Destined to fail

The trial design was set up in a way that would be very difficult to achieve primary outcome. If 40% of patients have extra hepatic disease, these subjects will progress if chemo is failing, irrespective of any benefits of spheres. The PFS in these patients, in both arms of the trial, should be the same as the treatment for the extra hepatic disease is the same in both arms of the trial.
Let me put it another way. A patient has a whopping 15cm tumour eating away his liver and a 2mm inconsequential lung secondary. Treatment with chemo/SIR spheres results in tumour response in liver, which shrinks to 2cm so a brilliant response. Lung met increases in size from 2mm to 3mm because chemo not holding it (and not a target for the spheres). Patient happy. Doctor happy. For the purposes of the trial "Progressive Disease" so primary endpoint failure.