ICG won the work through a competitive pitch. The win follows the appointment of John Higginson from Westbourne, who heads up ICG's corporate comms practice.
ICG will provide comms support to the company's diagnostic business focusing on pathology services, cancer and heart disease.
Neil Gadhok, ICG associate director, will lead the account team. He said: "We are thrilled to be working with the number one provider of diagnostic solutions to the NHS. Pathology and diagnostics are a vital part of the patient pathway as well as a key piece in the NHS sustainability jigsaw. This is a substantial win for our growing media relations practice."
ICG will report to Roche Diagnostics' comms manager Juliet Scott, who added: "The ICG team really shone with its understanding of our business and the media landscape. We look forward to working with it to raise awareness of the value of diagnostics."