*3.2. TKI Treatment*

The median duration of first TKI therapy was 15.7 months (mean 23.4 ± 19.3 months, range 0.9–76.2 months). At the last follow-up, 9/42 (21.4%) patients were still being treated, 27/42 (64.3%) patients discontinued therapy due to disease progression [20/27 (74.1%)] or other reasons (adverse events, patient decision) [7/27 (25.9%)], while 6/42 (14.3%) patients died.

The median PFS was 12.9 months (mean 16.6 ± 15.1, range 0.9–71.7 months). The best response, evaluable in 40/42 patients (95.2%), was partial response (PR) in 14/40 patients (35%), stable disease (SD) in 21/40 patients (52.5%), and progressive disease (PD) in 5/40 patients (12.5%).

The OS was assessed in a sub-population of 32 patients treated with only one TKI to avoid the potential bias due to those patients treated with more than one TKI. The median OS in this group was 16.8 months (mean 19.1 ± 13.4, range 0.9–56.1 months).
