ZURICH (Reuters) - More than 90 percent of young people with a deadly form of blood cancer showed complete remission after getting a new Novartis therapy, mirroring findings from previous smaller samples and buoying the drugmaker's hopes for U.S. approval in 2017.

The findings, from a study of Novartis's CTL019, a chimeric antigen receptor T cell, or CART, therapy, included 59 children and young adults with relapsed/refractory acute lymphoblastic leukemia, the Swiss company said on Monday on the sidelines of the American Society of Hematology conference in Orlando.

The ongoing Phase II study is on patients with advanced disease, who have not responded to standard treatment.

The findings show 93 percent initially had complete remission, Novartis said, while 55 percent had remission-free survival at 12 months. After 12 months, 18 patients had ongoing complete remission.

The cancer, caused by uncontrolled production of immature white blood cells, can cause death within a year of diagnosis.

Remission-free survival rates released Monday are comparable with earlier findings with only half as many patients, said Usman Azam, Novartis' global head of cell & gene therapies, increasing his optimism for a CTL019's regulatory submission in 2016 and U.S. approval the year after, with Europe to follow.

"This data set continues to impress everybody even more than before," Azam said. "It gives us greater confidence at Novartis that this is the right population that can really, really benefit."

Nearly 90 percent of the patients developed an inflammatory response common with such treatments that includes high fever, nausea and muscle pain. Just over a quarter required treatment for blood flow or respiratory instability, which Novartis said it successfully reversed in all cases.

CART therapies are made by extracting immune system T cells from a patient, re-engineering their DNA to help them spot and destroy cancer cells, and infusing them back into the same patient.

With its CTL019, Novartis has joined smaller rivals including Juno Therapeutics and Kite Pharma seeking to launch new, more-effective -- and likely very expensive treatments -- for blood cancers like leukemia.

While Novartis declines to say what CTL019 could cost, a U.S. bone-marrow transplant running between $500,000 and $1 million is a reference point as it develops the therapy.

"What we're doing on the price front is we're working extremely closely with every stakeholder," Azam said. "These are highly challenging and highly difficult therapies to manufacture and make, so we are spending a lot of time in how do we simplify manufacturing, how do we make this accessible."

(Reporting by John Miller, editing by David Evans)