1330P - Discontinuation of ICIs above 18 months of treatment in real-life patients with NSCLC: A multicentric retrospective study

Background

The optimal treatment duration of Immune checkpoint inhibitors (ICIs) treatment for advanced non-small-cell lung cancer (NSCLC) remains uncertain: results from CheckMate 153 suggest to continue beyond 1 year. In phase 3 clinical trials, the duration was set at to 2 years or until disease progression. Real life data are missing. This multi-centric retrospective study presents data on real-life patients who discontinued treatment after at least 18 months of ICI monotherapy, their tumour being still controlled.

Methods

Among patients who started ICI between 1st July 2015 and 1st January 2018 in 4 hospitals with a controlled tumour after at least 18 months of treatment, those who interrupted ICI were selected. Their characteristics, the causes of discontinuation of ICI, and their outcome are described.

Results

By 1srt March 2020, 52 patients had their tumour controlled after at least 18 months of treatment. Among them, 20 (38%) discontinued ICI : 14 (70%) male, median age 65 (52-74), 12 (63%) active smokers, 15 (75%) PS 1, 14 (70%) adenocarcinoma, 4 (20%) KRAS mutation, PD-L1 expression levels available for 6 (30%) patients (1 <1% and 5 > 50%), 18 (90%) treated after 1^st line, with Nivolumab in 90%. The median number of infusions was 47 (31-92); 15 (75%) had at least 1 immune-related adverse event (13 grade 1-2 and 2 grade 3 -4). Best RECIST response was partial response, complete response and stable disease in 80%, 15% and 5% respectively. Treatment was stopped by choice of the prescriber and toxicity in 60% and 10% respectively. Thirteen (65%) of patients had a 18F-FDG PET/CT at discontinuation, 6 (46%) complete metabolic response, 7(54%) partial metabolic response among which 2 received a localized therapy on the active site. With a median follow up of 12,4 months (4-34) from ICI discontinuation, 3 (15%) patients had a tumour progression at 4, 6, and 8 months, all isolated: 2 received localized therapy with a complete response and 1 experienced subsequent response to anti-PD1.

Conclusions

On this small real-life population, a minority of patients discontinued ICI after at least 18 months of tumour control and long-term results are encouraging. Updated data from 7 hospitals will be presented at the meeting.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.