The health ministry said Tuesday it has attributed 13 deaths to use of the anticancer drug gefitinib.
The ministry said 26 terminally ill cancer patients developed interstitial pneumonia and other side effects after being administered the drug, with half of them dying.
“The rate of side effects is not as high as those of other anticancer drugs, but the mortality rate is higher,” Shoji Kudo, a professor at Nippon Medical School, said at a news conference at the ministry.
The drug, which received expedited approval because of its reported benefits for people with progressive cancer, is manufactured and sold by AstraZeneca Pharmaceuticals LP of the United States under the name Iressa.
The ministry ordered the manufacturer Tuesday to issue an emergency advisory to alert medical institutions.
Gefitinib targets molecules and prevents the functions of receptors linked with cancer-cell multiplication.
The ministry approved the drug about five months after an application to import the drug was filed in January, an unusually speedy process for the ministry.
The drug has so far been approved only in Japan but is expected to be approved soon in the U.S. and Switzerland.
According to the ministry, a number of terminally ill cancer patients in their 40s and older developed interstitial pneumonia and other side effects over a period of about three months since the drug became available in mid-July.
The manufacturer, AstraZeneca, said about 7,000 people have so far used the drug.
Clinical data have shown that between 0.2 percent and 0.4 percent of those who took the drug developed acute lung injury and interstitial pneumonia. AstraZeneca has listed interstitial pneumonia as one possible side effect on the drug’s usage guidance.