Eli Lilly’s Most Consequential Weekend: New Mounjaro Data Meets a $3.8 Billion Vaccine Pivot

Eli Lilly closed last week with a flurry of news that turned the stock into a tale of two catalysts. On Friday, the company published long-awaited Phase 4 data for Mounjaro showing a decisive advantage over standard therapy in early-stage Type 2 diabetes. By the same bell, it had also announced a multi-billion-dollar push into vaccines, settled a Medicaid rebate dispute at the Supreme Court, and secured a critical coverage win for its obesity franchise. The shares slipped 2.03 percent to €948.40, but the pullback looks more like a breather after a 30.06 percent monthly rally.

The Phase 4 SURPASS-EARLY trial, published in Annals of Internal Medicine, followed 794 adults across 78 centers in ten countries, all diagnosed with Type 2 diabetes for no more than four years and inadequately controlled on diet, exercise and metformin. Over two years, tirzepatide cut HbA1c by 1.99 percentage points, compared with 1.32 points for intensified conventional therapy — a statistically significant difference of 0.68 points (P < 0.001). Patients on the drug also shed 8.0 kilograms more in body weight and lost 6.2 centimeters more from their waistlines. Perhaps most striking: 60.2 percent of those on tirzepatide achieved normoglycemia (HbA1c below 5.7 percent), versus just 24.0 percent in the control arm. Gastrointestinal side effects were the most common complaint in both groups.

The timing is deliberate. From June 5 to 8, Lilly will present fresh data at the American Diabetes Association’s 86th Scientific Sessions in New Orleans, covering Foundayo, Mounjaro and the next-generation incretin retatrutide. A management investor event is scheduled for June 6 at 6:00 p.m. CDT. With Phase 3 results from the ACHIEVE program and head-to-head comparisons on the agenda, the ADA week represents a concentrated catalyst window for the GLP-1 story.

Yet while diabetes and obesity remain the headline act, Lilly is quietly building a second revenue engine. This week the company announced it will spend up to $3.83 billion to acquire three vaccine specialists. The largest deal — up to $1.55 billion — targets a nanoparticle-based jab for the Epstein-Barr virus from Vaccine Company. A second, worth up to $1.5 billion, buys Curevo’s shingles vaccine amezosvatein, currently in Phase 2. The third, up to $780 million, takes LimmaTech Biologics’ bacterial vaccines, including LTB-SA7 against Staphylococcus aureus. The moves shift Lilly’s narrative from a pure-play metabolic powerhouse toward a broader portfolio in prevention.

Should investors sell immediately? Or is it worth buying Eli Lilly?

Juxtaposed against that expansion, a legal setback on Friday hardly dented confidence. The U.S. Supreme Court upheld a $220 million judgment against Lilly over Medicaid rebate calculations — a manageable sum for a company sitting on a cash pile fueled by Mounjaro and Zepbound. Far more consequential was the news that CVS Caremark will reinstate Zepbound on its formulary starting October 1, 2026, and add Foundayo to its preferred drug list from June 1, 2026. With all three major pharmacy benefit managers now covering Lilly’s full obesity portfolio, access barriers in the U.S. are melting away.

The financials underpin the bullish mood. First-quarter 2026 revenue surged 56 percent to $19.8 billion, topping the 55.5 percent growth some models had penciled in. Adjusted earnings per share hit $8.55, well above the $6.97 consensus. Mounjaro alone generated $8.7 billion in sales, up 125 percent, while Zepbound contributed $4.2 billion, an 80 percent increase. Together, the two GLP-1 drugs accounted for $13.4 billion. Management now guides for full-year revenue of $82.0 billion to $85.0 billion.

With the stock trading 76.61 percent above its 52-week low of €537.00 and just 2.03 percent below the record high of €968.10 hit on Wednesday, the relative strength index stands at 72.4 — edging into overbought territory. Chart watchers in the U.S. see support near $999.66 and resistance around $1,150. A dividend payment of $1.73 per share is due June 10.

Lilly enters ADA week with the wind at its back: compelling new efficacy data, a vaccine pipeline that adds long-term optionality, and improving U.S. reimbursement for its blockbuster weight-loss drugs. Whether the next few days stretch the multiple further will depend on how much of this story investors have already priced in.