(Bloomberg) -- Swiss drugmaker Roche Holding AG said its blood cancer medicine Gazyva failed to show a significant improvement over its best-seller Rituxan, a setback in efforts to defend the ageing drug blockbuster against copycats.

In an advanced study called Goya, Gazyva didn’t significantly reduce the risk of disease worsening or death in people with previously untreated diffuse large B-cell lymphoma compared with Rituxan, Roche said in a statement Monday.

While most analysts didn’t expect the trial to succeed, “this is still a disappointment for Roche,” Alistair Campbell and colleagues at Berenberg Bank in London wrote in a note. “A success in Goya would have completed the last piece of the puzzle in terms of protecting Rituxan from biosimilars in oncology.”

Roche shares fell as much as 2.2 percent to 250.10 Swiss francs in Zurich trading.

“We will continue to analyze the Goya data to better understand the results, and to study other investigational treatments in this disease with the goal of further helping these patients,” Sandra Horning, Roche chief medical officer and head of global product development, said in the statement.

To contact the reporter on this story: James Paton in Sydney at To contact the editors responsible for this story: Chitra Somayaji at, Marthe Fourcade

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