News Releases

Taiho Pharmaceutical Co., Ltd. (HQ: Tokyo, President: Masayuki Kobayashi) announced today that the Japan Clinical Cancer Research Organization (JACCRO), a specified non-profit corporation, has published a summary of the results of the Phase III clinical trial (JACCRO GC-05) of TS-1 on patients with unresectable or recurrent gastric cancer that is refractory to initial TS-1 therapy. JACCRO is the organization that was contracted to conduct the trial.

The objective of this trial was to investigate whether the combination therapy of TS-1+CPT-11 is superior to CPT-11 monotherapy as a second-line therapy (excluding patients whose cancer recurred after postoperative TS-1 adjuvant therapy) for patients with unresectable or recurrent gastric cancer that was refractory to initial TS-1 monotherapy or the combination therapy of TS-1 and another drug (except for combination therapy with CPT-11 [irinotecan]).

This trial was unable to statistically verify the superiority of TS-1+CPT-11 combination therapy over CPT-11 monotherapy in terms of survival. Furthermore, the trial showed that the TS-1+CPT-11 combination therapy had a higher frequency of leucopenia, neutropenia, and febrile neutropenia of Grade 3 or higher as defined in the Common Terminology Criteria for Adverse Events (CTCAE) than did CPT-11 monotherapy. JACCRO plans to further investigate the data and make a detailed announcement of the results at a medical conference in 2014.

Taiho Pharmaceutical maintains its ongoing commitment to develop new cancer treatments.

JACCRO website: http://www.jaccro.com (Japanese only)

A member of the fluoropyrimidine class of chemotherapeutic agents, TS-1 is a combination of three pharmacological compounds: tegafur, an antimetabolite agent that, after absorption, is converted into the anticancer agent fluorouracil (5-FU); gimeracil (5-chloro-2, 4-dihydroxypyridine, or CDHP), which decreases the degradation of 5-FU in the liver; and oteracil potassium (Oxo), which decreases 5-FU phosphorylation in the gastrointestinal tract. Developed as a gastric cancer treatment, TS-1 was first approved in Japan in 1999 and has become a standard of care for the treatment of gastric cancer. TS-1 was subsequently approved in Japan for six additional indications: for the treatment of colorectal, head and neck, non-small cell lung, and inoperable or recurrent breast, pancreatic, and biliary tract cancers. TS-1 is also approved for patients with gastric cancer in 7 countries and regions in Asia, and in 15 European countries.

This trial was conducted by JACCRO under contract with Taiho Pharmaceutical. Over 60 medical facilities participated, and data was collected from a total of 304 subjects. The subjects were patients with unresectable or recurrent gastric cancer that was shown to be refractory to TS-1 monotherapy or a combination therapy of TS-1 and another drug (except for combination therapy with CPT-11). They were assigned to either CPT-11 monotherapy group or TS-1+CPT-11 combination therapy group and compared. Overall survival, progression-free survival, antitumor effect, and safety were evaluated. The CPT-11 monotherapy group was administered CPT-11 intravenously once per day in dosages of 150 mg/m² in repetitive two-week schedules. The TS-1+CPT-11 combination therapy group was administered CPT-11 intravenously once per day in a dosages of 150 mg/m² and TS-1 orally in dosages determined by each patient's body surface area (80 mg, 100 mg, 120 mg/day) twice per day for 14 consecutive days with seven days of rest in each three-week course. Administration was continued in both groups until the subjects met the established criteria for cessation.