The drug and the signal

Rosiglitazone (Avandia), a thiazolidinedione insulin sensitizer, was one of the most commercially successful diabetes drugs ever launched. By 2006, it generated approximately $3.2 billion in annual revenue for GlaxoSmithKline. It was effective at lowering HbA1c and represented a mechanistically distinct approach to type 2 diabetes management.

In May 2007, Steven Nissen and Kathy Wolski published a meta-analysis in the New England Journal of Medicine combining data from 42 clinical trials. The analysis reported a statistically significant 43% relative increase in the risk of myocardial infarction and a non-significant 64% increase in cardiovascular death among patients randomized to rosiglitazone compared to controls.

The publication triggered immediate and intense scientific, regulatory, and political consequences.

The debate

The Nissen meta-analysis was methodologically controversial. Critics argued that combining heterogeneous trials with different comparators, durations, and patient populations introduced significant bias. The original trials were not designed or powered to detect cardiovascular events. Event ascertainment was inconsistent across studies.

GSK's RECORD trial — a prospective, randomized cardiovascular outcome study — was ongoing at the time of the meta-analysis. Interim data suggested the cardiovascular risk was less clear than the meta-analysis implied. The final RECORD results, published in 2009, showed a hazard ratio for cardiovascular hospitalization or death of 0.99, with confidence intervals that neither confirmed nor refuted the meta-analysis findings.

The FDA convened advisory committee meetings in 2007 and 2010. The panels were deeply divided. The 2010 vote resulted in a narrow decision to restrict rosiglitazone access through a REMS program rather than withdraw the drug — a regulatory middle ground that satisfied neither the drug's defenders nor its critics.

The lasting impact

In 2008, the FDA issued guidance requiring that all new drugs for type 2 diabetes demonstrate cardiovascular safety through dedicated cardiovascular outcome trials before and after approval. This guidance — a direct consequence of the rosiglitazone controversy — transformed diabetes drug development globally.

The requirement produced a generation of landmark cardiovascular outcome trials (EMPA-REG OUTCOME, LEADER, SUSTAIN-6, DECLARE-TIMI 58) that paradoxically revealed unexpected cardiovascular benefits of SGLT2 inhibitors and GLP-1 receptor agonists — benefits that would never have been discovered without the regulatory requirement born from the Avandia controversy.

In 2013, the FDA partially lifted rosiglitazone restrictions after re-evaluating the RECORD data. The drug remains available but is rarely prescribed. Its legacy, however, reshaped the entire regulatory approach to metabolic drug development.