Figure 2.

Kaplan-Meier survival curves according to the class of drugs. (A) Drug starts to work early and continues to be more active compared to the control arm following the proportional hazard assumption, without long-term survival benefit; (B) treatment starts to work early, however resistance occurs with absence of prolonged survival benefit (non-proportional hazard model); (C) treatment starts to work late, however a long-term survival benefit is observed (non-proportional hazard model).