* Canakinumab promises new way to fight heart attack risk
* Drug already approved as Ilaris for rare diseases
* Heart disease offers potential multibillion-dollar sales
* Boosts pipeline hopes, two days after good eye drug data (Adds analyst comments, details throughout, updates shares)
ZURICH/LONDON, June 22 (Reuters) - A Novartis anti-inflammatory drug cut cardiovascular risk for heart attack survivors in a pivotal trial, potentially changing ideas about treatment.
Canakinumab, already approved as Ilaris for rare autoimmune conditions, was also found to reduce further heart attacks or strokes, when used with current therapies, the Swiss drugmaker said on Thursday, boosting its share price.
The drug targets inflammatory atherosclerosis, where inflammation aggravates risks posed by clogged arteries.
Industry analysts said Thursday's announcement was unexpected, in part because GlaxoSmithKline's pursuit of anti-inflammatory approaches to heart risks with its experimental darapladib failed in 2013. Consequently, cholesterol-lowering strategies have remained the mainstay.
Baader Helvea analyst Bruno Bulica said Novartis's findings were "a ground-breaking discovery likely to transform the therapeutic paradigm". The result also boosts market confidence in Novartis's ability to revive sales growth from 2018.
Novartis shares rose more than 3 percent as the company said it would initiate discussions with regulatory authorities over approval. Novartis hopes to present trial data at the European Society of Cardiology Congress in late August.
"Sales estimates for Ilaris are going to have to be raised considerably," said Michael Nawrath, a Zuercher Kantonalbank analyst.
Bank Vontobel raised its estimate for the drug's chances of eventually hitting $2 billion in peak sales to 60 percent, up from 30 percent.
Because canakinumab works differently than existing drugs given after a heart attack, such as cholesterol-lowering statins or blood-thinners, it could be given on top of standard medicines.
Still, uncertainties linger about its clinical profile, pending presentation of full data, as well as the potential response from customers.
With Entresto, for instance, the heart failure drug that Novartis launched in 2015, uptake was initially sluggish despite stellar trial findings, amid resistance over the price of the drug and doctors' reluctance to switch patients who were stable on older drugs.
Combined, canakinumab and Entresto could help rejuvenate Novartis's leadership on heart disease, a role it relinquished after its blockbuster Diovan lost patent protection in 2012.
As a new injection, canakinumab will be much more expensive than generic cholesterol and blood-thinning pills, and the recent record with the new class of PCSK9 cholesterol injections from companies including Amgen and Sanofi suggests high prices can hinder uptake.
"We need to be careful before becoming too enthusiastic," Deutsche Bank's Tim Race said. "Canakinumab is an expensive injection and faces uptake hurdles."
Ilaris costs some $200,000 annually for treating rare diseases, according to Bernstein's Tim Anderson. But even at $15,000 per year -- the ballpark for PCSK9 cholesterol injections -- its potential for some 4 million eligible heart patients could still be substantial.
"The bottom line is that this could end up becoming a multi-billion dollar product," Anderson said.
The heart drug news comes just two days after Novartis reported positive results with another experimental drug for neovascular age-related macular degeneration, a leading cause of vision loss. (Reporting by John Miller and Ben Hirschler, editing by Michael Shields and Elaine Hardcastle)