Hansang Lee

Efficacy of BRAF Inhibitors in Asian Metastatic Melanoma Patients: Potential Implications of Genomic Sequencing in BRAF-Mutated Melanoma

BACKGROUND: The BRAF inhibitors vemurafenib and dabrafenib are currently the standard treatment for metastatic melanoma with BRAF V600 mutations. However, given the rarity of noncutaneous melanoma, including acral and mucosal subtypes, the efficacy of BRAF inhibitors for this subset of patients has not been extensively investigated. Acquired resistance generally appears 6 to 8 months after treatment with a BRAF inhibitor, and the mechanism of resistance is not well established. METHODS: We examined treatment outcomes for patients diagnosed with metastatic melanoma and treated with BRAF inhibitors at Samsung Medical Center between April 2013 and December 2015. We analyzed genomic alterations in selected patients using targeted sequencing. RESULTS: Twenty-seven patients with a median age of 49 years (range 23-82 years) with metastatic melanoma and treated with a BRAF inhibitor were identified. Of these patients, 19 (70.3%) had noncutaneous melanoma, including acral and mucosal melanoma. All patients had BRAFV600E mutations. The median progression-free survival of all patients was 9.2 months (95% confidence interval, 1.6-16.7), and the objective response rate was 78.9% in the mucosal/acral melanoma group and 75.0% in the cutaneous melanoma group. Three (11.1%) patients achieved complete response, and 19 (70.4%) showed a partial response. Targeted sequencing in five patients demonstrated NF1 mutations in three patients who did not respond to BRAF inhibitors. CONCLUSION: BRAF inhibitors were an effective therapeutic option for Korean patients with metastatic melanoma harboring a BRAF V600 mutation regardless of melanoma subtype (acral/mucosa versus cutaneous).

Clinical activity of fulvestrant in metastatic breast cancer previously treated with endocrine therapy and/or chemotherapy

Background/Aims We conducted a retrospective analysis of the clinical activity of fulvestrant in postmenopausal women with hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC) previously treated with endocrine therapy and/or chemotherapy. Methods We reviewed the medical records of all patients with MBC treated at Samsung Medical Center between January 2009 and August 2016. Patients received fulvestrant 250 mg intramuscularly every 28 days (from January 2009 to November 2010) or 500 mg intramuscularly every 28 days (from December 2010 to August 2016). Tumor responses were assessed every 8 weeks and at the end of treatment, as well as when disease progression was suspected. Results A total of 84 patients were included in this study. A median of two previous endocrine treatments had been performed; 79% of the patients had received two or more endocrine treatments. Forty-five patients (54%) had been treated with chemotherapy for MBC before the fulvestrant treatment course. Visceral metastasis was found in 49 patients (58%). The estimated median progression-free survival and overall survival were 4.4 months (95% confidence interval [CI], 3.4 to 5.5) and 32.5 months (95% CI, 17.6 to 47.4), respectively. The disease control rate was 40.5% (95% CI, 30.5 to 51.5); partial response was observed in 16% of the patients and stable disease was observed in 25% of the patients. The most frequently reported adverse reactions were mild-to-moderate grade myalgia (10.5% of the patients), injection site pain (7%), and fatigue (7%). Fulvestrant was generally well tolerated. Conclusions Fulvestrant showed encouraging clinical activity and favorable feasibility in postmenopausal women with MBC who had been treated with multiple endocrine therapies and/or cytotoxic chemotherapies.

Continuation of gefitinib beyond progression in patients with EGFR mutation-positive non-small-cell lung cancer: A phase II single-arm trial

OBJECTIVES Several studies have demonstrated the promise of continuation of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) beyond progression in patients with EGFR-mutant non-small-cell lung cancer (NSCLC). The aim of the present study is to clarify the efficacy of continuation of gefitinib in patients with NSCLC beyond progression. MATERIALS AND METHODS A total of 50 patients with EGFR-mutant NSCLC who progressed based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria during gefitinib treatment were eligible. The primary endpoint was progression-free survival-2 (PFS2; time from first gefitinib dose to off-gefitinib progression). Secondary endpoints were PFS1 (time from first gefitinib dose to RECIST 1.1 progression); the difference between PFS2 and PFS1 (PFS2-PFS1); overall survival (OS); and safety. Patients received gefitinib 250 mg/d orally until symptomatic progression or at the investigators discretion. RESULTS Between January 2016 and March 2017, 50 patients were enrolled in this study. One patient withdrew consent, leaving a total of 49 patients to be evaluated. The median PFS2-PFS1 was 5.1 months (95% CI, 2.5-7.8), and the median PFS2 was 27.7 months (95% CI, 21.6-33.9). Twelve patients (24.4%) continued gefitinib therapy for 14 months (median value, range 7.2-20.3 months) after RECIST 1.1 progression. The median OS was not reached. Patients were classified by the characteristics of progression at the time of enrollment. PFS2-PFS1 was significantly shorter in patients with pleural metastasis or pleural effusion compared with the other types of progression (1.8 months vs. 7.1 months, p-value = 0.005). CONCLUSION In patients with EGFR-mutant NSCLC who experience progression, it is beneficial to maintain gefitinib treatment with local treatment such as radiotherapy until symptomatic progression. However, in patients with pleural metastasis or effusion, continuation of gefitinib beyond progression should be carefully determined on a case by case basis.

Transient Asymptomatic Pulmonary Opacities During Osimertinib Treatment and its Clinical Implication

Introduction: Osimertinib is an oral, potent, irreversible third‐generation EGFR tyrosine kinase inhibitor approved for the treatment of T790M‐positive NSCLC patients who failed first‐ or second‐generation EGFR tyrosine kinase inhibitors. Interstitial lung disease (ILD) is a rare complication with osimertinib, occurring in 1% to 3% of patients. Recently, a relatively high incidence of transient asymptomatic pulmonary opacities (TAPOs), which are different from ILD, has been described. However, its clinical implication has not been fully determined yet. Methods: We retrospectively analyzed 74 EGFR T790M mutant NSCLC patients treated with osimertinib. Serial computed tomographic findings were reviewed by a thoracic radiologist independently, and TAPO was classified according to its radiologic pattern. We also analyzed the correlation of TAPO with clinical outcomes. Results: Among 74 patients, TAPOs were found in 15 (20.3%). The median time to TAPO development was 24.0 weeks (range, 1 to 72 weeks) and the median duration of TAPO was 6.0 weeks (range, 5 to 24 weeks) during continued osimertinib treatment. The most common radiological patterns of TAPO include cryptogenic organizing pneumonia and/or simple eosinophilic pneumonia. There was no significant difference in patient characteristics between TAPO‐positive and ‐negative groups. The duration of exposure to osimertinib was significantly longer in TAPO‐positive than ‐negative groups (25.0 months versus 13.0 months, p = 0.009). The median progression‐free survival and the median overall survival was numerically longer in TAPO‐positive than ‐negative groups (22 months versus 15 months for progression‐free survival, p = 0.293; 37 months versus 24 months for overall survival, p = 0.059), respectively. Conclusions: TAPOs are frequently observed with osimertinib treatment and may be mistaken for isolated pulmonary progression or drug‐induced ILD. Given the lack of serious clinical deterioration, it is reasonable to continue osimertinib with regular computed tomographic–scan follow‐up. For further clinical validation of TAPOs, long‐term follow‐up and large studies are warranted.

The Clinical Impact of c-MET Over-Expression in Advanced Biliary Tract Cancer (BTC)

Background: c-MET is a proto-oncogene that encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF). Activation of HGF-c-MET signaling involves cell invasiveness and evokes metastasis through direct involvement of tumor angiogenesis. However, the value of c-MET overexpression is still unknown in metastatic biliary tract cancer (BTC). Methods: We analyzed the incidence and clinicopathologic characteristics of c-MET overexpression in advanced BTC. Moreover, we investigated the value of c-MET overexpression in predicting response to gemicitabine plus cisplatin (GC), a first line standard regimen, and as a prognostic marker in metastatic BTC. Results: The BTC subtype distribution (N=44) was as follows: intrahepatic cholangiocarcinoma (IHCC, n=7), extrahepatic cholangiocarcinoma (EHCC, n=25) and gallbladder cancer (GBC, n=12). Liver (52.3%) was the predominant metastatic site, followed by lymph nodes (36.4%) and bone (15.9%). Among the 44 patients analyzed for c-MET expression, 15 (34.1%) exhibited c-MET overexpression in tumor tissues. There was no significant difference in the prevalence of c-MET overexpression among primary sites in EHCC (7/25, 28.0%), IHCC (3/7, 42.9%), and GBC (5/12, 41.7%). There was also no significant correlation between specific clinicopathologic variables and c-MET expression. Comparing the tumor-response to GC according to c-MET expression (overexpression vs. non-overexpression), there was no significant difference in either RR or DCR (p=0.394 and p >0.999, respectively). The median PFS for all 44 patients was 9.00 months (95% CI, 7.5-10.5 months) and there was no significant difference for PFS between patients with c-MET overexpression and those without (p=0.917). The median OS was 14.4 months (95% CI, 11.9-16.9 months). There was no significant difference in OS between patients with c-MET overexpression compared to those without (13.7 vs. 14.4 months, respectively; p=0.708). Conclusions: c-MET overexpression was detected in 34.1% of advanced BTC patients irrespective of tumor location. c-MET overexpression did not predict response to GC or survival. Further studies are needed to fully elucidate the value of c-MET overexpression as a novel biomarker in these patients.

Abstract 3815: The clinical impact of c-MET over-expression in advanced biliary tract cancers

Background: c-MET is a proto-oncogene that encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF). Activation of HGF-c-MET signaling involves cell invasiveness and evokes metastasis through direct involvement of tumor angiogenesis. However, the value of c-MET overexpression is still unknown in metastatic BTC. Methods: We analyzed the incidence and clinicopathologic characteristics of c-MET overexpression in advanced BTC. Moreover, we investigated the value of c-MET overexpression in predicting response to gemicitabine plus cisplatin (GC), a first line standard regimen, and as a prognostic marker in metastatic BTC. Results: The BTC subtype distribution (N=44) was as follows: intrahepatic cholangiocarcinoma (IHCC, n=7), extrahepatic cholangiocarcinoma (EHCC, n=25) and gallbladder cancer (GBC, n=12). Liver (52.3%) was the predominant metastatic site, followed by lymph nodes (36.4%) and bone (15.9%). Among the 44 patients analyzed for c-MET expression, 15 (34.1%) exhibited c-MET overexpression in tumor tissues. There was no significant difference in the prevalence of c-MET overexpression among primary sites in EHCC (7/25, 28.0%), IHCC (3/7, 42.9%), and GBC (5/12, 41.7%). There was also no significant correlation between specific clinicopathological variables and c-MET expression. Comparing the tumor-response to GC according to c-MET expression (overexpression vs. non-overexpression), there was no significant difference in either RR or DCR (p=0.394 and 1.000, respectively). PFS for all 44 patients was 9.00 months (95%CI, 7.47-10.53 months) and there was no significant difference for PFS between patients with c-MET overexpression and those without (p=0.917). The median OS was 14.4 months (95% CI, 12.8-19.2). There was a significant difference in OS between patients with c-MET overexpression compared to those without (13.7 vs. 14.4 months, respectively; p=0.708). Conclusions: c-MET overexpression was detected in 34.1% of advanced BTC patients irrespective of tumor location. c-MET overexpression did not predict response to GC or survival. Further studies are needed to fully elucidate the value of c-MET overexpression as a novel biomarker in these patients. Citation Format: Mi Hwa Heo, Seung Tae Kim, Young Suk Park, Joon Oh Park, Hansang Lee. The clinical impact of c-MET over-expression in advanced biliary tract cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3815. doi:10.1158/1538-7445.AM2017-3815