Tolerance and Effectiveness of Targeted Therapies in Aged Patients with Metastatic Melanoma.

PURPOSE: Melanoma's incidence is increasing, and elderly people could be significantly impacted since the majority occurs in people over 65 years of age. Combined BRAF and MEK targeted therapies (TT) are current standard regimen for BRAF mutated metastatic melanoma (MM). Except for subgroups of pivotal trials, little data are available for TT in this population. MATERIALS AND METHODS: Outcomes were explored in real life patients from MelBase, a French multicentric biobank dedicated to the prospective follow-up of unresectable stage III or IV melanoma. Patients treated by BRAF TT and/or MEK TT combined or not, were included from 2013 to 2017 in 2 groups: group 1 ≤ 65-year-old (yo), group 2 > 65 yo, analyzed for tolerance and efficacy. RESULTS: 353 patients were included: 231 in group 1, 122 in group 2. Median follow-up was 12 months (M). Median time of treatment was 6.9 M. A total of 80% had at least one Adverse Effect (AE). Most frequent AE (all grades) were mainly skin and subcutaneous, general, and gastrointestinal disorders. A total of 31% of AE were grade 3-4: 28% in group 1 and 39% in group 2 (p = 0.05). No differences were observed in all AE grades proportion, dose modifications, interruptions, and discontinuations. For each group, median overall survival was 20.3 M (CI 95%: 15.5-27.9) and 16.3 M (CI: 14.5-26.9), respectively (p = 0.8). Median progression free survival was 7.8 M (6.4-9.9) and 7.7 M (CI: 5.8-11.3) (p = 0.4). Objective response rate was 59% and 50% (p = 0.6). CONCLUSION: This study on a large multicentric cohort is the first to assess that TT is well tolerated in elderly BRAF-mutated patients such as in patients younger than 65. Efficacy was similar between groups with outcomes reaching those from pivotal studies. There is thus no argument against using TT in elderly people, although an onco-geriatric opinion is welcome for the most vulnerable.

Hemophagocytic lymphohistiocytosis in advanced melanoma treated with dabrafenib and trametinib combination: two cases.

Hemophagocytic lymphohistiocytosis (HLH) has been only rarely reported in patients with BRAF-mutated advanced melanoma treated with targeted therapies and never with first-line dabrafenib/trametinib combination thus far. Two patients treated with first-line dabrafenib and trametinib combination therapy for metastatic melanoma presented with sudden occurrence of fever, cytopenia, rhabdomyolysis, hepatic cytolysis, hypertriglyceridemia and very high ferritin levels after few weeks of treatment, associated with concomitant epstein-barr virus (EBV) reactivation in one patient. In both cases, drug-induced HLH was primarily considered owing to a high H-score and the absence of other etiology. Patients rapidly improved after treatment discontinuation associated with oral steroids in one patient and did not relapse after subsequent treatment resumption with a concurrent anti-BRAF/anti-MEK combination. In metastatic melanoma HLH may occur either spontaneously in the absence of any treatment as a paraneoplastic condition, related to an intercurrent infection or drug-induced mainly with various immunotherapy or with dabrafenib and trametinib following immunotherapy. However, such observations are scarce and these are the first cases of HLH occurring during first-line treatment with dabrafenib and trametinib in advanced melanoma to our knowledge. Pathomechanisms remain to be elucidated since triggering factors may encompass the treatment itself but also other significant actors including viral reactivation along with the underlying disease. The liability of treatment should be considered in cases of HLH occurring in patients with advanced melanoma successfully treated with a combined targeted therapy. A rechallenge with a concurrent anti-BRAF/anti-MEK can be proposed in this setting.

Clinical Relevance of Liquid Biopsy in Melanoma and Merkel Cell Carcinoma.

Melanoma and Merkel cell carcinoma are two aggressive skin malignancies with high disease-related mortality and increasing incidence rates. Currently, invasive tumor tissue biopsy is the gold standard for their diagnosis, and no reliable easily accessible biomarker is available to monitor patients with melanoma or Merkel cell carcinoma during the disease course. In these last years, liquid biopsy has emerged as a candidate approach to overcome this limit and to identify biomarkers for early cancer diagnosis, prognosis, therapeutic response prediction, and patient follow-up. Liquid biopsy is a blood-based non-invasive procedure that allows the sequential analysis of circulating tumor cells, circulating cell-free and tumor DNA, and extracellular vesicles. These innovative biosources show similar features as the primary tumor from where they originated and represent an alternative to invasive solid tumor biopsy. In this review, the biology and technical challenges linked to the detection and analysis of the different circulating candidate biomarkers for melanoma and Merkel cell carcinoma are discussed as well as their clinical relevance.

Identification and characterization of novel TRPM1 autoantibodies from serum of patients with melanoma-associated retinopathy.

Melanoma-associated retinopathy (MAR) is a rare paraneoplastic retinal disorder usually occurring in the context of metastatic melanoma. Patients present with night blindness, photopsias and a constriction of the visual field. MAR is an auto-immune disorder characterized by the production of autoantibodies targeting retinal proteins, especially autoantibodies reacting to the cation channel TRPM1 produced in melanocytes and ON-bipolar cells. TRPM1 has at least three different isoforms which vary in the N-terminal region of the protein. In this study, we report the case of three new MAR patients presenting different anti-TRPM1 autoantibodies reacting to the three isoforms of TRPM1 with variable binding affinity. Two sera recognized all isoforms of TRPM1, while one recognized only the two longest isoforms upon immunolocalization studies on overexpressing cells. Similarly, the former two sera reacted with all TRPM1 isoforms on western blot, but an immunoprecipitation enrichment step was necessary to detect all isoforms with the latter serum. In contrast, all sera labelled ON-bipolar cells on Tprm1+/+ but not on Trpm1-/- mouse retina as shown by co-immunolocalization. This confirms that the MAR sera specifically detect TRPM1. Most likely, the anti-TRPM1 autoantibodies of different patients vary in affinity and concentration. In addition, the binding of autoantibodies to TRPM1 may be conformation-dependent, with epitopes being inaccessible in some constructs (truncated polypeptides versus full-length TRPM1) or applications (western blotting versus immunohistochemistry). Therefore, we propose that a combination of different methods should be used to test for the presence of anti-TRPM1 autoantibodies in the sera of MAR patients.

Myasthenia Gravis Induced by Immune Checkpoint Inhibitors.

Immune checkpoint inhibitors deeply improved the prognosis of metastatic melanoma or other types of cancer, but their related adverse effects (AEs) can be very severe, especially when the neurological system is touched, as in myasthenia gravis (MG). It is a rare immune AE that can be life-threatening and can be revealed by several symptoms. We report a case of our experience and review the current literature of MG exacerbated or occurring during immunotherapy to describe characteristics of this AE, warn the oncologist about this toxicity, and summarize the treatments conducted. Thirty-four cases of MG were reported, mostly with anti-programmed cell death protein 1 checkpoint inhibitor, and with melanoma. Onset was quick after the first or second infusion. Treatment comprised corticosteroids, prostigmine, and more or less plasmapheresis or immunoglobulins. Prognosis is poor, as 13 patients died after MG. MG is a rare immune-related AE that must be rapidly evoked and treated in case of neurological symptoms emerging after immunotherapy.

Blocking Antibodies Targeting the CD39/CD73 Immunosuppressive Pathway Unleash Immune Responses in Combination Cancer Therapies.

Immune checkpoint inhibitors have revolutionized cancer treatment. However, many cancers are resistant to ICIs, and the targeting of additional inhibitory signals is crucial for limiting tumor evasion. The production of adenosine via the sequential activity of CD39 and CD73 ectoenzymes participates to the generation of an immunosuppressive tumor microenvironment. In order to disrupt the adenosine pathway, we generated two antibodies, IPH5201 and IPH5301, targeting human membrane-associated and soluble forms of CD39 and CD73, respectively, and efficiently blocking the hydrolysis of immunogenic ATP into immunosuppressive adenosine. These antibodies promoted antitumor immunity by stimulating dendritic cells and macrophages and by restoring the activation of T cells isolated from cancer patients. In a human CD39 knockin mouse preclinical model, IPH5201 increased the anti-tumor activity of the ATP-inducing chemotherapeutic drug oxaliplatin. These results support the use of anti-CD39 and anti-CD73 monoclonal antibodies and their combination with immune checkpoint inhibitors and chemotherapies in cancer.

PD-1 blockade at the time of tumor escape potentiates the immune-mediated antitumor effects of a melanoma-targeting monoclonal antibody.

Tumor antigen-targeting monoclonal antibodies (TA-targeting mAbs) are used as therapeutics in many malignancies and their capacity to mobilize the host immunity puts them at the forefront of anti-cancer immunotherapies. Both innate and adaptive immune cells have been associated with the therapeutic activity of such antibodies, but tumor escape from mAb-induced tumor immune surveillance remains one of the main clinical issues. In this preclinical study, we grafted immunocompetent and immunocompromised mice with the B16F10 mouse melanoma cell line and treated them with the TA99 TA-targeting mAb to analyze the immune mechanisms associated with the tumor response and resistance to TA99 monotherapy. In immunocompetent mice TA99 treatment strongly increased the fraction of CD8 and CD4 effector T cells in the tumor compared with isotype control, highlighting the specific immune modulation of the tumor microenvironment by TA99. However, in most mice, TA99 immunotherapy could not prevent immune effector exhaustion and the recruitment of regulatory CD4 T cells and consequently tumor escape from immune surveillance. Remarkably, anti-PD-1 treatment at the time of tumor emergence restored the Th1 effector functions of CD4 and CD8 T cells as well as of natural killer and γδT cells, which translated into a significant slow-down of tumor progression and extended survival. Our findings provide the first evidence that PD-1 blockade at the time of tumor emergence can efficiently boost the host anti-tumor immune response initiated several weeks before by the TA-targeting mAb. These results are promising for the design of combined therapies to sensitize non-responder or resistant patients.