A phase II study of abemaciclib in patients (pts) with brain metastases (BM) secondary to non-small cell lung cancer (NSCLC) or melanoma (MEL)

Abstract

Abstract Background Abemaciclib, a selective CDK4 & 6 inhibitor, demonstrated single-agent activity in NSCLC and melanoma (Patnaik et al., 2016). Clinical data demonstrate abemaciclib penetrates the blood brain barrier resulting in comparable concentrations in tissues and plasma (Sahebjam et al., 2016). Methods Study JPBO is a Simon 2-stage trial evaluating abemaciclib in 6\xa0pt cohorts with BM secondary to HR+ breast cancer, NSCLC, or melanoma. Here, we report NSCLC and melanoma cohorts. Pts with ≥1 new or not previously irradiated BM\xa0≥\xa010mm or a progressive BM previously irradiated were eligible. Abemaciclib was orally administered BID on a continuous dosing schedule. Primary endpoint was objective intracranial response rate (OIRR; [confirmed CR+PR]) based on Response Assessment in Neuro-Oncology BM response assessment criteria (RANO-BM). Secondary endpoints included intracranial clinical benefit rate, PFS, OS, and safety. Results 28 (NSCLC) and 23 (MEL) pts were enrolled and 23 (NSCLC) and 22 (MEL) were evaluable. Pts had a median of 2 prior systemic therapies in the metastatic setting. 35% (NSCLC) and 46% (MEL) of pts had prior whole brain radiotherapy. 35% (NSCLC) and 27% (MEL) pts had stereotactic radiotherapy. Median time from radiation to study enrollment was 4.8 (NSCLC) to 5.6 (MEL) months. No confirmed intracranial response was observed (OIRR 0% for both cohorts). 21.7% (NSCLC) and 13.6% (MEL) of pts showed a decrease in the sum of their intracranial target lesions. ICBR (CR+PR+SD persisting for > 6 months) was 26.1% (NSCLC) and 9.1% (MEL). Median PFS was 1.5 months (95% CI, 1.4-2.8) for NSCLC and 1.2 months (95% CI, 1.0-1.6) for MEL. Median OS was 7.1 months (95% CI, 3.7-9.4) for NSCLC and 2.9 months (95% CI, 1.2-4.3) for MEL. Based on efficacy results, enrollment closed at end of stage 1. Safety and tolerability were similar as previously reported for abemaciclib. Conclusions There was limited intracranial clinical activity for abemaciclib monotherapy in NSCLC and MEL pts in this study; OIRR and short median PFS suggest that no further studies for abemaciclib monotherapy are warranted in this pt population. Clinical trial identification NCT02308020. Editorial acknowledgement Medical writing assistance was provided by Kristi Gruver, employee of Eli Lilly and Company. Legal entity responsible for the study Eli Lilly and Company. Funding Eli Lilly and Company. Disclosure E. Le Rhun: Advisory / Consultancy, Research grant / Funding (institution), Oscar Lambert Center, Lille, FR: Mundipharma; Research grant / Funding (institution), University Hospital, Lille, FR: Amgen; Advisory / Consultancy, personal fees: Novartis; Advisory / Consultancy, personal fees: Daiichi Sankyo; Advisory / Consultancy, personal fees: Abbvie. G. Jerusalem: Advisory / Consultancy, Non-remunerated activity/ies, per patient investigator fee: Eli Lilly and Company; Research grant / Funding (self), Non-remunerated activity/ies, personal fees: Novartis; Research grant / Funding (self), Non-remunerated activity/ies, personal fees: Roche; Advisory / Consultancy, Non-remunerated activity/ies, personal fees: Pfizer; Advisory / Consultancy, personal fees: Celgene; Advisory / Consultancy, Non-remunerated activity/ies, personal fees: Amgen; Advisory / Consultancy, Non-remunerated activity/ies, personal fees: BMS; Advisory / Consultancy, personal fees: Puma Technology; Advisory / Consultancy, Non-remunerated activity/ies, personal fees: AstraZeneca; Advisory / Consultancy, personal fees: Daiichi Sankyo; Advisory / Consultancy, personal fees: Abbvie. D. Subramaniam: Advisory / Consultancy, personal fees: AstraZeneca; Advisory / Consultancy, personal fees: Takeda Oncology; Speaker Bureau / Expert testimony, Research grant / Funding (institution): Genentech. Y. Chen: Shareholder / Stockholder / Stock options, Full / Part-time employment, employee and stock options: Eli Lilly and Company. P.F. Conte: Research grant / Funding (self): Novartis; Travel / Accommodation / Expenses, travel grant: Eli Lilly and Company; Research grant / Funding (self): Roche; Research grant / Funding (self): AstraZeneca; Travel / Accommodation / Expenses, travel grant: Celgene; Travel / Accommodation / Expenses, travel grant: Tesaro. All other authors have declared no conflicts of interest.