Amgen Inc and Allergan Plc said a late-stage study showed their biosimilar candidate for a type of lung cancer was as effective as Roche AG's Avastin in preventing disease progression and improving survival.

Avastin is Roche's best-selling cancer drug, raking in about $6.5 billion in sales last year.
The arrival of biosimilars - copied versions of complex biotech drugs - represents a threat to companies such as Roche.

The U.S. Food and Drug Administration approved the country's first biosimilar, Novartis AG's white blood cell-boosting Zarxio, in March.

The drug went on sale earlier this month after Amgen, the owner of the original drug, failed to stop its launch by filing several lawsuits.

If approved, the Amgen-Allegan drug, ABP 215, would be Amgen's first biosimilar on the market. The company has eight others in development.