Adjuvant atezolizumab lowers relapse rate in resected NSCLC

An exploratory analysis from the Impower010 trial added support for the use of adjuvant immunotherapy post-chemotherapy for selected early-stage non-small cell lung cancer (NSCLC).

Despite treatment with curative intent, up to 60% of patients with stage I-III NSCLC still experience disease relapse [1]. Impower010 (NCT02486718) is the first randomised phase 3 study to show significant disease-free survival (DFS) improvement with adjuvant cancer immunotherapy (atezolizumab) after adjuvant chemotherapy in patients with early-stage resected NSCLC [2].

Enrolled patients had completely resected stage IB-IIIA NSCLC and ECOG performance status 0–1. A total of 1,280 patients received up to four 21-day cycles of cisplatin-based chemotherapy (plus pemetrexed, docetaxel, gemcitabine, or vinorelbine). Next, 1,005 patients without progression after adjuvant chemotherapy were randomised 1:1 to atezolizumab (1,200 mg every 3 weeks) for 16 cycles or until disease relapse or unacceptable toxicity or to best supportive care (BSC). The primary endpoint was DFS which was hierarchically tested in PD-L1 TC ≥1% (SP263) stage II-IIIA patients (n=476), then in all randomised stage II-IIIA patients (n=882), and then in intention-to-treat patients (n=1,005).

As previously reported, median DFS was significantly improved by atezolizumab in PD-L1 TC ≥1% patients (HR 0.66; P=0.004), and in all randomised patients (HR 0.79; P=0.02), but not in the ITT population (HR 0.81; P=0.04) [2]. Dr Enriqueta Felip (Vall d’Hebron Institute of Oncology, Spain) presented additional results from exploratory analyses in Impower010 [3].

In all randomised stage II-IIIA patients, DFS improvement was seen with increasing PD-L1 expression: TC <1% (n=383) HR 0.97; TC 1–49% (n=247) HR 0.87; and TC ≥50% (n=229) HR 0.43. Among PD-L1 TC ≥1% stage II-IIIA patients (n=676), 73 patients (29%) relapsed in the atezolizumab arm versus 102 patients (45%) in the BSC arm. Sites of relapse in both arms were comparable. Time to relapse appeared to favour the atezolizumab arm over the BSC arm in the PD-L1 TC ≥1% stage II-IIIA patients, with minimal differences seen in the all-randomised and intention-to-treat populations. A higher rate of post-relapse immunotherapy was seen in the BSC arm.

Dr Felip summarised that “in this interim DFS analysis, relapse rate was higher in the BSC arm versus the atezolizumab arm. However, there was no clear difference in pattern of relapse between the arms among patients who relapsed.”

1. Vansteenkiste J, et al. Ann Oncol. 2019;30:1244-1253.
2. Wakelee HA, et al. J Clin Oncol 39, 2021 (suppl 15; abstr 8500)
3. Felip E, et al. Impower010: patterns of relapse and subsequent therapy from a Phase III study of atezolizumab (atezo) vs best supportive care (BSC) after adjuvant chemotherapy (chemo) in stage IB-IIIA non-small cell lung cancer (NSCLC). Abstract LBA9, ESMO Congress 2021, 16–21 September.

 

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Posted on 19 November, 202115 February, 2024