The ability of avitinib to penetrate the blood brain barrier and its control of intra-/extra- cranial disease in patients of non-small cell lung cancer (NSCLC) harboring EGFR T790M mutation.

Abstract

e20613 Background: Avitinib is an oral, potent, irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor selective for T790M resistance mutations. We report the safety, the intracranial/extracranial efficacy, and the blood brain barrier (BBB) penetration rate of Avitinib in non-small cell lung cancer(NSCLC) patients with EGFR T790m mutation. The data come from Peking Union Medical College hospital-a single center of the Phase I, open-label, multicenter study (NCT02330367). Methods: NSCLC Patients with acquired EGFR T790m (+) were enrolled. Patients were orally administered with dose escalating from 150 mg to 300 mg twice daily for 28-continuous-day cycles until disease progression. Blood (2mL) and cerebrospinal fluid (CSF) samples (2ml) were collected for concentration analysis on day 29 in available patients with brain metastases (BM). Tumor response was assessed on day 29 and then every 8 weeks. Results: Sixteen patients were included. Nine patients had asymptomatic BM. The most frequent adverse events were the elevated hepatic transaminases (10/16, 62.5%) and diarrhea (5/16, 31.3%), Most were mild and reversible. 9 Patients (56.3%) achieved Partial Response (PR), 6 (37.5%) achieved Stable Disease (SD). Median Progress Free Survival (PFS) was 253 days (95%CI: 154.8-339.2). Of the 8 evaluable BM patients, intracranial PFS were shorter than extracranial in only two patients. The blood and CSF analysis of 6 BM patients showed the BBB penetration rate were 0.046%-0.146% (Table). Conclusions: Avitinib is well tolerated and efficacious in EGFR T790m(+) NSCLC patients. Its concentration in CSF is low, and the penetrability of BBB is weak. But it still showed a good control of BM. Further studies are proceeding. Clinical trial information: NCT02330367. [Table: see text]