Ladenburg Thalmann analyst Kevin DeGeeter downgraded Myriad Genetics (MYGN) to Sell citing a "significant and unexpected deterioration" in outlook for the company's companion diagnostic franchise. The analyst expects a lower growth outlook to drive "significant P/E multiple compression." Tesaro (TSRO) presented data this weekend that suggested its PARP inhibitor niraparib was active in a maintenance setting for recurrent ovarian cancer in patients with either positive or negative HRD scores. The analyst had expected the drug to benefit only HRD positive patients. As such, the use of niraparib will not require HRD testing, DeGeeter tells investors in a research note. The analyst has a $16 price target for the shares.