Abstract 65P
Background
Immunotherapy plus chemotherapy is the standard of care for metastatic non-small cell lung cancer (NSCLC). Radiotherapy (RT) achieved prolonged progression-free survival (PFS) and overall survival (OS) in well selected oligometastatic NSCLC patients. However, the value of additional RT to immuno-chemotherapy remains unclear.
Methods
SABRcure is a multi-center phase II study evaluating the efficacy and safety of durvalumab combined with chemotherapy and RT in patients with oligometastatic EGFR/ALKwt NSCLC. Patients received durvalumab and chemotherapy for 4 cycles, followed by RT to all lesion, and durvalumab monotherapy until disease progression, or intolerance, or up to 24 months(m). Stereotactic ablative body RT (SABR) and definitive RT was performed if feasible. The primary endpoint was PFS per RECIST v1.1. Secondary end points were objective response rate (ORR), OS and safety.
Results
Between Sep 2021 and Apr 2023, 35 patients from 5 hospitals were enrolled (median age 65 years, 57.1% adenocarcinoma). There were 28 (80%) patients received RT and 23 (65.7%) received SABR. As of December 10th, 2023, 11 patients were still on treatment with durvalumab. With median follow up of 15.7 m, median PFS was 10.4 m (95% CI 4.4, NE). One-year OS rate was 73.6% (95% CI 55.3%, 85.3%). ORR was 71.9%. Median PFS was 18.69 m (7.23, NE) and 24.3 m (7.6, NE) in patients with RT and SABR, respectively. More subgroup analyses were described in the table. Adverse events (AE) ≥grade 3 were reported in 57.1% (20/35). SAE was reported in 45.7% (16/35) and imAE occurred in 34.3% (12/35). Table: 65P
| Population (n) | Median PFS (95% CI) (m) | 1-year PFS rate % (95% CI) |
| FAS (35) | 10.4 (4.4, NE) | 43.0 (25.1, 59.0) |
| With RT (28) | 18.69 (7.23, NE) | 52.1 (30.8, 69.8) |
| With SABR (23) | 24.3 (7.6, NE) | 55.8 (31.7, 74.3) |
| With bone metastasis (18) | 10.4 (4.3, NE) | 38.6 (13.5, 63.6) |
| With visceral metastasis (17) | 7.2 (3.5, NE) | 37.6 (15.5, 59.9) |
Conclusions
In oligometastatic NSCLC, the combination of durvalumab, chemotherapy and RT is effective and tolerable. Patients without disease progression after upfront systematic therapy and receive RT/SABR have longer PFS, indicating that RT/SABR may be the key to improve efficacy.
Clinical trial identification
NCT04255836.
Legal entity responsible for the study
Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital).
Funding
AstraZeneca China.
Disclosure
All authors have declared no conflicts of interest.