Eli Lilly has asked to join in opposing a lawsuit brought by compounding pharmacies against the U.S. Food and Drug Administration over the agency's decision that Lilly's blockbuster weight-loss and diabetes drugs are no longer in short supply.

It hasn’t been a smooth year for the two pharma giants, but events in the fourth quarter widened the gap between them.

The United States Food and Drug Administration says the shortage of Eli Lilly’s Zepbound and Mounjaro drugs has been resolved and that specialty pharmacies and online companies need to stop selling off-brand versions of the weight-loss drugs. The FDA has issued warnings against the off-brand versions, citing safety concerns.

Eli Lilly is seeking to end a lawsuit filed by a pharmacy trade group against the Food and Drug Administration (FDA) by joining as a defendant, stating it wants to end the “entitlement” some pharmacies have practiced in mass-marketing copies of its highly popular GLP-1 medications.

The Food and Drug Administration approved Eli Lilly’s weight-loss drug Zepbound on Dec. 27 to treat sleep apnea, a common but potentially serious sleep-related breathing disorder, making it the first medication for certain patients with the condition.

Eli Lilly (NYSE:LLY) is reportedly seeking to oppose a lawsuit filed by compounding pharmacies over the FDA's determination that weight-loss and diabetes drugs such as Lilly's (NYSE:LLY) tirzepatide are no longer in short supply.