Comment by apparent
This isn't quite as bad as the garden variety "in mice" studies:
> The combination therapy also led to significant regression in genetically engineered mouse tumours and in human cancer tissues grown in lab mice, known as patient-derived tumour xenografts (PDX).
PDX is a double edged sword. Human tumors are engrafted into mice with no immune system. Immune-cancer interface is incredibly important, yet completely lacking in these models. Consider that some of the greatest cancer drugs ever work specifically on the immune system (e.g. checkpoint inhibitors like Keytruda).