Neoadjuvant Pembrolizumab and High-Dose IFNα-2b in Resectable Regionally Advanced Melanoma

Treatment of Stage III Resectable Melanoma-Adjuvant and Neoadjuvant Approaches

ABSTRACT

Patients with stage III resectable melanoma carry a high risk of melanoma recurrence that ranges from approximately 40% to 90% at 5 years following surgical management alone. Postoperative systemic adjuvant therapy targets residual micrometastatic disease that could be the source of future recurrence and death from melanoma. Randomized phase III adjuvant trials reported significant improvements in overall survival with high-dose interferon α in 2 of 3 studies (compared with observation and GMK ganglioside vaccine) and with anti-cytotoxic T-lymphocyte antigen 4 ipilimumab at 10 mg/kg compared with placebo and ipilimumab 3 mg/kg compared with high-dose interferon α. In the modern era, more recent phase III trials demonstrated significant recurrence-free survival improvements with anti-programmed cell death protein 1, pembrolizumab, and BRAF-MEK inhibitor combination dabrafenib-trametinib (for BRAF mutant melanoma) versus placebo. Furthermore, anti-programmed cell death protein 1, nivolumab and pembrolizumab have both been shown to significantly improve recurrence-free survival as compared with ipilimumab 10 mg/kg. For melanoma patients with clinically or radiologically detectable locoregionally advanced disease, emerging data support an important role for preoperative systemic neoadjuvant therapy. Importantly, a recent cooperative group trial (S1801) reported superior event-free survival rates with neoadjuvant versus adjuvant therapy. Collectively, current data from neoadjuvant immunotherapy and targeted therapy trials support a future change in clinical practice in favor of neoadjuvant therapy for eligible melanoma patients.

Educational Review: Clinical Application of Immune Checkpoint Blockade for the Treatment of Melanoma

In the last decade, immunotherapy has become the cornerstone in the management of patients with melanoma, the foremost cause of skin-cancer-related death in the USA. The emergence of immune checkpoint blockade as a crucial element in current immunotherapy and combination strategies has significantly transformed the treatments of resectable and advanced (unresectable or metastatic) melanoma. This paper reviews the landmark clinical trials that formed the basis of management of melanoma in the perioperative and metastatic setting. Furthermore, we discuss the rationale for the applications of PD-1 blockade and its combination with anti-CTLA-4 and anti-LAG-3. The review also explores new experimental combinations of PD-1 blockade with other immunomodulatory agents, including targeted therapies, anti-TIGIT antibodies, TLR-9 agonists, antiangiogenic agents, and mRNA vaccines.

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

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

Biomarker-Driven Personalization of Neoadjuvant Immunotherapy in Melanoma

The introduction of immunotherapy has ushered in a new era of anticancer therapy for many cancer types including melanoma. Given the increasing development of novel compounds and combinations and the investigation in earlier disease stages, the need grows for biomarker-based treatment personalization. Stage III melanoma is one of the front-runners in the neoadjuvant immunotherapy field, facilitating quick biomarker identification by its immunogenic capacity, homogeneous patient population, and reliable efficacy readout. In this review, we discuss potential biomarkers for response prediction to neoadjuvant immunotherapy, and how the neoadjuvant melanoma platform could pave the way for biomarker identification in other tumor types.

SIGNIFICANCE

In accordance with the increasing rate of therapy development, the need for biomarker-driven personalized treatments grows. The current landscape of neoadjuvant treatment and biomarker development in stage III melanoma can function as a poster child for these personalized treatments in other tumors, assisting in the development of new biomarker-based neoadjuvant trials. This will contribute to personalized benefit-risk predictions to identify the most beneficial treatment for each patient.

Antitumor activity of pegylated human interferon β as monotherapy or in combination with immune checkpoint inhibitors via tumor growth inhibition and dendritic cell activation

Type I interferons (IFN), especially human IFN alpha (IFNα), have been utilized for antitumor therapy for decades. Human interferon beta (IFNβ) is rarely used for cancer treatment, despite advantages over IFNα in biological activities such as tumor growth inhibition and dendritic cell (DC) activation. The utilization of pegylated human IFNβ (PEG-IFNβ), as monotherapy or in combination with immune checkpoint inhibitors (ICIs) was evaluated in this study through in vivo efficacy studies in syngeneic mouse melanoma, non-small cell lung cancer (NSCLC), and colon adenocarcinoma (COAD) models resistant to immune checkpoint inhibitors (ICIs). In vitro comparative study of PEG-IFNβ and pegylated IFNα-2b was performed in terms of tumor growth inhibition against human melanoma, NSCLC and COAD cell lines and activation of human monocyte-derived DCs (MoDCs). Our data demonstrate that the in vivo antitumor effects of PEG-IFNβ are partially attributable to tumor growth-inhibitory effects and DC-activating activities, superior to pegylated IFNα-2b. Our findings suggest that utilizing PEG-IFNβ as an antitumor therapy can enhance the therapeutic effect of ICIs in ICI-resistant tumors by directly inhibiting tumor growth and induction of DC maturation.

Long-term outcomes to neoadjuvant pembrolizumab based on pathological response for patients with resectable stage III/IV cutaneous melanoma

BACKGROUND

While neoadjuvant immunotherapy for melanoma has shown promising results, the data have been limited by a relatively short follow-up time, with most studies reporting 2-year outcomes. The goal of this study was to determine long-term outcomes for stage III/IV melanoma patients treated with neoadjuvant and adjuvant programmed cell death receptor 1 (PD-1) inhibition.

PATIENTS AND METHODS

This is a follow-up study of a previously published phase Ib clinical trial of 30 patients with resectable stage III/IV cutaneous melanoma who received one dose of 200 mg IV neoadjuvant pembrolizumab 3 weeks before surgical resection, followed by 1 year of adjuvant pembrolizumab. The primary outcomes were 5-year overall survival (OS), 5-year recurrence-free survival (RFS), and recurrence patterns.

RESULTS

We report updated results at 5 years of follow-up with a median follow-up of 61.9 months. No deaths occurred in patients with a major pathological response (MPR, <10% viable tumor) or complete pathological response (pCR, no viable tumor) (n = 8), compared to a 5-year OS of 72.8% for the remainder of the cohort (P = 0.12). Two of eight patients with a pCR or MPR had a recurrence. Of the patients with >10% viable tumor remaining, 8 of 22 patients (36%) had a recurrence. Additionally, the median time to recurrence was 3.9 years for patients with ≤10% viable tumor and 0.6 years for patients with >10% viable tumor (P = 0.044).

CONCLUSIONS

The 5-year results from this trial represent the longest follow-up of a single-agent neoadjuvant PD-1 trial to date. Response to neoadjuvant therapy continues to be an important prognosticator with regard to OS and RFS. Additionally, recurrences in patients with pCR occur later and are salvageable, with a 5-year OS of 100%. These results demonstrate the long-term efficacy of single-agent neoadjuvant/adjuvant PD-1 blockade in patients with a pCR and the importance of long-term follow-up for these patients.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT02434354.

Clinical updates in neoadjuvant immunotherapy for melanoma before surgery

INTRODUCTION

Locoregionally advanced melanoma represents a large group of high-risk melanoma patients at presentation and poses major challenges in relation to management and the risks of relapse and death.

AREAS COVERED

Melanoma systemic therapy has undergone substantial advancements with the advent of immune checkpoint inhibitors and molecularly targeted therapies, which have been translated to the neoadjuvant setting for the management of locoregionally advanced disease. Notably, PD1 blockade as monotherapy, in combination with CTLA4 blockade or LAG3 inhibition, has demonstrated significant progress in reducing the risk of relapse and mortality, attributed to high pathologic response rates. Likewise, BRAF-MEK inhibition for BRAF mutant melanoma has yielded comparable outcomes, albeit with lower response durability than immunotherapy. Localized intralesional therapies such as Talimogene laherparepvec (T-VEC) and Tavokinogene Telseplasmid (TAVO) electro-gene-transfer combined with anti-PD1 have demonstrated favorable pathologic responses and increased immune activation. Most importantly, the S1801 randomized trial has demonstrated for the first time the advantage of the neoadjuvant approach over standard surgery followed by adjuvant therapy.

EXPERT OPINION

Current evidence supports neoadjuvant therapy as a standard of care for locoregionally advanced melanoma. Ongoing research will define the optimal regimens and the biomarkers of therapeutic predictive and prognostic value.

Combining PD-1/PD-L1 blockade with type I interferon in cancer therapy

PD-1 and PD-L1 are crucial regulators of immunity expressed on the surface of T cells and tumour cells, respectively. Cancer cells frequently use PD-1/PD-L1 to evade immune detection; hence, blocking them exposes tumours to be attacked by activated T cells. The synergy of PD-1/PD-L1 blockade with type I interferon (IFN) can improve cancer treatment efficacy. Type I IFN activates immune cells boosts antigen presentation and controls proliferation. In addition, type I IFN increases tumour cell sensitivity to the blockade. Combining the two therapies increases tumoral T cell infiltration and activation within tumours, and stimulate the generation of memory T cells, leading to prolonged patient survival. However, limitations include heterogeneous responses, the need for biomarkers to predict and monitor outcomes, and adverse effects and toxicity. Although treatment resistance remains an obstacle, the combined therapeutic efficacy of IFNα/β and PD-1/PD-L1 blockade demonstrated considerable benefits across a spectrum of cancer types, notably in melanoma. Overall, the phases I and II clinical trials have demonstrated safety and efficiency. In future, further investigations in clinical trials phases III and IV are essential to compare this combinatorial treatment with standard treatment and assess long-term side effects in patients.

PD‑1/PD‑L1 immune checkpoint inhibitors in neoadjuvant therapy for solid tumors (Review)

A comprehensive search regarding programmed cell death protein 1 (PD‑1)/programmed death‑ligand 1 (PD‑L1) inhibitor monotherapy or combination therapy in neoadjuvant settings of 11 types of solid cancer was performed using the PubMed, Cochrane and Embase databases, and the abstracts of various conferences were screened. Data presented in 99 clinical trials indicated that preoperative treatment with PD‑1/PD‑L1 combined therapy, particularly immunotherapy plus chemotherapy, could achieve a higher objective response rate, a higher major pathologic response rate and a higher pathologic complete response rate, as well as a lower number of immune‑related adverse events compared with PD‑1/PD‑L1 monotherapy or dual immunotherapy. Although PD‑1/PD‑L1 inhibitor combination caused more treatment‑related adverse events (TRAEs) in patients, most of the TRAEs were acceptable and did not cause marked delays in operation. The data suggest that patients with pathological remission after neoadjuvant immunotherapy exhibit improved postoperative disease‑free survival compared with those without pathological remission. Further studies are still required to evaluate the long‑term survival benefit of neoadjuvant immunotherapy.

Neoadjuvant Therapy in Melanoma: Where Are We Now?

PURPOSEOF REVIEW

This review summarizes the current state of neoadjuvant immunotherapy and targeted therapy for locoregionally advanced melanoma.

RECENT FINDINGS

Melanoma systemic therapy has witnessed major advances with the development of immune checkpoint inhibitors and molecularly targeted therapy that have been translated into the neoadjuvant setting in managing locoregionally advanced disease. PD1 blockade as monotherapy and combined with CTLA4 blockade or LAG3 inhibition has demonstrated major improvements in reducing the risk of relapse and death that were associated with high pathologic response rates. Similar results were reported with BRAF-MEK inhibition for BRAF mutant melanoma with high pathologic response rates that appear to be less durable compared to immunotherapy. More importantly, in a recent randomized trial, event-free survival was significantly improved with neoadjuvant pembrolizumab compared to standard surgery and adjuvant therapy. Neoadjuvant therapy has become the standard of care for locoregionally advanced melanoma. Ongoing studies will define the most optimal combination regimens.

Systemic adjuvant therapy for high-risk cutaneous melanoma

Cutaneous melanoma continues to increase in incidence and poses a significant mortality risk. Surgical excision of melanoma in its early stages is often curative. However, patients with resected stages IIB-IV are considered at high risk for relapse and death from melanoma where systemic adjuvant therapy is indicated. The long-studied high-dose interferon-α was shown to improve relapse-free survival (RFS) and overall survival (OS) but is no longer in use. Adjuvant therapy with ipilimumab at 10 mg/kg (ipi10) demonstrated significant RFS and OS improvements but at a high cost in terms of toxicity, while adjuvant ipilimumab 3 mg/kg was shown to be equally effective and less toxic. More recently, the adjuvant therapy for resected stages III-IV melanoma in clinical practice has changed in favor of nivolumab, pembrolizumab, and BRAF-MEK inhibitors dabrafenib plus trametinib (for BRAF mutant melanoma) based on significant improvements in RFS as compared to ipi10 (nivolumab and pembrolizumab) and placebo (dabrafenib plus trametinib). For resected stages IIB-IIC melanoma, pembrolizumab achieved regulatory approval in the United States based on significant RFS benefits. In this article, we review completed and ongoing phase III adjuvant therapy trials. We also briefly discuss neoadjuvant therapy for locoregionally advanced melanoma. Finally, we explore recent studies on predictive and prognostic melanoma biomarkers in the adjuvant setting.

Neoadjuvant immunotherapy of locoregionally advanced solid tumors

Definitive management of locoregionally advanced solid tumors presents a major challenge and often consists of a combination of surgical, radiotherapeutic and systemic therapy approaches. Upfront surgical treatment with or without adjuvant radiotherapy carries the risks of significant morbidities and potential complications that could be lasting. In addition, these patients continue to have a high risk of local or distant disease relapse despite the use of standard adjuvant therapy. Preoperative neoadjuvant systemic therapy has the potential to significantly improve clinical outcomes, particularly in this era of expanding immunotherapeutic agents that have transformed the care of patients with metastatic/unresectable malignancies. Tremendous progress has been made with neoadjuvant immunotherapy in the treatment of several locoregionally advanced resectable solid tumors leading to ongoing phase 3 trials and change in clinical practice. The promise of neoadjuvant immunotherapy has been supported by the high pathologic tumor response rates in early trials as well as the durability of these responses making cure a more achievable potential outcome compared with other forms of systemic therapy. Furthermore, neoadjuvant studies allow the assessment of radiologic and pathological responses and the access to biospecimens before and during systemic therapy. Pathological responses may guide future treatment decisions, and biospecimens allow the conduct of mechanistic and biomarker studies that may guide future drug development. On behalf of the National Cancer Institute Early Drug Development Neoadjuvant Immunotherapy Working Group, this article summarizes the current state of neoadjuvant immunotherapy of solid tumors focusing primarily on locoregionally advanced melanoma, gynecologic malignancies, gastrointestinal malignancies, non-small cell lung cancer and head and neck cancer including recent advances and our expert recommendations related to future neoadjuvant trial designs and associated clinical and translational research questions.

Molecular imaging to support cancer immunotherapy

The advent of immune checkpoint inhibitors has reinvigorated the field of immuno-oncology. These monoclonal antibody-based therapies allow the immune system to recognize and eliminate malignant cells. This has resulted in improved survival of patients across several tumor types. However, not all patients respond to immunotherapy therefore predictive biomarkers are important. There are only a few Food and Drug Administration-approved biomarkers to select patients for immunotherapy. These biomarkers do not consider the heterogeneity of tumor characteristics across lesions within a patient. New molecular imaging tracers allow for whole-body visualization with positron emission tomography (PET) of tumor and immune cell characteristics, and drug distribution, which might guide treatment decision making. Here, we summarize recent developments in molecular imaging of immune checkpoint molecules, such as PD-L1, PD-1, CTLA-4, and LAG-3. We discuss several molecular imaging approaches of immune cell subsets and briefly summarize the role of FDG-PET for evaluating cancer immunotherapy. The main focus is on developments in clinical molecular imaging studies, next to preclinical studies of interest given their potential translation to the clinic.

Educational Review: Neoadjuvant Approaches to Melanoma

BACKGROUND

With the development of novel systemic therapies, the treatment of patients with melanoma has changed drastically over the past few years, especially with regard to neoadjuvant treatments. Standard of care for patients with resectable stage III/IV melanoma traditionally consisted of surgery, with possible adjuvant treatment. However, there have been promising improvements in patient outcomes with neoadjuvant treatment compared to upfront surgery, specifically with targeted and immune therapies.

METHODS

A review of clinical trials in the neoadjuvant treatment of stage III/IV melanoma was performed.

RESULTS

Multiple phase I-II clinical trials have investigated the utility of interferon, targeted therapies (i.e., BRAF and/or MEK inhibitors) and immune checkpoint inhibitors (i.e., PD-1 or CTLA-4 inhibitors) in the treatment of resectable clinical stage III/IV melanoma. Large strides have been made with regards to optimal treatment strategy and dosing, to maximize clinical and pathologic response rates while minimizing toxicities. Additionally, complete pathologic response to neoadjuvant therapies translates to a disease-free survival benefit. Current and future directions include individualizing surgical and adjuvant therapy based on patient response to neoadjuvant treatments.

CONCLUSIONS

The current evidence, represented by small phase I-II trials, demonstrates advantages to neoadjuvant treatment with targeted or immune therapy for patients with resectable stage III/IV melanoma. Future research is needed to determine the advantages of neoadjuvant compared to adjuvant treatment, and to further refine treatment strategies based on patient response.

Melanoma trials that defined surgical management: Brief overview of current/upcoming adjuvant/neoadjuvant trials

Adjuvant systemic therapy for cutaneous melanoma has experienced practice-changing shifts over the last decade. The successful results of immunotherapies and targeted therapies in the metastatic setting have allowed for investigative trials of the same therapies in the adjuvant and now neoadjuvant setting, with the potential for improved clinical outcomes in patients with high risk resected Stage III and IV melanoma.

Immunohistochemical detection of "ex novo" HLA-DR in tumor cells determines clinical outcome in laryngeal cancer patients

There are controversial results about the role of "ex novo" HLA-DR expression by tumor cells and its correlation with the oncological outcomes. Unfortunately, little is known about HLA-DR expression in laryngeal cancer tumor cells. The main purpose of this retrospective study is to strengthen the usefulness of studying "ex novo" HLA-DR expression on tumor cells from primary laryngeal squamous cell carcinoma (LSCC) patients and investigate its correlation with clinical outcome. We analyzed HLA-DR expression by immunohistochemical analysis in 56 patients with LSCC. The "ex novo" HLA-DR expression on laryngeal cancer tumor cells, assessing non-neoplastic LSCC - adjacent tissue, and the association of HLA-DR expression (HLA-DR+) with clinical outcomes were investigated. HLA-DR+ tumor cells were detected in 18/56 LSCC patients (32.1%). All specimens of non-neoplastic laryngeal carcinoma-adjacent tissue resulted HLA-DR negative (HLA-DR-). A statistically significant association was observed between HLA-DR + and well differentiated tumors (G1) (p<0.001). The Kaplan-Meier method showed how HLA-DR+ is significantly associated with both a better disease specific survival (HLA-DR+=100% vs. HLA-DR-=77.4%; p=0.047) and a better relapse free survival (HLA-DR+=100% vs. HLA-DR-=72.3%; p=0.021). Cox regression univariate analysis for death of disease confirmed a higher HR for HLA-DR absence on the surface of epithelial tumor cell [HR:37.489; 95% CI:0.750-18730.776; p=0.253] and for high-grade (G3) tumors [HR:18.601; 95% CI:3.613-95.764; p<0.0001]. Our results confirm that MHC class II HLA-DR expression is activated in a sub-set of LSCC patients. Evaluation of HLA-DR expression in LSCC could be useful for prognosis and future approaches towards personalized therapy.

Neoadjuvant Immunotherapy in Melanoma - The New Frontier

Neoadjuvant immunotherapy is gathering pace, particularly in melanoma. A recent study of pembrolizumab and HDI not only further supports the safety and activity of neoadjuvant anti-PD-1 based immunotherapy but also highlights neoadjuvant therapy as a solid platform for drug development that is likely to become a standard-of-care in the near future.See related article by Najjar et al., p. 4195.