New developments in the management of advanced melanoma - role of pembrolizumab

Rapid remission of symptomatic brain metastases in melanoma by programmed-death-receptor-1 inhibition

Although ∼40% of patients with metastatic melanoma develop brain metastases, the presence of brain metastases often precludes enrolment in clinical trials for advanced melanoma. However, the development of symptomatic brain metastases markedly increases mortality. The antiprogrammed-death-receptor-1 antibody pembrolizumab achieves extracranial metastases disease response rates of up to 50%. Here, we report the rapid and sustained response of symptomatic multifocal brain metastases in a melanoma ipilimumab-pretreated patient under pembrolizumab, combined with high-dose dexamethasone therapy during the induction phase of therapy. Complete remission has been maintained for over 1 year of follow-up and has correlated with the response rate observed in the extracranial metastases. Radiological disease response was identified during the first follow-up visit in the absence of adjuvant radiotherapy. This report highlights the need for further clinical studies to specifically address the therapeutic potential of antiprogrammed-death-receptor-1 monotherapy in the management of untreated brain metastases in melanoma.

CSPG4: a prototype oncoantigen for translational immunotherapy studies

Thanks to striking progress in both the understanding of anti-tumor immune response and the characterization of several tumor associated antigens (TAA), a more rational design and more sophisticated strategies for anti-tumor vaccination have been possible. However, the effectiveness of cancer vaccines in clinical trial is still partial, indicating that additional studies are needed to optimize their design and their pre-clinical testing. Indeed, anti-tumor vaccination success relies on the choice of the best TAA to be targeted and on the translational power of the pre-clinical model used to assess its efficacy. The chondroitin sulfate proteoglycan-4 (CSPG4) is a cell surface proteoglycan overexpressed in a huge range of human and canine neoplastic lesions by tumor cells, tumor microenvironment and cancer initiating cells. CSPG4 plays a central role in the oncogenic pathways required for malignant progression and metastatization. Thanks to these features and to its poor expression in adult healthy tissues, CSPG4 represents an ideal oncoantigen and thus an attractive target for anti-tumor immunotherapy. In this review we explore the potential of CSPG4 immune-targeting. Moreover, since it has been clearly demonstrated that spontaneous canine tumors mimic the progression of human malignancies better than any other pre-clinical model available so far, we reported also our results indicating that CSPG4 DNA vaccination is safe and effective in significantly increasing the survival of canine melanoma patients. Therefore, anti-CSPG4 vaccination strategy could have a substantial impact for the treatment of the wider population of spontaneous CSPG4-positive tumor affected dogs with a priceless translational value and a revolutionary implication for human oncological patients.

Highlights on immune checkpoint inhibitors in non-small cell lung cancer

The treatment of advanced or refractory non-small cell lung cancer has been historically difficult owing to the lack of studies on effective systemic cure. The progress in lung cancer treatment has plateaued, necessitating new options for additional benefits. Immune checkpoint proteins are co-inhibitory factors that can diminish the antigen-specific immune responses by attenuating the regulatory role of cytotoxic T-lymphocyte-associated protein 4, programmed cell death-1, lymphocyte-activation gene 3, and T-cell immunoglobulin mucin-3. The therapeutic strategies targeting immune checkpoints mainly focus on the monoclonal antibody of these regulatory factors, which may facilitate clinical decision making. An enhanced understanding of the drug-resistance mechanisms and the therapeutic efficacy regulation will provide opportunities to improve the clinical outcomes of non-small cell lung cancer patients. Preclinical and clinical trials on these key immune-regulatory agents, which has heralded a new era in immuno-oncology in non-small cell lung cancer treatment, are currently in development.

A rapid response to pembrolizumab in a patient with metastatic melanoma

Prognosis for patients with metastatic melanoma stays poor. Recent advances in the field of immuno-oncology increased treatment options for these patients and gave chances for obtaining partial and even complete response, prolonging survival in a subset of patients. Here, we describe a case of a 55-year-old man with multiple melanoma metastases into lungs who showed an extraordinary response to pembrolizumab used as a first-line treatment. The therapy was well tolerated, with no adverse reactions reported.

Point of care assessment of melanoma tumor signaling and metastatic burden from μNMR analysis of tumor fine needle aspirates and peripheral blood

This study evaluates μNMR technology for molecular profiling of tumor fine needle aspirates and peripheral blood of melanoma patients. In vitro assessment of melanocyte (MART-1, HMB45) and MAP kinase signaling (pERK, pS6K) molecule expression was performed in human cell lines, while clinical validation was performed in an IRB-approved study of melanoma patients undergoing biopsy and blood sampling. Tumor FNA and blood specimens were compared with BRAF genetic analysis and cross-sectional imaging. μNMR in vitro analysis showed increased expression of melanocyte markers in melanoma cells as well as increased expression of phosphorylated MAP kinase targets in BRAF-mutant melanoma cells. Melanoma patient FNA samples showed increased pERK and pS6K levels in BRAF mutant compared with BRAF WT melanomas, with μNMR blood circulating tumor cell level increased with higher metastatic burden visible on imaging. These results indicate that μNMR technology provides minimally invasive point-of-care evaluation of tumor signaling and metastatic burden in melanoma patients.

Unresectable cutaneous squamous cell carcinoma of the forehead with MLH1 mutation showing dramatic response to Programmed Cell Death Protein 1 Inhibitor Therapy

Treatment of refractory, unresectable cutaneous squamous cell carcinoma presents a great challenge in head and neck oncology with poor prognosis. Prior case reports have shown off-label pembrolizumab, a programed cell death receptor antagonist, can be effective in unresectable cutaneous squamous cell carcinoma. Furthermore, prior reports have suggested enhanced efficacy when high mutational burden is present. In this study we present a severe case of unresectable cutaneous squamous cell carcinoma invading the orbit and cavernous sinus with documented tumor MLH1 mutation. The patient had a complete response to palliative, off-label pembrolizumab therapy.

Cobimetinib and vemurafenib for the treatment of melanoma

INTRODUCTION

Cobimetinib combined with vemurafenib is a new approved MEK inhibitor for first line treatment of metastatic melanoma patients with BRAF V600 mutations. It improves tumor response rates and progression free survival compared to vemurafenib alone, while decreasing toxicities due to the paradoxical activation of the MAPK signaling pathway.

AREAS COVERED

This review covers the pharmacology, efficacy, and toxicity data derived from clinical and preclinical studies on cobimetinib. It also reports ongoing trials evaluating cobimetinib to better understand future developments for this drug.

EXPERT OPINION

The combination of cobimetinib and vemurafenib seems to be more toxic than the combination therapy dabrafenib and trametinib even if these four drugs have never been compared in a randomized trial. The future of this combination depends on its capacity to be combined simultaneously or sequentially with immune based therapies to improve the durability of responses.

[Adaptive drug licensing: A chance for patients?]

In recent years, various options have been discussed to accelerate the approval of new drugs, especially for conditions with high unmet needs. There is a trade-off between the earlier availability of new treatment options and a potentially higher safety risk of drugs which have not been investigated in long-lasting clinical trials and a broader patient population. It must also be taken into account that clinical trial data and results must be sufficient to allow for the reimbursement of the new treatment option. The difficult process of weighting the benefits against the potential risks of an accelerated drug approval should be discussed between patients, regulatory authorities, HTA institutions and pharmaceutical companies. Patients might benefit from a fair, balanced accelerated approval.

Limbic encephalitis following immunotherapy against metastatic malignant melanoma

Novel immunotherapies are increasingly being used to treat malignant melanoma. The use of such agents has been associated with triggering autoimmunity. However, there has been a paucity in reports of limbic encephalitis associated with these immunotherapies. Pembrolizumab, a monoclonal antibody against programmed cell death antigen (PD-1), is currently being trialled in the UK to treat malignant melanoma. We report a unique case of antibody-negative limbic encephalitis presenting 1 year after starting pembrolizumab, in the context of malignant melanoma. The patient presented with progressive cognitive decline. MRI of the brain revealed signal change within the limbic structures. Cerebrospinal fluid studies confirmed evidence of inflammation with raised white cell count and protein. We were able to prevent further progression of symptoms by stopping pembrolizumab and treating the patient instead with steroids. We advocate considering autoimmune neuroinflammation as a differential for neurological disorders presenting in patients receiving PD-1 antagonist treatment and immunotherapy in general.

Immune based therapy for melanoma

A few years ago therapeutic options in advanced melanoma were very limited and the prognosis was somber. Although recent progresses are far from providing a cure for advanced melanoma, yet these have kindled new hopes and searching for a cure does not seem unreasonable. Seven new medicines have been authorized in various regions of the world in the recent past in the therapy of advanced melanoma, over half of them acting by mechanisms involving the immune system of the host. The anti-CTLA-4 (cytotoxic T lymphocyte associated protein-4) ipilimumab has been followed by anti-PD1 (programmed death1) inhibitors, more effective and safer. Very recently, the first oncolytic immunotherapy, talimogene laherparepvec (T-VEC) has been authorized for placing on the market and a variety of combinations of the new therapies are currently being evaluated or considered. Besides, a plethora of other molecules and approaches, especially monoclonal antibodies, are in the preliminary phases of clinical investigation and are likely to bring new benefits for the treatment of this potentially fatal form of cancer.