Roche Holding AG is seeking a partner with experimental drugs that might help repair the damage caused to the nervous system by multiple sclerosis — considered a key step in managing the debilitating disease.

The Swiss drugmaker wants to find “compelling science” in what’s called remyelination, or repairing the protective sheath around nerve cells, according to Sanjay Keswani, the Basel-based head of neuroscience, opthalmology and rare diseases at Roche’s pharma research and early development group. Roche also has its own portfolio of experimental remyelination compounds, though none have reached human trials.

The world’s biggest maker of cancer therapies aims to expand its portfolio of multiple sclerosis treatments to tap into a market that’s projected to grow to $24 billion by 2020. Roche won its foothold in March, when it won U.S. approval for Ocrevus, a potential blockbuster that’s likely to be the only option for patients with a particular form of MS. In remyelination, Roche will have to catch up with Biogen Inc., which is already conducting human tests on its drug candidate.

“Frankly, we are currently looking at everything,” Keswani said in an interview on Tuesday. “What’s important for us is something that gets across the blood-brain barrier” and thus ensures a high concentration of the potential drug gets into the central nervous system, he said.