HLA-DR expression in melanoma: from misleading therapeutic target to potential immunotherapy biomarker.

Since the advent of anti-PD1 immune checkpoint inhibitor (ICI) immunotherapy, cutaneous melanoma has undergone a true revolution with prolonged survival, as available 5-year updates for progression-free survival and overall survival demonstrate a durable clinical benefit for melanoma patients receiving ICI. However, almost half of patients fail to respond to treatment, or relapse sooner or later after the initial response to therapy. Little is known about the reasons for these failures. The identification of biomarkers seems necessary to better understand this resistance. Among these biomarkers, HLA-DR, a component of MHC II and abnormally expressed in certain tumor types including melanoma for unknown reasons, seems to be an interesting marker. The aim of this review, prepared by an interdisciplinary group of experts, is to take stock of the current literature on the potential interest of HLA-DR expression in melanoma as a predictive biomarker of ICI outcome.

Real-life second-line epirubicin-paclitaxel regimen as treatment of relapsed small-cell lung cancer: EpiTax study.

BACKGROUND: Few therapeutic options are approved as second-line treatment after failure of platinum-based chemotherapy for patients with extensive-stage small-cell lung cancer (ES-SCLC). Topotecan widespread use remains challenged by the risk of severe toxicities in a pretreated population. Little is known about the efficacy and safety of epirubicin-paclitaxel doublet in second-line and beyond and especially cerebral outcomes. METHODS: EpiTax is a retrospective multicenter observational real-life study. We evaluated the efficacy of epirubicin 90 mg/m2 combined with paclitaxel 175 mg/m2 every 3 weeks in SCLC patients after failure of at least one line of platinum-based chemotherapy. The primary endpoint was progression-free survival (PFS). Secondary endpoints were overall survival (OS), objective response rate (ORR), disease control rate (DCR), intracranial control rate (ICR), and safety. RESULTS: A total of 29 patients were included. The median of previous systemic therapy lines was 2 (1-4). Eleven patients received the treatment in the second line. Characteristics of patients were a median age of 60 years (45-77), 65.5% of males with 72.4% of PS 0-1. Fifteen patients had a history of brain metastases. Median PFS and OS achieved 11.0 (95% CI, 8.1-16.3) and 23 (95% CI, 14.1-29.6) weeks, respectively. ORR was 34.5% and DCR was 55.2%. ICR was 3/15 (20%). Grade 3-4 adverse events were mainly hematological and concerned 7 patients. No case of febrile neutropenia or toxic death was reported. CONCLUSION: Epirubicin-paclitaxel association highlighted promising efficacy with PFS and OS of 11 and 23 weeks, respectively, ORR of 34.5%, and a tolerable safety profile. This doublet could represent another valuable therapeutic option for ES-SCLC patients treated in the second line and beyond.

Detection of NTRK fusions in glioblastoma: fluorescent in situ hybridisation is more useful than pan-TRK immunohistochemistry as a screening tool prior to RNA sequencing.

Glioblastomas are frequent malignant brain tumours with a very poor prognosis and a need for new and efficient therapeutic strategies. With the approval of anti-TRK targeted therapies to treat patients with advanced NTRK-rearranged cancers, independent of the type of cancer, potential new treatment opportunities are available for the 0.5-5% of patients with NTRK-rearranged glioblastomas. Identification of these rare NTRK-rearranged glioblastomas requires efficient diagnostic tools and strategies which are evaluated in this study. We compared the results of NTRK1, NTRK2 and NTRK3 fluorescent in situ hybridisation (FISH) assays to those of pan-TRK immunohistochemistry (IHC) using two EPR17341 and A7H6R clones in a set of 196 patients with glioblastomas. Cases with at least 15% of positive nuclei using FISH analyses were further analysed using RNA sequencing. Above the 15% threshold, seven positive glioblastomas (3.57%) were identified by FISH assays (4 NTRK1, 3 NTRK2, no NTRK3). NTRK rearrangements were confirmed by RNA sequencing analyses in four cases [1 LMNA-NTRK1, 1 PRKAR2A-NTRK2, 1 SPECC1L-NTRK2 and 1 NACC2-NTRK2 fusions, i.e., 4/196 (2%) of NTRK-rearranged tumours in our series] but no rearrangement was detected in three samples with less than 30% of positive tumour nuclei as determined by NTRK1 FISH. Pan-TRK immunostaining showed major discrepancies when using either the EPR17341 or the A7H6R clones for the following criteria: main intensity, H-Score based scoring and homogeneity/heterogeneity of staining (Kappa values <0.2). This led to defining adequate criteria to identify NTRK-rearranged gliomas exhibiting strong and diffuse immunostaining contrasting to the variable and heterogeneous staining in non-NTRK-rearranged gliomas (p<0.0001). As assessing NTRK rearrangements has become crucial for glioma therapy, FISH seems to be a valuable tool to maximise access to TRK testing in patients with glioblastomas. In contrast to other cancers, pan-TRK IHC appears of limited interest in this field because there is no 'on/off' IHC positivity criterion to distinguish between NTRK-rearranged and non-NTRK-rearranged gliomas. RNA sequencing analyses are necessary in FISH positive cases with less than 30% positive nuclei, to avoid false positivity when scoring is close to the detection threshold.