PHILADELPHIA (June 5, 2025) — Patients with metastatic colorectal cancer who were treated with a biweekly dose of trifluridine-tipiracil (TAS-102) saw similar treatment effectiveness and reduced toxicity compared with treatment using standard dosing schedules, according to a recent study in The Oncologist that was co-authored by a Fox Chase Cancer Center physician.
TAS-102, also known by the brand name Lonsurf, is a chemotherapy drug used to treat metastatic colorectal cancer in patients whose cancer is resistant to first- and second-line therapies and who cannot be treated with surgery. The standard treatment schedule is twice daily dosing on days 1 through 5 and then again on days 8 through 12 of a 28-day chemotherapy cycle.
“We’ve seen that this typical dosing schedule frequently causes significant bone marrow suppression, and patients often require dose reductions or treatment delays to recover. In other cases, patients have to use a medication called G-CSF, which helps to increase white blood cell counts. Use of this medication, however, can also cause side effects such as bone pain and other more serious complications,” said Christopher G. Cann, MD, lead author on the study and Assistant Professor in the Department of Hematology/Oncology at Fox Chase.
The retrospective study, which Cann conducted with researchers from several other institutions, is the first of its kind in the United States. The researchers examined 61 patients with metastatic colorectal cancer who were treated with a biweekly dose of TAS-102. Treatment on this new schedule began on days 1 through 5 and continued on days 15 through 19 within a 28-day cycle.
The study found that the alternative biweekly dosing not only remained effective at treating colorectal cancer, but also resulted in less treatment-related bone marrow suppression and dose delays overall compared to patients given standard dosing. Additionally, no patients treated with biweekly dosing required the use of G-CSF or developed neutropenic fever, which can be life threatening.
“These findings provide us an alternative way to dose chemotherapy that maintains efficacy but reduces the toxicity of the treatment,” said Cann. “This dosing schedule may be most useful for older patients or patients who have developed chemotherapy related toxicities. This schedule also allows us to combine TAS-102 with other effective chemotherapies more easily due to reduced toxicity.”
Cann said that although the results of the study are promising, additional prospective, multicenter data will be required to further validate findings and expand the use of biweekly dosing schedules for TAS-102.
The study, “Biweekly Dosing of TAS-102 Reduces Rates of Myelosuppression While Maintaining Efficacy in Patients with Metastatic Colorectal Cancer,” was published in The Oncologist.