Roche has acquired rights to an obesity therapy by Denmark's Zealand Pharma in a collaboration deal worth up to $5.3 billion, as the Swiss drugmaker seeks to boost its prospects in the booming weight-loss market.

The deal gives the Swiss pharma access to an experimental amylin-targeting treatment it will test in combination with drugs it acquired from Carmot.

Roche partnered with Zealand Pharma to license an experimental weight loss drug for $1.65 billion upfront, expanding its obesity pipeline.