Molecular Targeted Therapy Approaches for BRAF Wild-Type Melanoma

Patient-derived melanoma models

Melanoma is a very aggressive, rapidly metastasizing tumor that has been studied intensively in the past regarding the underlying genetic and molecular mechanisms. More recently developed treatment modalities have improved response rates and overall survival of patients. However, the majority of patients suffer from secondary treatment resistance, which requires in depth analyses of the underlying mechanisms. Here, melanoma models based on patients-derived material may play an important role. Consequently, a plethora of different experimental techniques have been developed in the past years. Among these are 3D and 4D culture techniques, organotypic skin reconstructs, melanoma-on-chip models and patient-derived xenografts, Every technique has its own strengths but also weaknesses regarding throughput, reproducibility, and reflection of the human situation. Here, we provide a comprehensive overview of currently used techniques and discuss their use in different experimental settings.

Bcl-2 family inhibitors sensitize human cancer models to therapy

BH3 mimetics, targeting the Bcl-2 family anti-apoptotic proteins, represent a promising therapeutic opportunity in cancers. ABT-199, the first specific Bcl-2 inhibitor, was approved by FDA for the treatment of several hematological malignancies. We have recently discovered IS21, a novel pan BH3 mimetic with preclinical antitumor activity in several tumor types. Here, we evaluated the efficacy of IS21 and other BH3 mimetics, both as single agents and combined with the currently used antineoplastic agents in T-cell acute lymphoblastic leukemia, ovarian cancer, and melanoma. IS21 was found to be active in T-cell acute lymphoblastic leukemia, melanoma, lung, pancreatic, and ovarian cancer cell lines. Bcl-xL and Mcl-1 protein levels predicted IS21 sensitivity in melanoma and ovarian cancer, respectively. Exploring IS21 mechanism of action, we found that IS21 activity depends on the presence of BAX and BAK proteins: complexes between Bcl-2 and Bcl-xL proteins and their main binding partners were reduced after IS21 treatment. In combination experiments, BH3 mimetics sensitized leukemia cells to chemotherapy, ovarian cancer cells and melanoma models to PARP and MAPK inhibitors, respectively. We showed that this enhancing effect was related to the potentiation of the apoptotic pathway, both in hematologic and solid tumors. In conclusion, our data suggest the use of inhibitors of anti-apoptotic proteins as a therapeutic strategy to enhance the efficacy of anticancer treatment.

Biocompatible gum arabic-gold nanorod composite as an effective therapy for mistreated melanomas

Advanced melanoma patients that are not included in common genetic classificatory groups lack effective and safe therapeutic options. Chemotherapy and immunotherapy show unsatisfactory results and devastating adverse effects for these called triple wild-type patients. New approaches exploring the intrinsic antitumor properties of gold nanoparticles might reverse this scenario as a safer and more effective alternative. Therefore, we investigated the efficacy and safety of a composite made of gum arabic-functionalized gold nanorods (GA-AuNRs) against triple wild-type melanoma. The natural polymer gum arabic successfully stabilized the nanorods in the biological environment and was essential to improve their biocompatibility. In vivo results obtained from treating triple wild-type melanoma-bearing mice showed that GA-AuNRs remarkably reduced primary tumor growth by 45%. Furthermore, GA-AuNRs induced tumor histological features associated with better prognosis while also reducing superficial lung metastasis depth and the incidence of intrapulmonary metastasis. GA-AuNRs' efficacy comes from their capacity to reduce melanoma cells ability to invade the extracellular matrix and grow into colonies, in addition to a likely immunomodulatory effect induced by gum arabic. Additionally, a broad safety investigation found no evidence of adverse effects after GA-AuNRs treatment. Therefore, this study unprecedentedly reports GA-AuNRs as a potential nanomedicine for advanced triple wild-type melanomas.

Active notch protects MAPK activated melanoma cell lines from MEK inhibitor cobimetinib

The crosstalk between Notch and MAPK pathway plays a role in MEK inhibitor resistance in BRAF^V600E metastatic melanoma (MM) and promotes migration in GNAQ^Q209L uveal melanoma (UM) cells. We determined the cytotoxicity of combinatorial inhibition of MEK and Notch by cobimetinib and γ-secretase inhibitor (GSI) nirogacestat, in BRAF^V600E and BRAF wt MM and GNAQ^Q209L UM cells displaying different Erk1/2 and Notch activation status, with the aim to elucidate the impact of Notch signaling in the response to MEK inhibitor. Overall the combination was synergic in BRAF^V600E MM and GNAQ^Q209L UM cells and antagonistic in BRAF wt one. Focusing on UM cells, we found that cobimetinib resulted in G0/G1 phase arrest and apoptosis induction, whereas the combination with GSI increased treatment efficacy by inducing a senescent-like state of cells and by blocking migration towards liver cancer cells. Mechanistically, this was reflected in a strong reduction of cyclin D1, in the inactivation of retinoblastoma protein and in the increase of p27^KIP1 expression levels. Of note, each drug alone prevented Notch signaling activation resulting in inhibition of c-jun(Ser63) and Hes-1 expression. The combination achieved the strongest inhibition on Notch signaling and on both c-jun(Ser63) and Erk1/2 activation level. In conclusion we unveiled a coordinate action of MAPK and Notch signaling in promoting proliferation of BRAF^V600E MM and GNAQ^Q209L UM cells. Remarkably, the simultaneous inhibition of MEK and Notch signaling highlighted a role for the second pathway in protecting cells against senescence in GNAQ^Q209L UM cells treated with the MEK inhibitor.

Pre-clinical modeling of cutaneous melanoma

Metastatic melanoma is challenging to manage. Although targeted- and immune therapies have extended survival, most patients experience therapy resistance. The adaptability of melanoma cells in nutrient- and therapeutically-challenged environments distinguishes melanoma as an ideal model for investigating therapy resistance. In this review, we discuss the current available repertoire of melanoma models including two- and three-dimensional tissue cultures, organoids, genetically engineered mice and patient-derived xenograft. In particular, we highlight how each system recapitulates different features of melanoma adaptability and can be used to better understand melanoma development, progression and therapy resistance.

Despite the new targeted and immunotherapies for metastatic melanoma, several patients show therapeutic plateau. Here, the authors review the current pre-clinical models of cutaneous melanoma and discuss their strengths and limitations that may help with overcoming therapeutic plateau.

Repurposing the serotonin agonist Tegaserod as an anticancer agent in melanoma: molecular mechanisms and clinical implications

BACKGROUND

New therapies are urgently needed in melanoma particularly in late-stage patients not responsive to immunotherapies and kinase inhibitors.

METHODS

Drug screening, IC50 determinations as well as synergy assays were detected by the MTT assay. Apoptosis using Annexin V and 7AAD staining was assessed using flow cytometry. TUNEL staining was performed using immunocytochemistry. Changes in phosphorylation of key molecules in PI3K/Akt/mTOR and other relevant pathways were detected by western blot as well as immunocytochemistry. To assess in vivo anti-tumor activity of Tegaserod, syngeneic intravenous and subcutaneous melanoma xenografts were used. Immunocytochemical staining was performed to detect expression of active Caspase-3, cleaved Caspase 8 and p-S6 in tumors. Evaluation of immune infiltrates was carried out by flow cytometry.

RESULTS

Using a screen of 770 pharmacologically active and/or FDA approved drugs, we identified Tegaserod (Zelnorm, Zelmac) as a compound with novel anti-cancer activity which induced apoptosis in murine and human malignant melanoma cell lines. Tegaserod (TM) is a serotonin receptor 4 agonist (HTR4) used in the treatment of irritable bowel syndrome (IBS). TM's anti-melanoma apoptosis-inducing effects were uncoupled from serotonin signaling and attributed to PI3K/Akt/mTOR signaling inhibition. Specifically, TM blunted S6 phosphorylation in both BRAF^V600E and BRAF wildtype (WT) melanoma cell lines. TM decreased tumor growth and metastases as well as increased survival in an in vivo syngeneic immune-competent model. In vivo, TM also caused tumor cell apoptosis, blunted PI3K/Akt/mTOR signaling and decreased S6 phosphorylation. Furthermore TM decreased the infiltration of immune suppressive regulatory CD4⁺CD25⁺ T cells and FOXP3 and ROR-γt positive CD4⁺ T cells. Importantly, TM synergized with Vemurafenib, the standard of care drug used in patients with late stage disease harboring the BRAF^V600E mutation and could be additively or synergistically combined with Cobimetinib in both BRAF^V600E and BRAF WT melanoma cell lines in inducing anti-cancer effects.

CONCLUSION

Taken together, we have identified a drug with anti-melanoma activity in vitro and in vivo that has the potential to be combined with the standard of care agent Vemurafenib and Cobimetinib in both BRAF^V600E and BRAF WT melanoma.

SF3B1, NRAS, KIT, and BRAF Mutation; CD117 and cMYC Expression; and Tumoral Pigmentation in Sinonasal Melanomas: An Analysis With Newly Found Molecular Alterations and Some Population-Based Molecular Differences

Sinonasal melanomas encompass melanoma arising in the nasal cavity and paranasal sinuses. Despite recent advances in tumor genomics, correlation between mutational status and protein expression with prognosis and tumor pigmentation has not been carried out in sinonasal melanomas. Ninety-five sinonasal melanomas from 95 patients were included. As per univariate analyses, age was the only variable that significantly correlated with progression-free survival. SF3B1, NRAS, KIT, and BRAF mutations were documented in 7% (5/72), 22% (16/72), 22% (16/72), and 8% (6/72) of cases, respectively. Comutation was detected in 6 cases: NRAS and KIT in 2 cases; NRAS and BRAF in 2 cases; SF3B1, KIT, and BRAF in one case; and SF3B1, NRAS, and KIT in one case. Correlations approaching statistical significance were observed between BRAF mutation status and poorer overall survival and progression-free survival (log-rank P-values=0.054 and 0.061). Increased CD117 expression (33%, 29/88) and decreased nuclear cMYC expression (40%, 39/84) significantly correlated with cytoplasmic pigmentation. Several SF3B1, NRAS, and KIT mutations not previously documented in sinonasal melanomas were detected in our series, suggesting a potential role for targeted therapies. A similar frequency of SF3B1, NRAS, and KIT mutations was noted in Asian cases, whereas NRAS, KIT, and BRAF mutations were predominant in the United States and European cases; however, the number of included cases was small. The significant association between CD117 and cMYC expression with increased cytoplasmic pigmentation in our series suggests that the pigmented morphologic appearance of sinonasal melanomas could be attributed to the underlying oncogenic mutations and metabolic interaction.

The Antitumor Effect of Lipophilic Bisphosphonate BPH1222 in Melanoma Models: The Role of the PI3K/Akt Pathway and the Small G Protein Rheb

Malignant melanoma is one of the most metastatic cancer types, and despite recent success with novel treatment strategies, there is still a group of patients who do not respond to any therapies. Earlier, the prenylation inhibitor hydrophilic bisphosphonate zoledronic acid (ZA) was found to inhibit melanoma growth in vitro, but only a weaker effect was observed in vivo due to its hydrophilic properties. Recently, lipophilic bisphosphonates (such as BPH1222) were developed. Accordingly, for the first time, we compared the effect of BPH1222 to ZA in eight melanoma lines using viability, cell-cycle, clonogenic and spheroid assays, videomicroscopy, immunoblot, and xenograft experiments. Based on 2D and spheroid assays, the majority of cell lines were more sensitive to BPH. The activation of Akt and S6 proteins, but not Erk, was inhibited by BPH. Additionally, BPH had a stronger apoptotic effect than ZA, and the changes of Rheb showed a correlation with apoptosis. In vitro, only M24met cells were more sensitive to ZA than to BPH; however, in vivo growth of M24met was inhibited more strongly by BPH. Here, we present that lipophilic BPH is more effective on melanoma cells than ZA and identify the PI3K pathway, particularly Rheb as an important mediator of growth inhibition.

Immunological effects of BRAF+MEK inhibition

Recent developments in immunotherapy have prolonged overall survival in metastatic melanoma with the possibility to reach a long-term benefit. Targeted therapies based on BRAF and MEK inhibition also seem to have a long-term beneficial effect, which is more evident in patients with favorable baseline characteristics, namely normal levels of lactate dehydrogenase, without brain metastases, and low tumor burden. This long-term benefit of targeted therapies might be related to an immune-modulation: indeed BRAF and MEK inhibitors affect tumor microenvironment and immune surveillance, and it has been shown that patients with complete response to targeted treatment have a pre-existing favorable immunologic signature.

(Arg)9-SH2 superbinder: a novel promising anticancer therapy to melanoma by blocking phosphotyrosine signaling

Background

Melanoma is a malignant tumor with high misdiagnosis rate and poor prognosis. The bio-targeted therapy is a prevailing method in the treatment of melanoma; however, the accompanying drug resistance is inevitable. SH2 superbinder, a triple-mutant of the Src Homology 2 (SH2) domain, shows potent antitumor ability by replacing natural SH2-containing proteins and blocking multiple pY-based signaling pathways. Polyarginine (Arg)₉, a powerful vector for intracellular delivery of large molecules, could transport therapeutic agents across cell membrane. The purpose of this study is to construct (Arg)₉-SH2 superbinder and investigate its effects on melanoma cells, expecting to provide potential new approaches for anti-cancer therapy and overcoming the unavoidable drug resistance of single-targeted antitumor agents.

Methods

(Arg)₉ and SH2 superbinder were fused to form (Arg)₉-SH2 superbinder via genetic engineering. Pull down assay was performed to identify that (Arg)₉-SH2 superbinder could capture a wide variety of pY proteins. Immunofluorescence was used to detect the efficiency of (Arg)₉-SH2 superbinder entering cells. The proliferation ability was assessed by MTT and colony formation assay. In addition, wound healing and transwell assay were performed to evaluate migration of B16F10, A375 and A375/DDP cells. Moreover, apoptosis caused by (Arg)₉-SH2 superbinder was analyzed by flow cytometry-based Annexin V/PI. Furthermore, western blot revealed that (Arg)₉-SH2 superbinder influenced some pY-related signaling pathways. Finally, B16F10 xenograft model was established to confirm whether (Arg)₉-SH2 superbinder could restrain the growth of tumor.

Results

Our data showed that (Arg)₉-SH2 superbinder had the ability to enter melanoma cells effectively and displayed strong affinities for various pY proteins. Furthermore, (Arg)₉-SH2 superbinder could repress proliferation, migration and induce apoptosis of melanoma cells by regulating PI3K/AKT, MAPK/ERK and JAK/STAT signaling pathways. Importantly, (Arg)₉-SH2 superbinder could significantly inhibit the growth of tumor in mice.

Conclusions

(Arg)₉-SH2 superbinder exhibited high affinities for pY proteins, which showed effective anticancer ability by replacing SH2-containing proteins and blocking diverse pY-based pathways. The remarkable ability of (Arg)₉-SH2 superbinder to inhibit cancer cell proliferation and tumor growth might open the door to explore the SH2 superbinder as a therapeutic agent for cancer treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0812-5) contains supplementary material, which is available to authorized users.

Differential expression of ABCB5 in BRAF inhibitor-resistant melanoma cell lines

BACKGROUND

More than 50% of metastatic melanoma patients have a specific mutation in the serine/threonine kinase BRAF. This results in constitutive activation of the RAS-RAF-MEK-ERK-MAP kinase pathway, which causes uncontrolled cell growth. Vemurafenib (PLX4032) is an oral chemotherapeutic agent that targets the specific mutation V600E in the BRAF protein. Initial response rates are high in patients with BRAF mutant melanoma treated with a BRAF inhibitor such as vemurafenib, but resistance nearly always develops and disease progression ensues. There are several different mechanisms by which melanoma develops BRAF inhibitor resistance. One potential component of resistance is increased drug efflux. Overexpressed ABCB5 (ATP-binding cassette transporter, subfamily B, member 5) has been shown to efflux anti-cancer drugs from cancer cells. The purpose of this study is to determine whether ABCB5 is highly expressed in BRAF inhibitor-resistant melanoma cells and to evaluate whether ABCB5 is involved in the development of resistance to BRAF inhibitors in cutaneous melanoma.

METHODS

We established three BRAF inhibitor-resistant melanoma cell lines with BRAF mutation. The expression level of ABCB5 in PLX-resistant cell lines was checked by real-time PCR and Western blot analysis. SK-MEL-2 melanoma cells with wild-type BRAF were used for comparison. The association of different levels of ABCB5 with the changes of ERK, p-ERK, Akt and p-Akt was also assessed by Western blotting. Re-sensitization of melanoma cells to PLX was tested by p-ERK inhibitor PD58059 and ABCB5 knockdown by ABCB5 siRNA, respectively.

RESULTS

We showed that ABCB5 was overexpressed in SK-MEL-28PLXr and A2058PLXr cells but not in A375PLXr cells. ABCB5 overexpression is associated with activation of p-ERK status but not Akt. Inhibition of p-ERK re-sensitized SK-MEL-28PLXr and A2058PLXr cells to PLX treatment, but knockdown of ABCB5 did not re-sensitize A2058 PLXr and SK-MEL-28 PLXr cells to PLX treatment.

CONCLUSION

These results confirm that, even though ABCB5 was overexpressed in SK-MEL-28 and A2058 melanoma cells that develop resistance to BRAF inhibitors, ABCB5 may not be a major targetable contributor to BRAF resistance. p-ERK inhibition may play important roles in BRAF resistance in these two melanoma cell lines.

Do you know your guidelines? Diagnosis and management of cutaneous head and neck melanoma

The following article is the next installment of the series "Do You Know Your Guidelines?" presented by the Education Committee of the American Head and Neck Society. Guidelines for the prevention, diagnosis, workup, and management of cutaneous melanoma are reviewed in an evidence-based fashion.

A novel compound which sensitizes BRAF wild-type melanoma cells to vemurafenib in a TRIM16-dependent manner

There is an urgent need for better therapeutic options for advanced melanoma patients, particularly those without the BRAFV600E/K mutation. In melanoma cells, loss of TRIM16 expression is a marker of cell migration and metastasis, while the BRAF inhibitor, vemurafenib, induces melanoma cell growth arrest in a TRIM16-dependent manner. Here we identify a novel small molecule compound which sensitized BRAF wild-type melanoma cells to vemurafenib. High throughput, cell-based, chemical library screening identified a compound (C012) which significantly reduced melanoma cell viability, with limited toxicity for normal human fibroblasts. When combined with the BRAFV600E/K inhibitor, vemurafenib, C012 synergistically increased vemurafenib potency in 5 BRAFWT and 4 out of 5 BRAFV600E human melanoma cell lines (Combination Index: CI < 1), and, dramatically reduced colony forming ability. In addition, this drug combination was significantly anti-tumorigenic in vivo in a melanoma xenograft mouse model. The combination of vemurafenib and C012 markedly increased expression of TRIM16 protein, and knockdown of TRIM16 significantly reduced the growth inhibitory effects of the vemurafenib and C012 combination. These findings suggest that the combination of C012 and vemurafenib may have therapeutic potential for the treatment of melanoma, and, that reactivation of TRIM16 may be an effective strategy for patients with this disease.

KIT mutations and CD117 overexpression are markers of better progression-free survival in vulvar melanomas

BACKGROUND

Few studies have addressed prognostic markers and none has correlated molecular status and prognosis in vulvar melanomas.

OBJECTIVES

To evaluate the clinicopathological features of 95 cases of vulvar melanoma.

METHODS

p53, CD117, Ki-67, neurofibromin, brafv600e and nrasq61r immunostains, and molecular analyses by either targeted next-generation or direct sequencing, were performed on available archival materials.

RESULTS

Molecular testing detected mutations in KIT (44%), BRAF (25%), NF1 (22%), TP53 (17%), NRAS (9%) and TERT promoter (9%). Co-mutation of KIT and NF1 and of KIT and NRAS were identified in two and one cases, respectively. KIT mutations were significantly associated with better progression-free survival in univariate analyses. In multivariate analyses CD117 expression was significantly associated with better progression-free survival. Tumour thickness was significantly associated with worse progression-free and overall survival, and perineural invasion significantly correlated with reduced melanoma-specific survival and reduced overall survival. Cases were from multiple centres and only a subset of samples was available for molecular testing.

CONCLUSIONS

KIT mutations and CD117 overexpression are markers of better progression-free survival. In addition to its prognostic value, molecular testing may identify cases that might respond to targeted agents or immunotherapeutic approaches.

RAF inhibitor LY3009120 sensitizes RAS or BRAF mutant cancer to CDK4/6 inhibition by abemaciclib via superior inhibition of phospho-RB and suppression of cyclin D1

KRAS, NRAS and BRAF mutations are among the most important oncogenic drivers in many major cancer types, such as melanoma, lung, colorectal and pancreatic cancer. There is currently no effective therapy for the treatment of RAS mutant cancers. LY3009120, a pan-RAF and RAF dimer inhibitor advanced to clinical study has been shown to inhibit both RAS and BRAF mutant cell proliferation in vitro and xenograft tumor growth in vivo. Abemaciclib, a CDK4/6-selective inhibitor, is currently in phase III studies for ER-positive breast cancer and KRAS mutant lung cancer. In this study, we found that combinatory treatment with LY3009120 and abemaciclib synergistically inhibited proliferation of tumor cells in vitro and led to tumor growth regression in xenograft models with a KRAS, NRAS or BRAF mutation at the doses of two drugs that were well tolerated in combination. Further in vitro screen in 328 tumor cell lines revealed that tumor cells with KRAS, NRAS or BRAF mutation, or cyclin D activation are more sensitive, whereas tumor cells with PTEN, PIK3CA, PIK3R1 or retinoblastoma (Rb) mutation are more resistant to this combination treatment. Molecular analysis revealed that abemaciclib alone inhibited Rb phosphorylation partially and caused an increase of cyclin D1. The combinatory treatment cooperatively demonstrated more complete inhibition of Rb phosphorylation, and LY3009120 suppressed the cyclin D1 upregulation mediated by abemaciclib. These results were further verified by CDK4/6 siRNA knockdown. Importantly, the more complete phospho-Rb inhibition and cyclin D1 suppression by LY3009120 and abemaciclib combination led to more significant cell cycle G₀/G₁ arrest of tumor cells. These preclinical findings suggest that combined inhibition of RAF and d-cyclin-dependent kinases might provide an effective approach to treat patients with tumors harboring mutations in RAS or RAF genes.

Identification of recurrent mutational events in anorectal melanoma

Anorectal melanoma is a rare disease that carries a poor prognosis. To date, limited genetic analyses confirmed KIT mutations as a recurrent genetic event similar to other mucosal melanomas, occurring in up to 30% of anorectal melanomas. Importantly, a subset of tumors harboring activating KIT mutations have been found to respond to c-Kit inhibitor-based therapy, with improved patient survival at advanced tumor stages. We performed comprehensive targeted exon sequencing analysis of 467 cancer-related genes in a larger series of 15 anorectal melanomas, focusing on potentially actionable variants based on gain- and loss-of-function mutations. We report the identification of oncogenic driver events in the majority (93%) of anorectal melanomas. These included variants in canonical MAPK pathway effectors rarely observed in cutaneous melanomas (including an HRAS mutation, as well as a BRAF mutation resulting in duplication of threonine 599), and recurrent mutations in the tumor suppressor NF1 in 20% of cases, which represented the second-most frequently mutated gene after KIT in our series. Furthermore, we identify SF3B1 mutations as a recurrent genetic event in mucosal melanomas. Our findings provide an insight into the genetic diversity of anorectal melanomas, and suggest significant potential for alternative targeted therapeutics in addition to c-Kit inhibitors for this melanoma subtype.

An exploratory study investigating the metabolic activity and local cytokine profile in patients with melanoma treated with pazopanib and paclitaxel

BACKGROUND

There is a medical need for new drugs in patients with BRAF wild-type metastatic melanoma. Pazopanib is a multitarget tyrosine kinase inhibitor with antitumour and antiangiogenic activity.

OBJECTIVES

The primary aim was to investigate the metabolic response to pazopanib monotherapy and pazopanib plus paclitaxel in patients with BRAF wild-type melanoma. Secondary end points were the early cytokine and chemokine profiles and histological findings.

METHODS

Pazopanib (400 mg twice daily) was administered orally from days 1 to 10 and from days 14 to 70. An intravenous infusion with paclitaxel (150 mg m^-2 body surface) was administered on days 14, 35 and 56. Metabolic response evaluation was performed before treatment, after treatment with pazopanib (day 10) and after treatment with pazopanib and paclitaxel (day 70). Skin biopsy of metastatic tissue for chemokine and cytokine expression analysis and histology and immunohistochemistry (CD68, CD163) evaluation, and blood samples were taken at the same time points.

RESULTS

Two patients failed screening and 17 were dosed. Of 67 adverse events, nine (13%) were grade 3 or 4. Five of 14 evaluable patients had a partial metabolic response at day 10 under pazopanib monotherapy. The response rate at day 70 under combined pazopanib-paclitaxel treatment was 0%. Immunohistochemistry revealed an increase of M2-like macrophages in nonresponders compared with responders. We observed a significant upregulation of five cytokines (CXCL1, CXCL2, CXCL13, CCL22 and SPP1) in responding vs. nonresponding lesions. Overall, the median progression-free survival was 70 days (range 5-331), which did not differ significantly between responders (148 days) and nonresponders (70 days, P = 0·17).

CONCLUSIONS

In this patient population pazopanib efficacy was limited. Response is associated with low M2-like macrophage density and increased expression of several chemokines.

Recurrent Olfactory Neuroblastoma Treated With Cetuximab and Sunitinib: A Case Report

Olfactory neuroblastoma (ONB) is a rare cancer originating in the olfactory epithelium of the nasal vault. The recurrence rate of ONB is high, as the standard treatment of surgery followed by radiotherapy and/or chemotherapy is usually unsuccessful. The use of targeted therapy based on individual genomic variations after cancer relapse has not been reported. Here, we present the case of a 44-year-old man who was diagnosed with recurrent ONB and treated with a regimen developed using whole exome sequencing. Potential targets were first identified and then matched to appropriate drugs. Gene mutations in the genes encoding EGFR, FGFR2, KDR, and RET were discovered in the patient's tumor tissue by whole exome sequencing and the patient was treated with a combination of the targeted drugs cetuximab and sunitinib. Five days after treatment, enhancement magnetic resonance imaging showed a 65% reduction in tumor size, and the Visual analog scale headache scores went down to 2/10 from 10/10. Repeat imaging at 1 month showed a complete response.This study represents the first demonstration of an effective personalized treatment of ONB by targeted drugs, and sheds light on how precision medicine can be used to treat recurrent ONB that fails to respond to routine tumor resection, radiotherapy, and/or chemotherapy.