Clinical stage biotechnology company Prothena Corp. tapped a Silicon Valley team from Latham & Watkins to guide it through a $600 million collaboration agreement with Swiss giant Roche, the company announced Wednesday.

The transaction marks Latham’s second such deal in a month. A team also led by Menlo Park-based corporate partner Judith Hasko helped OncoMed Pharmaceuticals ink a $177 million development agreement with Celgene Corp in November.