Eli Lilly and Co. ( LLY ) stock is trading lower on Tuesday after its weight loss drug rival, Novo Nordisk A/S ( NVO ) , trimmed its 2025 financial outlook.

The cut marks the second time this year Novo Nordisk ( NVO ) has lowered its guidance.

Novo Nordisk ( NVO ) now projects 2025 sales growth to be 8-14% at constant exchange rates, a notable reduction from its earlier forecast of 13-21%.

Similarly, the outlook for operating profit growth has been lowered to 10-16% from the previously anticipated 16-24%.

This revised guidance largely stems from a slower-than-expected penetration of its branded GLP-1 treatments, particularly in the United States, a market increasingly impacted by the persistent use of compounded GLP-1 alternatives.

GLP-1 Drugs

In a letter to the U.S. Food and Drug Administration (FDA) Commissioner Marty Makary on Friday, over 80 bipartisan members asked the agency to stop counterfeit and copycat versions of GLP-1 drugs like Novo Nordisk’s Wegovy (semaglutide) and Eli Lilly’s Zepbound from flooding the market.

The group wrote the letter urging immediate action against the rising threat of illegal, counterfeit anti-obesity medications entering the U.S. 

The group urged the FDA to issue warning letters, pursue civil enforcement, and monitor non-compliant online retailers and compounding pharmacies selling unapproved weight-loss drugs.

In April, after media reports on Hims & Hers Inc. partnering with the company, Eli Lilly ( LLY ) said in a statement that it has no affiliation with Hims & Hers.

Zepbound (tirzepatide) can be prescribed by any licensed healthcare professional. People who are commercially insured with coverage for Zepbound may be eligible to pay as little as $25.

Trial Data

On Tuesday, Eli Lilly ( LLY ) also released topline results from the Phase 3 BRUIN CLL-314 trial of Jaypirca (pirtobrutinib) versus Imbruvica (ibrutinib) in patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL).

Johnson & Johnson’s Imbruvica is a covalent BTK inhibitor.

The study enrolled patients with treatment-naïve CLL/SLL and those previously treated but were BTK inhibitor-naïve.

The study met its primary endpoint of non-inferiority on overall response rate (ORR) as assessed by an independent review committee (IRC) in both the pre-treated and intent-to-treat populations.

ORR favored pirtobrutinib with a nominal P-value for superiority (p