A randomised phase 2 study of intermittent versus continuous dosing of dabrafenib plus trametinib in patients with BRAFV600 mutant advanced melanoma (INTERIM).

BACKGROUND: BRAF+MEK inhibitors extend life expectancy of patients with BRAFV600 mutant advanced melanoma. Acquired resistance limits duration of benefit, but preclinical and case studies suggest intermittent dosing could overcome this limitation. INTERIM was a phase 2 trial evaluating an intermittent dosing regimen. METHODS: Patients with BRAFV600 mutant advanced melanoma due to start dabrafenib+trametinib were randomised to receive either continuous (CONT), or intermittent (INT; dabrafenib d1-21, trametinib d1-14 every 28 days) dosing. A composite primary endpoint included progression-free survival (PFS) and quality of life (QoL). Secondary endpoints included response rate (ORR), overall survival (OS) and adverse events (AEs). Mutant BRAFV600E ctDNA was measured by droplet digital PCR (ddPCR), using mutant allele frequency of > 1 % as the detection threshold. RESULTS: 79 patients (39 INT, 40 CONT) were recruited; median age 67 years, 65 % AJCC (7th ed) stage IV M1c, 29 % had brain metastases. With 19 months median follow-up, INT was inferior in all efficacy measures: median PFS 8.5 vs 10.7mo (HR 1.39, 95 %CI 0.79-2.45, p = 0.255); median OS 18.1mo vs not reached (HR 1.69, 95 %CI 0.87-3.28, p = 0.121), ORR 57 % vs 77 %. INT patients experienced fewer treatment-related AEs (76 % vs 88 %), but more grade > 3 AEs (53 % vs 42 %). QoL favoured CONT. Detection of BRAFV600E ctDNA prior to treatment correlated with worse OS (HR 2.55, 95 %CI 1.25-5.21, p = 0.01) in both arms. A change to undetected during treatment did not significantly predict better OS. CONCLUSION: INTERIM findings are consistent with other recent clinical trials reporting that intermittent dosing does not improve efficacy of BRAF+MEK inhibitors.

Life-threatening polymyositis with spontaneous hematoma induced by nivolumab in a patient with previously resected melanoma.

Single-agent anti-PD1 antibodies are usually very well tolerated, but serious toxicity can still occur. Despite the PD-1 pathway seems to be relevant in the pathogenesis of immune-related myositis, anti-PD1-related myositis is generally a rare side effect of the treatment and usually not serious. However, its frequency is likely to increase as the use of immune checkpoint blockades. We present here a case of life-threatening polymyositis with associated spontaneous muscular hematoma in a patient treated with single-agent nivolumab in the adjuvant setting. Spontaneous hematoma is an extremely rare complication with unclear etiology of idiopathic myositis. Very few cases have been reported in the literature and their outcome has been often fatal. To our knowledge, this is the first case of autoimmune myositis and spontaneous heamatoma associated with the administration of single-agent checkpoint blockade. Anti-PD1 antibodies have changed the treatment landscape for a number of cancer entities in the past few years. When given as single agent they are usually very well tolerated, but serious rare toxicity can still occur. We present here a case of polymyositis with associated spontaneous muscular hematoma in a patient treated with single agent nivolumab.

Effect of carboplatin when administered after dacarbazine failure: Clinical benefit of sequential therapy.

Dacarbazine chemotherapy has been the mainstay of melanoma treatment for >30 years. In the early 2000s, carboplatin (with or without other agents, such as paclitaxel) was the most commonly used second-line therapy in the UK. The aim of the present study was to report a significant response rate to second-line carboplatin in patients from three UK institutions who had been previously treated and failed to respond to dacarbazine, and investigate whether sequential therapy may be more effective compared with combination therapy. A total of 104 patients were identified, the majority of whom were treated with carboplatin (area under the curve 5-6) every 3 weeks for a maximum of 6 cycles. A total of 102 patients were evaluable for response, among whom 11 patients had an objective response (1 complete response and 10 partial responses) and 15 had stable disease, giving an overall response rate of 11% and disease control rate of 26%. The median progression-free survival was 1.8 months (range, 0.2-36+ months) and the median overall survival was 4.6 months (range, 0.2-36+ months). Surprisingly, the majority of the patients who benefited from second-line carboplatin therapy were those with visceral metastases, the survival of whom would not be expected to exceed 6 months after first-line treatment.

Serum Apolipoprotein E and Other Inflammatory Markers Can Identify Non-Responding Patients to a Dendritic Cell Vaccine.

BACKGROUND: Despite the majority of patients do not gain any benefit from dendritic cells (DC) vaccines, this approach has occasionally given rise to dramatic responses in melanoma. Biomarkers are crucial to identify which patients are more likely to respond. We looked for correlations between pre- or post- vaccination biomarkers and clinical outcomes to DC therapy in a cohort of patients with stage IV melanoma receiving a vaccine with autologous ex-vivo expanded DCs pulsed with allogeneic tumor cell lysate. METHODS: Serial serum samples were collected at baseline, week 4 and 12 and they were analyzed for a panel of different inflammatory markers using cytometric bead array technology and ELISA. RESULTS: Twenty-one patients were evaluable for response. Patients were separated into responders and non-responders based on clinical benefit. Responders were defined as patients who achieved a complete response, partial response or stable disease the latter lasting for at least 6 months. Responders (N = 9) showed a significantly longer Progression-free Survival (PFS; HR 0.23; 95% CI 0.08-062; P < .001) and Overall Survival (OS; HR 0.22; 95% CI 0.08-0.59; P < .001). The clinical non-responder phenotype correlated with an elevated pre-vaccination level of cytokines associated with inflammation compared to clinical responders (Apolipoprotein C111; IL-12 p40; MiP1α; Stem Cell Factor and TNFα). Apolipoprotein E (ApoE) was also significantly elevated in the pre-vaccine sera of the clinically non-responding group and in addition it was found to correlate with outcomes. Patients with increased levels of ApoE had a significantly shorter PFS (HR 3.02; 95% CI 1.09-8.35; P = .015) and OS (HR 2.40; 95% CI 0.9-6.3; P = .034). CONCLUSION: Our findings support the notion that treating the inflammatory background may have an impact on clinical outcome for patients receiving immunotherapy. A larger study is needed to confirm the significance of ApoE as a predictive biomarker for response to DC vaccines.

Enhanced effect of checkpoint inhibitors when given after or together with IMM-101: significant responses in four advanced melanoma patients with no additional major toxicity.

BACKGROUND: The use of checkpoint inhibitors (ipilimumab, pembrolizumab, nivolumab) has revolutionised the treatment of metastatic melanoma. However still more than the half the patients do not respond to single-agent immunotherapy. This has led to the development of combining these agents in an attempt to enhance the anti-cancer activity. More than 300 different studies with 15 different drug doses are currently ongoing. Combining different checkpoint inhibitors (CPIs) does indeed lead to an increase in response rate, but this is associated with significant toxicity. IMM-101 is a heat killed Mycobacterium preparation which induces marked immune modulation and little systemic toxicity. It has been reported as having activity in melanoma as single agent and in pancreatic cancer in combination with gemcitabine, the latter in a randomised study. METHODS: Here we report the effect of adding CPIs to 3 patients who had previously been on IMM-101, either as a trial or a named patient programme and a patient who received the IMM-101 together with nivolumab. RESULTS: All 4 patients had rapid and very good responses, three of them maintained over 18 months with no significant additional toxicity. CONCLUSIONS: The rapid and complete clinical responses seen in these patients may suggest that IMM-101 is activating a complementary pathway which is synergistic with CPI treatment.

The importance for immunoregulation for long-term cancer control.

Immune checkpoint blockades have recently emerged as a breakthrough treatment for solid tumors showing high response rates and long durability. In melanoma, the combination of ipilimumab with nivolumab showed high efficacy. However, still half the patients do not respond to this treatment. In order to increase the therapeutic ratio in melanoma and other cancers, different approaches are under evaluation. Three relevant questions are at the moment driving the research community: how to maximize benefit while minimizing toxicity; how to better identify patients who are more likely to benefit from immunotherapy; how to convert nonresponders into responders. In this review we summarize the most recent findings and we outline the most likely future challenges.

Molecular dissection of colorectal cancer in pre-clinical models identifies biomarkers predicting sensitivity to EGFR inhibitors.

Colorectal carcinoma represents a heterogeneous entity, with only a fraction of the tumours responding to available therapies, requiring a better molecular understanding of the disease in precision oncology. To address this challenge, the OncoTrack consortium recruited 106 CRC patients (stages I-IV) and developed a pre-clinical platform generating a compendium of drug sensitivity data totalling >4,000 assays testing 16 clinical drugs on patient-derived in vivo and in vitro models. This large biobank of 106 tumours, 35 organoids and 59 xenografts, with extensive omics data comparing donor tumours and derived models provides a resource for advancing our understanding of CRC. Models recapitulate many of the genetic and transcriptomic features of the donors, but defined less complex molecular sub-groups because of the loss of human stroma. Linking molecular profiles with drug sensitivity patterns identifies novel biomarkers, including a signature outperforming RAS/RAF mutations in predicting sensitivity to the EGFR inhibitor cetuximab.

Vasculogenic mimicry in small cell lung cancer.

Small cell lung cancer (SCLC) is characterized by prevalent circulating tumour cells (CTCs), early metastasis and poor prognosis. We show that SCLC patients (37/38) have rare CTC subpopulations co-expressing vascular endothelial-cadherin (VE-cadherin) and cytokeratins consistent with vasculogenic mimicry (VM), a process whereby tumour cells form 'endothelial-like' vessels. Single-cell genomic analysis reveals characteristic SCLC genomic changes in both VE-cadherin-positive and -negative CTCs. Higher levels of VM are associated with worse overall survival in 41 limited-stage patients' biopsies (P<0.025). VM vessels are also observed in 9/10 CTC patient-derived explants (CDX), where molecular analysis of fractionated VE-cadherin-positive cells uncovered copy-number alterations and mutated TP53, confirming human tumour origin. VE-cadherin is required for VM in NCI-H446 SCLC xenografts, where VM decreases tumour latency and, despite increased cisplatin intra-tumour delivery, decreases cisplatin efficacy. The functional significance of VM in SCLC suggests VM regulation may provide new targets for therapeutic intervention.

Application of Sequencing, Liquid Biopsies, and Patient-Derived Xenografts for Personalized Medicine in Melanoma.

UNLABELLED: Targeted therapies and immunotherapies have transformed melanoma care, extending median survival from ∼9 to over 25 months, but nevertheless most patients still die of their disease. The aim of precision medicine is to tailor care for individual patients and improve outcomes. To this end, we developed protocols to facilitate individualized treatment decisions for patients with advanced melanoma, analyzing 364 samples from 214 patients. Whole exome sequencing (WES) and targeted sequencing of circulating tumor DNA (ctDNA) allowed us to monitor responses to therapy and to identify and then follow mechanisms of resistance. WES of tumors revealed potential hypothesis-driven therapeutic strategies for BRAF wild-type and inhibitor-resistant BRAF-mutant tumors, which were then validated in patient-derived xenografts (PDX). We also developed circulating tumor cell-derived xenografts (CDX) as an alternative to PDXs when tumors were inaccessible or difficult to biopsy. Thus, we describe a powerful technology platform for precision medicine in patients with melanoma. SIGNIFICANCE: Although recent developments have revolutionized melanoma care, most patients still die of their disease. To improve melanoma outcomes further, we developed a powerful precision medicine platform to monitor patient responses and to identify and validate hypothesis-driven therapies for patients who do not respond, or who develop resistance to current treatments.

Optimal management of immune-related toxicities associated with checkpoint inhibitors in lung cancer.

Antibodies against immune checkpoints including CTLA-4, PD-1 and PD-L1 are increasingly being used in lung cancer. They are associated with novel, immune related toxicities not previously encountered with established treatments for lung cancer including colitis, hepatitis, rashes, neuropathies and other rarer immune mediated toxicities. Although generally these are low grade, there is a potential to be life threatening if not managed promptly. Early recognition of toxicity and institution of management algorithms are key to ensuring patient safety. We review the common toxicities and provide recommendations on their management.

Dabrafenib and its use in the treatment of metastatic melanoma.

Approximately 50% of melanomas have mutations in the gene encoding BRAF. In recent years, new targeted therapies have transformed the landscape of metastatic melanoma treatment. Dabrafenib, a potent kinase inhibitor of mutated BRAF, has been showed to have high response rates with a rapid onset of response, as well as improved overall and progression-free survival when compared with chemotherapy. Dabrafenib in combination with trametinib, a MEK inhibitor, has demonstrated higher responses and improved clinical efficacy compared with monotherapy. Toxicity is distinct compared with chemotherapy but manageable. This article summarizes the pharmacology, key clinical trial data as well as practical experience with dabrafenib in clinical practice, and future directions.

Paradox-breaking RAF inhibitors that also target SRC are effective in drug-resistant BRAF mutant melanoma.

BRAF and MEK inhibitors are effective in BRAF mutant melanoma, but most patients eventually relapse with acquired resistance, and others present intrinsic resistance to these drugs. Resistance is often mediated by pathway reactivation through receptor tyrosine kinase (RTK)/SRC-family kinase (SFK) signaling or mutant NRAS, which drive paradoxical reactivation of the pathway. We describe pan-RAF inhibitors (CCT196969, CCT241161) that also inhibit SFKs. These compounds do not drive paradoxical pathway activation and inhibit MEK/ERK in BRAF and NRAS mutant melanoma. They inhibit melanoma cells and patient-derived xenografts that are resistant to BRAF and BRAF/MEK inhibitors. Thus, paradox-breaking pan-RAF inhibitors that also inhibit SFKs could provide first-line treatment for BRAF and NRAS mutant melanomas and second-line treatment for patients who develop resistance.

PI3K/PTEN/AKT/mTOR polymorphisms: association with clinical outcome in patients with head and neck squamous cell carcinoma receiving cetuximab-docetaxel.

BACKGROUND: The purpose of this study was to determine whether single nucleotide polymorphisms (SNPs) in AKT1, AKT2, FRAP1, PIK3CA, and PTEN were associated with treatment response and clinical outcome in patients with head and neck squamous cell carcinoma (HNSCC). METHODS: Genomic DNA was extracted from formalin-fixed tissue of 45 patients with recurrent or initially metastatic HNSCC, and SNPs were genotyped by means of real-time polymerase chain reaction (PCR) system or direct sequencing. RESULTS: The AKT2:rs8100018 and the PTEN:rs12569998 homozygous variants resulted as associated with an increased risk of progression (hazard ratio [HR], 4.83; 95% confidence interval [CI], 1.11-21.03; and HR, 2.36; 95% CI, 1.24-4.50, respectively). An additive effect on risk of progression was observed. The AKT2:rs8100018 homozygous variant was significantly associated with a higher risk of death (HR, 3.57; 95% CI, 1.06-12.00), whereas the presence of at least one variant allele of AKT1:rs3803304 was associated with a lower risk of death (HR, 0.51; 95% CI, 0.27-0.97). CONCLUSION: We identified combined genotypes associated with outcome of HNSCC, which might have an impact for identification of a target population for cetuximab-docetaxel treatment. Results should be considered as an initial finding and warrant validation in larger clinical trials.

Expression and activity of EGFR in human cutaneous melanoma cell lines and influence of vemurafenib on the EGFR pathway.

Data regarding the expression of epidermal growth factor receptor (EGFR) in melanoma and its role in the tumor biology are conflicting. In BRAF V600-mutant melanomas, the expression of EGFR has been associated with acquired resistance to BRAF inhibitors. In this study, we assessed EGFR expression and downstream signaling activity in a panel of melanoma cell lines and we investigated the effects of the BRAF inhibitor vemurafenib on expression of EGFR and its downstream effectors in a subgroup of BRAF-mutant melanoma cells. Three out of 10 melanoma cell lines expressed EGFR. Downstream signaling via ERK and AKT was responsive to either stimulation by EGF or inhibition by erlotinib. Constitutive activation of ERK occurred in all the cell lines investigated whereas constitutive activation of AKT only in three cell lines. Constitutive activation of ERK and AKT was independent from EGFR expression. Vemurafenib did not affect EGFR expression in general, but it increased EGFR phosphorylation in the cell line SkMel5. Induced EGFR phosphorylation was sensitive to treatment with erlotinib. Vemurafenib efficiently blocked ERK activation in all the BRAF-mutant cell lines tested, whereas its effects on AKT activation were dissimilar in the different cell lines. Our data suggest that EGFR is functional but usually inactive in EGFR high-expressing cell lines. Basal EGFR expression unlikely represents a biomarker for predicting the sensitivity to vemurafenib in melanoma, but EGFR activation might represent a mechanism of vemurafenib resistance in a subset of melanoma cells.

Activity of the monocarboxylate transporter 1 inhibitor AZD3965 in small cell lung cancer.

PURPOSE: The monocarboxylate transporter 1 (MCT1) inhibitor, AZD3965, is undergoing phase I evaluation in the United Kingdom. AZD3965 is proposed, via lactate transport modulation, to kill tumor cells reliant on glycolysis. We investigated the therapeutic potential of AZD3965 in small cell lung cancer (SCLC) seeking rationale for clinical testing in this disease and putative predictive biomarkers for trial use. EXPERIMENTAL DESIGN: AZD3965 sensitivity was determined for seven SCLC cell lines, in normoxia and hypoxia, and for a tumor xenograft model. Proof of mechanism was sought via changes in intracellular/tumor lactate. Expression of MCT1 and related transporter MCT4 was assessed by Western blot analysis. Drug resistance was investigated via MCT4 siRNAi and overexpression. The expression and clinical significance of MCT1 and MCT4 were explored in a tissue microarray (TMA) from 78 patients with SCLC. RESULTS: AZD3965 sensitivity varied in vitro and was highest in hypoxia. Resistance in hypoxia was associated with increased MCT4 expression. In vivo, AZD3965 reduced tumor growth and increased intratumor lactate. In the TMA, high MCT1 expression was associated with worse prognosis (P = 0.014). MCT1 and hypoxia marker CA IX expression in the absence of MCT4 was observed in 21% of SCLC tumors. CONCLUSIONS: This study provides a rationale to test AZD3965 in patients with SCLC. Our results suggest that patients with tumors expressing MCT1 and lacking in MCT4 are most likely to respond.

The role of chemotherapy in the modern management of melanoma.

The last 4 years have seen dramatic changes in the treatment of advanced melanoma, largely based on advances in targeted therapy and immunotherapy. This article examines the role of chemotherapy in the modern management of melanoma. We examine the evidence for promising new agents and discuss their position in the sequencing of treatment options for patients with advanced disease. In addition, we discuss the combination of chemotherapy with targeted treatments and immune therapies. Finally, we discuss future areas of research for ensuring that we maximize the potential of all agents available to us and identify new, effective treatments.