Clinical Edge Journal Scan Commentary: Recent Lung Cancer Trial Results, May 2022

Jonathan W. Riess, MD, MS

In a European Society for Medical Oncology Virtual Plenary session, Dr Paz-Ares and colleagues presented interim analysis of the PEARLS/KEYNOTE-091 study of adjuvant pembrolizumab. In this triple-blind phase 3 trial, 1177 patients with stage IB (tumor ≥ 4 cm) to IIIA non–small cell lung cancer (NSCLC) (per American Joint Committee on Cancer [AJCC], version 7) were randomly assigned to receive pembrolizumab vs placebo. The dual primary endpoints were disease-free survival (DFS) in the overall population and in the population with high programmed death-ligand 1 (PD-L1) (tumor proportion score [TPS] ≥ 50%). The study met its primary endpoint where improved DFS was observed in the overall population that included lung cancers, whether they were PD-L1–negative (TPS = 0%) or –positive (TPS ≥ 1%) (53.6 months in the pembrolizumab group vs 42.0 months in the placebo group [hazard ratio (HR) 0.76; P = .0014]). Overall survival data are not yet clear. Of note, in the interim analysis presented, the subset of patients with high PD-L1 NSCLC (TPS ≥ 50%) did not show a DFS benefit whereas in other adjuvant and neoadjuvant studies, such as IMpower010 and CheckMate 816, the subset of high PD-L1 patients appeared to derive the most benefit. The results from the high PD-L1 subset and other subsets may change with future updated analyses as more events occur. The major co-primary endpoint was clearly met with the overall population clearly showing a positive DFS benefit. The results of the PEARLS trial adds to the current landscape of systemic treatment of early-stage NSCLC where neoadjuvant chemotherapy plus nivolumab is US Food and Drug Administration (FDA)–approved for stage IB (≥ 4 cm) to IIIA resected NSCLC regardless of level of PD-L1 expression, as is adjuvant atezolizumab after consideration of adjuvant chemotherapy in patients that are PD-L1–positive (≥ 1%) on the basis of a DFS benefit observed in this population.^1,2 For the future, it is important to see if the DFS benefit observed in these studies translates into a meaningful overall survival benefit.

Plasma cfDNA Levels as a Prognostic Marker in ALK+ NSCLC in the ALEX Trial

The ALEX trial is a pivotal global phase 3 randomized control trial that demonstrated superior progression-free survival (PFS) with the next-generation ALK inhibitor alectinib compared with the first-generation ALK inhibitor crizotinib as first-line treatment of ALK-positive NSCLC (HR 0.43; 95% CI 0.32-0.58; median PFS 34.8 vs 10.9 months crizotinib).³ In a study recently published in Clinical Cancer Research, Dr Dziadziuszko and colleagues retrospectively assessed the prognostic value of baseline cell-free DNA (cfDNA) levels in patients treated in the ALEX trial. Baseline plasma for cfDNA was quantified by the Foundation ACT next-generation sequencing assay. Clinical outcomes were assessed by quantitative cfDNA level stratified by the median value. In both the alectinib and crizotinib treatment arms, patients with cfDNA levels above the median were more likely to experience disease progression (alectinib adjusted HR 2.04; 95% CI 1.07-3.89; P = .03 and crizotinib adjusted HR 1.83; 95% CI 1.11-3.00, P = .016). Though survival data are incomplete, the study also suggested survival probability was lower when baseline cfDNA was above the median in both the alectinib and crizotinib treatment arms. Regardless of cfDNA levels, PFS was improved with alectinib compared with crizotinib. Previous studies have shown the value of cfDNA analysis at the time of progression to guide further treatment and target resistance mechanisms to ALK tyrosine kinase inhibitors (TKI), such as G1202R, or bypass tract pathways, such as MET amplification.^4,5 Assessment of the EML4-ALK variant type (V1 vs V3) has been shown to associate with certain types of resistance mechanisms (ie, on target ALK mutations, such as G1202R in V3) and clinical activity of specific ALK TKI (V3 > V1 for PFS with lorlatinib).⁶ This study examining baseline cfDNA levels and clinical outcomes on the ALEX trial shows the potential utility of baseline cfDNA levels as a prognostic factor for ALK TKI.

Lorlatinib in ROS1-Rearranged NSCLC After Progression on Prior ROS1 TKI

ROS1 rearrangements represent about 1.5% of lung adenocarcinoma. In advanced disease, both crizotinib and entrectinib are FDA-approved as agents targeting ROS1 with robust PFS. The third-generation TKI lorlatinib is approved and has substantial activity in ALK-rearranged NSCLC. In a recently published retrospective real-world cohort study by Girard and colleagues (LORLATU), 80 patients with ROS1-rearranged NSCLC were treated with lorlatinib as second-line treatment or beyond and after failure on at least one prior ROS1 TKI. Median PFS was 7.1 months (95% CI 5.0-9.9) and median overall survival was 19.6 months (95% CI 12.3-27.5). The overall response rate was 45% and the disease control rate was 82%. The central nervous system response rate was 72%. There were no new safety signals. This retrospective cohort study demonstrates that lorlatinib is a major targeted therapy treatment option in ROS1-rearranged NSCLC.

Checkmate 816: Neoadjuvant Nivolumab Plus Chemotherapy in Resectable NSCLC

In this open-label, phase 3 trial, 358 patients with stage IB (T ³ 4cm) to IIIA (per AJCC v7) resectable NSCLC were randomized 1:1 to receive nivolumab plus platinum-based chemotherapy or platinum-based chemotherapy alone for three cycles, followed by surgical resection. The primary endpoints were event-free survival (EFS) and pathological complete response (pCR) (0% viable tumor in resected lung and lymph nodes), both evaluated by blinded independent review. The median EFS was significantly increased in the nivolumab plus chemotherapy arm compared to chemotherapy alone: 31.6 months (95% CI 30.2 to not reached) vs 20.8 months (95% CI 14.0 to 26.7) (HR 0.63; 97.38% CI 0.43 to 0.91; P = .005). pCR rate was also increased in the nivolumab plus chemotherapy arm (24.0% vs 2.2%, respectively; odds ratio 13.94; 99% CI 3.49 to 55.75; P < .001). At the first prespecified interim analysis, the hazard ratio for death was 0.57 (99.67% CI 0.30 to 1.07), which currently does not meet the criterion for statistical significance. Of the randomized patients, 83.2% of those in the nivolumab-plus chemotherapy group and 75.4% of those in the chemotherapy-alone group were able to undergo surgery. Grade 3 or 4 treatment-related adverse events occurred in 33.5% of the patients in the nivolumab-plus-chemotherapy group and in 36.9% of those in the chemotherapy-alone group. In an exploratory analysis, EFS was longer in patients with pCR than patients without a pCR. In a subset analysis, patients with high PD-L1 expression (³50%) stood out in terms of particular benefit (HR 0.24, 95% CI 0.10–0.61). The Checkmate 816 trial is a landmark study. Neoadjuvant nivolumab plus chemotherapy represents a new standard of care in the systemic treatment of resectable NSCLC that is at a stage that warrants systemic treatment. It is FDA approved regardless of PD-L1 expression level including PD-L1 negative (0%) patients.² Adjuvant atezolizumab after adjuvant chemotherapy is also an FDA-approved treatment option for patients that are PD-L1 positive (³1%) based upon the IMpower 010 study.¹ It will be important to assess the overall survival benefit as the trial data matures, which seems to be trending in the right direction. Additional neoadjuvant clinical trials with chemoimmunotherapy have completed accrual and some of these trials also continued PD-(L)1 immune checkpoint inhibitor therapy in the adjuvant setting after surgery. An important question for the future is if combination of PD-(L)1 immune checkpoint blockade with chemotherapy in the neoadjuvant setting along with continuation of immunotherapy in the adjuvant setting post-surgery will further improve clinical outcomes.

References

1. Felip E, Altorki N, Zhou C, et al. Adjuvant atezolizumab after adjuvant chemotherapy in resected stage IB-IIIA non-small-cell lung cancer (IMpower010): a randomised, multicentre, open-label, phase 3 trial. Lancet. 2021;398(10308):1344-57. Doi: 10.1016/S0140-6736(21)02098-5 Source

2. Forde PM, Spicer J, Lu S, et al. Neoadjuvant nivolumab plus chemotherapy in resectable lung cancer. N Engl J Med. April 11, 2022. Doi: 10.1056/NEJMoa2202170 Source
   
3. Mok T, Camige DR, Gadgeel SM, et al. Updated overall survival and final progression-free survival data for patients with treatment-naive advanced ALK-positive non-small-cell lung cancer in the ALEX study. Ann Oncol. 2020;31:1056-1064. Doi: 10.1016/j.annonc.2020.04.478 Source

4. Shaw AT, Solomon BJ, Chiari R, et al. Lorlatinib in advanced ROS1-positive non-small-cell lung cancer: a multicentre, open-label, single-arm, phase 1-2 trial. Lancet Oncol. 2019;20:1691-1701. Doi: 10.1016/S1470-2045(19)30655-2 Source
   
5. Lawrence MN, Tamen RM, Martinez P, et al. SPACEWALK: A remote participation study of ALK resistance leveraging plasma cell-free DNA genotyping. JTO Clin Res Rep. 2021;2:100151. Doi: 10.1016/j.jtocrr.2021.100151 Source
   
6. Lin JJ, Zhu VW, Yoda S, et al. Impact of EML4-ALK variant on resistance mechanisms and clinical outcomes in ALK-positive lung cancer. J Clin Oncol. 2018;36:1199-1206. Doi: 10.1200/JCO.2017.76.2294 Source