In addition to claiming revenue of $19.3 billion for the fourth quarter, Eli Lilly executives offered a glimpse into their strategy to expand their GLP-1 franchise into the immunology and inflammation space, with trials currently underway in asthma, psoriatic arthritis, Crohn’s disease and ulcerative colitis.
As the weight loss juggernaut GLP-1s expand into other therapeutic areas, including cardiovascular and sleep apnea, Eli Lilly is doubling down, seeking to transform its tirzepatide franchise—marketed as Zepbound for weight loss—into a pipeline in a product.
Last month, Lilly reported data from a Phase 3b trial in psoriatic arthritis (PsA), testing a combination of tirzepatide and its autoimmune drug Taltz compared to Taltz alone. The trial met the primary and all key secondary endpoints, with the combo eliciting a 50% improvement in PsA. Notably, tirzepatide plus Taltz showed a relative increase in the proportion of patients who achieved a 50% reduction in their PsA symptoms compared to Taltz alone, and patients taking the combo lost 10% of their body weight at 36 weeks, compared to 0.8% weight loss in the Taltz monotherapy group.
“These results further support existing treatment guidelines for psoriatic arthritis that recommend treatment of comorbid obesity and shed further light on how incretins may have a positive effect on other diseases independent from weight loss,” Dan Skovronsky, chief scientific and product officer at Lilly, said during the company’s fourth quarter and full year earnings presentation on Wednesday.
Elsewhere in its immunology and inflammation pipeline, Lilly is trialing another combination—tirzepatide and Omvoh, an interleukin inhibitor, in Phase 3b studies for Crohn’s disease and ulcerative colitis, Skovronsky said on the call. Outside of tirzepatide, Lilly is testing brenipatide, a GIP/GLP-1 agonist, in a Phase 2 study for asthma, he added.
With the centralized mechanisms that apply to so many of these diseases, I&I is a unique space to target with a single product, Myles Minter, biotech analyst and partner at William Blair, told BioSpace in November 2025. Not to mention the resounding success of AbbVie’s Skyrizi and Rinvoq, which reeled in nearly $26 billion combined in 2025.
During the Q&A period of Lilly’s earnings call, in fact, Guggenheim Securities analyst Seamus Fernandez—who was given extra credit from Skovronsky for his non-obesity-related question—asked why Lilly could not “attack immunology broadly” in the same way it has obesity.
“There is really promising breaking science, including treating immunology diseases earlier, and we’re doing everything in our power to harness this science,” Skovronsky responded, adding his belief that Lilly’s current trials with incretins in immunology are “promising.”
Citibank analyst Geoff Meacham was also given credit for a non-obesity question when he asked Skovronsky how Lilly considers the potential Zepbound combinations in I&I or oncology: Does the drug or the indication drive the decision?
Skovronsky passed this question off to Adrienne Brown, president of Lilly Immunology, who responded that “patients who have both immune diseases and obesity tend to have a higher disease burden. So we’re really excited about the opportunity to find new ways to combat the . . . diseases and potentially unlock better, longer-lasting results for these patients.”
Brown added that Lilly has “broad efforts underway to look at additional combinations” in immunology.
