Interferon-gamma signature as prognostic and predictive marker in macroscopic stage III melanoma.

BACKGROUND: A substantial proportion of patients with macroscopic stage III melanoma do not benefit sufficiently from adjuvant anti-PD-1 therapy, as they either recur despite therapy or would never have recurred. To better inform adjuvant treatment selection, we have performed translational analyses to identify prognostic and predictive biomarkers. PATIENTS AND METHODS: Two cohorts of patients with macroscopic stage III melanoma from an ongoing biobank study were included. Clinical data were compared between an observation cohort (cohort 1) and an adjuvant intention cohort (cohort 2). RNA sequencing for translational analyses was performed and treatment subgroups (cohort 1A and cohort 2A) were compared for possible biomarkers, using a cut-off based on the treatment-naïve patients. In addition, two validation cohorts (Melanoma Institute Australia (MIA) and University Medical Centre Utrecht (UMCU)) were obtained. RESULTS: After a median follow-up of 26 months of the 98 patients in our discovery set, median recurrence-free survival (RFS) was significantly longer for the adjuvant intention cohort (cohort 2, n=49) versus the observation cohort (cohort 1, n=49). Median overall survival was not reached for either cohort, nor significantly different. In observation cohort 1A (n=24), RFS was significantly longer for patients with high interferon-gamma (IFNγ) score (p=0.002); for adjuvant patients of cohort 2A (n=24), a similar trend was observed (p=0.086). Patients with high B cell score had a longer RFS in cohort 1A, but no difference was seen in cohort 2A. The B cell score based on RNA correlated with CD20+ cells in tumor area but was not independent from the IFNγ score. In the MIA validation cohort (n=44), longer RFS was observed for patients with high IFNγ score compared with low IFNγ score (p=0.046), no difference in RFS was observed according to the B cell score. In both the observation (n=11) and the adjuvant (n=11) UMCU validation cohorts, no difference in RFS was seen for IFNγ and B cell. CONCLUSIONS: IFNγ has shown to be a prognostic marker in both patients who were and were not treated with adjuvant therapy. B cell score was prognostic but did not improve accuracy over IFNγ. Our study confirmed RFS benefit of adjuvant anti-PD-1 for patients with macroscopic stage III melanoma.

The features and management of acquired resistance to PD1-based therapy in metastatic melanoma.

BACKGROUND: Anti-PD-1 therapy (PD1) either alone or with anti-CTLA-4 (CTLA4), has high initial response rates, however 20% of patients (pts) with complete response (CR) and 30% with partial response (PR) within 12 months of treatment experience subsequent disease progression by 6 years. The nature and optimal management of this acquired resistance (AR) remains unknown. METHODS: Pts from 16 centres who responded to PD1-based therapy and who later progressed were examined. Demographics, disease characteristics and subsequent treatments were evaluated. RESULTS: 299 melanoma pts were identified, median age 64y, 44% BRAFV600m. 172 (58%) received PD1 alone, 114 (38%) PD1/CTLA4 and 13 (4%) PD1 and an investigational drug. 90 (30%) pts had CR, 209 (70%) PR. Median time to AR was 12.6 mo (95% CI, 11.3, 14.2). Most (N = 193, 65%) progressed in a single organ site, and in a solitary lesion (N = 151, 51%). The most frequent sites were lymph nodes (38%) and brain (25%). Management at AR included systemic therapy (ST, 45%), local therapy (LT) +ST (31%), LT alone (21%), or observation (3%). There was no statistical difference in PFS2 or OS based on management, however, PFS2 was numerically superior for pts treated with ST alone who progressed off PD1 therapy than those who progressed on PD1 (2-year PFS2 42% versus 25%, p = 0.249). mOS from AR was 38.0 months (95% CI, 29.5-NR); longer in single-site versus multi-site progression (2-year OS 70% vs 54%, p < 0·001). CONCLUSIONS: Acquired resistance to PD1 therapy in melanoma is largely oligometastatic, and pts may have a favorable survival outcome following salvage treatment.

IMPemBra: a phase 2 study comparing pembrolizumab with intermittent/short-term dual MAPK pathway inhibition plus pembrolizumab in patients with melanoma harboring the BRAFV600 mutation.

BACKGROUND: Continuous combination of MAPK pathway inhibition (MAPKi) and anti-programmed death-(ligand) 1 (PD-(L)1) showed high response rates, but only limited improvement in progression-free survival (PFS) at the cost of a high frequency of treatment-related adverse events (TRAE) in patients with BRAFV600-mutated melanoma. Short-term MAPKi induces T-cell infiltration in patients and is synergistic with anti-programmed death-1 (PD-1) in a preclinical melanoma mouse model. The aim of this phase 2b trial was to identify an optimal regimen of short-term MAPKi with dabrafenib plus trametinib in combination with pembrolizumab. METHODS: Patients with treatment-naïve BRAFV600E/K-mutant advanced melanoma started pembrolizumab 200 mg every 3 weeks. In week 6, patients were randomized to continue pembrolizumab only (cohort 1), or to receive, in addition, intermittent dabrafenib 150 mg two times per day plus trametinib 2 mg one time per day for two cycles of 1 week (cohort 2), two cycles of 2 weeks (cohort 3), or continuously for 6 weeks (cohort 4). All cohorts continued pembrolizumab for up to 2 years. Primary endpoints were safety and treatment-adherence. Secondary endpoints were objective response rate (ORR) at week 6, 12, 18 and PFS. RESULTS: Between June 2016 and August 2018, 33 patients with advanced melanoma have been included and 32 were randomized. Grade 3-4 TRAE were observed in 12%, 12%, 50%, and 63% of patients in cohort 1, 2, 3, and 4, respectively. All planned targeted therapy was given in 88%, 63%, and 38% of patients in cohort 2, 3, and 4. ORR at week 6, 12, and 18 were 38%, 63%, and 63% in cohort 1; 25%, 63%, and 75% in cohort 2; 25%, 50%, and 75% in cohort 3; and 0%, 63%, and 50% in cohort 4. After a median follow-up of 43.5 months, median PFS was 10.6 months for pembrolizumab monotherapy and not reached for patients treated with pembrolizumab and intermittent dabrafenib and trametinib (p=0.17). The 2-year and 3-year landmark PFS were both 25% for cohort 1, both 63% for cohort 2, 50% and 38% for cohort 3 and 75% and 60% for cohort 4. CONCLUSIONS: The combination of pembrolizumab plus intermittent dabrafenib and trametinib seems more feasible and tolerable than continuous triple therapy. The efficacy is promising and appears to be favorable over pembrolizumab monotherapy. TRIAL REGISTRATION NUMBER: NCT02625337.

Personalizing neoadjuvant immune-checkpoint inhibition in patients with melanoma.

Neoadjuvant immune-checkpoint inhibition is a promising emerging treatment approach for patients with surgically resectable macroscopic stage III melanoma. The neoadjuvant setting provides an ideal platform for personalized therapy owing to the very homogeneous nature of the patient population and the opportunity for pathological response assessments within several weeks of starting treatment, thereby facilitating the efficient identification of novel biomarkers. A pathological response to immune-checkpoint inhibitors has been shown to be a strong surrogate marker of both recurrence-free survival and overall survival, enabling timely analyses of the efficacy of novel therapies in patients with early stage disease. Patients with a major pathological response (defined as the presence of ≤10% viable tumour cells) have a very low risk of recurrence, which offers an opportunity to adjust the extent of surgery and any subsequent adjuvant therapy and follow-up monitoring. Conversely, patients who have only a partial pathological response or who do not respond to neoadjuvant therapy still might benefit from therapy escalation and/or class switch during adjuvant therapy. In this Review, we outline the concept of a fully personalized neoadjuvant treatment approach exemplified by the current developments in neoadjuvant therapy for patients with resectable melanoma, which could provide a template for the development of similar approaches for patients with other immune-responsive cancers in the near future.

Systemic LRG1 Expression in Melanoma is Associated with Disease Progression and Recurrence.

The response rates upon neoadjuvant immune checkpoint blockade (ICB) in stage III melanoma are higher as compared with stage IV disease. Given that successful ICB depends on systemic immune response, we hypothesized that systemic immune suppression might be a mechanism responsible for lower response rates in late-stage disease, and also potentially with disease recurrence in early-stage disease. Plasma and serum samples of cohorts of patients with melanoma were analyzed for circulating proteins using mass spectrometry proteomic profiling and Olink proteomic assay. A cohort of paired samples of patients with stage III that progressed to stage IV disease (n = 64) was used to identify markers associated with higher tumor burden. Baseline patient samples from the OpACIN-neo study (n = 83) and PRADO study (n = 49; NCT02977052) were used as two independent cohorts to analyze whether the potential identified markers are also associated with disease recurrence after neoadjuvant ICB therapy. When comparing baseline proteins overlapping between patients with progressive disease and patients with recurrent disease, we found leucine-rich alpha-2-glycoprotein 1 (LRG1) to be associated with worse prognosis. Especially nonresponder patients to neoadjuvant ICB (OpACIN-neo) with high LRG1 expression had a poor outcome with an estimated 36-month event-free survival of 14% as compared with 83% for nonresponders with a low LRG1 expression (P = 0.014). This finding was validated in an independent cohort (P = 0.0021). LRG1 can be used as a biomarker to identify patients with high risk for disease progression and recurrence, and might be a target to be combined with neoadjuvant ICB. Significance: LRG1 could serve as a potential target and as a biomarker to identify patients with high risk for disease recurrence, and consequently benefit from additional therapies and intensive follow-up.

IFN-γ signature enables selection of neoadjuvant treatment in patients with stage III melanoma.

Neoadjuvant ipilimumab + nivolumab has demonstrated high pathologic response rates in stage III melanoma. Patients with low intra-tumoral interferon-γ (IFN-γ) signatures are less likely to benefit. We show that domatinostat (a class I histone deacetylase inhibitor) addition to anti-PD-1 + anti-CTLA-4 increased the IFN-γ response and reduced tumor growth in our murine melanoma model, rationalizing evaluation in patients. To stratify patients into IFN-γ high and low cohorts, we developed a baseline IFN-γ signature expression algorithm, which was prospectively tested in the DONIMI trial. Patients with stage III melanoma and high intra-tumoral IFN-γ scores were randomized to neoadjuvant nivolumab or nivolumab + domatinostat, while patients with low IFN-γ scores received nivolumab + domatinostat or ipilimumab + nivolumab + domatinostat. Domatinostat addition to neoadjuvant nivolumab ± ipilimumab did not delay surgery but induced unexpected severe skin toxicity, hampering domatinostat dose escalation. At studied dose levels, domatinostat addition did not increase treatment efficacy. The baseline IFN-γ score adequately differentiated patients who were likely to benefit from nivolumab alone versus patients who require other therapies.

Dataset of a retrospective multicenter cohort study on characteristics of immune checkpoint inhibitor-induced encephalitis and comparison with HSV-1 and anti-LGI1 encephalitis.

Over the past decade, cancer immunotherapy with immune checkpoint inhibitors (ICIs) has significantly improved the outcome of many malignancies. However, with the broad use of ICIs, neurological immune related adverse events (irAE) are increasingly recognized. ICI-induced encephalitis (ICI-iE) is a particularly severe irAE, often leading to treatment termination, long-term sequalae or death. Despite its high morbidity and mortality, data on clinical features and diagnostic criteria are limited. We aimed to define clinical, radiologic and laboratory characteristics of ICI-iE and identify factors that discriminate it from anti-leucine-rich glioma-inactivated (anti-LGI)-1 encephalitis and herpes simplex virus (HSV)-1 encephalitis - two alternative causes of encephalitis - to increase the awareness of ICI-iE and improve its diagnosis and management. To that end, we retrospectively collected 30 cases of ICI-iE that were reported to the Side Effect Registry Immuno-Oncology (SERIO) and 46 cases of anti-LGI1 encephalitis or herpes simplex virus (HSV)-1 encephalitis that presented to a large German neurological referral center (Charité Universitätsmedizin Berlin) between January 2015 and September 2021. Signs and symptoms, imaging and electroencephalogram features, laboratory findings and outcome measures were assessed using standardized case report forms as well as patients' medical records and compared between the groups. The data reported here represents the largest primary cohort of patients with ICI-iE to date and the first comparison with other types of encephalitis. As all three disorders - ICI-iE, HSV-1 encephalitis and anti-LGI1 encephalitis - are rare neurological entities, this dataset can be used as a reference in future clinical studies on ICI-induced neurotoxicity, neurological autoimmune disorders, and central nervous system infections.

Real-world outcomes with ipilimumab and nivolumab in advanced melanoma: a multicentre retrospective study.

PURPOSE: To assess efficacy and toxicity of combination immunotherapy with ipilimumab plus nivolumab in routine practice in a retrospective multicentre cohort of patients with advanced melanoma. PATIENTS AND METHODS: This retrospective analysis included patients with advanced melanoma treated with ipilimumab and nivolumab between October 2015 and January 2020 at six centres in Australia, Europe and the United States of America. We describe efficacy outcomes (overall survival [OS], progression-free survival [PFS] and objective response rate [ORR]) in treatment-naïve and pre-treated patients, with and without brain metastases, plus treatment-related adverse events (trAEs) in all patients treated. RESULTS: A total of 697 patients were identified; 472 were treatment-naïve of which 138 (29.2%) had brain metastases, and 225 were previously treated of which 102 (45.3%) had brain metastases. At baseline, 32.3% had stage M1c and 34.4% stage M1d disease. Lactate dehydrogenase was high in 280 patients (40.2%). With a median follow-up of 25.9 months, median OS in the 334 treatment-naïve patients without brain metastases was 53.7 months (95% confidence interval [CI] 40.8-NR) and 38.7 months (95% CI 18.6-NR) for the 138 treatment-naïve patients with brain metastases. For the entire cohort the ORR was 48%, for treatment-naïve patients without brain metastases ORR was 56.6% with a median PFS of was 13.7 months (95% CI 9.6-26.5). Median PFS was 7.9 months (95% CI 5.8-10.4) and OS 38 months (95% CI 31-NR) for the entire cohort. Grade 3-4 trAE were reported in 44% of patients, and 4 (0.7%) treatment-related deaths (1 pneumonitis, 2 myocarditis and 1 colitis) were recorded. CONCLUSION: The outcome and toxicity of combination immunotherapy with ipilimumab and nivolumab in a real-world patient population are similar to those reported in pivotal trials.

Diet-driven microbial ecology underpins associations between cancer immunotherapy outcomes and the gut microbiome.

The gut microbiota shapes the response to immune checkpoint inhibitors (ICIs) in cancer, however dietary and geographic influences have not been well-studied in prospective trials. To address this, we prospectively profiled baseline gut (fecal) microbiota signatures and dietary patterns of 103 trial patients from Australia and the Netherlands treated with neoadjuvant ICIs for high risk resectable metastatic melanoma and performed an integrated analysis with data from 115 patients with melanoma treated with ICIs in the United States. We observed geographically distinct microbial signatures of response and immune-related adverse events (irAEs). Overall, response rates were higher in Ruminococcaceae-dominated microbiomes than in Bacteroidaceae-dominated microbiomes. Poor response was associated with lower fiber and omega 3 fatty acid consumption and elevated levels of C-reactive protein in the peripheral circulation at baseline. Together, these data provide insight into the relevance of native gut microbiota signatures, dietary intake and systemic inflammation in shaping the response to and toxicity from ICIs, prompting the need for further studies in this area.

Characteristics of immune checkpoint inhibitor-induced encephalitis and comparison with HSV-1 and anti-LGI1 encephalitis: A retrospective multicentre cohort study.

AIM: Immune checkpoint inhibitor-induced encephalitis (ICI-iE) is a rare but life-threatening toxicity of immune checkpoint inhibitor treatment. We aim to identify the characteristics of ICI-iE and describe factors that discriminate it from herpes simplex virus (HSV)-1 encephalitis and anti-leucine-rich glioma-inactivated 1 (anti-LGI1) encephalitis, as two alternative entities of encephalitis. METHODS: In this retrospective multicentre cohort study, we collected patients with ICI-iE reported to the Side Effect Registry Immuno-Oncology from January 2015 to September 2021 and compared their clinical features and outcome with 46 consecutive patients with HSV-1 or anti-LGI1 encephalitis who were treated at a German neurological referral centre. RESULTS: Thirty cases of ICI-iE, 25 cases of HSV-1 encephalitis and 21 cases of anti-LGI1 encephalitis were included. Clinical presentation of ICI-iE was highly variable and resembled that of HSV-1 encephalitis, while impairment of consciousness (66% vs. 5%, p = .007), confusion (83% vs. 43%; p = .02), disorientation (83% vs. 29%; p = .007) and aphasia (43% vs. 0%; p = .007) were more common in ICI-iE than in anti-LGI1 encephalitis. Antineuronal antibodies (17/18, 94%) and MRI (18/30, 60%) were mostly negative in ICI-iE, but cerebrospinal fluid (CSF) showed pleocytosis and/or elevated protein levels in almost all patients (28/29, 97%). Three patients (10%) died of ICI-iE. Early immunosuppressive treatment was associated with better outcome (r = 0.43). CONCLUSIONS: ICI-iE is a heterogeneous entity without specific clinical features. CSF analysis has the highest diagnostic value, as it reveals inflammatory changes in most patients and enables the exclusion of infection. Early treatment of ICI-iE is essential to prevent sequelae and death.

Efficacy of anti-PD-1 and ipilimumab alone or in combination in acral melanoma.

BACKGROUND: Acral melanoma is a rare melanoma subtype with poor prognosis. Importantly, these patients were not identified as a specific subgroup in the landmark melanoma trials involving ipilimumab and the anti-programmed cell death protein-1 (PD-1) agents nivolumab and pembrolizumab. There is therefore an absence of prospective clinical trial evidence regarding the efficacy of checkpoint inhibitors (CPIs) in this population. Acral melanoma has lower tumor mutation burden (TMB) than other cutaneous sites, and primary site is associated with differences in TMB. However the impact of this on the effectiveness of immune CPIs is unknown. We examined the efficacy of CPIs in acral melanoma, including by primary site. METHODS: Patients with unresectable stage III/IV acral melanoma treated with CPI (anti-PD-1 and/or ipilimumab) were studied. Multivariable logistic and Cox regression analyses were conducted. Primary outcome was objective response rate (ORR); secondary outcomes were progression-free survival (PFS) and overall survival (OS). RESULTS: In total, 325 patients were included: 234 (72%) plantar, 69 (21%) subungual and 22 (7%) palmar primary sites. First CPI included: 184 (57%) anti-PD-1, 59 (18%) anti-PD-1/ipilimumab combination and 82 (25%) ipilimumab. ORR was significantly higher with initial anti-PD-1/ipilimumab compared with anti-PD-1 (43% vs 26%, HR 2.14, p=0.0004) and significantly lower with ipilimumab (15% vs 26%, HR 0.49, p=0.0016). Landmark PFS at 1 year was highest for anti-PD-1/ipilimumab at 34% (95% CI 24% to 49%), compared with 26% (95% CI 20% to 33%) with anti-PD-1 and 10% (95% CI 5% to 19%) with ipilimumab. Despite a trend for increased PFS, anti-PD-1/ipilimumab combination did not significantly improve PFS (HR 0.85, p=0.35) or OS over anti-PD-1 (HR 1.30, p=0.16), potentially due to subsequent therapies and high rates of acquired resistance. No outcome differences were found between primary sites. CONCLUSION: While the ORR to anti-PD-1/ipilimumab was significantly higher than anti-PD-1 and PFS numerically higher, in this retrospective cohort this benefit did not translate to improved OS. Future trials should specifically include patients with acral melanoma, to help determine the optimal management of this important melanoma subtype.

Diagnostic performance of early increase in S100B or LDH as outcome predictor for non-responsiveness to anti-PD-1 monotherapy in advanced melanoma.

As a subset of advanced melanoma patients derive long-term benefit from anti-PD-1 therapy, early identification of non-responsiveness would enable an early switch to next line therapies. This study assessed if an early increase in S100B or lactate dehydrogenase (LDH) could be predictive for non-responsiveness to anti-PD-1. We retrospectively analysed advanced melanoma patients treated with anti-PD-1 monotherapy. Serum S100B and LDH levels were measured at baseline and before every infusion. Non-response was defined as progression or death at 6 months. Marker cut-offs were defined based on > 95% specificity and feasibility in clinical practice. For validation an independent cohort was analysed. In total, 313 patients were included (166 patients in training cohort, 147 patients in validation cohort). Increase of > 50% in LDH or > 100% in S100B above upper limit of normal at week 6 compared to baseline was determined as criterion to positively test for non-responsiveness. In the validation cohort, obtained specificity of the combination test was > 95% with a positive predictive value of 82%; obtained sensitivity was lower (21%), with a negative predictive value of 55%. Early increase in S100B or LDH is a strong parameter for non-responsiveness to anti-PD-1 in advanced melanoma. Prospective confirmation is needed before clinical implementation.

Personalized response-directed surgery and adjuvant therapy after neoadjuvant ipilimumab and nivolumab in high-risk stage III melanoma: the PRADO trial.

Neoadjuvant ipilimumab and nivolumab induces high pathologic response rates (pRRs) in clinical stage III nodal melanoma, and pathologic response is strongly associated with prolonged relapse-free survival (RFS). The PRADO extension cohort of the OpACIN-neo trial ( NCT02977052 ) addressed the feasibility and effect on clinical outcome of using pathologic response after neoadjuvant ipilimumab and nivolumab as a criterion for further treatment personalization. In total, 99 patients with clinical stage IIIb-d nodal melanoma were included and treated with 6 weeks of neoadjuvant ipilimumab 1 mg kg-1 and nivolumab 3 mg kg-1. In patients achieving major pathologic response (MPR, ≤10% viable tumor) in their index lymph node (ILN, the largest lymph node metastasis at baseline), therapeutic lymph node dissection (TLND) and adjuvant therapy were omitted. Patients with pathologic partial response (pPR; >10 to ≤50% viable tumor) underwent TLND only, whereas patients with pathologic non-response (pNR; >50% viable tumor) underwent TLND and adjuvant systemic therapy ± synchronous radiotherapy. Primary objectives were confirmation of pRR (ILN, at week 6) of the winner neoadjuvant combination scheme identified in OpACIN-neo; to investigate whether TLND can be safely omitted in patients achieving MPR; and to investigate whether RFS at 24 months can be improved for patients achieving pNR. ILN resection and ILN-response-tailored treatment were feasible. The pRR was 72%, including 61% MPR. Grade 3-4 toxicity within the first 12 weeks was observed in 22 (22%) patients. TLND was omitted in 59 of 60 patients with MPR, resulting in significantly lower surgical morbidity and better quality of life. The 24-month relapse-free survival and distant metastasis-free survival rates were 93% and 98% in patients with MPR, 64% and 64% in patients with pPR, and 71% and 76% in patients with pNR, respectively. These findings provide a strong rationale for randomized clinical trials testing response-directed treatment personalization after neoadjuvant ipilimumab and nivolumab.

Clinical Models to Define Response and Survival With Anti-PD-1 Antibodies Alone or Combined With Ipilimumab in Metastatic Melanoma.

PURPOSE: Currently, there are no robust biomarkers that predict immunotherapy outcomes in metastatic melanoma. We sought to build multivariable predictive models for response and survival to anti-programmed cell death protein 1 (anti-PD-1) monotherapy or in combination with anticytotoxic T-cell lymphocyte-4 (ipilimumab [IPI]; anti-PD-1 ± IPI) by including routine clinical data available at the point of treatment initiation. METHODS: One thousand six hundred forty-four patients with metastatic melanoma treated with anti-PD-1 ± IPI at 16 centers from Australia, the United States, and Europe were included. Demographics, disease characteristics, and baseline blood parameters were analyzed. The end points of this study were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The final predictive models for ORR, PFS, and OS were determined through penalized regression methodology (least absolute shrinkage and selection operator method) to select the most significant predictors for all three outcomes (discovery cohort, N = 633). Each model was validated internally and externally in two independent cohorts (validation-1 [N = 419] and validation-2 [N = 592]) and nomograms were created. RESULTS: The final model for predicting ORR (area under the curve [AUC] = 0.71) in immunotherapy-treated patients included the following clinical parameters: Eastern Cooperative Oncology Group Performance Status, presence/absence of liver and lung metastases, serum lactate dehydrogenase, blood neutrophil-lymphocyte ratio, therapy (monotherapy/combination), and line of treatment. The final predictive models for PFS (AUC = 0.68) and OS (AUC = 0.77) included the same variables as those in the ORR model (except for presence/absence of lung metastases), and included presence/absence of brain metastases and blood hemoglobin. Nomogram calculators were developed from the clinical models to predict outcomes for patients with metastatic melanoma treated with anti-PD-1 ± IPI. CONCLUSION: Newly developed combinations of routinely collected baseline clinical factors predict the response and survival outcomes of patients with metastatic melanoma treated with immunotherapy and may serve as valuable tools for clinical decision making.

The role of local therapy in the treatment of solitary melanoma progression on immune checkpoint inhibition: A multicentre retrospective analysis.

INTRODUCTION: In patients with metastatic melanoma, progression of a single tumour lesion (solitary progression) after response to immune checkpoint inhibition (ICI) is increasingly treated with local therapy. We evaluated the role of local therapy for solitary progression in melanoma. PATIENTS AND METHODS: Patients with metastatic melanoma treated with ICI between 2010 and 2019 with solitary progression as first progressive event were included from 17 centres in 9 countries. Follow-up and survival are reported from ICI initiation. RESULTS: We identified 294 patients with solitary progression after stable disease in 15%, partial response in 55% and complete response in 30%. The median follow-up was 43 months; the median time to solitary progression was 13 months, and the median time to subsequent progression after treatment of solitary progression (TTSP) was 33 months. The estimated 3-year overall survival (OS) was 79%; median OS was not reached. Treatment consisted of systemic therapy (18%), local therapy (36%), both combined (42%) or active surveillance (4%). In 44% of patients treated for solitary progression, no subsequent progression occurred. For solitary progression during ICI (n = 143), the median TTSP was 29 months. Both TTSP and OS were similar for local therapy, ICI continuation and both combined. For solitary progression post ICI (n = 151), the median TTSP was 35 months. TTSP was higher for ICI recommencement plus local therapy than local therapy or ICI recommencement alone (p = 0.006), without OS differences. CONCLUSION: Almost half of patients with melanoma treated for solitary progression after initial response to ICI had no subsequent progression. This study suggests that local therapy can benefit patients and is associated with favourable long-term outcomes.

Neoadjuvant ipilimumab plus nivolumab in synchronous clinical stage III melanoma.

BACKGROUND: Patients with synchronous clinical stage III melanoma can present with primary melanoma lesions, locally recurrent melanoma or in-transit metastases. Neoadjuvant ipilimumab plus nivolumab induces high pathologic response rates and an impressive relapse-free survival in patients with nodal macroscopic stage III melanoma. Whether primary site melanoma and in-transit metastases respond similarly to lymph node metastases with neoadjuvant immunotherapy is largely unknown. Such data would clarify whether surgical excision of these melanoma lesions should be performed before neoadjuvant therapy or whether it could be deferred and performed in conjunction with lymphadenectomy following neoadjuvant immunotherapy. PATIENTS: Patients with synchronous clinical stage III melanoma were identified from the OpACIN, OpACIN-neo and PRADO neoadjuvant trials, where all patients were treated with ipilimumab plus nivolumab. An additional case treated outside those clinical trials was included. RESULTS: Seven patients were identified; six patients had a concordant response in primary site melanoma lesions or in-transit metastasis and the lymph node metastases. One patient had concordant progression in both the primary and nodal tumour lesions and developed stage IV disease during neoadjuvant treatment, and thus, no resection was performed. CONCLUSION: Pathologic response following neoadjuvant ipilimumab plus nivolumab in primary site melanoma lesions or in-transit metastasis is concordant with a response in the lymph node metastases, indicating that there may be no need to perform upfront surgery to these melanoma lesions prior to neoadjuvant treatment.

Melanoma recurrence patterns and management after adjuvant targeted therapy: a multicentre analysis.

BACKGROUND: Adjuvant targeted therapy (TT) improves relapse free survival in patients with resected BRAF mutant stage III melanoma. The outcomes and optimal management of patients who relapse after adjuvant TT is unknown. METHODS: Patients from twenty-one centres with recurrent melanoma after adjuvant TT were included. Disease characteristics, adjuvant therapy, recurrence, treatment at relapse and outcomes were examined. RESULTS: Eighty-five patients developed recurrent melanoma; nineteen (22%) during adjuvant TT. Median time to first recurrence was 18 months and median follow-up from first recurrence was 31 months. Fifty-eight (68%) patients received immunotherapy (IT) or TT as 1st line systemic therapy at either first or subsequent recurrence and had disease that was assessable for response. Response to anti-PD-1 (±trial agent), combination ipilimumab-nivolumab, TT rechallenge and ipilimumab monotherapy was 63%, 62% 25% and 10% respectively. Twenty-eight (33%) patients had died at census, all from melanoma. Two-year OS was 84% for anti-PD-1 therapy (±trial agent), 92% for combination ipilimumab and nivolumab, 49% for TT and 45% for ipilimumab monotherapy (p = 0.028). CONCLUSIONS: Patients who relapse after adjuvant TT respond well to subsequent anti-PD-1 based therapy and have outcomes similar to those seen when first line anti-PD-1 therapy is used in stage IV melanoma.

Rationalizing the pathway to personalized neoadjuvant immunotherapy: the Lombard Street Approach.

Neoadjuvant chemo(radio)therapy is part of the established standard of care in cancer treatment; neoadjuvant application of immunotherapy, however, is only performed within recent trials. Combination of programmed cell death protein 1 and cytotoxic T lymphocyte antigen 4 blockade shows promising results with high pathologic response rates in the neoadjuvant setting and a very low relapse rate in the responding patients. In addition, neoadjuvant administration allows direct determination of treatment efficacy within the individual patient, and offers easy access to paired tumor material, both pretherapy and post-therapy, thus facilitates the rational development of new combinations driven by preclinical analyses. Patient-derived human tumor explant systems such as a recently developed human patient-derived tumor fragment platform can provide an additional tool to further rationalize the development of new treatment combinations. We will discuss neoadjuvant immunotherapy as a unique opportunity for rational trial design, the development of immune signatures for non-responding patients to steer clinical trial development, and the use of patient-derived ex vivo models to identify new personalized immunotherapy combinations. In this context, we propose the 'Lombard Street Approach', a back and forth approach of characterizing non-responders on neoadjuvant immunotherapy combinations, identifying promising new combinations for this group in the tumor fragment platform, and performing subsequently signature-driven small proof-of-concept combination trials. Repeating this approach with smaller and smaller groups of non-responders will step by step increase the percentage of patients benefiting from neoadjuvant immunotherapy in a rational and fast manner.

Learning from clinical trials of neoadjuvant checkpoint blockade.

Neoadjuvant checkpoint inhibition, in which the therapy is administered before surgery, is a promising new approach to managing bulky but resectable melanoma, and is also being explored in other cancers. This strategy has a high pathologic response rate, which correlates with survival outcomes. The fact that biopsies are routinely available provides a unique opportunity for understanding the responses to therapy and carrying out reverse translation in which these data are used to select therapies in the clinic or in trials that are more likely to improve patient outcomes. In this Perspective, we discuss the rationale for neoadjuvant immunotherapy in resectable solid tumors based on preclinical and human translational data, summarize the results of recent clinical trials and ongoing research, and focus on future directions for enhancing reverse translation.