(Adds background on other rival products)
June 15 (Reuters) - Adamis Pharmaceuticals Corp said on Thursday it received U.S. approval for its emergency epinephrine syringes to treat severe allergic reactions that would compete with Mylan NV's widely used EpiPen, sending its shares up more than 50 percent.
Adamis said the Food and Drug Administration also approved the brand name Symjepi. The company expects to begin selling the pre-filled syringes in the second half of this year.
Adamis did not disclose the price for a pair of Symjepi syringes and did not immediately respond to requests for pricing, but the product was expected to cost less than EpiPen.
Mylan has faced severe criticism and congressional and legal investigations after it doubled the cost for a pair of EpiPens to $600, enraging consumers. It has since offered its own generic version for about $300 in response to the furor.
"With an anticipated lower cost, small size and user-friendly design, we believe Symjepi could be an attractive option for a significant portion of both the retail (patient) and non-retail (professional) sectors of the epinephrine market," Adamis Chief Executive Dennis Carlo said in a statement.
Epinephrine is the life-saving recommended treatment for severe allergic reactions, such as to bee stings, exposure to peanuts or medications.
Mylan has for years owned more than 90 percent of the market for emergency epinephrine injectors and its own authorized generic has recently surpassed sales of the branded version.
But other rival products are available. Impax Laboratories Inc's Adrenaclick device is being sold through CVS Health Corp's drugstore chain for about $110 a pair.
Privately held Kaleo earlier this year began selling its Auvi-Q epinephrine auto-injector that it reacquired from Sanofi SA under an unusual pricing strategy but with little success so far. The company said it would make the product available at no cost to many consumers but charge insurers $4,500.
Sanofi in April sued Mylan, accusing it of engaging in illegal practices to squash EpiPen competition when the French drugmaker held the Auvi-Q rights.
Adamis shares soared 53.3 percent to close at $5.75 on the Nasdaq and further rose to $6.00 in extended trading. Mylan shares closed down 2.4 percent at $36.98. (Reporting by Bill Berkrot in New York; Editing by Andrew Hay and Matthew Lewis)