At the American Society of Clinical Oncology (ASCO) annual meeting in Chicago, Roche Holding AG reported disappointing news from the phase III Sandpiper study testing the phosphoinositide 3-kinase (PI3K) inhibitor taselisib in breast cancer, news that rocked the beleaguered drug class yet again. MEI Pharma Inc., however, is keeping faith with its PI3K prospect, which also yielded results at ASCO – and impressive ones.