(Reuters) - Switzerland’s Roche has a potential new multi-billion-dollar drug to help it diversify beyond cancer treatments following the success of ocrelizumab against a hard-to-treat type of multiple sclerosis.

The logo of Swiss pharmaceutical company Roche is seen outside the Shanghai Roche Pharmaceutical Co. Ltd. headquarters in Shanghai May 22, 2014. REUTERS/Aly Song

The injectable antibody medicine is the first product to show positive study results in both the progressive form of the disease and more common relapsing forms, which analysts believe should make it a compelling treatment for doctors.

Deutsche Bank’s Tim Race said the surprise success in primary progressive multiple sclerosis (PPMS) suggested the drug could generate annual sales of around $5 billion.

That is well above current consensus forecasts of $720 million in 2020, according to Thomson Reuters Cortellis.

Chief Executive Severin Schwan had told Reuters in an interview earlier this month that ocrelizumab’s success in relapsing multiple sclerosis (MS) already made it a “huge opportunity” and a positive result in PPMS would be “pure upside”.

The drugmaker now plans to file for regulatory approval for both forms of MS in early 2016, implying ocrelizumab could reach the market around a year later.

Results from a pivotal Phase III study of the drug in PPMS showed that treatment with ocrelizumab significantly reduced the progression of clinical disability and the effect was sustained for at least 12 weeks.

The incidence of serious adverse events associated with ocrelizumab, including serious infections, was also similar to placebo.

Safety is crucial to success. Because MS is caused by abnormal immune system attacks on the protective sheath surrounding nerve cells, treatments need to adjust the body’s immune response, which can lead to dangerous side effects.

CROWDED MARKET

The current market for MS drugs is worth around $20 billion a year, derived from the approximately 85 percent of MS patients with relapsing disease.

Multiple treatments are already available, ranging from long-established interferons such as Merck KGaA’s Rebif, through new tablets including Novartis’ Gilenya and Biogen’s Tecfidera, and potent injectables such as Biogen’s Tysabri and Sanofi’s Lemtrada.

Roche, however, is confident its new drug has a better balance of efficacy and safety than rivals.

Ocrelizumab is delivered twice-yearly via an intravenous drip. As an antibody-based medicine it is likely to be expensive but Roche, the world’s biggest cancer drugs company, has not yet given any indications on price.

Preliminary data from the PPMS clinical trial will be presented at the annual congress of the European Committee for Treatment and Research in Multiple Sclerosis on Oct. 10.

Roche shares rose 2 percent by 0800 GMT. The group also reported results at the weekend for its new immunotherapy drug atezolizumab in lung and bladder cancer, which may help it win quick regulatory approval.