick, Lilly's senior vice president of product development, emphasized the significance of ongoing treatment for obesity, stating, "Patients, providers, and the public do not always understand that obesity is a chronic disease that often requires continuous treatment. However, studies like Surmount-4 demonstrate that continued therapy can help individuals living with obesity maintain their weight loss."

In the study, approximately 650 adults who took Zepbound lost an average of 20.9% of their weight over an eight-month period. However, those who switched to a placebo gained back around 14% of the weight over the course of a year. On the other hand, patients who continued taking Zepbound experienced an additional 5.5% weight loss.

It is important to note that patients who switched to the placebo still achieved a net benefit in terms of weight loss. Throughout the 88-week study, those who took Zepbound lost an average of 25.3% of their weight. Even after switching to the placebo at 36 weeks, patients still managed to lose 9.9% of their weight.

Despite these findings, shares of Eli Lilly stock fell below its 50-day moving average, currently trading near 571.25 in morning trades. Additionally, shares of rival company Novo Nordisk (NVO) also experienced a decline of over 1%, reaching 95.38.

Eli Lilly shares have exhibited strong performance, with an IBD Digital Relative Strength Rating of 95, placing them among the top 5% of all stocks in the past year.

The study's results shed light on the importance of continuous treatment for individuals dealing with obesity and highlight the potential impact of discontinuing weight-loss drugs. Further research is needed to better understand and address the long-term challenges faced by patients in managing their weight.