Onyx Pharmaceuticals Inc. reported that an experimental drug cafilzomib showed a response in a quarter of patients with advanced multiple myeloma whose condition could not be treated with other therapies.

Multiple myeloma is a lethal cancer caused by uncontrolled growth of blood plasma cells that can lead to bone tumors and affect the body’s ability to make infection-fighting cells.

Emeryville, California-based company Onyx researchers recruited 266 patients for the trial and found that 24 percent registered at least a partial response to the therapy, and their improvement lasted a mediam of 7.4 months.

Multiple myeloma is the second-most-common type of blood cancer with more than 50,000 people in the U.S. and 180,000 worldwide living with the disease, according to the company in a statement.“Despite recent advances in treating multiple myeloma, all patients eventually relapse,” said Michael G. Kauffman, Onyx’s chief medical officer, in the statement. “The unmet medical need remains great, as the outlook for patients with relapsed and refractory disease is grim.”