EpiPen, a life-saving allergy treatment widely criticized for its high price tag, will get generic competition for the first time since the autoinjector was approved more than two decades ago.

The Food and Drug Administration on Thursday cleared Teva Pharmaceutical Industries Ltd.’s generic EpiPen and EpiPen Jr. for sale, several years after the Israeli drugmaker filed for approval. Mylan NV has attempted to thwart competition from Teva, claiming that differences in how the epinephrine-injecting devices work would confuse patients. While Teva’s device isn’t identical to the EpiPen, it will be fully substitutable at the pharmacy, the FDA said.

Mylan once took in about $1 billion a year in EpiPen sales, and before Thursday’s action it faced little direct competition. Teva’s American depositary receipts rose 6.9 percent to $24.03 at 2:33 p.m. in New York. Mylan fell 0.1 percent to $37.77.

Read more at Bloomberg.