Being molecular in the molecular age

© The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: [email protected].

Downloaded from http://annonc.oxfordjournals.org/ at New York University on March 1, 2016

We congratulate the authors for completion of this large study, LUX Lung 5, to address an important question of the role of afatinib in combination with chemotherapy after progression of lung cancer on afatinib alone. In this phase III randomized study of patients with advanced nonsmall-cell lung cancer (NSCLC) treated with one or more lines of chemotherapy followed by an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) and afatinib, the authors show that continuing afatinib beyond progression in combination with paclitaxel resulted in a 2.5-fold increase in overall response rate and a doubling of progression-free survival (PFS) compared with investigator choice chemotherapy [1]. No significant improvement in overall survival was seen. This is a positive study that has met its primary end point of improvement in PFS. The challenge is to translate this finding into clinical practice. For this, we should ask two basic questions, ‘Who may benefit?’ and ‘Why should there be a benefit?’ Afatinib is an irreversible ErbB blocker. Preclinical data show that it is a more potent blocker of EGFR and human epidermal growth factor receptor (HER) signaling compared with the firstgeneration EGFR TKIs and has efficacy in lung cancer cells with resistance to EGFR TKIs due to development of the T790M exon 20 mutation or upregulation of the HER signaling pathway [2]. In the LUX Lung 3 and LUX Lung 6 trials, afatinib has demonstrated clinical efficacy as first-line treatment in patients with advanced NSCLC molecularly selected for activating EGFR mutation [3, 4]. However, its efficacy in clinically selected patients who have progressed on EGFR TKIs has been modest. In the LUX Lung 1, phase IIb/III study of advanced NSCLC patients progressing after chemotherapy and ‘clinically enriched’ for EGFR TKI response, the response rate to afatinib monotherapy was only 7%–11%. About 50% of patients had stable disease for 8 weeks [5]. Similar response rates were also seen in the phase II Lux Lung 4 trial where patients received afatinib after initial clinical benefit from EGFR TKI, although no prior chemotherapy was given [6]. In both of these studies, as in current study (LUX Lung 5), progression after disease control for ≥12 weeks with gefitinib/erlotinib was used as a surrogate for acquired resistance to EGFR TKIs. We must understand that this ‘clinically enriched’ population is a heterogeneous group that comprises wild-type and mutated EGFR (with or without concurrent exon 20 T790M) [7]. According to the TAILOR study that compared docetaxel with erlotinib in patients with wild-type EGFR, ∼30% of patients were progression-free after 12 weeks on erlotinib and these patients would have been eligible for LUX Lung 5 [8]. It may not be appropriate to use the word ‘acquired resistance’ for this population as it is unlikely

that these patients were having a true response to EGFR TKI [9]. In LUX Lung 5, the patients who met the modified ‘higher clinical enrichment criteria’ of complete remission/partial remission to EGFR TKI or ≥48 weeks of disease control were more likely, but not exclusively, to be representative of an EGFR mutant population [7, 10]. The benefit of paclitaxel plus afatinib beyond progression was statistically significant for the subgroup with positive ‘higher clinical enrichment criteria’ [hazard ratio (HR): 0.56 (0.36–0.87)] while the benefit was more marginal [HR: 0.65 (0.39–1.08)] for the negative subgroup. Thus, we should explore the potential reasons for the benefit of the combination independently in both EGFR mutation-positive and -negative population. Patients with an EGFR mutation can be genuinely considered as ‘oncogene addicted’. The concept of treatment beyond RECIST progression in EGFR mutant patients with advanced NSCLC was explored in the ASPIRATION study and in the IMPRESS study [11, 12]. In the ASPIRATION study, erlotinib was continued as a single agent beyond RECIST progression and showed an improvement in PFS by 3.1 months. Exploratory analyses suggested that the benefit of continuation was best seen in those with good initial response to erlotinib. The IMPRESS study showed no significant benefit of gefitinib beyond progression in combination with platinum-based chemotherapy compared with chemotherapy alone. However, subgroup analysis suggested that the combination may benefit T790M mutation-negative patients with improvement in PFS from 5.4 to 6.7 months (HR 0.67, 95% confidence interval 0.43–1.03, P = 0.0745) [13]. With the recent approval of osimertinib (third-generation EGFR TKI) for patients with T790M, there will be no role for combination of paclitaxel plus afatinib in this population. The combination, plausibly, may be worthy of consideration in the T790M-negative patients. Afatinib resistance in the T790M-negative population may be related to upregulation of the extracellular-regulated kinase and v-Akt murine thymoma viral oncogene/mammalian target of rapamycin (mTOR) signaling pathways, bypassing EGFR [14]. Paclitaxel, in preclinical studies, has been shown to inhibit the mTOR signaling pathway and also phosphorylate the downstream target of mTOR, p70 S6 kinase [15, 16]. Afatinib in combination with paclitaxel has demonstrated preclinical synergy in solid tumor cell lines and xenografts and has been studied in the phase I setting. In the phase I study including different solid tumor patients, nine patients with NSCLC were treated, three obtained clinical benefit and one of these patients had a wildtype EGFR [16, 17]. It is possible that afatinib and paclitaxel may have synergistic effect in the T790M-negative population. Potentially, authors may study the T790M status of patients from LUX Lung 5 if plasma cfDNA is available. Benefit of the combination in patients with predominantly wild-type EGFR remains a challenge to explain. PFS benefit of

editorials

Annals of Oncology 27: 367–368, 2016 doi:10.1093/annonc/mdw002

editorials

editorials

R. Raghupathy & T. Mok* Department of Clinical Oncology, Faculty of Medicine, State Key Laboratory in Oncology in South China, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China (*E-mail: [email protected])

disclosure TM is a speaker with AstraZeneca, Roche/Genentech, Pfizer, Eli Lilly, BI, MSD, Amgen, Janssen, Clovis Oncology, GSK, Novartis, BMS, and prIME Oncology. He has received honoraria from AstraZeneca, Roche/Genentech, Pfizer, Eli Lilly, BI, Merck Serono, MSD, Janssen, Clovis Oncology, BioMarin, GSK, Novartis, SFJ Pharmaceutical, ACEA Biosciences, Inc., Vertex Pharmaceuticals, BMS, AVEO & Biodesix, prIME Oncology, and Amgen. He is a major shareholder in Sanomics LTD. He is on the advisory board of AstraZeneca, Roche/Genentech, Pfizer, Eli Lilly, BI, Merck Serono, MSD, Janssen, Clovis Oncology, BioMarin, GSK, Novartis, SFJ Pharmaceutical, ACEA Biosciences, Inc., Vertex Pharmaceuticals, Aveo & Biodesix and BMS. The remaining author has declared no conflicts of interest.

references 1. Schuler M, Yang JC, Park K et al. Afatinib beyond progression in patients with non-small-cell lung cancer following chemotherapy, erlotinib/gefitinib and afatinib: phase III randomized LUX-Lung 5 trial. Ann Oncol 2016; 27: 417–423.

 | Raghupathy and Mok

2. Li D, Ambrogio L, Shimamura T et al. BIBW2992, an irreversible EGFR/HER2 inhibitor highly effective in preclinical lung cancer models. Oncogene 2008; 27(34): 4702–4711. 3. Sequist LV, Yang JC, Yamamoto N et al. Phase III study of afatinib or cisplatin plus pemetrexed in patients with metastatic lung adenocarcinoma with EGFR mutations. J Clin Oncol 2013; 31(27): 3327–3334. 4. Wu YL, Zhou C, Hu CP et al. Afatinib versus cisplatin plus gemcitabine for firstline treatment of Asian patients with advanced non-small-cell lung cancer harbouring EGFR mutations (LUX-Lung 6): an open-label, randomised phase 3 trial. Lancet Oncol 2014; 15(2): 213–222. 5. Miller VA, Hirsh V, Cadranel J et al. Afatinib versus placebo for patients with advanced, metastatic non-small-cell lung cancer after failure of erlotinib, gefitinib, or both, and one or two lines of chemotherapy (LUX-Lung 1): a phase 2b/3 randomised trial. Lancet Oncol 2012; 13(5): 528–538. 6. Katakami N, Atagi S, Goto K et al. LUX-Lung 4: a phase II trial of afatinib in patients with advanced non-small-cell lung cancer who progressed during prior treatment with erlotinib, gefitinib, or both. J Clin Oncol 2013; 31(27): 3335–3341. 7. Jackman DM, Miller VA, Cioffredi LA et al. Impact of epidermal growth factor receptor and KRAS mutations on clinical outcomes in previously untreated nonsmall cell lung cancer patients: results of an online tumor registry of clinical trials. Clin Cancer Res 2009; 15(16): 5267–5273. 8. Garassino MC, Martelli O, Broggini M et al. Erlotinib versus docetaxel as secondline treatment of patients with advanced non-small-cell lung cancer and wild-type EGFR tumours (TAILOR): a randomised controlled trial. Lancet Oncol 2013; 14 (10): 981–988. 9. Jackman D, Pao W, Riely GJ et al. Clinical definition of acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors in non-small-cell lung cancer. J Clin Oncol 2010; 28(2): 357–360. 10. Mok TS, Wu YL, Thongprasert S et al. Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma. N Engl J Med 2009; 361(10): 947–957. 11. Park K, Yu CJ, Kim SW et al. First-line erlotinib therapy until and beyond response evaluation criteria in solid tumors progression in Asian patients with epidermal growth factor receptor mutation-positive non-small-cell lung cancer: the ASPIRATION Study. JAMA Oncol 2015 Dec 30 [epub ahead of print], doi: 10.1001/jamaoncol.2015.4921. 12. Soria JC, Wu YL, Nakagawa K et al. Gefitinib plus chemotherapy versus placebo plus chemotherapy in EGFR-mutation-positive non-small-cell lung cancer after progression on first-line gefitinib (IMPRESS): a phase 3 randomised trial. Lancet Oncol 2015; 16(8): 990–998. 13. Soria JC, Kim SW, Wu YL et al. Gefitinib/chemotherapy vs chemotherapy. In EGFR mutation-positive NSCLC resistant to first-line gefitinib: IMPRESS T790M subgroup analysis. World Conference on Lung Cancer: Abstract ORAL 17.08, 2015. 14. Kim Y, Ko J, Cui Z et al. The EGFR T790M mutation in acquired resistance to an irreversible second-generation EGFR inhibitor. Mol Cancer Ther 2012; 11(3): 784–791. 15. Rocha GZ, Dias MM, Ropelle ER et al. Metformin amplifies chemotherapy-induced AMPK activation and antitumoral growth. Clin Cancer Res 2011; 17(12): 3993–4005. 16. Le XF, Hittelman WN, Liu J et al. Paclitaxel induces inactivation of p70 S6 kinase and phosphorylation of Thr421 and Ser424 via multiple signaling pathways in mitosis. Oncogene 2003; 22(4): 484–497. 17. Suder A, Ang JE, Kyle F et al. A phase I study of daily afatinib, an irreversible ErbB family blocker, in combination with weekly paclitaxel in patients with advanced solid tumours. Eur J Cancer 2015; 51(16): 2275–2284.

Volume 27 | No. 3 | March 2016

Downloaded from http://annonc.oxfordjournals.org/ at New York University on March 1, 2016

the afatinib paclitaxel combination was more striking in squamous cell histology [n = 17; HR: 0.15 (0.03–0.62)] compared with adenocarcinoma [n = 174; HR: 0.69 (0.49–0.99)]; in Caucasians [n = 77, HR:0.47 (0.27–0.82)] compared with East Asians [n = 82, HR: 0.67 (0.39–1.15)] and in those that had received previous taxane [n = 105; HR: 0.51 (0.32–0.80)] compared with those that had not [n = 97, HR:0.75 (0.45–1.24])]. However, the true benefit of the combination should be compared against only paclitaxel in the control arm. According to the supplementary Table S4, available at Annals of Oncology online, the median PFS of different agents in the control arm was 3.8 months for paclitaxel, 2.9 months for pemetrexed and 2.1 months for others. The difference between the combination and the paclitaxel alone subgroup was not statistically significant. It remains unclear if there is a true benefit of the combination over single-agent paclitaxel alone for patients with predominantly wild-type EGFR. The past decade of investigation has confirmed lung cancer to be a heterogeneous, molecularly diverse disease. We have learnt from LUX Lung 5 but we would have learnt a lot more if patients were selected according to molecular profile.

Annals of Oncology

Being molecular in the molecular age.

Being molecular in the molecular age. - PDF Download Free
57KB Sizes 0 Downloads 10 Views