The accelerated approval by the U.S. FDA of Immunogen Inc.’s landmark antibody-drug conjugate Elahere (mirvetuximab soravtansine-gynx) injected further oomph into the NaPi2b space, where a handful of developers are due to yield important data shortly. In play are such names as Mersana Therapeutics Inc. and Zymeworks Inc., encouraged by historical – if not entirely successful – efforts by giant Roche Holding AG.