Grade 4 Neutropenia Secondary to Immune Checkpoint Inhibition - A Descriptive Observational Retrospective Multicenter Analysis

Introduction

Immune checkpoint inhibitors (ICI) are increasingly being used to treat numerous cancer types. Together with improved recognition of toxicities, this has led to more frequent identification of rare immune-related adverse events (irAE), for which specific treatment strategies are needed. Neutropenia is a rare hematological irAE that has a potential for a high mortality rate because of its associated risk of sepsis. Prompt recognition and timely treatment of this life-threatening irAE are therefore critical to the outcome of patients with immune-related neutropenia.

Methods

This multicenter international retrospective study was conducted at 17 melanoma centers to evaluate the clinical characteristics, diagnostics, treatment, and outcomes of melanoma patients with grade 4 neutropenia (<500 neutrophils/µl blood) treated with ICI between 2014 and 2020. Some of these patients received metamizole in addition to ICI (ICI+/met+). Bone marrow biopsies (BMB) of these patients were compared to BMB from non-ICI treated patients with metamizole-induced grade 4 neutropenia (ICI-/met+).

Results

In total, 10 patients (median age at neutropenia onset: 66 years; seven men) with neutropenia were identified, equating to an incidence of 0.14%. Median onset of neutropenia was 6.4 weeks after starting ICI (range 1.4–49.1 weeks). Six patients showed inflammatory symptoms, including fever (n=3), erysipelas (n=1), pharyngeal abscess (n=1), and mucositis (n=1). Neutropenia was diagnosed in all patients by a differential blood count and additionally performed procedures including BMB (n=5). Nine of 10 patients received granulocyte colony-stimulating factors (G-CSF) to treat their grade 4 neutropenia. Four patients received systemic steroids (including two in combination with G-CSF, and one in combination with G-CSF and additional ciclosporin A). Four patients were treated with one or more antibiotic treatment lines, two with antimycotic treatment, and one with additional antiviral therapy. Five patients received metamizole concomitantly with ICI. One fatal outcome was reported. BMB indicated a numerically lower CD4+ to CD8+ T cells ratio in patients with irNeutropenia than in those with metamizole-induced neutropenia.

Conclusion

Grade 4 neutropenia is a rare but potentially life-threatening side effect of ICI treatment. Most cases were sufficiently managed using G-CSF; however, adequate empiric antibiotic, antiviral, and antimycotic treatments should be administered if neutropenic infections are suspected. Immunosuppression using corticosteroids may be considered after other causes of neutropenia have been excluded.

Response durability after cessation of immune checkpoint inhibitors in patients with metastatic Merkel cell carcinoma: a retrospective multicenter DeCOG study

BACKGROUND

Immune checkpoint inhibitors (ICI) have led to a prolongation of progression-free and overall survival in patients with metastatic Merkel cell carcinoma (MCC). However, immune-mediated adverse events due to ICI therapy are common and often lead to treatment discontinuation. The response duration after cessation of ICI treatment is unknown. Hence, this study aimed to investigate the time to relapse after discontinuation of ICI in MCC patients.

METHODS

We analyzed 20 patients with metastatic MCC who have been retrospectively enrolled at eleven skin cancer centers in Germany. These patients have received ICI therapy and showed as best overall response (BOR) at least a stable disease (SD) upon ICI therapy. All patients have discontinued ICI therapy for other reasons than disease progression. Data on treatment duration, tumor response, treatment cessation, response durability, and tumor relapse were recorded.

RESULTS

Overall, 12 of 20 patients (60%) with MCC relapsed after discontinuation of ICI. The median response durability was 10.0 months. Complete response (CR) as BOR to ICI-treatment was observed in six patients, partial response (PR) in eleven, and SD in three patients. Disease progression was less frequent in patients with CR (2/6 patients relapsed) as compared to patients with PR (7/11) and SD (3/3), albeit the effect of initial BOR on the response durability was below statistical significance. The median duration of ICI therapy was 10.0 months. Our results did not show a correlation between treatment duration and the risk of relapse after treatment withdrawal. Major reasons for discontinuation of ICI therapy were CR (20%), adverse events (35%), fatigue (20%), or patient decision (25%). Discontinuation of ICI due to adverse events resulted in progressive disease (PD) in 71% of patients regardless of the initial response. A re-induction of ICI was initiated in 8 patients upon tumor progression. We observed a renewed tumor response in 4 of these 8 patients. Notably, all 4 patients showed an initial BOR of at least PR.

CONCLUSION

Our results from this contemporary cohort of patients with metastatic MCC indicate that MCC patients are at higher risk of relapse after discontinuation of ICI as compared to melanoma patients. Notably, the risk of disease progression after discontinuation of ICI treatment is lower in patients with initial CR (33%) as compared to patients with initial PR (66%) or SD (100%). Upon tumor progression, re-induction of ICI is a feasible option. Our data suggest that the BOR to initial ICI therapy might be a potential predictive clinical marker for a successful re-induction.

Clinical determinants of long-term survival in metastatic uveal melanoma

This study aimed to identify prognostic factors in patients with metastatic uveal melanoma (UM) that were associated with long-term survival in a real-world setting. A total of 94 patients with metastatic UM were included from German skin cancer centers and the German national skin cancer registry (ADOReg). Data were analyzed for the response to treatment, progression-free survival, and overall survival (OS). Prognostic factors were explored with univariate Cox regression, log-rank, and χ2-tests. Identified factors were subsequently validated after the population was divided into two cohorts of short-term survival (< 2 years OS, cohort A, n = 50) and long-term survival (> 2 years OS, cohort B, n = 44). A poor ECOG performance status (hazard ratio [HR] 2.0, 95% confidence interval [CI] 1.0–3.9) and elevated serum LDH (HR 2.0, 95% CI 1.0–3.8) were associated with a poor OS, whereas a good response to immune checkpoint blockade (ICB, p < 0.001), radiation therapy (p < 0.001), or liver-directed treatments (p = 0.01) were associated with a prolonged OS. Long-term survivors (cohort B) showed a higher median number of organs affected by metastasis (p < 0.001), while patients with liver metastases only were more common in cohort A (40% vs. 9%; p = 0.002). A partial response to ICB was observed in 16% (12/73), being 21% (8/38) for combined ICB, 17% (1/6) for single CTLA4 inhibition, and 10% (3/29) for single PD1 inhibition. One complete response occurred in cohort B with combined ICB. We conclude that the response to ICB and the presence of extrahepatic disease were favorable prognostic factors for long-term survival.

Encorafenib, binimetinib plus pembrolizumab triplet therapy in patients with advanced BRAFV600 mutant melanoma: safety and tolerability results from the phase I IMMU-TARGET trial

BACKGROUND

Combination of immune checkpoint inhibitors and mitogen-activated protein kinase (MAPK) pathway inhibitors (MAPKi) has been proposed to enhance the durability of anti-tumour responses induced by MAPKi. Here, we present phase I safety results from an open-label, phase I/II study of pembrolizumab (PEM), encorafenib (ENC) and binimetinib (BIN) triplet therapy in advanced, B-Raf proto-oncogene serine/threonine kinase (BRAF)V600-mutated melanoma (IMMU-TARGET, NCT02902042).

METHODS

The dose finding phase I part used a 3 + 3 design, starting with the approved doses of PEM (200 mg every three weeks), ENC (450 mg once daily [QD]) and BIN (45 mg twice daily [BID]) as dose level (DL) 0. Reduction of the ENC and BIN doses (300 mg QD and 30 mg BID at DL-1 and 200 mg QD and 30 mg BID at DL-2) was preplanned in case of ≥2 dose-limiting toxicities (DLTs). Primary objectives were to estimate the recommended phase II dose of the triplet combination, DLT and safety. As per the sponsor's decision, the study was terminated after the phase I part, as the clinical efficacy of the combination is currently being investigated in a pivotal, placebo-controlled (PEM mono), double-blinded phase III trial (STARBOARD,NCT04657991).

RESULTS

Fifteen patients were enrolled. DLTs of DL0 were creatine phosphokinase (CPK) elevation plus cytokine release syndrome (n = 1) and gamma glutamyl transferase (GGT) increase (n = 1). No DLT was observed in further 3 + 3 patients at DL-1. One (isolated GGT elevations) DLT of DL0 was questionable, as the patient had further episodes of isolated GGT elevations after treatment discontinuation. Hence, further 6 patients were enrolled at DL0: here, no DLT occurred. In total, 13 of 15 patients (87%) experienced a treatment-related adverse event (TRAE) and 8 patients (53%), a grade ≥III TRAE; there were no TRAE-related deaths. Increases in aspartate aminotransferases, GGT (6/15 patients) and CPK elevations (4/15) were the most common grade III-IV TRAE. In median, patients received triplet therapy for 24 weeks (interquartile range [IQR], 12-45). Of the 14 patients evaluable for efficacy, the overall response rate was 64% (95% confidence interval [CI], 35-87). At a median follow-up of 25 months (IQR, 9-28), progression-free survival at 12 months was 41% (95% CI, 13-68).

CONCLUSIONS

Triplet therapy with PEM, ENC and BIN as used in the study was feasible and safe and led to clinically meaningful disease control.

Digital Quantification of Tumor PD-L1 Predicts Outcome of PD-1-Based Immune Checkpoint Therapy in Metastatic Melanoma

Background

PD-1-based immune checkpoint blockade (ICB) is a highly effective therapy in metastatic melanoma. However, 40-60% of patients are primarily resistant, with valid predictive biomarkers currently missing. This study investigated the digitally quantified tumor PD-L1 expression for ICB therapy outcome prediction.

Patients and Methods

Tumor tissues taken prior to PD-1-based ICB for unresectable metastatic disease were collected within the prospective multicenter Tissue Registry in Melanoma (TRIM). PD-L1 expression (clone 28-8; cut-off=5%) was determined by digital and physician quantification, and correlated with therapy outcome (best overall response, BOR; progression-free survival, PFS; overall survival, OS).

Results

Tissue samples from 156 patients were analyzed (anti-PD-1, n=115; anti-CTLA-4+anti-PD-1, n=41). Patients with PD-L1-positive tumors showed an improved response compared to patients with PD-L1-negative tumors, by digital (BOR 50.5% versus 32.2%; p=0.026) and physician (BOR 54.2% versus 36.6%; p=0.032) quantification. Tumor PD-L1 positivity was associated with a prolonged PFS and OS by either digital (PFS, 9.9 versus 4.6 months, p=0.021; OS, not reached versus 13.0 months, p=0.001) or physician (PFS, 10.6 versus 5.6 months, p=0.051; OS, not reached versus 15.6 months, p=0.011) quantification. Multivariable Cox regression revealed digital (PFS, HR=0.57, p=0.007; OS, HR=0.44, p=0.001) and physician (OS, HR=0.54, p=0.016) PD-L1 quantification as independent predictors of survival upon PD-1-based ICB. The combination of both methods identified a patient subgroup with particularly favorable therapy outcome (PFS, HR=0.53, p=0.011; OS, HR=0.47, p=0.008).

Conclusion

Pre-treatment tumor PD-L1 positivity predicted a favorable outcome of PD-1-based ICB in melanoma. Herein, digital quantification was not inferior to physician quantification, and should be further validated for clinical use.

Immune checkpoint inhibition therapy for advanced skin cancer in patients with concomitant hematological malignancy: a retrospective multicenter DeCOG study of 84 patients

BACKGROUND

Skin cancers are known for their strong immunogenicity, which may contribute to a high treatment efficacy of immune checkpoint inhibition (ICI). However, a considerable proportion of patients with skin cancer is immuno-compromised by concomitant diseases. Due to their previous exclusion from clinical trials, the ICI treatment efficacy is poorly investigated in these patients. The present study analyzed the ICI treatment outcome in advanced patients with skin cancer with a concomitant hematological malignancy.

METHODS

This retrospective multicenter study included patients who were treated with ICI for locally advanced or metastatic melanoma (MM), cutaneous squamous cell carcinoma (cSCC), or Merkel cell carcinoma (MCC), and had a previous diagnosis of a hematological malignancy irrespective of disease activity or need of therapy at ICI treatment start. Comparator patient cohorts without concomitant hematological malignancy were extracted from the prospective multicenter skin cancer registry ADOREG. Treatment outcome was measured as best overall response, progression-free (PFS), and overall survival (OS).

RESULTS

84 patients (MM, n=52; cSCC, n=15; MCC, n=17) with concomitant hematological malignancy were identified at 20 skin cancer centers. The most frequent concomitant hematological malignancies were non-Hodgkin's lymphoma (n=70), with chronic lymphocytic leukemia (n=32) being the largest entity. While 9 patients received ICI in an adjuvant setting, 75 patients were treated for advanced non-resectable disease (55 anti-PD-1; 8 anti-PD-L1; 5 anti-CTLA-4; 7 combinations). In the latter 75 patients, best objective response (complete response+partial response) was 28.0%, disease stabilization was 25.3%, and 38.6% showed progressive disease (PD). Subdivided by skin cancer entity, best objective response was 31.1% (MM), 26.7% (cSCC), and 18.8% (MCC). Median PFS was 8.4 months (MM), 4.0 months (cSCC), and 5.7 months (MCC). 1-year OS rates were 78.4% (MM), 65.8% (cSCC), and 47.4% (MCC). Comparison with respective ADOREG patient cohorts without hematological malignancy (n=392) revealed no relevant differences in ICI therapy outcome for MM and MCC, but a significantly reduced PFS for cSCC (p=0.002).

CONCLUSIONS

ICI therapy showed efficacy in advanced patients with skin cancer with a concomitant hematological malignancy. Compared with patients without hematological malignancy, the observed ICI therapy outcome was impaired in cSCC, but not in MM or MCC patients.

Response to combined peptide receptor radionuclide therapy and checkpoint immunotherapy with ipilimumab plus nivolumab in metastatic Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a highly aggressive neuroendocrine cancer of the skin. For patients who are refractory to immune checkpoint inhibition (ICI), treatment options are limited. Few cases of MCCs with high somatostatin receptor (SSTR) expression were reported to show responses upon SSTR-directed peptide receptor radionuclide therapy (PRRT). A combination of PRRT and ICI has not been reported in MCC to date. A 60-year old man with metastatic MCC, who was primarily resistant to the anti-PD-L1 ICI with avelumab and secondarily resistant to the anti-CTLA4 plus anti-PD-1 ICI therapy with ipilimumab plus nivolumab (IPI/NIVO) with additional RT, presented with multiple bone and lymph node metastases. After confirmation of SSTR expression, the patient was treated with a salvage therapy of additional four doses of IPI/NIVO combined with two cycles of PRRT. Treatment was well tolerated with transient hematoxicity and mild nausea. Re-staging three months after therapy start showed an exceptional good response. This case report demonstrates the feasibility of a combined treatment with IPI/NIVO and PRRT as a salvage option for MCC patients progressing under ICI therapy. Prospective evidence confirming the additive value of combining ICI and radionuclide therapy in a larger cohort is needed.

[Cutaneous angiosarcoma clinically presenting as Quincke's edema]

We report a case of a 75-year-old man with facial edema that also affected the periorbital area who was admitted to the hospital with the suspected diagnosis of Quincke's edema. The diagnosis of cutaneous angiosarcoma was made by microscopic examination and immunohistochemical staining. Chemotherapy was initially initiated because the angiosarcoma was unresectable and the radiation situation was difficult. Therapy has to be switched to second and third line therapy due to disease progression. The case illustrates the complexity of diagnosis and therapy in patients with cutaneous angiosarcoma.

Apoptotic Gastritis in Melanoma Patients Treated With PD-1-Based Immune Checkpoint Inhibition - Clinical and Histopathological Findings Including the Diagnostic Value of Anti-Caspase-3 Immunohistochemistry

Background

Gastritis induced by checkpoint inhibitors (CPI) is a rare but severe drug-related side effect. The reference standard for confirming CPI-associated gastritis (CPI-assGastritis) is histopathological assessment; however, the histopathological features of CPI-assGastritis are not yet adequately defined.

Materials and Methods

Gastric biopsies of melanoma patients with histopathologically suspected CPI-assGastritis were compared with gastric biopsies of patients with inflammation free gastric mucosa (IFGM), type A, B, and C gastritis with respect to apoptosis count and predominant histopathological features. Immunohistochemical anti-caspase-3 staining was performed to identify apoptosis. Quantification was performed by manually counting the number of apoptotic events per 10 high-power fields (HPF). Clinical symptoms, treatment, and follow-up data of patients with CPI-assGastritis were examined. The nonparametric Mann–Whitney U test was used for statistical testing.

Results

Five melanoma patients (three women, two men; median age: 45 years) were treated with PD-1-based CPI. The patients reported epigastric pain, weight loss, nausea, and vomiting. Histologically, the patients with CPI-assGastritis showed a partly lymphocytic, partly granulocytic inflammatory infiltrate. Manual counting of apoptotic cells in biopsy tissue slides stained against caspase 3 revealed a median of 6 apoptotic events/10 HPF (95% CI, 2.75-17.30) in the patients with CPI-assGastritis. Results for the comparison cohort (patients n = 21) were a median of 1 apoptotic event/10 HPF (95% CI, 0.5–4.5) for type-A gastritis (six patients), a median of 2 apoptotic events/10 HPF (95% CI, 0–4.5) for type-B gastritis (five patients), and no apoptosis for IFGM and type-C gastritis (five patients). Patients with CPI-assGastritis had a significantly higher apoptosis count than patients with IFGM (p<0.01), type A (p<0.05), B (p<0.05), and C gastritis (p<0.01). None of the CPI-assGastritis biopsies showed evidence of Helicobacter pylori. All CPI-assGastritis patients responded to systemic treatment with corticosteroids.

Conclusion

CPI-assGastritis manifests with nonspecific symptoms but histologically shows a high number of apoptotic events, which can best be visualized by anti-caspase-3 immunohistochemistry. This histopathological feature may help to histologically differentiate CPI-assGastritis from other forms of gastritis and inform decision-making regarding its optimal management.

Targeting early stages of cardiotoxicity from anti-PD1 immune checkpoint inhibitor therapy

AIMS

Cardiac immune-related adverse events (irAEs) from immune checkpoint inhibition (ICI) targeting programmed death 1 (PD1) are of growing concern. Once cardiac irAEs become clinically manifest, fatality rates are high. Cardio-oncology aims to prevent detrimental effects before manifestation of severe complications by targeting early pathological changes. We therefore aimed to investigate early consequences of PD1 inhibition for cardiac integrity to prevent the development of overt cardiac disease.

METHODS AND RESULTS

We investigated cardiac-specific consequences from anti-PD1 therapy in a combined biochemical and in vivo phenotyping approach. Mouse hearts showed broad expression of the ligand PDL1 on cardiac endothelial cells as a main mediator of immune-crosstalk. Using a novel melanoma mouse model, we assessed that anti-PD1 therapy promoted myocardial infiltration with CD4+ and CD8+ T cells, the latter being markedly activated. Left ventricular (LV) function was impaired during pharmacological stress, as shown by pressure-volume catheterization. This was associated with a dysregulated myocardial metabolism, including the proteome and the lipidome. Analogous to the experimental approach, in patients with metastatic melanoma (n = 7) receiving anti-PD1 therapy, LV function in response to stress was impaired under therapy. Finally, we identified that blockade of tumour necrosis factor alpha (TNFα) preserved LV function without attenuating the anti-cancer efficacy of anti-PD1 therapy.

CONCLUSIONS

Anti-PD1 therapy induces a disruption of cardiac immune homeostasis leading to early impairment of myocardial functional integrity, with potential prognostic effects on the growing number of treated patients. Blockade of TNFα may serve as an approach to prevent the manifestation of ICI-related cardiotoxicity.

The concepts of rechallenge and retreatment with immune checkpoint blockade in melanoma patients

Forty to 60% of patients with advanced or metastatic melanoma respond to first-line immune checkpoint inhibitors (ICI) and half of all patients in the metastatic setting eventually progress. This review evaluated the latest long-term data from clinical trials. It also considered data from recent retrospective studies, as these address important questions for clinical practice. 'Retreatment' defined as 'repeated treatment with the same therapeutic class following relapse after adjuvant treatment has ended' and showed activity in selected patients with recurrence after regular completion of adjuvant PD-1 treatment. In melanoma patients with adjuvant PD-1 monotherapy who recur during adjuvant treatment, further treatment with PD-1 monotherapy seems to have no clinical utility, indicating the need for a therapy switch or escalation in these patients. Targeted therapy with BRAF/MEK inhibitors and ipilimumab-based therapy (alone or combined with PD-1 blockade) show clinical activity in patients who recur during and after adjuvant treatment. 'Rechallenge', defined as 'repeated treatment with the same therapeutic class following disease progression in patients who had clinical benefit with prior treatment for unresectable or metastatic disease', with pembrolizumab at progression in the advanced setting achieving additional disease control. If possible, 'escalation' (PD-1 inhibitors combined with additional agents) should be preferred to PD-1 inhibitor monotherapy rechallenge as higher response rates were demonstrated. The combination of PD-1 plus CTLA-4 was found to be more effective but not more toxic than CTLA-4 alone. Promising antitumor activity was observed for escalation to lenvatinib plus pembrolizumab, entinostat plus pembrolizumab, and relatlimab plus nivolumab. Retreatment, rechallenge and escalation are available options for patients with melanoma who relapse in the adjuvant or advanced setting.

Immune Checkpoint Blockade for Metastatic Uveal Melanoma: Patterns of Response and Survival According to the Presence of Hepatic and Extrahepatic Metastasis

BACKGROUND

Since there is no standardized and effective treatment for advanced uveal melanoma (UM), the prognosis is dismal once metastases develop. Due to the availability of immune checkpoint blockade (ICB) in the real-world setting, the prognosis of metastatic UM has improved. However, it is unclear how the presence of hepatic and extrahepatic metastasis impacts the response and survival after ICB.

METHODS

A total of 178 patients with metastatic UM treated with ICB were included in this analysis. Patients were recruited from German skin cancer centers and the German national skin cancer registry (ADOReg). To investigate the impact of hepatic metastasis, two cohorts were compared: patients with liver metastasis only (cohort A, n = 55) versus those with both liver and extra-hepatic metastasis (cohort B, n = 123). Data were analyzed in both cohorts for response to treatment, progression-free survival (PFS), and overall survival (OS). The survival and progression probabilities were calculated with the Kaplan-Meier method. Log-rank tests, χ² tests, and t-tests were performed to detect significant differences between both cohorts.

RESULTS

The median OS of the overall population was 16 months (95% CI 13.4-23.7) and the median PFS, 2.8 months (95% CI 2.5-3.0). The median OS was longer in cohort B than in cohort A (18.2 vs. 6.1 months; p = 0.071). The best objective response rate to dual ICB was 13.8% and to anti-PD-1 monotherapy 8.9% in the entire population. Patients with liver metastases only had a lower response to dual ICB, yet without significance (cohort A 8.7% vs. cohort B 16.7%; p = 0.45). Adverse events (AE) occurred in 41.6%. Severe AE were observed in 26.3% and evenly distributed between both cohorts.

CONCLUSION

The survival of this large cohort of patients with advanced UM was more favorable than reported in previous benchmark studies. Patients with both hepatic and extrahepatic metastasis showed more favorable survival and higher response to dual ICB than those with hepatic metastasis only.

Activity of ipilimumab plus nivolumab in avelumab-refractory Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine cutaneous malignancy with poor prognosis. In Europe, approved systemic therapies are limited to the PD-L1 inhibitor avelumab. For avelumab-refractory patients, efficient and safe treatment options are lacking.

METHODS

At three different sites in Germany, clinical and molecular data of patients with metastatic MCC being refractory to the PD-L1 inhibitor avelumab and who were later on treated with combined IPI/NIVO were retrospectively collected and evaluated.

RESULTS

Five patients treated at three different academic sites in Germany were enrolled. Three out of five patients investigated for this report responded to combined IPI/NIVO according to RECIST 1.1. Combined immunotherapy was well tolerated without any grade II or III immune-related adverse events. Two out of three responders to IPI/NIVO received platinum-based chemotherapy in between avelumab and combined immunotherapy.

CONCLUSION

In this small retrospective study, we observed a high response rate and durable responses to subsequent combined immunotherapy with IPI/NIVO in avelumab-refractory metastatic MCC patients. In conclusion, our data suggest a promising activity of second- or third-line PD-1- plus CTLA-4-blockade in patients with anti-PD-L1-refractory MCC.

High tumour mutational burden and EGFR/MAPK pathway activation are therapeutic targets in metastatic porocarcinoma

BACKGROUND

Eccrine porocarcinoma (EPC) is a rare skin cancer arising from the eccrine sweat glands. Due to the lack of effective therapies, metastasis is associated with a high mortality rate.

OBJECTIVES

To investigate the drivers of EPC progression.

METHODS

We carried out genomic and transcriptomic profiling of metastatic EPC (mEPC), validation of the observed alterations in an EPC patient-derived cell line, confirmation of relevant observations in a large patient cohort of 30 tumour tissues, and successful treatment of a patient with mEPC under the identified treatment regimens.

RESULTS

mEPC was characterized by a high tumour mutational burden (TMB) with an ultraviolet signature, widespread copy number alterations and gene expression changes that affected cancer-relevant cellular processes such as cell cycle regulation and proliferation, including a pathogenic TP53 (tumour protein 53) mutation, a copy number deletion in the CDKN2A (cyclin dependent kinase inhibitor 2A) region and a CTNND1/PAK1 [catenin delta 1/p21 (RAC1) activated kinase 1] gene fusion. The overexpression of EGFR (epidermal growth factor receptor), PAK1 and MAP2K1 (mitogen-activated protein kinase kinase 1; also known as MEK1) genes translated into strong protein expression and respective pathway activation in the tumour tissue. Furthermore, a patient-derived cell line was sensitive to EGFR and MEK inhibition, confirming the functional relevance of the pathway activation. Immunohistochemistry analyses in a large patient cohort showed the relevance of the observed changes to the pathogenesis of EPC. Our results indicate that mEPC should respond to immune or kinase inhibitor therapy. Indeed, the advanced disease of our index patient was controlled by EGFR-directed therapy and immune checkpoint inhibition for more than 2 years.

CONCLUSIONS

Molecular profiling demonstrated high TMB and EGFR/MAPK pathway activation to be novel therapeutic targets in mEPC.

Impact of a preceding radiotherapy on the outcome of immune checkpoint inhibition in metastatic melanoma: a multicenter retrospective cohort study of the DeCOG

Background

Immune checkpoint inhibition (ICI) is an essential treatment option in melanoma. Its outcome may be improved by a preceding radiation of metastases. This study aimed to investigate the impact of a preceding radiotherapy on the clinical outcome of ICI treatment.

Methods

This multicenter retrospective cohort study included patients who received anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) or anti-programmed cell death protein 1 (PD-1) ICI with or without preceding radiotherapy for unresectable metastatic melanoma. ICI therapy outcome was measured as best overall response (BOR), progression-free (PFS) and overall survival (OS). Response and survival analyses were adjusted for confounders identified by directed acyclic graphs. Adjusted survival curves were calculated using inverse probability treatment weighting.

Results

835 patients who received ICI (anti-CTLA-4, n=596; anti-PD-1, n=239) at 16 centers were analyzed, whereof 235 received a preceding radiotherapy of metastatic lesions in stage IV disease. The most frequent organ sites irradiated prior to ICI therapy were brain (51.1%), lymph nodes (17.9%) and bone (17.9%). After multivariable adjustment for confounders, no relevant differences in ICI therapy outcome were observed between cohorts with and without preceding radiotherapy. BOR was 8.7% vs 13.0% for anti-CTLA-4 (adjusted relative risk (RR)=1.47; 95% CI=0.81 to 2.65; p=0.20), and 16.5% vs 25.3% for anti-PD-1 (RR=0.93; 95% CI=0.49 to 1.77; p=0.82). Survival probabilities were similar for cohorts with and without preceding radiotherapy, for anti-CTLA-4 (PFS, adjusted HR=1.02, 95% CI=0.86 to 1.25, p=0.74; OS, HR=1.08, 95% CI=0.81 to 1.44, p=0.61) and for anti-PD-1 (PFS, HR=0.84, 95% CI=0.57 to 1.26, p=0.41; OS, HR=0.73, 95% CI=0.43 to 1.25, p=0.26). Patients who received radiation last before ICI (n=137) revealed no better survival than those who had one or more treatment lines between radiation and start of ICI (n=86). In 223 patients with brain metastases, we found no relevant survival differences on ICI with and without preceding radiotherapy.

Conclusions

This study detected no evidence for a relevant favorable impact of a preceding radiotherapy on anti-CTLA-4 or anti-PD-1 ICI treatment outcome in metastatic melanoma.

Clinical characteristics and therapy response in unresectable melanoma patients stage IIIB-IIID with in-transit and satellite metastases

INTRODUCTION

Cutaneous melanoma is notorious for the development of in-transit metastases (ITM). For unknown biological reasons, ITM remain the leading tumour manifestation without progression to distant sites in some patients.

METHODS

In total, 191 patients with initially unresectable stage III ITM and satellite metastases from 16 skin cancer centres were retrospectively evaluated for their tumour characteristics, survival and therapy response. Three groups according to disease kinetics (no distant progress, slow (>6 months) and fast (<6 months) distant progression) were analysed separately.

RESULTS

Median follow-up time was 30.5 (range 0.8-154.0) months from unresectable ITM. Progression to stage IV was observed in 56.5% of cases. Patients without distant metastasis were more often female, older (>70 years) and presented as stage III with lymph node or ITM at initial diagnosis in 45.7% of cases. Melanoma located on the leg had a significantly better overall survival (OS) from time of initial diagnosis compared to non-leg localised primaries (hazard ratio [HR] = 0.61, 95% confidence interval [CI] 0.40-0.91; p = 0.017), but not from diagnosis of unresectable stage III (HR = 0.67, 95% CI 0.45-1.02; p = 0.06). Forty percent of patients received local therapy for satellite and ITM. Overall response rate (ORR) to all local first-line treatments was 38%; disease control rate (DCR) was 49%. In total, 72.3% of patients received systemic therapy for unresectable stage IIIB-D. ORR for targeted therapy (n = 19) was highest with 63.2% and DCR was 84.2% compared to an ORR of 31.4% and a DCR of 54.3% in PD-1 treated patients (n = 70). Patients receiving PD-1 and intralesional talimogene laherparepvec (n = 12) had an ORR of 41.7% and a DCR of 75%.

CONCLUSION

Patients with unresectable ITM and without distant progression are more often female, older, and have a primary on the leg. Response to PD-1 inhibitors in this cohort was lower than expected, but further investigation is required to elucidate the biology of ITM development and the interplay with the immune system.

Early Exanthema Upon Vemurafenib Plus Cobimetinib Is Associated With a Favorable Treatment Outcome in Metastatic Melanoma: A Retrospective Multicenter DeCOG Study

Background

The combination of BRAF and MEK inhibitors has become standard of care in the treatment of metastatic BRAF V600-mutated melanoma. Clinical factors for an early prediction of tumor response are rare. The present study investigated the association between the development of an early exanthema induced by vemurafenib or vemurafenib plus cobimetinib and therapy outcome.

Methods

This multicenter retrospective study included patients with BRAF V600-mutated irresectable AJCC-v8 stage IIIC/D to IV metastatic melanoma who received treatment with vemurafenib (VEM) or vemurafenib plus cobimetinib (COBIVEM). The development of an early exanthema within six weeks after therapy start and its grading according to CTCAEv4.0 criteria was correlated to therapy outcome in terms of best overall response, progression-free (PFS), and overall survival (OS).

Results

A total of 422 patients from 16 centers were included (VEM, n=299; COBIVEM, n=123). 20.4% of VEM and 43.1% of COBIVEM patients developed an early exanthema. In the VEM cohort, objective responders (CR/PR) more frequently presented with an early exanthema than non-responders (SD/PD); 59.0% versus 38.7%; p=0.0027. However, median PFS and OS did not differ between VEM patients with or without an early exanthema (PFS, 6.9 versus 6.0 months, p=0.65; OS, 11.0 versus 12.4 months, p=0.69). In the COBIVEM cohort, 66.0% of objective responders had an early exanthema compared to 54.3% of non-responders (p=0.031). Median survival times were significantly longer for patients who developed an early exanthema compared to patients who did not (PFS, 9.7 versus 5.6 months, p=0.013; OS, not reached versus 11.6 months, p=0.0061). COBIVEM patients with a mild early exanthema (CTCAEv4.0 grade 1-2) had a superior survival outcome as compared to COBIVEM patients with a severe (CTCAEv4.0 grade 3-4) or non early exanthema, respectively (p=0.047). This might be caused by the fact that 23.6% of patients with severe exanthema underwent a dose reduction or discontinuation of COBIVEM compared to only 8.9% of patients with mild exanthema.

Conclusions

The development of an early exanthema within 6 weeks after treatment start indicates a favorable therapy outcome upon vemurafenib plus cobimetinib. Patients presenting with an early exanthema should therefore be treated with adequate supportive measures to provide that patients can stay on treatment.

Tumor PD-L1 expression and gene panel mutational profile as outcome predictors of PD-1-based checkpoint inhibition therapy in metastatic melanoma: A prospective multicenter DeCOG study

9568

Background: PD-1 checkpoint inhibition (CPI) has recently advanced to one of the most effective treatment strategies in melanoma. However, since a considerable proportion of patients shows upfront therapy resistance, baseline predictive biomarkers of therapy outcome are needed. Methods: This prospective multicenter study included metastatic melanoma patients whose formalin-fixed paraffin-embedded tumor tissue samples taken prior to the start of a systemic non-adjuvant therapy of any line were analyzed for PD-L1 expression on tumor cells by immunohistochemistry (clone 28-8, DAKO) and for COSMIC-annotated oncogenic mutations by 29-gene panel sequencing (MiSeq, Illumina). Clinical baseline and follow-up data were collected within the DeCOG multicenter skin cancer registry ADOREG. Results: From 09/2015 until 10/2020, 706 enrolled patients from 15 centers were evaluable for the endpoints best overall response (BOR), progression-free (PFS) and overall survival (OS). Thereof, 540 patients received PD-1-based CPI as first systemic treatment after tumor tissue analysis. 197/540 patients tested positive for PD-L1 (cut-off = 5%) in pre-treatment tumors, and revealed a favourable BOR (objective response 34.4% versus 19.1%; p < 0.0001), PFS (median 10.4 versus 4.2 months; p < 0.0001) and OS (median 45.1 versus 18.8 months; p = 0.001) compared to patients with PD-L1 negative tumors. 47/540 patients presented oncogenic mutations of three or more genes in pre-treatment tumors, and revealed a favourable BOR (objective response 46.8% versus 32.1%; p = 0.041), PFS (median 15.1 versus 6.1 months; p = 0.008) and OS (median not reached versus 25.2 months; p = 0.027) compared to patients whose tumors showed mutations in two or less genes. Multivariable Cox regression including sex, primary site, non-adjuvant systemic pre-treatment, serum LDH, and ECOG performance state demonstrated tumor PD-L1 expression and gene panel mutational profile as independent predictors of survival upon treatment with PD-1-based CPI. In contrast, in 106/706 patients treated with BRAF/MEK inhibitors as first systemic treatment after tumor tissue analysis, no association was found between tumor PD-L1 expression or gene panel mutational profile and therapy outcome. Conclusions: PD-L1 expression quantification and gene panel mutational profiling provide useful outcome predictors of PD-1-based CPI therapy in metastatic melanoma patients.

Factors Influencing the Adjuvant Therapy Decision: Results of a Real-World Multicenter Data Analysis of 904 Melanoma Patients

Adjuvant treatment of melanoma patients with immune-checkpoint inhibition (ICI) and targeted therapy (TT) significantly improved recurrence-free survival. This study investigates the real-world situation of 904 patients from 13 German skin cancer centers with an indication for adjuvant treatment since the approval of adjuvant ICI and TT. From adjusted log-binomial regression models, we estimated relative risks for associations between various influence factors and treatment decisions (adjuvant therapy yes/no, TT vs. ICI in BRAF mutant patients). Of these patients, 76.9% (95% CI 74-80) opted for a systemic adjuvant treatment. The probability of starting an adjuvant treatment was 26% lower in patients >65 years (RR 0.74, 95% CI 68-80). The most common reasons against adjuvant treatment given by patients were age (29.4%, 95% CI 24-38), and fear of adverse events (21.1%, 95% CI 16-28) and impaired quality of life (11.9%, 95% CI 7-16). Of all BRAF-mutated patients who opted for adjuvant treatment, 52.9% (95% CI 47-59) decided for ICI. Treatment decision for TT or ICI was barely associated with age, gender and tumor stage, but with comorbidities and affiliated center. Shortly after their approval, adjuvant treatments have been well accepted by physicians and patients. Age plays a decisive role in the decision for adjuvant treatment, while pre-existing autoimmune disease and regional differences influence the choice between TT or ICI.

Computed tomography-guided biopsy of radiologically unclear lesions in advanced skin cancer: A retrospective analysis of 47 cases

BACKGROUND

Radiological imaging such as computed tomography (CT) is used frequently for disease staging and therapy monitoring in advanced skin cancer patients. Detected lesions of unclear dignity are a common challenge for treating physicians. The aim of this study was to assess the frequency and outcome of CT-guided biopsy (CTGB) of radiologically unclear, suspicious lesions and to depict its usefulness in different clinical settings.

METHODS

This retrospective monocentric study included advanced skin cancer patients (melanoma, Merkel cell carcinoma, squamous cell carcinoma, angiosarcoma, cutaneous lymphoma) with radiologically unclear lesions who underwent CTGB between 2010 and 2018.

RESULTS

Of 59 skin cancer patients who received CTGB, 47 received CTGB to clarify radiologically suspicious lesions of unclear dignity. 32 patients had no systemic therapy (cohort A), while 15 patients received systemic treatment at CTGB (cohort B). In both cohorts, CTGB revealed skin cancer metastasis in a large proportion of patients (37.5%, 40.0%, respectively), but benign tissue showing inflammation, fibrosis or infection in an equally large percentage (37.5%, 46.7%, respectively). Additionally, a significant number of other cancer entities was found (25.0%, 13.3%, respectively). In patients receiving BRAF/MEK inhibitors, CTGB confirmed suspicious lesions as skin cancer metastasis in 83.3%, leading to treatment change. In immune checkpoint inhibitor-treated patients, skin cancer metastasis was confirmed in 11.1% of patients only, whereas benign tissue changes (inflammation/fibrosis) were found in 77.8%.

CONCLUSIONS

Our results highlight the relevance of clarifying radiologically unclear lesions by CTGB before start or change of an anti-tumour therapy to exclude benign alterations and secondary malignancies.