Overview: What the ACHIEVE-4 Trial Means
The Phase 3 ACHIEVE-4 trial is the largest and longest study of Foundayo in type 2 diabetes to date. It enrolled over 2,700 participants across 15 countries and compared Foundayo against insulin glargine in adults with type 2 diabetes who were overweight or obese and faced elevated cardiovascular risk. The results, released on April 16, 2026, mark a turning point. They provide exactly the safety data the FDA requested after approving Foundayo for obesity — and they open the door to a diabetes label expansion later this quarter.
FDA Safety Concerns Behind the Trial
The FDA’s approval of Foundayo for chronic weight management came with strings attached. In its approval letter, the agency noted that existing data were insufficient to fully characterize several potential risks linked to orforglipron. Specifically, the FDA flagged concerns around major adverse cardiovascular events (MACE), drug-induced liver injury (DILI), delayed stomach emptying, and long-term thyroid cancer risk. The agency also asked Lilly to gather at least 15 years of data on thyroid cancer — consistent with the boxed warning that injectable GLP-1 therapies such as Wegovy and Zepbound already carry.
Unlike Novo Nordisk’s oral Wegovy, which uses semaglutide — an ingredient approved since 2017 — Foundayo is built on a brand-new active ingredient. That distinction is central to the FDA’s caution. Because orforglipron lacks the long safety track record of existing molecules, the agency requested a series of post-approval studies before it would feel fully assured of the drug’s risk profile.
Key Cardiovascular and Mortality Findings
ACHIEVE-4 met its primary endpoint. Foundayo demonstrated non-inferior cardiovascular risk compared to insulin glargine, with a 16% relative reduction in the composite endpoint of cardiovascular death, heart attack, stroke, or hospitalization for unstable chest pain (hazard ratio: 0.84; 95% CI: 0.59 to 1.20). That result crossed the prespecified non-inferiority threshold. Moreover, a pre-planned analysis found Foundayo associated with a 57% lower risk of all-cause death compared to insulin glargine (hazard ratio: 0.43; 95% CI: 0.25 to 0.75). Lilly acknowledged the all-cause mortality finding was not adjusted for multiplicity.
Additionally, participants on Foundayo saw A1C levels drop by 16% compared to insulin glargine, and body weight fall by 8.8% versus a 1.7% increase in the insulin group at 52 weeks. These figures demonstrate meaningful benefit across blood sugar control and weight management — two pillars critical for managing type 2 diabetes effectively.
Liver Safety: Clearing a Critical Hurdle
Perhaps the most closely watched element of ACHIEVE-4 was its liver safety data. The FDA had listed drug-induced liver injury as a specific concern that required clinical trial evidence — not observational data — to resolve. The trial delivered a clear result: no signs of DILI were detected across the study population. Lilly noted this finding aligns with results across its other Foundayo trials.
Thomas Seck, Lilly’s senior vice president of cardiometabolic product development, put it plainly: across seven Phase 3 studies enrolling more than 11,000 patients, Foundayo has demonstrated a consistent safety and efficacy profile. ACHIEVE-4, he said, adds a new dimension — cardiovascular safety data and a lower observed risk of all-cause death in patients who carry elevated cardiovascular risk.
Diabetes Filing: Lilly’s Next Move
Lilly has confirmed plans to submit Foundayo for a type 2 diabetes indication to the FDA before the end of Q2 2026. The filing will rely on the Commissioner’s National Priority Review Voucher program — the same mechanism the company used to accelerate Foundayo’s obesity approval. That program, launched in 2025, targets medicines deemed to address critical national health priorities. It offers rolling review and enhanced agency communication to shorten the approval timeline to approximately two months.
If the diabetes filing succeeds, Foundayo would become a once-daily oral pill alternative to injectable insulin for patients with type 2 diabetes. Notably, it carries a key convenience advantage: it can be taken at any time of day without food or water restrictions.
How Foundayo Stacks Up Against Novo Nordisk
Foundayo and Novo Nordisk’s oral Wegovy (semaglutide) are now competing directly in the US oral GLP-1 market. Both drugs target obesity and are moving toward a diabetes label. However, their profiles differ in important ways.
Foundayo can be taken freely throughout the day. Oral Wegovy, by contrast, must be taken on an empty stomach in the morning with limited water intake. On pricing, Lilly has set a sliding-scale cash-pay rate of $149 to $349 per month, with a coupon that may reduce costs to as low as $25 for commercially insured patients.
Novo Nordisk counters by pointing to greater average weight loss (16.6% vs. Foundayo’s 12.4% in respective trials, though cross-trial comparisons have limitations). Novo also notes that oral Wegovy does not carry the restriction against concurrent use with oral contraceptives or the cholesterol-lowering drug simvastatin — a limitation that applies to Foundayo. Furthermore, injectable Wegovy already carries cardiovascular risk reduction on its label, giving Novo a head start in that narrative. ACHIEVE-4 data, if added to Foundayo’s labelling, could help Lilly close that gap.
What Comes Next for Foundayo
Lilly’s Q1 2026 earnings call on April 30 will likely shed light on Foundayo’s commercial rollout. Analysts at BMO Capital Markets have described the FDA’s post-approval safety requests as “manageable” and do not expect them to significantly affect the drug’s market trajectory.
Beyond diabetes, Foundayo is being studied for obstructive sleep apnea, osteoarthritis knee pain, hypertension, peripheral artery disease, and stress urinary incontinence. Lilly has also submitted orforglipron for weight management and/or type 2 diabetes in more than 40 countries, with launches planned after each regional approval.
Gastrointestinal side effects — nausea, vomiting, diarrhoea, and constipation — remain the most common adverse events. The 52-week discontinuation rate in ACHIEVE-4 reached 10.6%, mainly tied to these GI issues. Prescribers and patients should weigh these tolerability factors when considering Foundayo as a long-term option.
