Jimenez has been CEO since 2010, although he has been with the company for a decade. He will step down at the end of January and remain available for advice until his official retirement at the end of August 2018. He will then return home to Silicon Valley.

Narasimhan, who is currently Novartis’s global head of drug development and chief medical officer, has been with the company since 2005 and is already on its executive committee. Unlike Jimenez, who started his career in consumer goods, Narasimhan is a physician.

“During his tenure, Joe focused Novartis on leading global businesses, while divesting non-core divisions,” Novartis chairman Joerg Reinhardt said in a statement, referring to Jimenez’s decision to offload the company’s animal health business to Eli Lilly and its vaccines and over-the-counter drugs businesses (the latter through the formation of a joint venture) to GlaxoSmithKline.

Get Data Sheet, Fortune’s technology newsletter.

The news comes days after Novartis scored approval from the U.S. Food and Drug Administration (FDA) for Kymriah, a form of gene therapy that treats leukemia by training the patient’s immune cells to target the blood cancer. A course of the treatment costs $475,000, although Novartis doesn’t get reimbursed unless the patient responds to the treatment within a month.

Along with the introduction of other new drugs such as psoriasis treatment Cosentyx, Novartis is hoping that Kymriah will help turn things around after the patent protections expired for its Gleevec cancer drug and Gilenya multiple sclerosis treatment, opening the door to cheaper competitors.

“Under [Jimenez’s] leadership the innovation pipeline was rejuvenated, and we successfully navigated the patent expirations of our two largest products,” Reinhardt said. “We anticipate a smooth transition as Joe built a strong leadership team and mentored his successor.”