* Novartis aims to challenge Roche's Ocrevus
* Says MS drug ofatumumab met study goals
* Analyst: direct comparison would be better (Adds shares, analyst comment, background)
By John Miller
ZURICH, Aug 30 (Reuters) - Swiss drugmaker Novartis on Friday stepped up its challenge to Roche's multiple sclerosis franchise, highlighting study results for its MS hopeful ofatumumab that could compete with its cross-town rival's drug Ocrevus.
Novartis said ofatumumab, already approved as Arzerra to treat leukaemia, reduced annual relapses better than Sanofi's Aubagio in two head-to-head late-stage studies against relapsing forms of MS (RMS). Detailed study results are due at an MS conference in Sweden next month.
Novartis said it plans to start asking health authorities for approvals by the end of the year.
Novartis shares rose 1.7% by 0845 GMT, compared with a rise of 0.5% in the European drugs sector index.
The company's real target with ofatumumab is Ocrevus, the $2.4 billion-per-year MS blockbuster that Roche has said is its most successful drug launch ever.
Ofatumumab and Ocrevus work similarly by targeting the immune system's B cells that damage nerve tissue, potentially putting the drugs on course for head-to-head competition when doctors choose which one to prescribe.
Novartis managers have highlighted ofatumumab's prospects against Ocrevus, pointing to its monthly home injections as a convenient option for patients who with Ocrevus get twice-yearly infusions at clinics.
"If approved, ofatumumab will potentially become a treatment for a broad RMS population and the first B-cell therapy that can be self-administered at home," said Novartis. The company is also repurposing Arzerra for MS as it seeks to strengthen its neurological drugs business, which already includes older MS drugs Gilenya and recently approved Mayzent.
Across the Rhine River from Novartis's Basel campus, Roche drugs division head Bill Anderson has countered Novartis's ofatumumab offensive, saying rivals' attempts to move in on the MS drugs market had only boosted its own sales, helping it to capture a 17% market share.
Anderson has said that since Novartis's Mayzent launch in March, Ocrevus has actually gained market share.
Zuercher Kantonalbank analysts highlighted Novartis's progress in advancing an Ocrevus rival, but also saw shortcomings.
They pointed out that the studies compared ofatumumab not to Roche's drug, but to Sanofi's Aubagio, whose annual sales after seven years on the market are 1.65 billion euros ($1.84 billion).
"It would have been better to see a direct comparison between two MS drugs with the same mechanism of action," ZKB's Michael Nawrath wrote. "As it stands, we'll only be able to make an indirect comparison of the data to predict whether the Novartis drug will be a threat to the market leader and, at this time, the best MS medicine, Ocrevus."
Nawrath rates Novartis "overweight."
In addition to relapsing MS, Ocrevus is the only approved treatment for primary progressive MS characterised by steady advance of debilitating symptoms, rather than periodic flare-ups.
($1 = 0.8973 euros) (Reporting by John Miller; Editing by Michael Shields and Jane Merriman)