Gamma-interferon-inducible lysosomal thiol reductase (GILT) is critical for MHC class II restricted presentation of multiple melanoma antigens. There is variable GILT protein expression in malignant ...melanocytes in melanoma specimens. High GILT mRNA expression in melanoma specimens is associated with improved overall survival, before the advent of immune checkpoint inhibitors (ICI). However, the association of GILT in metastatic melanoma with survival in patients treated with ICI and the cell type expressing GILT associated with survival have not been determined. Using RNA sequencing datasets, high GILT mRNA expression in metastatic melanoma specimens was associated with improved progression-free and overall survival in patients treated with ICI. A clinical dataset of metastatic melanoma specimens was generated and annotated with clinical information. Positive GILT immunohistochemical staining in antigen presenting cells and melanoma cells was observed in 100% and 65% of metastatic melanoma specimens, respectively. In the subset of patients treated with ICI in the clinical dataset, high GILT protein expression within melanoma cells was associated with improved overall survival. The association of GILT mRNA and protein expression with survival was independent of cancer stage. These studies support that high GILT mRNA expression in bulk tumor samples and high GILT protein expression in melanoma cells is associated with improved survival in ICI-treated patients. These findings support further investigation of GILT as a biomarker to predict the response to ICI.
Although Src was the first oncogene to be discovered as the transforming protein of the Rous sarcoma virus almost three decades ago, the role of Src and the Src family kinases in human oncogenesis is ...still not completely understood. Recent studies have shown that Src regulates cell adhesion, invasiveness and motility in cancer cells and in tumor vasculature, rather than directly influencing cell replication. The role of the Src family kinases in human cancer is evolving and elevated levels of Src kinase activity have been reported in a number of human cancers in vitro and in vivo. Src expression and activity are increased in melanoma cell lines and in melanoma tumors in vivo. Src can activate STAT3, STAT5 and other downstream targets in melanoma. Src and STAT3 are expressed in their activated forms in both primary and metastatic melanoma in humans, although the expression level is variable. Cumulatively, these data mark Src signaling as attractive therapeutic targets in melanoma. Studies are currently underway with novel Src inhibitors in melanoma and in other tumor types.
CT-2106 is a 20(S)-camptothecin poly-L-glutamate conjugate. This linkage stabilizes the active lactone form of camptothecin and enhances aqueous solubility. In addition, poly-L-glutamate is ...postulated to increase tumor delivery of the active compound through enhanced permeability and retention effect in tumor. We studied a weekly schedule of CT-2106 in patients with refractory solid tumor malignancies.
CT-2106 was infused (10 min i.v. infusion) on days 1, 8, and 15 of each 28-day cycle. Plasma and urine were analyzed for total and unconjugated camptothecin by high-performance liquid chromatography equipped with a fluorescence detector. Toxicity and response assessments were done with Common Toxicity Criteria for Adverse Events version 3 and Response Evaluation Criteria in Solid Tumors, respectively.
Twenty-six patients were enrolled. Median age was 58 years (range, 36-83) and median number of doses was 6 (range, 1-9). The most frequent tumor type (50%) was melanoma. Dose limiting toxicities were thrombocytopenia and fatigue. A weekly dose of 25 mg/m2 given every 3 of 4 weeks was the maximum tolerated dose. The majority of grade 3 and 4 toxicities were hematologic. The pharmacokinetic profile of conjugated and unconjugated camptothecin showed a polyexponential decline with similar terminal half life (t1/2 range was 44-63 and 31-48 h for conjugated and unconjugated, respectively). Pharmacokinetics of conjugated and unconjugated camptothecin were dose and time independent in the tested dose range. Urinary excretion of conjugated and unconjugated camptothecin accounted for about 30% and 4% of the administered dose, respectively.
CT-2106 has a more manageable toxicity profile compared with unconjugated camptothecin. The maximum tolerated dose is 25 mg/m2 weekly given 3 of 4 weeks. This compound results in prolonged release of unconjugated camptothecin.
Immunotherapy has been in use for the treatment of melanoma since a very long time, but only recently have the cytotoxic T-lymphocyte antigen-4 (CTLA-4) antibody ipilimumab and programmed cell ...death-1 inhibitors such as nivolimumab and pembrolizumab been shown to induce marked improvements in survival in patients with metastatic melanoma. An important concern arises in terms of the safety of the use of these agents in patients with autoimmune diseases, solid organ transplant recipients on immunosuppression, patients with a history of previous hepatitis B or C, and patients with HIV infections as these patients were excluded from pivotal immunotherapy studies. Here, we report on the safety and efficacy of pembrolizumab in a melanoma patient with multiple medical problems including poorly controlled rheumatoid arthritis and we review the available literature on the use of immunotherapy and autoimmune diseases. The weight of evidence suggests that these patients should be offered the opportunity to benefit from immune check point inhibitors, with drugs targeting programmed cell death-1 being preferred. More research is required to study the long-term effects of immunotherapy on patients with autoimmune diseases.
Melanoma is a disease process which has been increasing in incidence over the past three decades and metastatic melanoma carries a poor prognosis. Through genetic studies of this disease, it has been ...determined that the BRAF V600 mutation plays a major role in the pathophysiology of the disease and this has led to the utilization of targeted therapy (BRAF and MEK inhibitors) in its treatment. Other BRAF mutations (non-V600 mutations) are rare in melanoma and targeted therapy is not indicated for patients with these mutations due to reduced response rates. An emerging option for metastatic melanoma with uncommon BRAF mutations is immunotherapy using checkpoint inhibitors such as PD-1 inhibitors or CTLA-4 inhibitors. Currently, it is unknown how patients with BRAF non-V600 mutations respond to immunotherapy. This report will examine the effect of immunotherapy on two distinct metastatic melanoma patients, each with uncommon BRAF mutations, occurring outside the V600 locus (E586K and G469E). These patients were noted to have a durable, complete response when treated with immunotherapy and continue to exhibit a response 9 and 15 months after discontinuing therapy. Further research and clinical trials are needed to study patients with uncommon BRAF mutations and the potential therapeutic benefit of immunotherapy.
Src signaling has been implicated in several malignancies including melanoma. The prevalence of Src activation in human melanoma and the effect of the newer Src inhibitors, dasatinib, and bosutinib ...(SKI-606), as single agents or in combination, on melanoma cell lines is not well established. In the melanoma cell lines, A-375, SK-Mel-5, and SK-Mel-28, activity of Src inhibitors was assessed alone or in combination with standard chemotherapy agents; 50% growth inhibitory concentration was determined by MTS assay and immunoblotting was used to measure Src activation and downstream signaling. Staining for Src activation was measured by Src-phosphotyrosine 416. Immunohistochemistry was performed on primary cutaneous, mucosal, and metastatic melanoma. Src inhibitors blocked the growth of melanoma cell lines; furthermore, Src inhibitor treatment was synergized with cisplatin but not temozolomide or paclitaxel. Treatment with dasatanib increased the levels of pS473 Akt in A-375 melanoma cells but not in the other two cell lines. Forty-eight percent (17 of 35) of all melanoma stained weakly, moderately, or strongly for pY416 Src: cutaneous 61% (eight of 13), mucosal 31% (four of 13), metastatic 55% (five of nine). Most positive biopsies stained weakly and only one metastatic melanoma specimen stained strongly for Src-phosphotyrosine 416. pY416 Src is expressed in cutaneous, mucosal, and metastatic melanoma in various degrees. Src inhibitors may be a promising therapy in melanoma, either by themselves or in combination with chemotherapy (especially with platinum compounds) or inhibitors of the Akt/PI3k pathway.
No systemic therapies have been approved for the treatment of advanced cutaneous squamous-cell carcinoma. This cancer may be responsive to immune therapy, because the mutation burden of the tumor is ...high and the disease risk is strongly associated with immunosuppression. In the dose-escalation portion of the phase 1 study of cemiplimab, a deep and durable response was observed in a patient with metastatic cutaneous squamous-cell carcinoma.
We report the results of the phase 1 study of cemiplimab for expansion cohorts of patients with locally advanced or metastatic cutaneous squamous-cell carcinoma, as well as the results of the pivotal phase 2 study for a cohort of patients with metastatic disease (metastatic-disease cohort). In both studies, the patients received an intravenous dose of cemiplimab (3 mg per kilogram of body weight) every 2 weeks and were assessed for a response every 8 weeks. In the phase 2 study, the primary end point was the response rate, as assessed by independent central review.
In the expansion cohorts of the phase 1 study, a response to cemiplimab was observed in 13 of 26 patients (50%; 95% confidence interval CI, 30 to 70). In the metastatic-disease cohort of the phase 2 study, a response was observed in 28 of 59 patients (47%; 95% CI, 34 to 61). The median follow-up was 7.9 months in the metastatic-disease cohort of the phase 2 study. Among the 28 patients who had a response, the duration of response exceeded 6 months in 57%, and 82% continued to have a response and to receive cemiplimab at the time of data cutoff. Adverse events that occurred in at least 15% of the patients in the metastatic-disease cohort of the phase 2 study were diarrhea, fatigue, nausea, constipation, and rash; 7% of the patients discontinued treatment because of an adverse event.
Among patients with advanced cutaneous squamous-cell carcinoma, cemiplimab induced a response in approximately half the patients and was associated with adverse events that usually occur with immune checkpoint inhibitors. (Funded by Regeneron Pharmaceuticals and Sanofi; ClinicalTrials.gov numbers, NCT02383212 and NCT02760498 .).
In a pilot study involving patients with cutaneous squamous-cell carcinoma, a high percentage of patients had a pathological complete response with the use of two doses of neoadjuvant cemiplimab ...before surgery. Data from a phase 2 study are needed to confirm these findings.
We conducted a phase 2, confirmatory, multicenter, nonrandomized study to evaluate cemiplimab as neoadjuvant therapy in patients with resectable stage II, III, or IV (M0) cutaneous squamous-cell carcinoma. Patients received cemiplimab, administered at a dose of 350 mg every 3 weeks for up to four doses, before undergoing surgery with curative intent. The primary end point was a pathological complete response (the absence of viable tumor cells in the surgical specimen) on independent review at a central laboratory, with a null hypothesis that a pathological complete response would be observed in 25% of patients. Key secondary end points included a pathological major response (the presence of viable tumor cells that constitute ≤10% of the surgical specimen) on independent review, a pathological complete response and a pathological major response on investigator assessment at a local laboratory, an objective response on imaging, and adverse events.
A total of 79 patients were enrolled and received neoadjuvant cemiplimab. On independent review, a pathological complete response was observed in 40 patients (51%; 95% confidence interval CI, 39 to 62) and a pathological major response in 10 patients (13%; 95% CI, 6 to 22). These results were consistent with the pathological responses determined on investigator assessment. An objective response on imaging was observed in 54 patients (68%; 95% CI, 57 to 78). Adverse events of any grade that occurred during the study period, regardless of whether they were attributed to the study treatment, were observed in 69 patients (87%). Grade 3 or higher adverse events that occurred during the study period were observed in 14 patients (18%).
Neoadjuvant therapy with cemiplimab was associated with a pathological complete response in a high percentage of patients with resectable cutaneous squamous-cell carcinoma. (Funded by Regeneron Pharmaceuticals and Sanofi; ClinicalTrials.gov number, NCT04154943.).
Immune checkpoint blockade therapy has been successful in treating some types of cancer but has not shown clinical benefits for treating leukaemia
. This result suggests that leukaemia uses unique ...mechanisms to evade this therapy. Certain immune inhibitory receptors that are expressed by normal immune cells are also present on leukaemia cells. Whether these receptors can initiate immune-related primary signalling in tumour cells remains unknown. Here we use mouse models and human cells to show that LILRB4, an immunoreceptor tyrosine-based inhibition motif-containing receptor and a marker of monocytic leukaemia, supports tumour cell infiltration into tissues and suppresses T cell activity via a signalling pathway that involves APOE, LILRB4, SHP-2, uPAR and ARG1 in acute myeloid leukaemia (AML) cells. Deletion of LILRB4 or the use of antibodies to block LILRB4 signalling impeded AML development. Thus, LILRB4 orchestrates tumour invasion pathways in monocytic leukaemia cells by creating an immunosuppressive microenvironment. LILRB4 represents a compelling target for the treatment of monocytic AML.
Melanoma is the sixth most common cancer in the US. Immunotherapies, such as anti‐CTLA‐4 and anti‐PD‐1, have transformed the treatment of advanced melanoma; however, a subset of patients fail to ...respond to immunotherapy. Thus, improved predictors of the anti‐melanoma immune response and response to immunotherapy are needed. We have previously shown that 1) gamma‐interferon‐inducible lysosomal thiol reductase (GILT) is critical for MHC class II‐restricted presentation of a melanoma antigen, 2) there is variable GILT protein expression in melanoma cells from primary and cutaneous metastatic melanoma specimens, and 3) high GILT mRNA expression in melanoma specimens is associated with improved overall survival. Here, we created a database of n = 43 metastatic melanoma patients (stage III or IV) annotated with clinical outcome. Formalin‐fixed, paraffin‐embedded sections of pre‐treatment metastatic melanoma specimens were tested for GILT protein expression using immunohistochemistry and scored by a dermatopathologist and dermatologist. GILT expression in melanoma cells was detected in 65% of lymph node and distant organ metastases, consistent with our prior finding of GILT expression in 58% of cutaneous metastases. The frequency of GILT‐staining melanoma cells was determined by the ratio of the area of tumor cells with positive GILT staining to the total area of tumor cells. The frequency of GILT‐staining melanoma cells among specimens with positive GILT staining was 15.2% ± 24.7% (mean ± SD). The median frequency of GILT staining was used to divide the patients into no/low and high GILT expression groups. The median overall survival was 52.8 months in the no/low GILT expression group, while the median overall survival was not reached in the high GILT expression group (log‐rank, p = 0.67). For the n = 34 patients who were treated with immunotherapy targeting CTLA‐4 and/or PD‐1, the median overall survival was 38.2 months in the no/low GILT expression group, while the median overall survival was not reached in the high GILT expression group (log‐rank, p = 0.83). These data suggest that high GILT expression in melanoma cells may be associated with improved overall survival, although a statistically significant association of GILT with survival was not observed in the whole group or the subset of patients treated with immunotherapy. A limitation of the current analysis is that 65% of patients have incomplete clinical outcome data. This study demonstrates variable GILT protein expression in tumor cells in metastatic melanoma specimens. Updated clinical outcome data will allow us to better evaluate the association of GILT protein expression in melanoma cells with overall survival and response to immunotherapy in metastatic melanoma patients.
PDF
