Vemurafenib plus Rituximab in Refractory or Relapsed Hairy-Cell Leukemia.

BACKGROUND: Hairy-cell leukemia (HCL) is a CD20+ indolent B-cell cancer in which a BRAF V600E kinase-activating mutation plays a pathogenetic role. In clinical trials involving patients with refractory or relapsed HCL, the targeting of BRAF V600E with the oral BRAF inhibitor vemurafenib led to a response in 91% of the patients; 35% of the patients had a complete response. However, the median relapse-free survival was only 9 months after treatment was stopped. METHODS: In a phase 2, single-center, academic trial involving patients with refractory or relapsed HCL, we assessed the safety and efficacy of vemurafenib (960 mg, administered twice daily for 8 weeks) plus concurrent and sequential rituximab (375 mg per square meter of body-surface area, administered for 8 doses over a period of 18 weeks). The primary end point was a complete response at the end of planned treatment. RESULTS: Among the 30 enrolled patients with HCL, the median number of previous therapies was 3. A complete response was observed in 26 patients (87%) in the intention-to-treat population. All the patients who had HCL that had been refractory to chemotherapy (10 patients) or rituximab (5) and all those who had previously been treated with BRAF inhibitors (7) had a complete response. Thrombocytopenia resolved after a median of 2 weeks, and neutropenia after a median of 4 weeks. Of the 26 patients with a complete response, 17 (65%) were cleared of minimal residual disease (MRD). Progression-free survival among all 30 patients was 78% at a median follow-up of 37 months; relapse-free survival among the 26 patients with a response was 85% at a median follow-up of 34 months. In post hoc analyses, MRD negativity and no previous BRAF inhibitor treatment correlated with longer relapse-free survival. Toxic effects, mostly of grade 1 or 2, were those that had previously been noted for these agents. CONCLUSIONS: In this small study, a short, chemotherapy-free, nonmyelotoxic regimen of vemurafenib plus rituximab was associated with a durable complete response in most patients with refractory or relapsed HCL. (Funded by the European Research Council and others; HCL-PG03 EudraCT number, 2014-003046-27.).

FOXD1 promotes dedifferentiation and targeted therapy resistance in melanoma by regulating the expression of connective tissue growth factor.

Metastatic melanoma is an aggressive skin cancer and associated with a poor prognosis. In clinical terms, targeted therapy is one of the most important treatments for patients with BRAFV600E -mutated advanced melanoma. However, the development of resistance to this treatment compromises its therapeutic success. We previously demonstrated that forkhead box D1 (FOXD1) regulates melanoma migration and invasion. Here, we found that FOXD1 was highly expressed in melanoma cells and was associated with a poor survival of patients with metastatic melanoma. Upregulation of FOXD1 expression enhanced melanoma cells' resistance to vemurafenib (BRAF inhibitor [BRAFi]) or vemurafenib and cobimetinib (MEK inhibitor) combination treatment whereas loss of FOXD1 increased the sensitivity to treatment. By comparing gene expression levels between FOXD1 knockdown (KD) and overexpressing (OE) cells, we identified the connective tissue growth factor (CTGF) as a downstream factor of FOXD1. Chromatin immunoprecipitation and luciferase assay demonstrated the direct binding of FOXD1 to the CTGF promoter. Similar to FOXD1, knockdown of CTGF increased the sensitivity of BRAFi-resistant cells to vemurafenib. FOXD1 KD cells treated with recombinant CTGF protein were less sensitive towards vemurafenib compared to untreated FOXD1 KD cells. Based on these findings, we conclude that FOXD1 might be a promising new diagnostic marker and a therapeutic target for the treatment of targeted therapy resistant melanoma.

Dose-escalation study of vemurafenib with sorafenib or crizotinib in patients with BRAF-mutated advanced cancers.

BACKGROUND: BRAF inhibitors are effective in melanoma and other cancers with BRAF mutations; however, patients ultimately develop therapeutic resistance through the activation of alternative signaling pathways such as RAF/RAS or MET. The authors hypothesized that combining the BRAF inhibitor vemurafenib with either the multikinase inhibitor sorafenib or the MET inhibitor crizotinib could overcome therapeutic resistance. METHODS: Patients with advanced cancers and BRAF mutations were enrolled in a dose-escalation study (3 + 3 design) to determine the maximum tolerated dose (MTD) and the dose-limiting toxicities (DLTs) of vemurafenib with sorafenib (VS) or vemurafenib with crizotinib (VC). RESULTS: In total, 38 patients (VS, n = 24; VC, n = 14) were enrolled, and melanoma was the most represented tumor type (VS, 38%; VC, 64%). In the VS arm, vemurafenib 720 mg twice daily and sorafenib 400 mg am/200 mg pm were identified as the MTDs, DLTs included grade 3 rash (n = 2) and grade 3 hypertension, and partial responses were reported in 5 patients (21%), including 2 with ovarian cancer who had received previous treatment with BRAF, MEK, or ERK inhibitors. In the VC arm, vemurafenib 720 mg twice daily and crizotinib 250 mg daily were identified as the MTDs, DLTs included grade 3 rash (n = 2), and partial responses were reported in 4 patients (29%; melanoma, n = 3; lung adenocarcinoma, n = 1) who had received previous treatment with BRAF, MEK, and/or ERK inhibitors. Optional longitudinal collection of plasma to assess dynamic changes in circulating tumor DNA demonstrated the elimination of BRAF-mutant DNA from plasma during therapy (P = .005). CONCLUSIONS: Vemurafenib combined with sorafenib or crizotinib was well tolerated with encouraging activity, including among patients who previously received treatment with BRAF, MEK, or ERK inhibitors.

Alternative use of BRAF inhibitors in patients with metastatic melanoma unable to swallow pills.

INTRODUCTION: BRAF and MEK inhibitors have been approved for use in metastatic melanoma therapies. All of them are administered as oral capsules or pills. We report two cases treated applying an alternative method of vemurafenib or debrafenib-trametinib administration in patients unable to swallow. CASE REPORT: The first case involved a 38-year-old man who was referred to a dermatologist for dysphagia and anorexia. After a computerized tomography (CT) scan it was concluded that the dysphagia was due to compression by mediastinal metastasis in a context of metastatic BRAF mutant melanoma. The second case involved a 35-year-old man who was diagnosed in March 2017 with melanoma of the back of the hand. Several months later a positron emission tomography (PET)/CT scan was performed. It revealed multiple disseminated metastasis.Management & Outcome: The first patient presented total dysphagia and was unable to swallow pills. It was decided to dissolve vemurafenib in order to facilitate administration. Dysphagia was improved 48 hours later, and oral feeding was reintroduced. Due to severe tablet phobia, the second patient was unable to swallow pills. Dabrafenib capsules were emptied and trametinib pills were grinded. One month later, we noted improved health associated with reduction of the metastases. DISCUSSION: Our study highlights the possibility of crushing or dissolving BRAF and MEK inhibitors in metastatic melanoma patients for whom it is impossible to swallow pills, eliciting a response and achieving significant if temporary clinical benefit.

Methiothepin Increases Chemotherapy Efficacy against Resistant Melanoma Cells.

We previously reported that methiothepin, a small molecule known as a nonselective serotonin 5-HT receptor antagonist, inhibited the doxorubicin efflux activity of the Hedgehog receptor Ptch1 and enhanced the cytotoxic, pro-apoptotic, anti-proliferative, and anti-clonogenic effects of doxorubicin on adrenocortical carcinoma cells. Here, we show that methiothepin also inhibits doxorubicin efflux and increases doxorubicin cytotoxicity in melanoma cells which endogenously overexpress Ptch1. Melanoma patients having the BRAFV600E mutation are treated with vemurafenib, an inhibitor of BRAFV600E, often in combination with trametinib, an inhibitor of MEK. Almost all patients ultimately acquire resistance to the treatment leading to disease progression. Here, we report that methiothepin overcomes the resistance of BRAFV600E melanoma cells by enhancing the cytotoxicity of vemurafenib and trametinib on these cells leading to melanoma cells death. We observe that the addition of methiothepin to vemurafenib prevents migration of resistant melanoma cells more efficiently than vemurafenib alone. Our results provide an additional proof that Ptch1 drug efflux inhibition increases the effectiveness of anti-cancer treatments and overcomes resistance of melanoma cells expressing Ptch1.

Risk factors for severe rash with use of vemurafenib alone or in combination with cobimetinib for advanced melanoma: pooled analysis of clinical trials.

BACKGROUND: Rash is one of the most common severe adverse events associated with use of vemurafenib for the treatment of melanoma, either as monotherapy or in combination with cobimetinib. The study aimed to identify pre-treatment patient characteristics predictive of developing severe rash with vemurafenib therapy. METHODS: This was a secondary pooled analysis of individual patient data from the BRIM-2, BRIM-3 and coBRIM clinical trials, including all patients treated with vemurafenib alone and vemurafenib plus cobimetinib. Patient age, sex, performance status, body weight, body mass index, liver function markers and estimated glomerular filtration rate were assessed for association with development of severe (grade 3 or 4) rash using logistic regression. RESULTS: Of 962 patients treated with vemurafenib, 150 (16%) patients experienced severe rash. Female sex was identified as a significant risk factor for severe rash development (P < 0.001), having a two-fold increased risk compared to males (22% vs 11%, odds ratio [OR] 2.17; 95% CI 1.52 to 3.09). Low body weight was also associated with increased risk of severe rash (P = 0.002), but this association was not significant after adjustment for sex. The association between sex and risk of severe rash was consistent across clinical trials and treatments (vemurafenib monotherapy, vemurafenib plus cobimetinib). CONCLUSION: Females had approximately two-fold increased risk of developing severe rash compared to males in clinical trials of vemurafenib alone or in combination with cobimetinib.

BRAF mutant colorectal cancer: ErbB2 expression levels as predictive factor for the response to combined BRAF/ErbB inhibitors.

BACKGROUND: Colorectal cancer (CRC) is a heterogeneous disease with a complex biology and a wide number of altered genes such as BRAF, KRAS and PIK3CA. Advances with new-targeted therapies have been achieved and available treating options have prolonged patient's survival. However, BRAF-mutated CRC patients remain unresponsive to available therapies with RAF inhibitors (RAFi) alone or combined with ErbB inhibitors (ErbBi). These unmet needs require further exploitation of oncogenic signaling in order to set up individualized treatments. METHODS: To this end, we tested the efficacy of single agent or combined treatments using the BRAFi, vemurafenib and two different ErbBi: panitumumab and afatinib in CRC cells characterized by different molecular phenotypes. RESULTS: Combination strategies with BRAFi and ErbBi achieved a better response in BRAFV600E mutated cells expressing high levels of ErbB2. CONCLUSIONS: Our findings support the importance of ErbB2 evaluation in BRAF-mutated CRC patients and its role as a positive predictor factor of response to BRAFi/ErbBi combination.

Partial response in hairy cell leukemia with vemurafenib despite early discontinuation due to agranulocytosis.

Vemurafenib is an oral BRAF kinase inhibitor approved since 2012 for the treatment of patients with unresectable or metastatic melanoma with BRAF mutations. Vemurafenib also demonstrated efficacy for patients with hairy cell leukemia genetically characterized by BRAF mutation. Here, we report the case of a 38-year-old female patient without any previous medical history who experienced agranulocytosis associated with erythrodermia after vemurafenib initiation for the treatment of hairy cell leukemia. Agranulocytosis was confirmed with bone marrow examination. Vemurafenib was considered the most probable drug responsible for this agranulocytosis and was thus stopped. We observed a full neutrophils recovery 10 days after vemurafenib cessation without any haematopoietic growth factors. A bone marrow biopsy performed 1 month after aplasia ending showed a good partial response with less than 5% of hairy cells remaining. To our knowledge, this is the first case ever described by vemurafenib-induced agranulocytosis. Thus, physicians should be warned about this risk given the growing number of patients treated with vemurafenib.

The positive correlation between drug addiction and drug dosage in vemurafenib-resistant melanoma cells is underpinned by activation of ERK1/2-FRA-1 pathway.

Malignant melanoma is a kind of highly invasive and deadly diseases. The BRAF inhibitor (BRAFi) such as vemurafenib could achieve a high response rate in melanoma patients with BRAF mutation. However, melanoma cells could easily develop resistance as well as addiction to BRAFi. Based on the drug addiction, intermittent treatment has been proposed to select against BRAFi-resistant melanoma cells. Because different dosages of BRAFi might be used in patients, it is necessary to know about the relationship between drug dosage and the degree of addiction. To address the problem, four drug-resistant melanoma cell sublines (A375/R0.5, A375/R2.0, M14/R0.5 and M14/R2.0) were established by continuously exposure of melanoma A375 or M14 cells to 0.5 or 2.0 µM vemurafenib. Vemurafenib withdrawal resulted in much stronger suppression on clone formation in A375/R2.0 and M14/R2.0, compared with A375/R0.5 and M14/R0.5, respectively. Meanwhile, stronger upregulation of ERK1/2-FRA-1 pathway could be observed in A375/R2.0 and M14/R2.0. Further detection showed that some proinflammatory cytokines downstream of ERK1/2-FRA-1 pathway were upregulated after drug withdrawal, and the conditioned medium collected from the resistant A375 cells could inhibit clone formation. Furthermore, vemurafenib withdrawal resulted in suppressed cell proliferation rather than cell senescence, with stronger effect on A375/R2.0 compared with A375/R0.5. This study suggested that the depth of vemurafenib addiction in resistant melanoma cells is positively correlated to the drug dosage, which might be underpinned by the ERK1/2-FRA-1 pathway and the related cytokines.

Molecularly matched therapy in the context of sensitivity, resistance, and safety; patient outcomes in end-stage cancer - the MetAction study.

Background: In precision cancer medicine, the challenge is to prioritize DNA driver events, account for resistance markers, and procure sufficient information for treatment that maintains patient safety. The MetAction project, exploring how tumor molecular vulnerabilities predict therapy response, first established the required workflow for DNA sequencing and data interpretation (2014-2015). Here, we employed it to identify molecularly matched therapy and recorded outcome in end-stage cancer (2016-2019).Material and methods: Metastatic tissue from 26 patients (16 colorectal cancer cases) was sequenced by the Oncomine assay. The study tumor boards interpreted called variants with respect to sensitivity or resistance to matched therapy and recommended single-agent or combination treatment if considered tolerable. The primary endpoint was the rate of progression-free survival 1.3-fold longer than for the most recent systemic therapy. The objective response rate and overall survival were secondary endpoints.Results: Both common and rare actionable alterations were identified. Thirteen patients were found eligible for therapy following review of tumor sensitivity and resistance variants and patient tolerability. The interventions were inhibitors of ALK/ROS1-, BRAF-, EGFR-, FGFR-, mTOR-, PARP-, or PD-1-mediated signaling for 2-3 cases each. Among 10 patients who received treatment until radiologic evaluation, 6 (46% of the eligible cases) met the primary endpoint. Four colorectal cancer patients (15% of the total study cohort) had objective response. The only serious adverse event was a transient colitis, which appeared in 1 of the 2 patients given PD-1 inhibitor with complete response. Apart from those two, overall survival was similar for patients who did and did not receive study treatment.Conclusions: The systematic MetAction approach may point forward to a refined framework for how to interpret the complexity of sensitivity versus resistance and patient safety that resides in tumor sequence data, for the possibly improved outcome of precision cancer medicine in future studies. ClinicalTrials.gov, identifier: NCT02142036.

Vemurafenib and cobimetinib-induced toxic epidermal necrolysis in a patient with metastatic melanoma.

Combination therapy in the treatment of metastatic melanoma has been associated with more durable response rate compared to monotherapy. However, previous studies have shown that combined target therapy commonly causes a wide spectrum of adverse events. These adverse reactions are usually manageable, however, it is always necessary to compare drug efficacy with its potential adverse effects. Toxic epidermal necrolysis represents severe mucocutaneous reaction, usually triggered by medications and characterized by extensive necrosis and detachment of the epidermis. Here we present a first case of toxic epidermal necrolysis induced by combined target therapy (vemurafenib plus cobimetinib). The case was observed in a young patient with BRAF mutant melanoma who was started on first-line metastatic immunotherapy with pembrolisumab.

Treatment exceeds expectations with vemurafenib monotherapy in a patient with BRAFV600E-mutant metastatic melanoma.

INTRODUCTION: Patients with distant metastatic melanoma has a poor prognosis, with a reported median survival time of six to eight months. In modern era, survival has prolonged with the immunotherapy and targeted therapy options. Potent and selective BRAF inhibitors have been developed that specifically inhibit mutated BRAF over other RAF kinases. Vemurafenib was the first selective tyrosine kinase inhibitor developed to target the V600E allele of BRAF-mutant melanoma. CASE REPORT: In this report, we present a case of BRAFV600E-mutant metastatic melanoma, which is being treated with vemurafenib monotherapy with complete response for about seven years. MANAGEMENT AND OUTCOME: The patient is still being treated with vemurafenib and radiologic complete response is ongoing for about seven years. DISCUSSION: Patients treated with BRAF inhibitors monotherapy had promising response rates and improvement in the progression-free survival and overall survival, but melanoma cells became resistant very quickly, affecting the progression. In this case, we present a case that has permanent response to vemurafenib monotherapy.

Combination of BRAF and MEK inhibition in BRAF V600E mutant low-grade ganglioglioma.

WHAT IS KNOWN AND OBJECTIVE: Post-surgical management of low grade gangliogliomas is controversial with paucity of data for the use of chemotherapy. BRAF mutations are present in a number of glioma subtypes and offer an opportunity for treatment with targeted therapy. CASE SUMMARY: A 32-year-old man with an unresectable, BRAF V600E mutant, WHO grade 1 ganglioglioma is commenced on combination BRAF and MEK inhibition (vemurafenib and cobimetinib). Partial radiological and clinical response was noted after 13 weeks of treatment. Treatment complication with grade 2 skin and liver toxicity was resolved with dose interruption and reduction. WHAT IS NEW AND CONCLUSION: Combination BRAF and MEK inhibition present a safe and feasible treatment strategy in unresectable BRAF V600E mutant low grade ganglioglioma.

A benzoxazole compound as a novel MEK inhibitor for the treatment of RAS/RAF mutant cancer.

Mutations in RAS/RAF occur in large portion of malignancies and are associated with aggressive clinical behaviors and poor prognosis. Therefore, we developed a novel benzoxazole compound (KZ-001) as a highly potent and selective MEK 1/2 inhibitor. Our efforts were focused on enhancing the activity of the known MEK inhibitor AZD6244 and overcoming the shortcomings existing in current MEK inhibitors. Here we show that compound KZ-001 exhibits approximately 30-fold greater inhibition against BRAF- and KRAS-mutant tumor cells than that of AZD6244. These results were also demonstrated using in vivo xenograft models. Furthermore, pharmacokinetics (PK) analysis was performed for KZ-001, and this compound showed good orally bioavailability (28%) and exposure (AUC0-∞ = 337 ± 169 ng h/mL). To determine its potential clinical application, the synergistic effect of KZ-001 with other agents was investigated both in vitro and in vivo (xenograft models). KZ-001 exhibited synergistic anti-cancer effect in combination with BRAF inhibitor vemurafenib and a microtubule-stabilizing chemotherapeutic agent docetaxel. In addition, KZ-001 inhibited the MAPK pathway like known MEK inhibitors. In summary, KZ-001, a structurally novel benzoxazole compound, was developed as a MEK inhibitor that has potential for cancer treatment.

Phase 1 study of the combination of vemurafenib, carboplatin, and paclitaxel in patients with BRAF-mutated melanoma and other advanced malignancies.

BACKGROUND: BRAF inhibitors are effective against selected BRAFV600 -mutated tumors. Preclinical data suggest that BRAF inhibition in conjunction with chemotherapy has increased therapeutic activity. METHODS: Patients with advanced cancers and BRAF mutations were enrolled into a dose-escalation study (3+3 design) to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs). RESULTS: Nineteen patients with advanced cancers and BRAF mutations were enrolled and received vemurafenib (480-720 mg orally twice a day), carboplatin (area under the curve [AUC] 5-6 intravenously every 3 weeks), and paclitaxel (100-135 mg/m2 intravenously every 3 weeks). The MTD was not reached, and vemurafenib at 720 mg twice a day, carboplatin at AUC 5, and paclitaxel at 135 mg/m2 were the last safe dose levels. DLTs included a persistent grade 2 creatinine elevation (n = 1), grade 3 transaminitis (n = 1), and grade 4 thrombocytopenia (n = 1). Non-dose-limiting toxicities that were grade 3 or higher and occurred in more than 2 patients included grade 3/4 neutropenia (n = 5), grade 3/4 thrombocytopenia (n = 5), grade 3 fatigue (n = 4), and grade 3 anemia (n = 3). Of the 19 patients, 5 (26%; all with melanoma) had a partial response (PR; n = 4) or complete response (CR; n = 1); these responses were mostly durable and lasted 3.1 to 54.1 months. Of the 13 patients previously treated with BRAF and/or mitogen-activated protein kinase kinase (MEK) inhibitors, 4 (31%) had a CR (n = 1) or PR (n = 3). Patients not treated with prior platinum therapy had a higher response rate than those who did (45% vs 0%; P = .045). CONCLUSIONS: The combination of vemurafenib, carboplatin, and paclitaxel is well tolerated and demonstrates encouraging activity, predominantly in patients with advanced melanoma and BRAFV600 mutations, regardless of prior treatment with BRAF and/or MEK inhibitors.

Impact of depth of response on survival in patients treated with cobimetinib ± vemurafenib: pooled analysis of BRIM-2, BRIM-3, BRIM-7 and coBRIM.

BACKGROUND: This pooled analysis investigated the prognostic value of depth of response in two cohorts of patients with BRAFV600-mutated metastatic melanoma treated with vemurafenib or cobimetinib plus vemurafenib. METHODS: The data were pooled from BRIM-2, BRIM-3, BRIM-7 and coBRIM. Association of depth of response with survival was estimated by Cox proportional hazards regression, adjusted for clinically relevant covariates. Depth of response was analysed in previously identified prognostic subgroups based on disease characteristics and gene signatures. RESULTS: Greater tumour reduction and longer time to maximal response were significantly associated with longer progression-free survival (PFS) and overall survival (OS) when evaluated as continuous variables. Patients with the deepest responses had long-lasting survival outcomes (median PFS: 14 months; OS: 32 months with vemurafenib; not estimable with cobimetinib plus vemurafenib). Cobimetinib plus vemurafenib improved depth of response versus vemurafenib monotherapy regardless of other prognostic factors, including gene signatures. CONCLUSIONS: Greater depth of response was associated with improved survival, supporting its utility as a measure of treatment efficacy in melanoma and further evaluation of its incorporation into existing prognostic models. Cobimetinib plus vemurafenib improved outcomes across quartiles of response regardless of prognostic factors or gene signatures and provided durable survival benefits in patients with deep responses.

Targeting B-Raf inhibitor resistant melanoma with novel cell penetrating peptide disrupters of PDE8A - C-Raf.

BACKGROUND: Recent advances in the treatment of melanoma that involve immunotherapy and B-Raf inhibition have revolutionised cancer care for this disease. However, an un-met clinical need remains in B-Raf inhibitor resistant patients where first-generation B-Raf inhibitors provide only short-term disease control. In these cases, B-Raf inhibition leads to paradoxical activation of the C-Raf - MEK - ERK signalling pathway, followed by metastasis. PDE8A has been shown to directly interact with and modulate the cAMP microdomain in the vicinity of C-Raf. This interaction promotes C-Raf activation by attenuating the PKA-mediated inhibitory phosphorylation of the kinase. METHODS: We have used a novel cell-penetrating peptide agent (PPL-008) that inhibits the PDE8A - C-Raf complex in a human malignant MM415 melanoma cell line and MM415 melanoma xenograft mouse model to investigate ERK MAP kinase signalling. RESULTS: We have demonstrated that the PDE8A - C-Raf complex disruptor PPL-008 increased inhibitory C-Raf-S259 phosphorylation and significantly reduced phospho-ERK signalling. We have also discovered that the ability of PPL-008 to dampen ERK signalling can be used to counter B-Raf inhibitor-driven paradoxical activation of phospho-ERK in MM415 cells treated with PLX4032 (Vemurafenib). PPL-008 treatment also significantly retarded the growth of these cells. When applied to a MM415 melanoma xenograft mouse model, PPL-008C penetrated tumour tissue and significantly reduced phospho-ERK signalling in that domain. CONCLUSION: Our data suggests that the PDE8A-C-Raf complex is a promising therapeutic treatment for B-Raf inhibitor resistant melanoma.

Fluvastatin exerts an antitumor effect in vemurafenib-resistant melanoma cells.

Although vemurafenib has been shown to improve the overall survival of patients with metastatic melanoma harboring the BRAF V600E mutation, its efficacy is often hampered by drug resistance acquired within a relatively short period through several distinct mechanisms. In the present study, we investigated the effect of fluvastatin as a possible strategy to overcome such acquired resistance using a cultured cell line model. We established vemurafenib-resistant (VR) cells from three BRAF (V600E)-mutated melanoma lines (C32, HMY-1, and SK-MEL-28) and evaluated the mechanism of acquired resistance of VR cells by water-soluble tetrazolium salts assay, western blot, real-time quantitative PCR, and immunofluorescent microscopy. The efficacy of the combination of growth inhibitory effect of vemurafenib and fluvastatin on respective parental and VR cells were assessed by calculating combination index and western blot. IC50 values of three VR cells were ~5-100-fold higher than those for the respective parental cells. The VR cells derived from HMY-1 and SK-MEL-28 showed constitutive activation of AKT kinase, and the specific AKT inhibitor MK-2208 or the PI3K inhibitor wortmannin increased the cellular sensitivity to vemurafenib. Intriguingly, application of a statin-related drug, fluvastatin, also resulted in a synergistic increase of sensitivity to vemurafenib in the VR cells (combination index: 0.73-0.86) probably by alleviating constitutive AKT activation, whereas the same treatment did not notably alter the vemurafenib sensitivity of the parental cells. Our results suggest the possible usefulness of statin-related drugs for overcoming vemurafenib resistance acquired through constitutive activation of the PI3K-AKT axis.

Efficacy and safety of BRAF inhibitors and anti-CTLA4 antibody in melanoma patients-real-world data.

PURPOSE: In the management of melanoma, BRAF inhibitors yield fast disease control; however, the duration of response does not last very long. Ipilimumab-an anti-CTLA4 antibody on the other hand-provides longer-lasting results of treatment but achieves less favorable responses. The aim of this study was to assess the efficacy and safety of novel drugs for advanced melanoma in daily routine practice. METHODS: A retrospective observational study was conducted on all Polish patients (1170 patients), diagnosed with advanced metastatic melanoma, treated with the following drugs: vemurafenib, dabrafenib, and ipilimumab. The antitumor efficacy of these agents was retrospectively assessed by Response Evaluation Criteria in Solid Tumors in the case of BRAF inhibitors and by Immune-Related Response Criteria in the case of ipilimumab therapy. Adverse events were assessed in relation to the morphologic parameters of blood, nephrotoxicity, and hepatotoxicity. RESULTS: The overall response to treatment with BRAF inhibitors (vemurafenib and dabrafenib) was similar with a slightly better outcome in the group treated with vemurafenib. Compared to clinical trials, the objective response rate was slightly worse for both BRAF inhibitors (30% and 42% for dabrafenib and vemurafenib, respectively), as well as the immune-related response for ipilimumab (1%). There was no significant difference in patient's response rates regardless of what lines of treatment (first, second, or next) vemurafenib was applied in. A few severe adverse events (mostly anemia and hyperbilirubinemia) were observed during treatment. CONCLUSIONS: The lack of evidence in responses observed regardless of what line of treatment vemurafenib was applied in suggests there is no clinical reason for restricting BRAF inhibitors to only the first line of therapy. Our study confirms that novel agents brought about a major advancement in the management of melanoma. In line with literature, BRAF inhibitors and ipilimumab significantly improved the antitumor response rate with manageable adverse events.

Targeted agents or immuno-oncology therapies as first-line therapy for BRAF-mutated metastatic melanoma: a real-world study.

Aim: Targeted therapy (TT) and immuno-oncology (IO) drugs are approved for patients with BRAF mutant metastatic melanoma (MM). We compared real-world outcomes for first-line (1L) TT versus 1L IO to evaluate optimal sequencing. Materials & methods: Physicians-identified BRAF mutant MM patients initiating 1L TT or IO therapies and extracted treatment, disease and clinical outcomes including disease response which were compared between TT and IO and individual regimens. Results: 440 MM patients (TT = 283, IO = 157) were identified. A higher proportion of TT patients had liver metastases (46.3 vs 35.0%) and abnormal lactate dehydrogenase (61.1 vs 42.7%). IO-treated had a RECIST-determined response rate of 45.9 versus 60.1% for TT and time on treatment of 7.2 versus 11.4 months, respectively. There was no survival difference between cohorts. Conclusion: Despite higher risk patients, 1L TT resulted in higher response rate and longer treatment duration suggesting a preferred 1L sequence.