U.S. payers are unlikely to start covering only 6 months of trastuzumab unless the drug’s label is changed based on new data or clinical practice guidelines begin to endorse that shorter duration, according to Dr. Schilsky. “Until one of those things occurs, there is not really a rationale for a payer to mandate that a physician undertake a course of treatment that they may not think is in the patient’s best interest,” he elaborated.
As roughly 12% to 15% of women with early breast cancer have HER2+ disease, the PERSEPHONE findings could have considerable implications for treatment costs, noted Bruce E. Johnson, MD, FASCO, president of ASCO.
However, longer follow-up will be needed before any change to the standard is made, he agreed. “One has to be circumspect about how long you wait and how much more data one has before making a definitive statement. With 8% deaths and 12% recurrences, it may be a bit early to make a definite change in practice.”
While important, the more favorable safety of the 6-month therapy is not sufficient, according to Dr. Johnson, who is also a professor of medicine at the Dana-Farber Cancer Institute and a leader of the Dana-Farber/Harvard Cancer Center Lung Cancer Program, both in Boston. “In my opinion, the efficacy drives most of the therapeutic decision making. We are encouraged by this, and 5-year follow-up is certainly a reasonable initial step. But to be sure of the efficacy, you probably need a bit more time and a few more events,” he explained.