Taiho Oncology Inc. and Cullinan Therapeutics Inc ( CGEM ). shared new data on Sunday from the central nervous system (CNS) involvement cohort of the REZILIENT2 study of zipalertinib for advanced or metastatic non-small cell lung cancer (NSCLC) harboring EGFR exon 20 insertion mutations (ex20ins) or uncommon non-ex20ins EGFR mutations.

Data will be presented at the European Society for Medical Oncology (ESMO) Congress 2025.

The mini oral presentation will highlight preliminary efficacy and safety data from the CNS involvement cohort of the ongoing parallel cohort Phase 2b REZILIENT2 trial of zipalertinib.

An incidence of baseline brain metastases in EGFR ex20ins NSCLC patients ranging from 23% to 39% has been reported.

Patients with lung cancer with CNS involvement have a worse prognosis and require more aggressive therapy, including surgery and radiotherapy.

Also Read: FDA Breakthrough Status Awarded To Lilly-Merck Combo Drug For Advanced Non-Small Cell Lung Cancer

Summary of Preliminary Efficacy

As of the February 2025 data cutoff, 32 patients enrolled in the CNS involvement cohort of the ongoing parallel cohort Phase 2b REZILIENT2 trial received zipalertinib 100 mg orally twice daily. Patients received a median of 2 prior lines of therapy. Among all enrolled patients, 21 had ex20ins mutations and 13 had other uncommon mutations.

In the Response Assessment in Neuro-Oncology for Brain Metastases (RANO-BM) criteria evaluable population with measurable CNS disease (n=16, including three patients with leptomeningeal disease (LMD), the intracranial objective response rate was 31.3% including one intracranial complete response.

In the same population, the intracranial disease control rate (iDCR) was 68.8% and the median intracranial duration of response (DOR) was 8.1 months.

Measured in 29 of the cohort’s patients, the preliminary systemic objective response rate (ORR) was 27.6% and the median DOR was 7.6 months.

Intracranial antitumor activity was similar to its overall systemic anticancer activity in this cohort of patients.

Summary Of Preliminary Safety And Tolerability

Administered at 100 mg orally twice daily, zipalertinib was well tolerated, with no new safety signals observed.

Treatment-related adverse events of grade 3 or higher occurred in 8 patients (25%) and included anemia (n=3) and interstitial lung disease (n=2). There was one death due to interstitial lung disease.

Price Action: CGEM stock is up 4.96% to $7.77 as of the last check on Monday.

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