Adamis Pharmaceuticals is selling U.S. commercial rights to Symjepi, a competitor to Mylan’s EpiPen, to Novartis.

U.S. regulators said Mylan NV’s EpiPen products are in shortage, due to manufacturing delays that are creating intermittent supply constraints of the emergency allergy treatment.

Mylan N.V.’s emergency allergy antidote EpiPen is in short supply in Canada and Britain, but remains available in the United States, the treatment’s manufacturer said.