Table 1.

Endpoint characteristics.

Endpoint	Definition	Advantages	Disadvantages
Response rate (RR)	Assessed by the RECIST criteria on the basis of imaging studies. GCIG has defined changes in CA-125 as a response criterion	Objective Quantifiable Results quickly available Tumor shrinkage appealing to patient and physician	Difficult to measure accurately and reproducibly in ovarian cancer Not considered sufficient as a primary endpoint for phase III trials Not necessarily a clinically relevant benefit for the patient
Patient-recorded out-  comes (PRO)	Symptom-based parameters	Direct clinical benefit as perceived and quantified by patient	Need randomized blinded studies Subjective and dependent on limited validation instruments
Progression-free surviva  (PFS)	Time from entry into trial to progression of disease, death or lost to follow up	Provides answer sooner Avoids the impact of post-progression thera- py Preferred to TTP by regulatory agencies	Requires blinded, placebo-controlled design Requires careful and symmetric timing of assess ments
Time to progression  (TIP)	Time from entry into trial to progression of disease	Similar to PFS	Does not include deaths
Overall survival	Time from entry into trial to death or lost to follow up	Clear cut end point of death Indisputably indicative of clinical benefit	Longer time to answer Impacted by post-progression therapy
Time to tumor growth	Utilizes prescribed longitudinal tumor models	Novel metric In some models best predictor of OS Reduces time and cost	Not validated in ovarian cancer Subjectivity in assessment