Eli Lilly Reports Near-Perfect Clinical Trial Success Rate Across Multiple Therapeutic Areas

Eli Lilly achieved positive outcomes for nearly all R&D key events in 2025, a rare set of results in the pharmaceutical industry, according to the company's chief scientific and medical officer, Daniel Skovronsky. The success rate stands in stark contrast to industry norms, where phase 2 studies succeed only about 50% of the time and phase 3 studies reach 59%.

The majority of those results were in weight management or diabetes. Eli Lilly's retatrutide, a next-gen anti-obesity medicine, performed well in a phase 3 study, as did orforglipron, an oral GLP-1 racing toward approval. The company's strong performance in recent years is due in large part to its clinical and commercial progress with tirzepatide, a medicine approved for diabetes and weight loss. This therapy's sales are growing rapidly, helping the pharmaceutical leader post excellent financial results.

However, Eli Lilly also made solid clinical progress in other areas. The company's cancer medicine, Jaypirca, aced a phase 3 study and is well on its way to earning label expansions. In 2025, Eli Lilly also reported that its Alzheimer's disease medicine, Kisunla, is helping slow cognitive decline in a long-term study.

Estimates for clinical trial success rates vary, and these rates are not uniform across different therapeutic areas. Alzheimer's disease, for instance, is a particularly tough nut to crack. A surprisingly high percentage of medicines, even those that make it to late-stage studies, don't end up on the market.

Eli Lilly is looking to further boost its clinical trial success rate by investing in artificial intelligence. The drugmaker is building what will become the industry's largest AI supercomputer, among other initiatives. Eli Lilly hopes to leverage AI to accelerate drug development.

The U.S. Food and Drug Administration announced last year that it was phasing out animal models in favor of other methods, including AI-based models. The company is recording strong financial results, boasts a deep pipeline, and continues to reward shareholders with growing dividends and share buybacks.