Balleny (right), a life science specialist, joins as a partner and brings with her Lucy Sewter, a legal executive.
The firm acts for big pharma companies including Novartis and Johnson & Johnson, as well as growing companies such as Gilead, Shire and Vertex.
The appointment comes after the firm recently launched an IP litigation practice with the hiring of Ian Kirby and Jonathan Day from Arnold & Porter. It is one of several patent attorney firms to develop integrated practices ahead of the launch of the Unitary Patent and Unified Patent Court.
Balleny has been a partner of Pinsent Masons for four years, and was previously at Arnold & Porter. Sewter led the IP litigation support team at Pinsent Masons.