RET-rearranged Lung Cancers Research Articles

Targeting RET in Patients With RET-Rearranged Lung Cancers: Results From the Global, Multicenter RET Registry.

Purpose In addition to prospective trials for non-small-cell lung cancers (NSCLCs) that are driven by less common genomic alterations, registries provide complementary information on patient response to targeted therapies. Here, we present the results of an international registry of patients with RET-rearranged NSCLCs, providing the largest data set, to our knowledge, on outcomes of RET-directed therapy thus far. Methods A global, multicenter network of thoracic oncologists identified patients with pathologically confirmed NSCLC that harbored a RET rearrangement. Molecular profiling was performed locally by reverse transcriptase polymerase chain reaction, fluorescence in situ hybridization, or next-generation sequencing. Anonymized data-clinical, pathologic, and molecular features-were collected centrally and analyzed by an independent statistician. Best response to RET tyrosine kinase inhibition administered outside of a clinical trial was determined by RECIST v1.1. Results By April 2016, 165 patients with RET-rearranged NSCLC from 29 centers across Europe, Asia, and the United States were accrued. Median age was 61 years (range, 29 to 89 years). The majority of patients were never smokers (63%) with lung adenocarcinomas (98%) and advanced disease (91%). The most frequent rearrangement was KIF5B-RET (72%). Of those patients, 53 received one or more RET tyrosine kinase inhibitors in sequence: cabozantinib (21 patients), vandetanib (11 patients), sunitinib (10 patients), sorafenib (two patients), alectinib (two patients), lenvatinib (two patients), nintedanib (two patients), ponatinib (two patients), and regorafenib (one patient). The rate of any complete or partial response to cabozantinib, vandetanib, and sunitinib was 37%, 18%, and 22%, respectively. Further responses were observed with lenvantinib and nintedanib. Median progression-free survival was 2.3 months (95% CI, 1.6 to 5.0 months), and median overall survival was 6.8 months (95% CI, 3.9 to 14.3 months). Conclusion Available multikinase inhibitors had limited activity in patients with RET-rearranged NSCLC in this retrospective study. Further investigation of the biology of RET-rearranged lung cancers and identification of new targeted therapeutics will be required to improve outcomes for these patients.

MA16.03 Global RET Registry (GLORY): Activity of RET-Directed Targeted Therapies in RET-Rearranged Lung Cancers

MA16.03 Global RET Registry (GLORY): Activity of RET-Directed Targeted Therapies in RET-Rearranged Lung Cancers

OA11.05 A Phase 2 Study of Cabozantinib for Patients with Advanced RET-Rearranged Lung Cancers

OA11.05 A Phase 2 Study of Cabozantinib for Patients with Advanced RET-Rearranged Lung Cancers

P3.02c-017 ‘2nd Line’ RET-Inhibition in a Female Patient with Non-KIF5B RET-Translocation: Topic: Targeted Therapy

RET-rearrangement in unselected non-small cell lung cancer (NSCLC) is expected in 1-2%, most common in adenocarcinomas, young, never or former light smoker. Multikinase Inhibitors such as cabozantinib or vandetanib have shown acitivity against RET-rearranged lung cancer in vitro and in vivo. ORR is about 40% and median duration of response about 8 month with cabozantinib. Progression after RET-inhibition warrants further strategies. 2nd line RET-inhibition might overcome resistance. We report about a 77 year old female patient with primary diagnosis of adenocarcinoma of the lung with malignant pleural effusion, stage IV, in 08/13. EFGR-mutation, ALK- and ROS1-translocation were negative at initial diagnosis. 1st line therapy with carboplatin and paclitaxel resulted in stable disease and clinical deterioration. A VATS was performed with partial resolution of pleural effusion. 2nd line therapy with pemetrexed for 16 months resulted in a clinical benefit (cough and dyspnoe, ECOG raised from 2 to 0). In 07/15 CT scan revealed a dissiminated progression with multiple intrapulmonary nodules, clinically corresponding with cough and dyspnoe again. Molecular diagnostic for cMET, BRAF, KRAS, HER2, PD-L1 revealed no new targets, but a positive RET-FISH testing from initial biopsy. From 10/15 to 03/16 the patient had a good clinical benefit from cabozantinib (multikinase inhibition, including RET). Clinical symptoms resolved in 10 days and ECOG raised from 1 to 0. In 03/16 new hepatic and lymphonodular lesions occurred and the patient suffered again from former clincical symptoms. One cycle gemcitabine was without any benefit. In 04/16 we started with docetaxel 35mg/m2 on day 1 and 8, q3w, combined with nintedanib 200mg twice daily (except day 1 and 8). Again, the patient had an immediate clinical benefit (within 1 week; cough and dyspnoe) and the ECOG raised from 1 to 0. FISH analysis from initial biopsy revealed a non-KIF5B-RET-fusion. This type might show a substatial benefit in the preliminary literature. Nintedanib (plus docetaxel) in a patient with PD on cabozantinib resulted in good clinical response in a patient with a non-KIF5B-RET-mutation. This case illustrates that treatment with a 'second-line' TKI (such as nintedanib) can be effective in RET-rearranged NSCLC.

Cabozantinib in patients with advanced RET-rearranged non-small-cell lung cancer: an open-label, single-centre, phase 2, single-arm trial

SUMMARYBackgroundRET rearrangements are found in 1–2% of non-small cell lung cancers. Cabozantinib is a multikinase RET inhibitor that produced a 10% response rate in unselected patients with lung cancers. To evaluate the activity of cabozantinib in patients with RET-rearranged lung cancers, we conducted a prospective phase 2 trial in this molecular subgroup.MethodsWe enrolled patients in this open-label, Simon two-stage, phase 2 trial if they met the following criteria: metastatic or unresectable lung cancer harboring a RET rearrangement, Karnofsky performance status of >70%, and measurable disease. Cabozantinib was administered at 60 mg daily. The primary objective was to determine the overall response rate (RECIST v1·1). This analysis was performed in an intent to treat fashion in patients who received at least one dose of cabozantinib and underwent imaging performed at baseline and at least one protocol-specified follow up time point. The secondary objectives were to determine progression-free survival, overall survival, and toxicity. The accrual of RET-rearranged lung cancer patients to this protocol has been completed. This study was registered with ClinicalTrials.gov, number NCT01639508.FindingsTwenty six patients with RET-rearranged lung adenocarcinomas were treated with cabozantinib. KIF5B-RET was the predominant fusion type identified in 16 (62%) patients. The study met its primary endpoint with confirmed partial responses observed in seven of 25 response-evaluable patients (overall response rate 28% [95% CI 12–49%]). The most common grade 3 treatment-related adverse events were asymptomatic lipase elevation in four patients (15%), increased alanine aminotransferase in two patients (8%), increased aspartate aminotransferase in two patients (8%), thrombocytopenia in two patients (8%), and hypophosphatemia in two patients (8%). No drug-related deaths were observed. Nineteen patients (73%) required dose reduction due to drug-related adverse events.InterpretationThe observed activity of cabozantinib in patients with RET-rearranged lung cancers defines RET rearrangements as actionable drivers in patients with lung cancers. An improved understanding of tumor biology and novel therapeutic approaches will be required to improve outcomes with RET-directed targeted therapy.

Targeted therapy outcomes in RET-rearranged lung cancers: drug or driver?

Targeted therapy outcomes in RET-rearranged lung cancers: drug or driver?

Clinical outcomes with pemetrexed-based systemic therapies in RET-rearranged lung cancers

RET rearrangements are targetable, oncogenic lung cancer drivers. While previous series have shown durable clinical benefit with pemetrexed-based therapies in ALK- and ROS1-rearranged lung cancers, the benefits of pemetrexed-based treatments in patients with RET-rearranged lung cancers relative to other genomic subsets have not previously been explored. A retrospective review of patients with pathologically confirmed stage IIIB/IV lung adenocarcinomas and evidence of a RET, ROS1, or ALK rearrangement, or a KRAS mutation was conducted. Patients were eligible if they received treatment with pemetrexed alone or in combination. The primary outcome of progression-free survival (PFS), and secondary outcomes of overall response rate (ORR, RECIST v1.1), time to progression (TTP), and time to treatment discontinuation were compared between RET-rearranged and groups of ROS1-rearranged, ALK-rearranged, and KRAS-mutant lung cancers. We evaluated 104 patients. Patients with RET-rearranged lung cancers (n = 18) had a median PFS of 19 months [95% confidence interval (CI) 12-not reached (NR)] that was comparable with patients with ROS1- (23 months, 95% CI 14-NR, n = 10) and ALK-rearranged (19 months, 95% CI 15-36, n = 36) lung cancers, and significantly improved compared with patients with KRAS-mutant lung cancers (6 months, 95% CI 5-9, P < 0.001, n = 40). ORR (45%), median TTP (20 months, 95% CI 17-NR), and median time to treatment discontinuation (21 months, 95% CI 6-NR) in patients with RET-rearranged lung cancers were not significantly different compared with patients with ALK- and ROS1-rearranged lung cancers, and improved compared with patients with KRAS-mutant lung cancers. Durable benefits with pemetrexed-based therapies in RET-rearranged lung cancers are comparable with ALK- and ROS1-rearranged lung cancers. When selecting therapies for patients with RET-rearranged lung cancers, pemetrexed-containing regimens should be considered.

MDM2 amplification (Amp) to mediate cabozantinib resistance in patients (Pts) with advanced RET-rearranged lung cancers.

9068Background: The RET inhibitor cabozantinib is active in pts with RET-rearranged lung cancers. We previously reported an overall response rate of 38% on an ongoing phase 2 study (Drilon ASCO 201...

Clinicopathological Characteristics of RET Rearranged Lung Cancer in European Patients

IntroductionRearrangements of RET are rare oncogenic events in patients with non–small cell lung cancer (NSCLC). While the characterization of Asian patients suggests a predominance of nonsmokers of young age in this genetically defined lung cancer subgroup, little is known about the characteristics of non-Asian patients. We present the results of an analysis of a European cohort of patients with RET rearranged NSCLC. MethodsNine hundred ninety-seven patients with KRAS/EGFR/ALK wildtype lung adenocarcinomas were analyzed using fluorescence in situ hybridization for RET fusions. Tumor specimens were molecularly profiled and clinicopathological characteristics of the patients were collected. ResultsRearrangements of RET were identified in 22 patients, with a prevalence of 2.2% in the KRAS/EGFR/ALK wildtype subgroup. Co-occurring genetic aberrations were detected in 10 patients, and the majority had mutations in TP53. The median age at diagnosis was 62 years (range, 39–80 years; mean ± SD, 61 ± 11.7 years) with a higher proportion of men (59% versus 41%). There was only a slight predominance of nonsmokers (54.5%) compared to current or former smokers (45.5%). ConclusionsPatients with RET rearranged adenocarcinomas represent a rare and heterogeneous NSCLC subgroup. In some contrast to published data, we see a high prevalence of current and former smokers in our white RET cohort. The significance of co-occurring aberrations, so far, is unclear.

From genotype to phenotype: Are there imaging characteristics associated with lung adenocarcinomas harboring RET and ROS1 rearrangements?

Recurrent gene rearrangements are important drivers of oncogenesis in non-small cell lung cancers. RET and ROS1 rearrangements are each found in 1-2% of lung adenocarcinomas and represent distinct molecular subsets. This study assessed the computed tomography (CT) imaging features of patients with RET- and ROS1-rearranged lung cancers. Eligible patients included pathologically-confirmed lung adenocarcinomas of any stage with a RET or ROS1 rearrangement via fluorescence in-situ hybridization or next-generation sequencing, and available pre-treatment baseline imaging for review. A cohort of EGFR-mutant lung cancers was identified as a control group. CT features assessed included location, consistency, contour, presence of cavitation, and calcification of the primary tumor. Presence of an effusion, lung metastases, adenopathy and extrathoracic disease were recorded. The Wilcoxon rank-sum/Kruskal-Wallis and Fisher's exact tests were used to compare features between groups. 73 patients with lung adenocarcinomas were identified: 17 (23%) with ROS1 fusions, 25 (34%) with RET fusions and 31 (43%) with EGFR mutations. ROS1-rearranged lung cancers were more likely to present as peripheral tumors in comparison to EGFR-mutant lung cancers (32% vs. 65%, p=0.04). RET-rearranged lung cancers did not significantly differ from EGFR-mutant lung cancers radiographically. The consistency of the primary lesion for RET and ROS fusions and EGFR mutations were most frequently solid and spiculated. Lung adenocarcinomas with RET and ROS1 fusions share many radiographic features and those with ROS1 fusions are more likely to present as peripheral lesions in comparison to EGFR-mutant lung cancers.

Abstract 773: Alectinib shows potent antitumor activity against both ALK- and RET-rearranged non-small cell lung cancers

Abstract We have shown that alectinib is a potent ALK inhibitor and is being evaluated in clinical trials for the treatment of ALK fusion-positive non-small cell lung cancer (NSCLC). Recently, RET and ROS1 fusion genes have been implicated as driver oncogenes in 1-2% of NSCLC and have been developed into promising molecular targets for antitumor agents. Here, we investigate the additional target indication of alectinib by testing its ability to inhibit the activity of RET and ROS1 kinases. In enzyme assay, alectinib showed kinase inhibitory activity against RET as wells as ALK but did not show against ROS1. Alectinib inhibited the growth of LC-2/ad cells harboring CCDC6-RET and Ba/F3 cells expressing KIF5B-RET by suppressing RET phosphorylation. Alectinib also showed antitumor activity in mouse models of RET fusion-positive tumors (LC-2/ad cells and Ba/F3 cells expressing KIF5B-RET) and of ALK fusion-positive tumors (NCI-H2228 cells harboring EML4-ALK). In addition, alectinib showed kinase inhibitory activity against RET gatekeeper mutations (RET V804L and V804M) and blocked KIF5B-RET gatekeeper mutation-driven cell growth. Our results suggest that alectinib is effective against RET fusion-positive tumors, as observed in ALK fusion-positive tumors. Thus, alectinib might be a therapeutic option for patients with RET fusion-positive NSCLC. Citation Format: Tatsushi Kodama, Toshiyuki Tsukaguchi, Yasuko Satoh, Miyuki Yoshida, Yoshiaki Watanabe, Osamu Kondoh, Hiroshi Sakamoto. Alectinib shows potent antitumor activity against both ALK- and RET-rearranged non-small cell lung cancers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 773. doi:10.1158/1538-7445.AM2015-773

Systemic and CNS activity of the RET inhibitor vandetanib combined with the mTOR inhibitor everolimus in KIF5B-RET re-arranged non-small cell lung cancer with brain metastases

In-frame fusion KIF5B (the-kinesin-family-5B-gene)-RET transcripts have been characterized in 1-2% of non-small cell lung cancers and are known oncogenic drivers. The RET tyrosine kinase inhibitor, vandetanib, suppresses fusion-induced, anchorage-independent growth activity. In vitro studies have shown that vandetanib is a high-affinity substrate of breast cancer resistance protein (Bcrp1/Abcg2) but is not transported by P-glycoprotein (P-gp), limiting its blood-brain barrier penetration. A co-administration strategy to enhance the brain accumulation of vandetanib by modulating P-gp/Abcb1- and Bcrp1/Abcg2-mediated efflux with mTOR inhibitors, specifically everolimus, was shown to increase the blood-brain barrier penetration. We report the first bench-to-bedside evidence that RET inhibitor combined with an mTOR inhibitor is active against brain-metastatic RET-rearranged lung cancer and the first evidence of blood-brain barrier penetration. A 74-year-old female with progressive adenocarcinoma of the lung (wild-type EGFR and no ALK rearrangement) presented for therapy options. A deletion of 5'RET was revealed by FISH assay, indicating RET-gene rearrangement. Because of progressive disease in the brain, she was enrolled in a clinical trial with vandetanib and everolimus (NCT01582191). Comprehensive genomic profiling revealed fusion of KIF5B (the-kinesin-family-5B-gene) and RET, in addition to AKT2 gene amplification. After two cycles of therapy a repeat MRI brain showed a decrease in the intracranial disease burden and PET/CT showed systemic response as well. Interestingly, AKT2 amplification seen is a critical component of the PI3K/mTOR pathway, alterations of which has been associated with both de novo and acquired resistance to targeted therapy. The addition of everolimus may have both overcome the AKT2 amplification to produce a response in addition to its direct effects on the RET gene. Our case report forms the first evidence of blood-brain barrier penetration by vandetanib in combination with everolimus. Further research is required in this setting.