Yan Kong

Phase II, Open-Label, Single-Arm Trial of Imatinib Mesylate in Patients With Metastatic Melanoma Harboring c-Kit Mutation or Amplification

PURPOSE Melanomas harbor aberrations in the c-Kit gene. We tested the efficiency of the tyrosine kinase inhibitor imatinib in selected patients with metastatic melanoma harboring c-Kit mutations or amplifications. PATIENTS AND METHODS Forty-three patients with metastatic melanoma harboring c-Kit aberrations were enrolled on this phase II trial. Each patient received a continuous dose of imatinib 400 mg/d unless intolerable toxicities or disease progression occurred. Fifteen patients who experienced progression of disease were allowed to escalate the dose to 800 mg/d. RESULTS Forty-three patients were eligible for evaluation, and the median follow-up time was 12.0 months. The median progression-free survival (PFS) was 3.5 months, and the 6-month PFS rate was 36.6%. Rate of total disease control was 53.5%: 10 patients (23.3%; 95% CI, 10.2% to 36.4%) and 13 patients (30.2%; 95% CI, 16.0% to 44.4%) achieved partial response (PR) and stable disease (SD), respectively. Eighteen patients (41.9%) demonstrated regression of tumor mass. Notably, nine of the 10 PRs were observed in patients with mutations in exons 11 or 13. The 1-year overall survival (OS) rate was 51.0%. The median PFS and OS times for patients who had PR or SD versus disease progression were 9.0 months versus 1.5 months (P < .001) and 15.0 months versus 9.0 months (P = .036), respectively. Imatinib 400 mg/d was well tolerated, and only one of the 15 patients who received dose escalation to 800 mg/d achieved SD. CONCLUSION Imatinib demonstrated significant activity in patients with metastatic melanoma harboring genetic c-Kit aberrations, with an overall response rate of 23.3%. Escalation to 800 mg/d could not restore disease control.

Large-Scale Analysis of KIT Aberrations in Chinese Patients with Melanoma

Purpose:KIT aberrations were described in acral and mucosal melanomas in largely Caucasian populations. Asian populations are more prone to develop acral and mucosal than cutaneous melanomas, and may harbor a high frequency of KIT aberrations. Experimental Design: Melanoma subtypes (n = 502) were analyzed histologically to determine melanoma subtype. Tissue samples were analyzed for mutations in exons 9, 11, 13, 17, and 18 of KIT gene in genomic DNA by PCR amplification and Sanger sequencing. The copy numbers of the KIT gene were analyzed by quantitative PCR, and protein expression levels of KIT (CD117) were determined by immunohistochemistry. Results: The most common melanoma subtypes were acral (38.4%) and mucosal (33.3%) melanomas in this population. The overall incidence of somatic mutations within the KIT gene was 10.8% (54/502), and all subtypes of melanoma contained KIT mutations. Increases in KIT gene copy numbers were correlated to CD117 overexpression. The genetic mutations of KIT were unrelated to the age, gender, stage, thickness, and ulceration of primary melanomas. Importantly, the overall survival of melanoma patients with KIT mutations (P = 0.001) or with KIT aberrations (mutation plus amplification, P = 0.0002) was significantly shorter than that of patients without such alterations. Conclusion: In China, the prevalent melanomas are acral and mucosal melanomas. KIT mutations are detected in all melanoma subtypes. Our study suggests that increases in KIT gene copy numbers, but not KIT mutations, may be correlated to CD117 overexpression. For the first time, our study suggests that genetic KIT aberration is an adverse prognostic factor for melanoma. Clin Cancer Res; 17(7); 1684–91. ©2011 AACR.

Prevalence of BRAF V600E mutation in Chinese melanoma patients: large scale analysis of BRAF and NRAS mutations in a 432-case cohort.

BACKGROUND Mutations of NRAS and BRAF have been described in Caucasian melanomas. However, the status and the clinical significance of BRAF and NRAS mutations in the Asian population have not been investigated on a large scale. METHODS Melanoma samples (n=432) were analysed for mutations in exons 11 and 15 of the BRAF gene, and exons 1 and 2 of the NRAS gene in genomic DNA by polymerase chain reaction (PCR) amplification and Sanger sequencing. Mutations of BRAF and NRAS genes were correlated to clinicopathologic features and prognosis of the patients. RESULTS The incidence of somatic mutations within the BRAF and NRAS genes was 25.5% (110/432) and 7.2% (31/432), respectively. Among the 110 patients with BRAF mutations, 98 patients (89.1%) had V600E mutations. Melanomas without chronic sun-induced damage (Non-CSD) were more likely (P<0.01) to show BRAF mutations while NRAS mutation frequency was unbiased between melanoma subtypes. Patients with genetic mutations in BRAF (P<0.01) or NRAS (P=0.04) gene are more likely to have ulceration as compared to patients without BRAF or NRAS mutations, respectively. Both BRAF (P=0.003) and NRAS mutations (P=0.031) are inversely correlated to overall survival. CONCLUSIONS BRAF mutation is frequent while mutations in NRAS gene are rare. The most prevalent BRAF mutation type is V600E. Patients with mutations in BRAF or NRAS gene are frequently present with ulceration, and mutation in BRAF or NRAS gene is indicator for poor prognosis. Our study may warrant a clinical trial of kinase inhibitors targeting BRAF V600E in Chinese and Asian melanoma patients.

Phase II randomized trial comparing high-dose IFN-α2b with temozolomide plus cisplatin as systemic adjuvant therapy for resected mucosal melanoma.

Purpose: Mucosal melanoma is rare and associated with extremely poor prognosis. However, standard adjuvant therapy for mucosal melanoma has not been established. We conducted a randomized phase II clinical trial in patients with resected mucosal melanoma to compare the efficacy and safety of high-dose IFN-α2b (HDI) and temozolomide-based chemotherapy as adjuvant therapy. Experimental Design: Patients with mucosal melanoma in stage II/III after surgery were randomized into three groups: observation group (group A, surgery alone), HDI group (group B, treated with 15 × 106 U/m2/d IFN-α2b, followed by 9 × 106 U IFN-α2b), and temozolomide (200 mg/m2/d) plus cisplatin (75 mg/m2) group (group C). The endpoints were relapse-free survival (RFS), overall survival (OS), and toxicities. Results: One hundred and eighty-nine patients were enrolled and finally analyzed. With a median follow-up of 26.8 months, the median RFS was 5.4, 9.4, and 20.8 months for group A, B, and C, respectively. Estimated median OS for group A, B, and C was 21.2, 40.4, and 48.7 months, respectively. Patients treated with temozolomide plus cisplatin showed significant improvements in RFS (P < 0.001) and OS (P < 0.01) than those treated with either HDI or surgery alone. Toxicities were generally mild to moderate. Conclusion: Both temozolomide-based chemotherapy and HDI are effective and safe as adjuvant therapies for resected mucosal melanoma as compared with observation alone. However, HDI tends to be less effective than temozolomide-based chemotherapy for patients with resected mucosal melanoma in respect to RFS. The temozolomide plus cisplatin regimen might be a better choice for patients with resected mucosal melanoma. Clin Cancer Res; 19(16); 4488–98. ©2013 AACR.

A phase II, randomized, double-blind, placebo-controlled multicenter trial of endostar in patients with metastatic melanoma

Endostatin is a potent endogenous angiogenic inhibitor with implicated antitumor activity. However, efficacy of recombinant human endostatin (rhES) in clinical trials is controversial, and application of rhES in treatment of metastatic melanoma awaits further investigations. This phase II trial evaluated the efficacy and safety of a soluble and stable rhES (Endostar) plus dacarbazine in patients with metastatic melanomas that contains no mutations in c-kit and BRAF genes. A total of 110 patients received placebo plus dacarbazine (250 mg/m², n = 54) or Endostar (7.5 mg/m²) plus dacarbazine (250 mg/m², n = 56). The primary end points were progression-free survival (PFS) and overall survival (OS). Median PFS in the Endostar plus dacarbazine arm was 4.5 months versus 1.5 months in the placebo plus dacarbazine arm (hazard ratio (HR) = 0.578; P = 0.013). There were statistically significant improvements in OS (median, 12.0 months versus 8.0 months; HR, 0.522; P = 0.005) in favor of the Endostar plus dacarbazine arm. The regimen was generally well tolerated and had a manageable toxicity profile. Our trial suggests that Endostar plus dacarbazine is well tolerated in patients with metastatic melanoma harboring no genetic mutations popular for targeted therapy and yields a significant improvement in PFS and OS.

Large-scale Analysis of PDGFRA Mutations in Melanomas and Evaluation of Their Sensitivity to Tyrosine Kinase Inhibitors Imatinib and Crenolanib

Purpose: Platelet-derived growth factor receptor α (PDGFRA) is a target for tyrosine kinase inhibitor (TKI)-based targeted therapy. Dysregulation of PDGFRA has been reported in many cancers. However, PDGFRA mutations in melanomas have not been well studied. We analyzed the genetic mutations of PDGFRA in Chinese patients with melanoma and determined the inhibitory potency of TKIs, such as imatinib and crenolanib, on mutant PDGFRA. Experimental Design: Of note, 351 melanoma tissue samples were examined for genetic mutations in exons 12, 14, and 18 of PDGFRA. Activities of mutations in response to imatinib and crenolanib were analyzed by Western blotting of tyrosine-phosphorylated PDGFRA and cell proliferation assays. Results: PDGFRA mutations were observed in 4.6% (16 of 351) of melanomas, and these mutations were mainly detected in acral and mucosal melanomas. PDGFRA mutations seem to be mutually exclusive with KIT mutations, but may coexist with BRAF and NRAS mutations. The genetic mutations of PDGFRA were unrelated to the age, thickness, and ulceration status of primary melanomas. Thirteen mutations were not reported before, and five (P577S, V658A, R841K, H845Y, and G853D) of them resulted in strong autophosphorylation of PDGFRA. Crenolanib showed higher potency than imatinib in inhibiting the kinase activity of PDGFRA. Except that V658A mutation was imatinib-resistant, all the other mutations were sensitive to both imatinib and crenolanib. Conclusions: PDGFRA mutations are detected in a small population of melanoma patients. Our study suggests that patients with melanoma harboring certain PDGFRA mutations may benefit from imatinib and crenolanib treatment. Clin Cancer Res; 19(24); 6935–42. ©2013 AACR.

Prognostic factors for conjunctival melanoma: a study in ethnic Chinese patients.

Background/objective In patients with conjunctival melanomas, surgery is the first choice of treatment, but no standard adjuvant therapy has been established. In this study, we evaluated prognostic factors for conjunctival melanoma in ethnic Chinese patients. Methods Demographic data, known (published) prognostic factors, BRAF and KIT gene mutations, treatment strategies and outcomes were reviewed in 53 patients with pathologically confirmed conjunctival melanomas. Univariate and multivariate analyses of factors associated with survival were performed by the Kaplan–Meier method and a Cox proportional hazard model, respectively. Results Univariate analyses for 50 patients in whom data were available showed that a higher T stage (p=0.041), greater tumour thickness (p=0.006), local resection (p=0.033) and no adjuvant therapy (p=0.006) were associated with a worse recurrence-free survival (RFS) and metastasis-free survival (MFS). Patients with more involved quadrants also had worse MFS (p=0.039), while a higher T stage (p<0.001), local resection (p=0.008), and no adjuvant therapy (p=0.028) were associated with worse overall survival (OS). However, BRAF or KIT mutations showed no correlations with RFS, MFS or OS. Patients who received high-dose interferon (HDI) adjuvant therapy had a better RFS (p=0.004), MFS (p=0.001) and OS (p=0.005) than those who did not. Multivariate analysis showed that adjuvant therapy and tumour thickness were significant predictive factors for RFS, and the T stage was a significant predictive factor for OS. Conclusions Adjuvant therapy and tumour thickness are significantly associated with RFS and T stage is a significant predictor of OS in Chinese patients with conjunctival melanomas. Patients may benefit from adjuvant therapy with HDI.

Analysis of mTOR Gene Aberrations in Melanoma Patients and Evaluation of Their Sensitivity to PI3K-AKT-mTOR Pathway Inhibitors.

Purpose: mTOR is a validated target in cancer. It remains to be determined whether melanoma patients bearing mTOR mutation could be selected for treatment with PI3K–AKT–mTOR pathway inhibitors. Experimental Design: A total of 412 melanoma samples were included. Gene aberrations in all exons of mTOR were detected by Sanger sequencing and confirmed by using Agilents SureSelect Target Enrichment System. HEK293T cells stably expressing mTOR mutants were constructed by using transcription activator-like effector nucleases technique. Function of mTOR mutants and in vitro sensitivity of gain-of-function mTOR mutations to PI3K–AKT–mTOR pathway inhibitors were analyzed. Results: The overall incidence of somatic nonsynonymous mutations of mTOR was 10.4% (43/412). mTOR nonsynonymous mutations were relatively more frequent in acral (11.0%) and mucosal (14.3%) melanomas than in chronic sun-induced damage (CSD; 6.7%) and non-CSD (3.4%) melanomas. Of the 43 cases with mTOR mutations, 41 different mutations were detected, affecting 25 different exons. The median survival time for melanoma patients with mTOR nonsynonymous mutation was significantly shorter than that for patients without mTOR nonsynonymous mutation (P = 0.028). Transient expression of mTOR mutants in HEK293T cells strongly activated the mTOR–p70S6K pathway. In HEK293T cells with stable expression of H1968Y or P2213S mTOR mutants, LY294002 and AZD5363 showed higher potency than temsirolimus or BYL719 in inhibiting the PI3K–AKT–mTOR pathway and cell proliferation. Conclusions: mTOR nonsynonymous mutations are frequent in melanoma patients. mTOR nonsynonymous mutation may predict a worse prognosis of melanoma. Clinical trials with PI3K–AKT–mTOR pathway inhibitors may be beneficial for melanoma patients with specific mTOR mutations. Clin Cancer Res; 22(4); 1018–27. ©2015 AACR.

Frequent Genetic Aberrations in the CDK4 Pathway in Acral Melanoma Indicate the Potential for CDK4/6 Inhibitors in Targeted Therapy

Purpose: Effective therapies for the majority of metastatic acral melanoma patients have not been established. Thus, we investigated genetic aberrations of CDK4 pathway in acral melanoma and evaluated the efficacy of CDK4/6 inhibitors in targeted therapy of acral melanoma. Experimental Design: A total of 514 primary acral melanoma samples were examined for the copy number variations (CNV) of CDK4 pathway-related genes, including Cdk4, Ccnd1, and P16INK4a, by QuantiGenePlex DNA Assay. The sensitivity of established acral melanoma cell lines and patient-derived xenograft (PDX) containing typical CDK4 aberrations to CDK4/6 inhibitors was evaluated. Results: Among the 514 samples, 203 cases, 137 cases, and 310 cases, respectively, showed Cdk4 gain (39.5%), Ccnd1 gain (26.7%), and P16INK4a loss (60.3%). The overall frequency of acral melanomas that contain at least one aberration in Cdk4, Ccnd1, and P16INK4a was 82.7%. The median overall survival time for acral melanoma patients with concurrent Cdk4 gain with P16INK4a loss was significantly shorter than that for patients without such aberrations (P = 0.005). The pan-CDK inhibitor AT7519 and selective CDK4/6 inhibitor PD0332991 could inhibit the cell viability of acral melanoma cells and the tumor growth of PDX with Cdk4 gain plus Ccnd1 gain, Cdk4 gain plus P16INK4a loss, and Ccnd1 gain plus P16INK4a loss. Conclusions: Genetic aberration of CDK4 pathway is a frequent event in acral melanoma. Acral melanoma cell lines and PDX containing CDK4 pathway aberrations are sensitive to CDK4/6 inhibitors. Our study provides evidence for the testing of CDK4/6 inhibitors in acral melanoma patients. Clin Cancer Res; 23(22); 6946–57. ©2017 AACR.

Systemic Immune-Inflammation Index and Circulating T-Cell Immune Index Predict Outcomes in High-Risk Acral Melanoma Patients Treated with High-Dose Interferon

High-dose interferon alfa-2b (IFN-α-2b) improves the survival of patients with high-risk melanoma. We aimed to identify baseline peripheral blood biomarkers to predict the outcome of acral melanoma patients treated with IFN-α-2b. Pretreatment baseline parameters and clinical data were assessed in 226 patients with acral melanoma. Relapse-free survival (RFS) and overall survival (OS) were assessed using the Kaplan-Meier method, and multivariate Cox regression analyses were applied after adjusting for stage, lactate dehydrogenase (LDH), and ulceration. Univariate analysis showed that neutrophil-to-lymphocyte ratio ≥2.35, platelet-to-lymphocyte ratio ≥129, systemic immune-inflammation index (SII) ≥615 × 109/l, and elevated LDH were significantly associated with poor RFS and OS. The SII is calculated as follows: platelet count × neutrophil count/lymphocyte count. On multivariate analysis, the SII was associated with RFS [hazard ratio (HR)=1.661, 95% confidence interval (CI): 1.066-2.586, P=.025] and OS (HR=2.071, 95% CI: 1.204-3.564, P=.009). Additionally, we developed a novel circulating T-cell immune index (CTII) calculated as follows: cytotoxic T lymphocytes/(CD4+ regulatory T cells × CD8+ regulatory T cells). On univariate analysis, the CTII was associated with OS (HR=1.73, 95% CI: 1.01-2.94, P=.044). The SII and CTII might serve as prognostic indicators in acral melanoma patients treated with IFN-α-2b. The indexes are easily obtainable via routine tests in clinical practice.