Abstract 91P
Background
There is limited real-world data about CNS efficacy of crizotinib in advanced ROS1+NSCLC.
Methods
Patients diagnosed with advanced ROS1+NSCLC with CNS metastases treated with crizotinib from multiple tertiary hospitals in China were retrospectively collected. Intracranial efficacy of crizotinib was evaluated by RECIST 1.1 (namely at most two target lesions (≥1 cm in MRI) could be chose). The definition of CNS progressive disease was that for patients with CNS target lesion, the sum of the largest diameter of target lesion was increased by at least 20% and 5 mm in number or new CNS lesion was reported; for patients without CNS target lesion, at least one non-target lesion enlarged significantly (at least increased by 5 mm) or new CNS lesion was found. CNS-PFS was calculated from the start date of crizotinib to the time of CNS progression.
Results
78 patients were included in this research. In patients with CNS target lesions (n=54), CNS-ORR was 66.7% and median CNS tumor shrinkage rate was 45% (0–100%). CNS-PFS was 22.2months (95%CI: 15.5–28.9m) in overall population. CNS-ORR (62.5% vs 78.6%, p=ns) and CNS-PFS (22.2 m vs 27.5 m, HR=1.16, p=0.687)was similar between patients who did not received brain-RT before or during the treatment of crizotinib and their counterparts. In patients with 1–5 CNS lesions, the addition of brain-RT did not prolong CNS-PFS (without RT: 26.6 mvs with RT: 27.5m, HR=1.24, p=0.65), for patients with >5 CNS lesions, similar outcomes were also reported (without RT: 15.9 m vs with RT: 21.1m, HR=1.44, p=0.58). The extra benefit by RT was also not confirmed in patients with larger CNS lesions (the sum of the largest diameter of CNS target lesions≥20 mm) (21.1 vs 18.8 m, HR=0.92, p=0.89), while CNS-PFS was numerically improved by RT in patients with smaller CNS lesions (the sum of the largest diameter of CNS target lesions
Conclusions
In contrast to the prior results, crizotinib demonstrated favourable CNS efficacy in ROS1+NSCLC even if brain-RT was not administered in our research. CNS-PFS was not significantly extended by RT in patients with multiple CNS metastases (>5) or larger CNS lesion (≥20 mm). A numerical improvement in CNS-PFS by RT was found in patients with smaller CNS lesion.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.