Entrectinib ( Rozlytrek ) is a potent, selective, CNS active, ROS1 tyrosine kinase inhibitor ( TKI ).
In a preliminary analysis ( data cut-off: 31 May 2018 ) of patients with ROS1 fusion-positive ( ROS1-fp ) non-small cell lung cancer ( NSCLC ) enrolled in phase 1/2 studies ( ALKA-372-001, STARTRK-1, STARTRK-2; EudraCT 2012-000148-88, NCT02097810, NCT02568267 ), treatment with Entrectinib produced clinically meaningful and durable systemic responses with a manageable safety profile.
Researchers have reported on an updated integrated analysis in a larger patient population with longer follow-up ( data cut-off: 1 May 2019 ).
Enrolled patients were ROS1 TKI naïve with measurable disease; most received Entrectinib 600mg once daily.
Tumours were assessed by blinded independent central review using RECIST v1.1, after 4 weeks and every 8 weeks thereafter.
Primary endpoints were objective response rate ( ORR ) and duration of response ( DoR ).
Progression-free survival ( PFS ), overall survival ( OS ), efficacy in patients with / without baseline CNS metastases, and safety were also assessed.
The efficacy-evaluable population comprised 161 patients with ROS1-fp NSCLC.
Median follow-up was 15.8 months ( range 0.1–43.2 ); objective response rate, 67.1% ( 95% CI 59.3–74.3 ); 14 patients ( 8.7% ) achieved complete response, 94 ( 58.4% ) partial response, 14 ( 8.7% ) stable disease, 15 ( 9.3% ) disease progression.
Median duration of response was 15.7 months ( 95% CI 13.9–28.6 ); median progression-free survival, 15.7 months ( 95% CI 11.0–21.1 ); median overall survival, not estimable ( NE ) ( 95% CI 28.3–NE ).
In the subgroup with prior immunotherapy ( n=24 ), objective response rate was 70.8% ( 95% CI 48.9–87.4 ).
In patients with investigator-assessed CNS metastases at baseline, objective response rate was 62.5% ( 95% CI 48.6–75.1 ).
The safety profile was similar to that previously reported.
In conclusion, this updated analysis, using a larger dataset with longer follow-up, has shown that Entrectinib induces clinically meaningful responses in patients with ROS1 fusion-positive non-small cell lung cancer, including patients with CNS metastases at baseline. ( Xagena )
Source: European Society for Medical Oncology ( ESMO ) Virtual Meeting, 2020