** Brokerage Leerink Partners downgrades drug developer Compass Therapeutics CMPX.O to "market perform" from "outperform," cuts PT to $4 from $5
** Cites "uncertainties" in CMPX's experimental drug, CTX-009, developed for colorectal cancer that affects the large intestine
** Brokerage says it is disappointed by the drug's 5% response rate in Western patients, compared with 33% in South Korean ones; response rate refers to the proportion of patients whose tumors shrank or disappeared
** Leerink says the drug also needs to show a benefit for patient survival, apart from a favorable response rate
** Six of seven analysts rate CMPX stock "buy" or higher and one "hold"; their median PT is $7.50 - LSEG
** As of last close, CMPX stock has risen 1.9% YTD
(Reporting by Kamal Choudhury in Bengaluru)
((Kamal.Choudhury@thomsonreuters.com;))