ESTRO 2022 - Abstract Book

S324

Abstract book

ESTRO 2022

adjuvant durvalumab results in an additional probability on developing grade ≥ 2 RP, especially when the MLD is high (Figure 2). The 2-years OS in the durvalumab group was 80.8% compared to 57.5% after CRT only (p=0.027). Patients treated with durvalumab had a decreased hazard on death in the first 2 years after completing CRT (HR 0.42, 95%CI: 0.18–0.95, p=0.038).

Conclusion Treatment with adjuvant durvalumab significantly increased the incidence of grade ≥ 2 RP in this cohort of real-world NSCLC patients. Furthermore, the time patients are prone to develop grade ≥ 2 RP after ending CRT was longer in patients receiving adjuvant durvalumab compared to patients treated with CRT only.

MO-0388 Outcome of immunotherapy in non-small cell lung cancer patients with brain metastasis (NCT03870464)

B. Bjørnhart 1 , K. Holmskov Hansen 2 , J. Thor Asmussen 3 , T. Lembrecht Jørgensen 4 , J. Herrstedt 5 , T. Schytte 6

1 Department of Clinical Research, University of Southern Denmark, The Department of Oncology, Odense University Hospital, Odense, Denmark; 2 Odense University Hospital, Department of Oncology, Odense, Denmark; 3 Odense University Hospital, Department of Radiology, Odense, Denmark; 4 Odense University Hospital, Academy of Geriatric Cancer Research, Odense, Denmark; 5 Zealand University Hospital Roskilde, Department of Clinical Oncology and Palliative Care, Roskilde, Denmark; 6 Department of Clinical Research, University of Southern Denmark, Department of Oncology, Odense University Hospital, Odense, Denmark Purpose or Objective Immune checkpoint inhibition (ICI) has improved long-term survival in NSCLC patients, but little data on the effect and long-term prognosis of the subgroup of patients with active and/or symptomatic brain metastasis (BM) exist. This lack of data concerns both patients receiving local therapy (whole brain radiation therapy (WBRT), stereotactic RT (SRT) or neurosurgery) preceding or concomitant with early cycles of ICI as well as those with untreated BM. The aims of this study were to investigate intracranial response rates and survival in these subgroups. Materials and Methods Prospective non-randomized study (NCT03870464) in advanced NSCLC patients initiating palliative ICI (PD-1 inhibitor alone or in combination with chemotherapy) during April 1st 2018 through April 31st 2021 at a single-center. Magnetic resonance imaging of the brain (MR-C) was performed at baseline (-30 days to + 7 days after first ICI). As intracranial response evaluation, a MR-C was performed at week 8-9 using mRECIST criteria. Patients with BM at baseline were divided in two groups. Group A: Patients with BM treated with local therapy (within 4 weeks prior to ICI or concomitant within first evaluation), and Group B: Patients with BM without local treatment. Clinical decision on administration of local therapy was based on symptoms, size, number and anatomic location of BM. Results A total of 159 patients were included in this prospective trial. At baseline, 45 (28%) patients had BM. Eight patients with BM were excluded, they had local therapy more than 4 weeks before first ICI and had stable intra-cranial disease at baseline, leaving 21 patients in group A and 16 in group B. According, 37 patients had active BM and 16/37 (43%) were symptomatic. Median follow-up was 23.2 months (95% 21.5-26.6). For group A, nine of the 21 patients had local therapy concomitant with ICI. Intracranial response was 8/21, 38% (complete (CR) or partial response (PR)) for group A versus 8/16, 50% for group B. For patients without BM median overall survival was 22.4 months (95% 16.2-26.3) compared to 12.3 (5.2-NR) and 20.5 months (4.9-NR) (NS) for Cohort A and B, respectively. For patients with intracranial PR more than 70% were alive at 40 months of follow-up compared to 25% of those with stable disease. Conclusion Early intracranial response whether due to treatment with an ICI regimen alone or in combination with early local therapy may induce long-term survival in NSCLC patients with active BM.