Jefferies analyst Biren Amin downgraded Alkermes (ALKS) to Hold from Buy with an unchanged price target of $66. The shares closed yesterday down $1.56 to $63.19. The stock is fairly valued and price in “significant value” for the late-stage pipeline, Amin tells investors in a research note. He believes that Vivitrol and Aristada continue to experience “modest growth,” which is unlikely to drive Alkermes shares higher. Further, following a “deep dive” on immuno-oncology candidate ALKS 4230, Amin believes preclinical data suggest the drug may be weaker on efficacy than Nektar Therapeutics’ (NKTR) interleukin-2 receptor NKTR-214. ALKS 4230 is “inherently different” from NKTR-214 based on cross comparison of preclinical data, Amin writes in a research note partially titled “Closer Look at IL-2 Science Suggests Not All IL-2s Are The Same.”