Mersana Therapeutics Inc. followed grim June news with an even worse headline as the phase Ib/II study called Uplift with upifitamab rilsodotin (upri) did not meet its primary endpoint in platinum-resistant ovarian cancer (prOC). The antibody-drug conjugate (ADC) targets the sodium-dependent phosphate transport protein NaPi2b and was developed via the company’s platform called Dolaflexin. Shares of Mersana (NASDAQ:MRSN) tumbled 73%, or $2.84, to close July 27 at $1.07 on word of the failure of the trial.