The company carried out the worldwide Phase III RECOURSE trial in 800 patients who were earlier treated for mCRC. It met the primary efficacy endpoint of statistically significant improvement in overall survival (OS) compared to placebo.
Taiho Oncology claimed that the risk of death was reduced by 32% when compared to placebo. Median OS was 7.1 months and 5.3 months for Lonsurf and placebo, respectively.
Taiho said Lonsurf caused severe and life-threatening myelosuppression, featuring anemia (18%), neutropenia (38%), thrombocytopenia (5%), and febrile neutropenia (3.8%).
The company noted that patients should obtain complete blood counts before and on day 15 of each cycle of Lonsurf.
In March last year, Lonsurf was approved in Japan for treating unresectable advanced or recurrent colorectal cancer.
Taiho Oncology president and CEO Eric Benn said: "Patients with metastatic colorectal cancer, whose disease has progressed after treatment with standard therapies, have had limited therapeutic options to treat their disease.
"Lonsurf helps address this unmet medical need by providing patients with a new therapeutic option that can help extend their overall survival. As the first FDA approval for Taiho Oncology, Lonsurf also represents a major milestone for our company."
Taiho said colorectal cancer is the third most common type of cancer and is the second leading cause of cancer-associated deaths in the US.
Last year, there were an estimated 136,830 patients diagnosed with cancer of the colon or rectum in the US.