Plain language summary of the CheckMate 76K study results: nivolumab given after stage 2B/2C melanoma is removed by surgery.

WHAT IS THIS SUMMARY ABOUT?: In this article, we summarize results from the ongoing phase 3 CheckMate 76K clinical study published online in Nature Medicine in October 2023. The study goal was to learn whether nivolumab works as an adjuvant therapy (that is, helps to keep cancer from coming back when it is given after surgery) for stage 2 melanoma (skin cancer) that has not spread to other parts of the body. Nivolumab is an immunotherapy that activates a person's immune system so it can destroy cancer cells. In melanoma, staging describes the severity of the cancer. Melanoma staging ranges from 0 (very thin and confined to the upper layer of the skin) to 4 (spread to distant parts of the body), with earlier stages removed by surgery. The people in this study had stage 2 melanoma that had not spread to the lymph nodes or other organs in the body. HOW WAS THE STUDY DESIGNED?: People 12 years and older with stage 2 melanoma that had not spread and had been removed by surgery were included in CheckMate 76K. People were randomly assigned to receive either nivolumab (526 patients) or placebo (264 patients). A placebo resembles the test medicine but does not contain any active medicines. The researchers assessed whether people who received nivolumab lived longer without their cancer returning and/or spreading to other parts of their bodies (compared with placebo) and if nivolumab was well tolerated. WHAT WERE THE RESULTS?: Researchers found that people who received nivolumab were 58% less likely to have their cancer return and 53% less likely of having their cancer spread to distant parts of their body, compared with placebo. These reductions in risk with nivolumab were seen in different subgroups of people with a range of characteristics, and regardless of how deep the melanoma had gone into the skin. People taking nivolumab had more side effects than those taking placebo, but most were mild to moderate and manageable. WHAT DO THE RESULTS MEAN?: Results from CheckMate 76K support the benefit of using nivolumab as a treatment option for people with stage 2 melanoma post-surgery.

A tailored approach to horizon scanning for cancer medicines.

BACKGROUND: Horizon scanning (HS) is the systematic identification of emerging therapies to inform policy and decision-makers. We developed an agile and tailored HS methodology that combined multi-criteria decision analysis weighting and Delphi rounds. As secondary objectives, we aimed to identify new medicines in melanoma, non-small cell lung cancer and colorectal cancer most likely to impact the Australian government's pharmaceutical budget by 2025 and to compare clinician and consumer priorities in cancer medicine reimbursement. METHOD: Three cancer-specific clinician panels (total n = 27) and a consumer panel (n = 7) were formed. Six prioritisation criteria were developed with consumer input. Criteria weightings were elicited using the Analytic Hierarchy Process (AHP). Candidate medicines were identified and filtered from a primary database and validated against secondary and tertiary sources. Clinician panels participated in a three-round Delphi survey to identify and score the top five medicines in each cancer type. RESULTS: The AHP and Delphi process was completed in eight weeks. Prioritisation criteria focused on toxicity, quality of life (QoL), cost savings, strength of evidence, survival, and unmet need. In both curative and non-curative settings, consumers prioritised toxicity and QoL over survival gains, whereas clinicians prioritised survival. HS results project the ongoing prevalence of high-cost medicines. Since completion in October 2021, the HS has identified 70 % of relevant medicines submitted for Pharmaceutical Benefit Advisory Committee assessment and 60% of the medicines that received a positive recommendation. CONCLUSION: Tested in the Australian context, our method appears to be an efficient and flexible approach to HS that can be tailored to address specific disease types by using elicited weights to prioritise according to incremental value from both a consumer and clinical perspective. POLICY SUMMARY: Since HS is of global interest, our example provides a reproducible blueprint for adaptation to other healthcare settings that integrates consumer input and priorities.

Adjuvant nivolumab in resected stage IIB/C melanoma: primary results from the randomized, phase 3 CheckMate 76K trial.

Patients with resected stage IIB/C melanoma have high recurrence risk, similar to those with resected stage IIIA/B disease. The phase 3, double-blind CheckMate 76K trial assessed 790 patients with resected stage IIB/C melanoma randomized 2:1 (stratified by tumor category) to nivolumab 480 mg or placebo every 4 weeks for 12 months. The primary endpoint was investigator-assessed recurrence-free survival (RFS). Secondary endpoints included distant metastasis-free survival (DMFS) and safety. At 7.8 months of minimum follow-up, nivolumab significantly improved RFS versus placebo (hazard ratio (HR) = 0.42; 95% confidence interval (CI): 0.30-0.59; P < 0.0001), with 12-month RFS of 89.0% versus 79.4% and benefit observed across subgroups; DMFS was also improved (HR = 0.47; 95% CI: 0.30-0.72). Treatment-related grade 3/4 adverse events occurred in 10.3% (nivolumab) and 2.3% (placebo) of patients. One treatment-related death (0.2%) occurred with nivolumab. Nivolumab is an effective and generally well-tolerated adjuvant treatment in patients with resected stage IIB/C melanoma. ClinicalTrials.gov identifier: NCT04099251 .

Detection of metastases using circulating tumour DNA in uveal melanoma.

BACKGROUND: Approximately 50% of uveal melanoma (UM) patients will develop metastatic disease depending on the genetic features of the primary tumour. Patients need 3-12 monthly scans, depending on their prognosis, which is costly and often non-specific. Circulating tumour DNA (ctDNA) quantification could serve as a test to detect and monitor patients for early signs of metastasis and therapeutic response. METHODS: We assessed ctDNA as a biomarker in three distinct UM cohorts using droplet-digital PCR: (A) a retrospective analysis of primary UM patients to predict metastases; (B) a prospective analysis of UM patients after resolution of their primary tumour for early detection of metastases; and (C) monitoring treatment response in metastatic UM patients. RESULTS: Cohort A: ctDNA levels were not associated with the development of metastases. Cohort B: ctDNA was detected in 17/25 (68%) with radiological diagnosis of metastases. ctDNA was the strongest predictor of overall survival in a multivariate analysis (HR = 15.8, 95% CI 1.7-151.2, p = 0.017). Cohort C: ctDNA monitoring of patients undergoing immunotherapy revealed a reduction in the levels of ctDNA in patients with combination immunotherapy. CONCLUSIONS: Our proof-of-concept study shows the biomarker feasibility potential of ctDNA monitoring in for the clinical management of uveal melanoma patients.

First-Line, Fixed-Duration Nivolumab Plus Ipilimumab Followed by Nivolumab in Clinically Diverse Patient Populations With Unresectable Stage III or IV Melanoma: CheckMate 401.

PURPOSE: To address the paucity of data in patients with historically poor outcomes, we conducted the single-arm phase IIIb CheckMate 401 study to evaluate the safety and efficacy of nivolumab plus ipilimumab followed by nivolumab monotherapy in clinically diverse patient populations with advanced melanoma. METHODS: Treatment-naive patients with unresectable stage III-IV melanoma received nivolumab 1 mg/kg plus ipilimumab 3 mg/kg once every 3 weeks (four doses) followed by nivolumab 3 mg/kg (240 mg following a protocol amendment) once every 2 weeks for ≤24 months. The primary end point was the incidence of grade 3-5 select treatment-related adverse events (TRAEs). Overall survival (OS) was a secondary end point. Outcomes were evaluated in subgroups defined by Eastern Cooperative Oncology Group performance status (ECOG PS), brain metastasis status, and melanoma subtype. RESULTS: In total, 533 patients received at least one dose of study drug. Grade 3-5 select TRAEs affecting the GI (16%), hepatic (15%), endocrine (11%), skin (7%), renal (2%), and pulmonary (1%) systems occurred in the all-treated population; similar incidence rates were observed across all subgroups. At 21.6 months' median follow-up, 24-month OS rates were 63% in the all-treated population, 44% in the ECOG PS 2 subgroup (including patients with cutaneous melanoma only), 71% in the brain metastasis subgroup, 36% in the ocular/uveal melanoma subgroup, and 38% in the mucosal melanoma subgroup. CONCLUSION: Nivolumab plus ipilimumab followed by nivolumab monotherapy was tolerable in patients with advanced melanoma and poor prognostic characteristics. Efficacy was similar between the all-treated population and patients with brain metastases. Reduced efficacy was observed in patients with ECOG PS 2, ocular/uveal melanoma, and/or mucosal melanoma, highlighting the continued need for novel treatment options for these difficult-to-treat patients.

Feasibility of supervised telehealth exercise for patients with advanced melanoma receiving checkpoint inhibitor therapy.

PURPOSE: To determine the feasibility, safety and preliminary efficacy of a telehealth supervised exercise programme in patients with advanced melanoma receiving checkpoint inhibitor therapy. METHODS: A 8-week non-randomised feasibility pilot trial utilising a telehealth delivered multimodal exercise programme undertaken thrice weekly with assessments at baseline and post-intervention. The study was considered feasible if there were no severe or life-threatening adverse events as a result of exercise, and three or more of the following criteria were met: the recruitment rate was >50%, completion rate was >80%, median programme attendance was >75%, median exercise compliance >75%, and average tolerance was >70%. Preliminary efficacy was assessed for objective measures of physical function (2-min step test, repeated chair stand test, 30-s push-up test, and a modified static balance test) and quality of life (QoL), fatigue and other patient-reported outcomes were assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30. RESULTS: Eleven patients (32-80 years) were included in the study (6 female, 5 male). The recruitment rate was 48%, completion rate 91%, programme attendance 88%, median exercise compliance 82.1% and 84.9% for resistance and aerobic exercise, respectively, and tolerance 88%, with no severe or life-threatening adverse events as a result of exercise. In terms of preliminary efficacy, physical function significantly improved while QoL was maintained following the intervention. CONCLUSION: An 8-week telehealth exercise intervention is feasible and safe for patients with advanced melanoma and appears to improve physical function while preserving QoL during checkpoint inhibitor therapy.

Skeletal muscle morphology in patients receiving primary versus interval cytoreductive surgery for advanced high-grade serous ovarian cancer.

OBJECTIVE: Our primary aim was to compare muscle morphology (skeletal muscle mass and density) between patients who underwent primary cytoreductive surgery versus interval cytoreductive surgery for advanced high-grade serous ovarian cancer. Secondarily, we explored the associations of muscle morphology with survival outcomes. METHODS: We retrospectively analysed computed tomography (CT) images for 88 ovarian cancer patients (aged 38-89 years) to calculate skeletal muscle index (cm2/m2) and skeletal muscle density (Hounsfield units (HU)). A skeletal muscle index of <38.5 cm2/m2 and skeletal muscle density of <33.7 HU were classified as low. Analyses included repeated measures analysis of covariance and multivariable Cox proportional hazards regression. RESULTS: At baseline, 44.3% of patients had low skeletal muscle index and 50.6% had low skeletal muscle density, with interval surgery patients having significantly lower mean skeletal muscle density than primary surgery patients (32.2±8.9 vs 37.3±8.6 HU, p=0.014). Although both groups had similar reductions in skeletal muscle index following treatment (p=0.49), primary surgery patients had a greater reduction in skeletal muscle density compared with interval surgery patients (-2.4 HU, 95% CI -4.3 to -0.5, p=0.016). Patients who experienced skeletal muscle density loss >2% during treatment (HR 5.16, 95% CI 1.33 to 20.02) and had low skeletal muscle density post-treatment (HR 58.87, 95% CI 3.70 to 935.68) had significantly worse overall survival. CONCLUSION: Low skeletal muscle index and skeletal muscle density were prevalent at ovarian cancer diagnosis. While both groups experienced muscle mass loss, greater reductions in skeletal muscle density occurred in patients undergoing primary surgery. In addition, skeletal muscle density loss during treatment and low skeletal muscle density post-treatment were associated with poorer overall survival. Supportive care involving resistance exercise targeting muscle hypertrophic drive, and nutrition counseling during and after ovarian cancer treatment may help preserve/enhance muscle mass and density.

Supervised resistance exercise for women with ovarian cancer who have completed first-line treatment: a pragmatic study.

OBJECTIVES: In ovarian cancer (OC), suboptimal muscle morphology (i.e., low muscle mass and density) is associated with poor clinical outcomes, yet little is known about the effect of interventions aimed at improving these measures. We investigated the effect of resistance exercise after first-line treatment on muscle mass and density, muscle strength and physical function, health-related quality of life (QoL), and pelvic-floor function in advanced-stage OC survivors. METHODS: Fifteen OC survivors participated in supervised resistance exercise twice weekly for 12 weeks (in-clinic or by telehealth). Assessments included muscle mass and density (dual-energy X-ray absorptiometry, peripheral quantitative computed tomography), muscle strength (1-repetition maximum [1RM] chest press, 5RM leg press, handgrip strength), physical function (400-m walk, timed up-and-go [TUG]), QoL (QLQ-C30 questionnaire), and self-reported pelvic floor function (Australian Pelvic Floor Questionnaire). RESULTS: The median age was 64 (range 33-72) years, 10 women underwent neoadjuvant chemotherapy and five underwent adjuvant chemotherapy. All participants completed the intervention (median attendance = 92%; range 79-100%). Post-intervention improvements were observed for whole-body lean mass (1.0 ± 1.4 kg, p = 0.015), appendicular lean mass (0.6 ± 0.9 kg, p = 0.013), muscle density (p = 0.011), upper and lower body strength (p ≤ 0.001), 400-m walk (p = 0.001), TUG (p = 0.005), and social and cognitive QoL domains (p = 0.002 and 0.007), with no change to pelvic floor symptoms (p > 0.05). CONCLUSION: In this study, supervised resistance exercise effectively improved muscle mass and density, muscle strength, and physical functioning without deleterious effects on the pelvic floor. Considering the prognostic value of these outcomes, larger studies are needed to confirm the benefits of resistance exercise in OC supportive care.

Genetic analysis of heterogeneous subsets of circulating tumour cells from high grade serous ovarian carcinoma patients.

Circulating tumour cells (CTCs) are heterogenous and contain genetic information from the tumour of origin. They bear specific intra- and extra-cellular protein markers aiding in their detection. However, since these markers may be shared with other rare cells in the blood, only genetic testing can confirm their malignancy. Herein, we analyse different CTC subsets using single cell whole genome DNA sequencing to validate their malignant origin. We randomly selected putative CTCs identified by immunostaining that were isolated from 4 patients with high grade serous ovarian cancer (HGSOC) and one with benign cystadenoma. We specifically targeted CTCs positive for epithelial (CK/EpCAMpos), mesenchymal (vimentinpos), and pseudoendothelial (CK/EpCAMpos plus CD31pos) markers. We isolated these cells and performed whole genome amplification (WGA) and low-pass whole-genome sequencing (LP-WGS) for analysis of copy number alterations (CNA). Of the CK/EpCAMpos cells analysed from the HGSOC patients, 2 of 3 cells showed diverse chromosomal CNAs. However, the 4 pseudoendothelial cells (CK/EpCAMpos plus CD31pos) observed in the HGSOC cases did not carry any CNA. Lastly, two of the clusters of vimentin positive cells sequenced from those found in the benign cystadenoma case had CNA. Despite the low number of cells analysed, our results underscore the importance of genetic analysis of putative CTCs to confirm their neoplastic origin. In particular, it highlights the presence of a population of CK/EpCAMpos cells that are not tumour cells in patients with HGSOC, which otherwise would be counted as CTCs.

Identification of TP53 mutations in circulating tumour DNA in high grade serous ovarian carcinoma using next generation sequencing technologies.

Plasma circulating tumour DNA (ctDNA) has been suggested to be a viable biomarker of response to treatment in patients with high grade serous ovarian carcinoma (HGSOC). TP53 mutations are present in more than 90% of HGSOCs but somatic variants are distributed across all exonic regions of the gene, requiring next generation sequencing (NGS) technologies for mutational analysis. In this study, we compared the suitability of the Accel (Swift) and Oncomine (ThermoFisher) panels for identification of TP53 mutations in ctDNA of HGSOC patients (N = 10). Only 6 patients (60%) were found to have TP53 mutations using the ACCEL panel but the addition of molecular tags in the Oncomine panel improved ctDNA detection with at least one mutation detected in all cases (100%). Orthogonal validation of the 14 somatic variants found by Oncomine, using droplet digital PCR, confirmed 79% (11/14) of the identified mutations. Overall, the Oncomine panel with unique molecular identifiers (UMI) appears more useful for ctDNA analysis in HGSOC.

KEYNOTE - D36: personalized immunotherapy with a neoepitope vaccine, EVX-01 and pembrolizumab in advanced melanoma.

Despite improvements made with checkpoint inhibitor (CPI) therapy, a need for new approaches to improve outcomes for patients with unresectable or metastatic melanoma remains. EVX-01, a personalized neoepitope vaccine, combined with pembrolizumab treatment, holds the potential to fulfill this need. Here we present the rationale and novel design behind the KEYNOTE - D36 trial: an open label, single arm, phase II trial aiming to establish the clinical proof of concept and evaluate the safety of EVX-01 in combination with pembrolizumab in CPI naive patients with unresectable or metastatic melanoma. The primary objective is to evaluate if EVX-01 improves best overall response after initial stable disease or partial response to pembrolizumab treatment, in patients with advanced melanoma. The novel end points ensure a decisive readout which may prove helpful before making major investments in phase III trials with limited phase I data. Clinical Trial Registration: NCT05309421 (ClinicalTrials.gov).

Drugs targeting the immune system have improved the outcomes for patients with advanced melanoma. However, a significant proportion of patients do not benefit and there is a need for better therapeutic agents to be used alone or in combination with immune modulating agents. This article summarizes the rationale and design of a new trial with a personalized vaccine (EVX-01) that may improve outcomes for patients with advanced melanoma (unresectable stage III or IV melanoma). The EVX-01 vaccine aims to stimulate the patient's immune system to generate T cells that target specific molecules that can only be found on the surface of the individual patients' cancer cells (i.e. neoepitopes), resulting in cancer cell death. The trial will investigate if the personalized EVX-01 vaccine together with checkpoint inhibitor therapy works better for patients with advanced melanoma, than checkpoint inhibitor therapy alone.

Detection of clinical progression through plasma ctDNA in metastatic melanoma patients: a comparison to radiological progression.

BACKGROUND: The validity of circulating tumour DNA (ctDNA) as an indicator of disease progression compared to medical imaging in patients with metastatic melanoma requires detailed evaluation. METHODS: Here, we carried out a retrospective ctDNA analysis of 108 plasma samples collected at the time of disease progression. We also analysed a validation cohort of 66 metastatic melanoma patients monitored prospectively after response to systemic therapy. RESULTS: ctDNA was detected in 62% of patients at the time of disease progression. For 67 patients that responded to treatment, the mean ctDNA level at progressive disease was significantly higher than at the time of response (P < 0.0001). However, only 30 of these 67 (45%) patients had a statistically significant increase in ctDNA by Poisson test. A validation cohort of 66 metastatic melanoma patients monitored prospectively indicated a 56% detection rate of ctDNA at progression, with only two cases showing increased ctDNA prior to radiological progression. Finally, a correlation between ctDNA levels and metabolic tumour burden was only observed in treatment naïve patients but not at the time of progression in a subgroup of patients failing BRAF inhibition (N = 15). CONCLUSIONS: These results highlight the low efficacy of ctDNA to detect disease progression in melanoma when compared mainly to standard positron emission tomography imaging.

Dual PD-1 and CTLA-4 Checkpoint Blockade Using Balstilimab and Zalifrelimab Combination as Second-Line Treatment for Advanced Cervical Cancer: An Open-Label Phase II Study.

PURPOSE: Balstilimab (antiprogrammed death-1) and zalifrelimab (anticytotoxic T-lymphocyte-associated antigen-4) are two new checkpoint inhibitors emerging as promising investigational agents for the treatment of advanced cervical cancer. This phase II trial (ClinicalTrials.gov identifier: NCT03495882) evaluated the combination of balstilimab plus zalifrelimab in patients with recurrent and/or metastatic cervical cancer who relapsed after prior platinum-based therapy. PATIENTS AND METHODS: Patients were intravenously dosed with balstilimab 3 mg/kg once every 2 weeks and zalifrelimab 1 mg/kg once every 6 weeks, for up to 24 months. The primary end point was objective response rate (ORR, RECIST version 1.1, assessed by independent central review). Secondary end points included duration of response, safety and tolerability, and survival. RESULTS: In total, 155 women (median age, 50 years [range, 24-76 years]) were enrolled and treated with balstilimab plus zalifrelimab; 125 patients had measurable disease at baseline and one prior line of platinum-based therapy in the advanced setting, and these patients constituted the efficacy-evaluable population. The median follow-up was 21 months. The confirmed ORR was 25.6% (95% CI, 18.8 to 33.9), including 10 complete responders and 22 partial responders, with median duration of response not reached (86.5%, 75.5%, and 64.2% at 6, 9, and 12 months, respectively). The ORRs were 32.8% and 9.1% in patients with programmed death ligand-1-positive and programmed death ligand-1-negative tumors, respectively. For patients with squamous cell carcinoma, the ORR was 32.6%. The overall disease control rate was 52% (95% CI, 43.3 to 60.6). Hypothyroidism (14.2%) and hyperthyroidism (7.1%) were the most common immune-mediated adverse events. CONCLUSION: Promising and durable clinical activity, with favorable tolerability, was seen in this largest trial to date evaluating dual programmed death-1/cytotoxic T-lymphocyte-associated antigen-4 blockade in patients with recurrent and/or metastatic cervical cancer. Further investigation of the balstilimab and zalifrelimab combination in this setting is continuing.

Multi-Marker Immunofluorescent Staining and PD-L1 Detection on Circulating Tumour Cells from Ovarian Cancer Patients.

Detection of ovarian cancer (OC) circulating tumour cells (CTCs) is primarily based on targeting epithelial markers, thus failing to detect mesenchymal tumour cells. More importantly, the immune checkpoint inhibitor marker PD-L1 has not been demonstrated on CTCs from OC patients. An antibody staining protocol was developed and tested using SKOV-3 and OVCA432 OC cell lines. We targeted epithelial (cytokeratin (CK) and EpCAM), mesenchymal (vimentin), and OC-specific (PAX8) markers for detection of CTCs, and CD45/16 and CD31 were used for the exclusion of white blood and vascular endothelial cells, respectively. PD-L1 was used for CTC characterisation. CTCs were enriched using the Parsortix™ system from 16 OC patients. Results revealed the presence of CTCs in 10 (63%) cases. CTCs were heterogeneous, with 113/157 (72%) cells positive for CK/EpCAM (epithelial marker), 58/157 (37%) positive for vimentin (mesenchymal marker), and 17/157 (11%) for both (hybrid). PAX8 was only found in 11/157 (7%) CTCs. In addition, 62/157 (39%) CTCs were positive for PD-L1. Positivity for PD-L1 was significantly associated with the hybrid phenotype when compared with the epithelial (p = 0.007) and mesenchymal (p = 0.0009) expressing CTCs. Characterisation of CTC phenotypes in relation to clinical outcomes is needed to provide insight into the role that epithelial to mesenchymal plasticity plays in OC and its relationship with PD-L1.

Associations of Physical Activity and Exercise with Health-related Outcomes in Patients with Melanoma During and After Treatment: A Systematic Review.

PURPOSE: Although exercise medicine is recommended to counter treatment-related side-effects and improve health-related outcomes of patients affected by different cancers, no specific recommendations exist for patients with melanoma. As a result, we systematically examined the current evidence regarding the effects of physical activity and exercise on objectively-measured and patient-reported outcomes among patients with melanoma. METHODS: Searches were conducted in PubMed, CINAHL, EMBASE, SPORTDiscus, and Web of Science databases. This review included published data involving physical activity or exercise and objectively-measured or patient-reported outcomes of patients with cutaneous melanoma. The quality of included studies was assessed using the McMaster University Critical Appraisal Tool for Quantitative Studies. RESULTS: Six studies including 882 patients with melanoma were included. Studies presented heterogeneity of design with 2 cross-sectional surveys, 2 retrospective analyses, and 2 non-randomized intervention trials. No statistically significant change in quality of life, fatigue, physical function, cardiorespiratory fitness, body composition, psychological distress, cognitive function, or treatment-related side-effects were attributable to physical activity or exercise. Importantly, physical activity or exercise during melanoma treatment or into survivorship did not adversely impact patients/survivors. CONCLUSION: In summary, physical activity or exercise did not adversely impact quality of life, objectively-measured or patient-reported outcomes in patients with melanoma. In addition, there is a paucity of quality studies examining the effects of physical activity or exercise on patients with melanoma throughout the cancer care continuum.

Changes in expression of PD-L1 on peripheral T cells in patients with melanoma and lung cancer treated with PD-1 inhibitors.

Advances in cancer immunology have increased the use of immune checkpoint inhibitors in clinical practice, however not all patients respond, and treatment can have severe side-effects. Blood-based immunological biomarkers are an attractive method for predicting which patients will respond to therapy, however, reliable biomarkers for immune checkpoint blockade are lacking. This study aimed to identify patients before or early in treatment who would best respond to PD-1 inhibitors. We hypothesised that higher baseline PD-L1 and/or PD-1 on peripheral blood T cells could predict radiological response to PD-1 inhibitors. This pilot prospective cohort study assessed 26 patients with melanoma or non-small cell lung cancer, treated with pembrolizumab, nivolumab, or nivolumab/ipilimumab combined. Response was assessed by RECIST 1.1. Peripheral blood lymphocytes collected at baseline, after one cycle, 10 weeks and at discontinuation of therapy were analysed by flow cytometry. Patients with a higher proportion of PD-L1+ T cells at baseline had improved objective response to PD-1 inhibitor therapy, and patients with a lower proportion of regulatory T cells at baseline experienced more immune-related adverse events. These findings may prove useful to assist in clinical decision making. Further studies with larger cohorts are required to validate these findings.

The Prognostic Impact of Circulating Tumour DNA in Melanoma Patients Treated with Systemic Therapies-Beyond BRAF Mutant Detection.

In this study, we evaluated the predictive value of circulating tumour DNA (ctDNA) to inform therapeutic outcomes in metastatic melanoma patients receiving systemic therapies. We analysed 142 plasma samples from metastatic melanoma patients prior to commencement of systemic therapy: 70 were treated with BRAF/MEK inhibitors and 72 with immunotherapies. Patient-specific droplet digital polymerase chain reaction assays were designed for ctDNA detection. Plasma ctDNA was detected in 56% of patients prior to first-line anti-PD1 and/or anti-CTLA-4 treatment. The detection rate in the immunotherapy cohort was comparably lower than those with BRAF inhibitors (76%, p = 0.0149). Decreasing ctDNA levels within 12 weeks of treatment was strongly concordant with treatment response (Cohen's k = 0.798, p < 0.001) and predictive of longer progression free survival. Notably, a slower kinetic of ctDNA decline was observed in patients treated with immunotherapy compared to those on BRAF/MEK inhibitors. Whole exome sequencing of ctDNA was also conducted in 9 patients commencing anti-PD-1 therapy to derive tumour mutational burden (TMB) and neoepitope load measurements. The results showed a trend of high TMB and neoepitope load in responders compared to non-responders. Overall, our data suggest that changes in ctDNA can serve as an early indicator of outcomes in metastatic melanoma patients treated with systemic therapies and therefore may serve as a tool to guide treatment decisions.