“…although an earlier publication (Rini et al 2011) showed a median progression-free survival (PFs) benefit that favored axitinib (6.7 vs 4.7 months, hazard ratio 0.665; p < 0.0001], the final results showed no difference in overall survival (Os) 3) (hazard ratio [HR] 0.969, p = 0.3744]. since the study did not permit crossover, the authors attempted to explain the negative outcome with this disclaimer, "being able to show a survival advantage is especially challenging when survival post-progression is long, that is, 12 months or longer, because the variability added during a long survival post-progression might dilute the ability to detect statistically significant difference in overall survival (Motzer et al 2013).…”