OA04 NEW DATA FROM RARE EGFR ALTERATIONS FRIDAY, JANUARY 29, 2021 - 11:45-12:45| Volume 16, ISSUE 3, SUPPLEMENT , S108, March 2021

OA04.03 Mobocertinib in NSCLC With EGFR Exon 20 Insertions: Results From EXCLAIM and Pooled Platinum-Pretreated Patient Populations


      Mobocertinib is a potent first-in-class tyrosine kinase inhibitor (TKI) designed to target EGFR exon 20 insertion (EGFRex20ins) mutations. We report first results from the EXCLAIM extension cohort of a phase 1/2 study (NCT02716116) and results in patients with EGFRex20ins-mutant NSCLC who received prior platinum-based therapy from the dose-escalation/expansion parts of the study and the EXCLAIM extension cohort.


      This 3-part, open-label, multicenter study included dose-escalation/expansion cohorts and the EXCLAIM extension cohort. Data are presented for all patients treated in EXCLAIM (N=96) and for platinum-pretreated patients from the dose-escalation/expansion cohorts (n=28) and from EXCLAIM (n=86); all received mobocertinib 160 mg orally QD. Enrolled patients had locally advanced/metastatic EGFRex20ins NSCLC, ECOG performance status 0–1, and ≥1 prior line of therapy for locally advanced/metastatic disease. The primary endpoint is confirmed ORR assessed by IRC per RECIST v1.1.


      In EXCLAIM, 96 patients were enrolled and treated; median age, 59 years [range: 27–80]; female, 65%; Asian, 69%; ≥2 prior systemic anticancer lines, 49% (range: 1–4). Median time on treatment was 6.5 months (range: 0–14). Confirmed ORR was 23% (22/96; 95% CI: 15%–33%) per IRC and 32% (95% CI: 23%–43%) per investigator; median DoR (Kaplan-Meier estimates) was not mature; median PFS was 7.3 months. See Table. In the analysis of platinum-pretreated patients (n=114), median age, 60 years [range: 27–84]; female, 66%; Asian, 60%; ≥2 prior systemic anticancer lines, 59% (range: 1–7). Median time on treatment was 7 months (range: 0–31); 38 patients (33%) remained on treatment as of 29-May-2020. Confirmed ORR was 26% (30/114; 95% CI: 19%–35%) per IRC and 35% (40/114; 26%–45%) per investigator. Median PFS was 7.3 months: 12-month PFS rate was 33% (95% CI: 21%–47%). Responses were observed among all prespecified subgroups, including Asian/non-Asian patients and those with/without baseline stable brain metastases. The most common treatment-related adverse events (TRAEs; ≥30%): diarrhea (90%), rash (45%), paronychia (34%), nausea (32%), decreased appetite (32%), dry skin (30%), and vomiting (30%); grade ≥3 TRAEs (≥5%): diarrhea (22%), anemia (5%), and dyspnea (5%). Nineteen patients (17%) discontinued due to AEs, most commonly diarrhea (4%) and nausea (4%). The safety profile observed in EXCLAIM was largely consistent with that observed in the platinum-pretreated population.
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      Mobocertinib demonstrated clinically meaningful benefit in previously treated patients with NSCLC and EGFRex20ins mutations, with a manageable safety profile.


      mobocertinib, EGFR exon 20 insertions, non-small cell lung cancer