SAN DIEGO Dec 3 (Reuters) - Amgen Inc, updating the first trial of its bispecific antibody for multiple myeloma, on Monday said seven out of ten patients given the second-highest dose of AMG420 responded to the drug, including four with no detectable cancer.
Six patients were still responding at 7.5 months of follow-up, according to research presented in San Diego at the annual meeting of the American Society of Hematology.
Amgen also said that AMG420, which targets a protein linked to multiple myeloma known as BCMA, has been given fast track status by the U.S. Food and Drug Administration.
"Based on these data, we plan to open an expanded trial," David Reese, Amgen's head of research and development, said in an interview. "We want to begin exploring quickly enrollment in earlier lines of therapy."
The Amgen bispecific antibody is designed to attach to a cancer cell and an immune cell, bringing them together so the body's immune system can kill the cancer.
Other companies are exploring different ways to attack the same BCMA target, including bluebird bio Inc and Johnson & Johnson.
Earlier at the ASH meeting, bluebird and partner Celgene Corp presented early trial data showing that experimental cell therapy bb21217 induced responses in 10 out of 12 heavily pretreated myeloma patients.
Bb21217 is a next generation version of bb2121, the companies' more advanced, but still experimental therapy in a class called CAR-T that requires harvesting a patient’s own disease-fighting T-cells, modifying them in a laboratory so they target specific proteins on cancer cells and infusing them back into the patient. The manufacturing process for bb21217 is designed to improve the persistence of the altered cells.
Amgen has suggested the "off the shelf" nature of its antibody could be an advantage from both a clinical and commercial standpoint, but oncologists say more data is needed.
Trial patients are hospitalized for their first cycle of AMG420, after which they receive the drug by continuous 24-hour infusion for four weeks, followed by two weeks off therapy, for up to 10 cycles.
Amgen is working on another BCMA-targeting antibody that would last longer in the body, requiring less frequent infusions, but that research is at an earlier stage.
In the current study, 42 patients with multiple myeloma that worsened after at least two prior treatments were given AMG420 at varying doses - the highest dose was discontinued due to toxicity. A total of 13 patients responded to the treatment, including seven who achieved remission.
Serious side effects included nerve damage, infections, and liver failure. Of the 20 patients with serious adverse events, 17 required hospitalization and four had prolonged hospitalization. (Reporting By Deena Beasley Editing by Susan Thomas)