Leerink analyst Joseph Schwartz says his talk with a key opinion leader who has extensive experience in paroxysmal nocturnal hemoglobinuria clinical development and patient care suggests the recent selloff in shares of Achillion Pharmaceuticals is overdone. The feedback indicates that investors are overemphasizing lactate dehydrogenase data without assigning much credit to the promise that other parameters, such as hemoglobin, fatigue score, and PNH clone size, seem to suggest, Schwartz tells investors in a research note. He reiterates an Overweight rating on shares of Achillion.