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L. Austin Doyle



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    P2.13 - Targeted Therapy (Not CME Accredited Session) (ID 962)

    • Event: WCLC 2018
    • Type: Poster Viewing in the Exhibit Hall
    • Track:
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/25/2018, 16:45 - 18:00, Exhibit Hall
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      P2.13-44 - Targeting NFE2L2 Mutations in Advanced Squamous Cell Lung Cancers with the TORC1/2 Inhibitor TAK-228 (ID 12591)

      16:45 - 18:00  |  Author(s): L. Austin Doyle

      • Abstract

      Background

      Despite research efforts over the past decade, no targeted therapy options exist for patients with SQCLC. Analyses by TCGA and others (Paik Cancer Disc 2015) have identified a heretofore untargeted, frequently mutated oncogene (NFE2L2)/tumor suppressor (KEAP1) pair, each mutated in ~20% of patients with SQCLC. NFE2L2 encodes Nrf2, a transcription factor involved in the oxidative stress response which is targeted for degradation by Keap1. NFE2L2 mutations occur exclusively in an exon 2 hotspot that encodes the Neh2 domain (~aa.1-86), which is the binding site for Keap1. Mutations in this region disrupt Keap1 binding, leading to Nrf2 nuclear translocation and increased mTOR signaling through regulation of RagD (Shibata Cancer Res 2010). We now report translational studies and preliminary results from a phase 2 trial of the oral TORC1/2 inhibitor TAK-228 in SQCLC patients with these mutations.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      Cytotoxicity, signaling, and xenograft experiments were performed using LK-2 SQCLC cells harboring an NFE2L2 E79K mutation treated with TAK-228, everolimus, rapamycin, or deforolimus with requisite vehicle controls. Patients with stage IV SQCLC harboring NFE2L2 mutations were treated on an NCI CTEP- single-institution phase 2 study of TAK228 3mg po qd (continuous, 28 day cycles; NCT02417701). Primary endpoint: ORR. Secondary endpoints: PFS/OS. The study utilizes a Simon 2-stage design with H0=5% (N≥1/5 responses), HA=40% (N≥2/10 responses).

      4c3880bb027f159e801041b1021e88e8 Result

      TAK-228 exhibited significantly increased anti-tumor activity over TORC1 rapalogs in LK-2 cells. TAK-228 alone was cytotoxic at sub-[μM] (IC50 68nM); all other rapalogs exhibited IC50s >10μM. This was associated with an 80% decrease in downstream S6 phosphorylation. Tumor response (-55% shrinkage) was also seen in an LK-2 xenograft treated with TAK228. No anti-tumor/growth inhibitory response was seen with any other rapalog tested.

      N=4 patients have been treated on study (exon 2 del, D29H, F37V, W24C). 3 are evaluable for response. 2 related-SAEs (G3 hyperglycemia, G3 confusion) were seen; no other G3 AEs reported. ORR=67% (2 PR, 1 SD, 0 PD). Prolonged disease response is present, with DOR= 12mo, 10mo (ongoing), 8mo (ongoing).

      8eea62084ca7e541d918e823422bd82e Conclusion

      TAK228 is tolerable with evidence of pre-clinical and clinical activity in this biomarker-selected population. The trial has met its first-stage endpoint and has expanded to N=10 patients. The trial has also expanded to included patients with KRAS mutant lung cancers harboring co-alterations in NFE2L2 or KEAP1.

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