Efficacy comparison between anti-PD-1 antibody monotherapy and anti-PD-1 plus anti-CTLA-4 combination therapy as first-line immunotherapy for advanced acral melanoma: A retrospective, multicenter study of 254 Japanese patients

Clinical Characteristics and Special Considerations in the Management of Rare Melanoma Subtypes

Rare histologic subtypes of melanoma, including acral, mucosal, uveal, and desmoplastic melanomas, only make up 5% of all diagnosed melanomas and are often underrepresented in large, randomized trials. Recent advancements in systemic therapy have shown marked improvement in pathologic response rates, improving progression-free and overall survival among cutaneous melanoma patients, but there are limited data to demonstrate improved survival among rarer subtypes of melanoma. Acral melanoma has a poor response to immunotherapy and is associated with worse survival. Mucosal melanoma has a large variability in its presentation, a poor prognosis, and a low mutational burden. Uveal melanoma is associated with a high rate of liver metastasis; recent adoption of infusion and perfusion therapies has demonstrated improved survival among these patients. Desmoplastic melanoma, a high-risk cutaneous melanoma, is associated with high locoregional recurrence rates and mutational burden, suggesting this melanoma may have enhanced response to immunotherapy. While these variants of melanoma represent distinct disease entities, this review highlights the clinicopathologic characteristics and treatment recommendations for each of these rare melanomas and highlights the utility of modern therapies for each of them.

Adjuvant treatment with anti-PD-1 in acral melanoma: A nationwide study

Previous studies demonstrated limited efficacy of immune checkpoint inhibitors in unresectable acral melanoma (AM); it remains unclear how this translates to the adjuvant setting. This study investigates clinical outcomes of acral compared to cutaneous melanoma (CM) patients treated with adjuvant anti-PD-1 after complete resection. All stages III-IV AM and CM patients receiving adjuvant anti-PD-1 after complete resection between 2018 and 2022 were included from the prospective nationwide Dutch Melanoma Treatment Registry. We analyzed recurrence-free survival (RFS), distant metastasis-free survival (DMFS), and overall survival (OS). A multivariable Cox regression analysis of RFS was performed to adjust for potential confounders. We included 1958 (86 AM and 1872 CM) patients. At baseline, AM patients more frequently had KIT mutations, higher disease stages, and Eastern Cooperative Oncology Group Performance Status, and fewer BRAF and NRAS mutations. Median RFS was 14.8 months (95% confidence interval [CI]: 11.5-29.3) in AM and 37.4 months (95% CI: 34.6 to not reached) in CM (p = .002). After correcting for potential confounders, AM remained associated with a higher risk of recurrence (HRadj 1.53; 95% CI: 1.07-2.17; p = .019). Two-year DMFS tended to be worse for AM than for CM: 64.5% versus 79.7% (p = .050). Two-year OS was significantly lower in AM (71.5% vs. 84.3%; p = .027). The results of this study suggest a poorer outcome of adjuvant-treated AM compared to CM. Studies assessing the added value of adjuvant treatment in AM are needed. Future research should investigate alternative treatment strategies to improve outcomes of high-risk AM.

Optimal strategy in managing advanced melanoma

The advent of immune checkpoint inhibitors and combination therapy with BRAF inhibitors and MEK inhibitors has dramatically improved the prognosis of advanced melanoma. However, since acral melanoma and mucosal melanoma, which are rare in Western countries but are major subtypes of melanoma in East Asia, including Japan, have a low frequency of BRAF mutations, there are currently no treatment options other than immune checkpoint inhibitors in most such cases. Furthermore, owing to a lower tumor mutation burden, immune checkpoint inhibitors are less effective in acral and mucosal melanoma than in cutaneous melanoma. The aim of this review was to summarize the current status and future prospects for the treatment of advanced melanoma, comparing cutaneous melanoma, acral melanoma, and mucosal melanoma.

Long-term survival with systemic therapy in the last decade: Can melanoma be cured?

Immune checkpoint inhibitors have been shown to prolong survival of patients with several types of cancer, and the finding was first established in melanoma. Previously, systemic therapy for advanced melanoma aimed only at tumor control and palliation of symptoms. However, in recent years, some patients who received systemic therapy have achieved a complete response and survived without continuous treatment for more than several years. This review discusses the long-term survival rates achieved with currently used systemic therapies and their future perspectives. Long-term survival is currently most likely to be achieved with the use of the standard-dose combination of nivolumab plus ipilimumab, however, this regimen is associated with a high frequency of serious or persistent immune-related adverse events. Several new anti-PD-1-based combination therapies with a better risk-benefit balance are currently under development. Although the acral and mucosal subtypes tend to be less responsive to immune checkpoint inhibitors, anti-PD-1-based combination therapy should continue to be investigated for these subtypes owing to its potential for better long-term survival. With the development of efficacious immunotherapy and targeted therapy, it is important to determine the optimal duration of systemic therapy to avoid unnecessary health and financial burdens as well as to improve efforts to support long-term cancer survivors. As the goal of systemic therapy shifts from tumor control to long-term survival, in future clinical trials, long-term clinical outcomes should be evaluated to assess the benefits of novel agents.

Multidisciplinary approach and treatment of acral and mucosal melanoma

Acral and mucosal melanoma are uncommon variants of melanoma. Acral melanoma has an age-adjusted incidence of approximately 1.8 cases per million individuals per year, accounting for about 2% to 3% of all melanoma cases. On the other hand, mucosal melanoma, with an incidence of 2.2 cases per million per year, makes up around 1.3% of all melanoma cases. These melanomas, in addition to being biologically and clinically distinct from cutaneous melanoma, share certain clinical and pathologic characteristics. These include a more aggressive nature and a less favorable prognosis. Furthermore, they exhibit a different mutational pattern, with KIT mutations being more prevalent in acral and mucosal melanomas. This divergence in mutational patterns may partially account for the relatively poorer prognosis, particularly to immune checkpoint inhibitors. This review explores various aspects of acral and mucosal melanoma, including their clinical presentation, pathologic features, mutational profiles, current therapeutic approaches, outcomes associated with systemic therapy, and potential strategies to address resistance to existing treatments.

Management of acral lentiginous melanoma: current updates and future directions

Acral lentiginous melanoma is a rare subtype of melanoma generally associated with poor outcomes, even when diagnosed at an early stage. The tumor genetic profile remains poorly understood, but it is known to have a suppressed immune environment compared to that of non-acral cutaneous melanomas, which limits therapy options. There is significant attention on the development of novel therapeutic approaches, although studies are limited due to disease rarity. For local disease, wide local excision remains the standard of care. Due to frequent under-staging on preoperative biopsy, wider margins and routine sentinel lymph node biopsy may be considered if morbidity would not be increased. For advanced disease, anti-PD1 monotherapy or combination therapy with anti-PD1 and anti-CTLA4 agents have been used as first-line treatment modalities. Anti-PD1 and anti-CTLA4 combination therapies have been shown to be particularly beneficial for patients with BRAF-mutant acral lentiginous melanoma. Other systemic combination regimens and targeted therapy options may be considered, although large studies with consistent results are lacking. Regional and intralesional therapies have shown promise for cutaneous melanomas, but studies generally have not reported results for specific histologic subtypes, especially for acral melanoma. Overall, the unique histologic and genetic characteristics of acral lentiginous melanoma make therapy options significantly more challenging. Furthermore, studies are limited, and data reporting has been inconsistent. However, more prospective studies are emerging, and alternative therapy pathways specific to acral lentiginous melanoma are being investigated. As further evidence is discovered, reliable treatment guidelines may be developed.

A single-center retrospective analysis of prognoses in patients with melanoma brain metastases and effectiveness of treatment in Japan

BACKGROUND

Melanoma brain metastasis (MBM) has a poor prognosis, although recent treatments, including immune checkpoint inhibitors and targeted therapy, have improved the prognosis. However, these systemic therapies have been reported to be less efficient for Asian patients. We investigated the survival of Asian patients with MBM and the effectiveness of systemic therapies.

METHODS

We retrospectively reviewed the survival rates of patients diagnosed with MBM between January 2011 and December 2021 at the National Cancer Center Hospital in Tokyo, Japan. In addition, we identified factors associated with survival using Cox regression analysis.

RESULTS

A total of 135 patients were included. The median overall survival (OS) after an MBM diagnosis was 7.8 months (95% confidence interval [CI] 6.1-9.6). The 6-month and 1-year survival rates were 60.7% and 34.8%, respectively. We identified the prognostic factors of MBM, including non-acral primary location, low serum LDH levels, systemic therapy of single-agent immune checkpoint inhibitors (ICIs) or targeted therapies (TTs), and radiotherapy of stereotactic irradiation (STI). We found no significant difference in effectiveness between single-agent ICIs, the combination of Nivolumab and Ipilimumab (COMBI-ICI), and TTs (COMBI-ICI vs. single-agent ICI, hazard ratio 0.71, 95% confidence interval 0.27-1.88, p = 0.49; COMBI-ICI vs. TT: hazard ratio 0.46, 95% confidence interval 0.14-1.55, p = 0.21).

CONCLUSIONS

Systemic therapy and radiotherapy have improved the survival of MBM patients, but the survival of Asian patients remains poor. Our findings suggest that COMBI-ICIs are not significantly more effective than single-agent ICI or TT in treating MBM.

Efficacy of salvage therapies for advanced acral melanoma after anti-PD-1 monotherapy failure: a multicenter retrospective study of 108 Japanese patients

Background

Anti-programmed cell death protein 1 (PD-1) monotherapy is one of the standard systemic therapies for advanced melanoma; however, the efficacy of salvage systemic therapies after PD-1 monotherapy failure (PD-1 MF), particularly in acral melanoma (AM), the main clinical melanoma type in Japanese patients, is unclear. This study aimed to investigate the efficacy of salvage systemic therapies in Japanese patients with AM after PD-1 MF.

Patients and methods

The study included 108 patients with advanced AM (palm and sole, 72; nail apparatus, 36) who underwent salvage systemic therapy at 24 Japanese institutions. We mainly assessed the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

Results

Thirty-six (33%) patients received ipilimumab, 23 (21%) received nivolumab and ipilimumab (nivo/ipi), 10 (9%) received cytotoxic chemotherapy, 4 (4%) received BRAF and MEK inhibitors (BRAFi/MEKi), and the remaining 35 (32%) continued with PD-1 monotherapy after disease progression. The ORRs in the ipilimumab, nivo/ipi, cytotoxic chemotherapy, and BRAFi/MEKi groups were 8, 17, 0, and 100%, respectively. The nivo/ipi group showed the longest OS (median, 18.9 months); however, differences in ORR, PFS, and OS between the groups were insignificant. The OS in the nivo/ipi group was higher in the palm and sole groups than in the nail apparatus group (median: not reached vs. 8.7 months, p < 0.001). Cox multivariate analysis demonstrated that nail apparatus melanoma independently predicted unfavorable PFS and OS (p = 0.006 and 0.001). The total OS (from PD-1 monotherapy initiation to death/last follow-up) was insignificant between the groups.

Conclusion

Nivo/ipi was not more effective than cytotoxic chemotherapy and ipilimumab after PD-1 MF in patients with advanced AM. The prognosis after PD-1 MF would be poorer for nail apparatus melanoma than for palm and sole melanoma.

Camrelizumab Plus Apatinib and Temozolomide as First-Line Treatment in Patients With Advanced Acral Melanoma: The CAP 03 Phase 2 Nonrandomized Clinical Trial

Importance

Acral melanoma, known for low tumor mutation burden, responds poorly to immunotherapy. A standard therapy is still lacking.

Objective

To investigate the activity and safety of camrelizumab (an anti-programmed cell death-1 antibody) plus apatinib (a vascular endothelial growth factor receptor 2 inhibitor) and temozolomide as first-line treatment in patients with advanced acral melanoma.

Design, Setting, and Participants

In this single-arm, single-center, phase 2 nonrandomized clinical trial, patients with treatment-naive unresectable stage III or IV acral melanoma were enrolled at Peking University Cancer Hospital and Institute between June 4, 2020, and August 24, 2021. The data cutoff date was April 10, 2022.

Interventions

Patients received 4-week cycles of intravenous camrelizumab, 200 mg, every 2 weeks; oral apatinib 250 mg, once daily; and intravenous temozolomide, 200 mg/m2, once daily on days 1 to 5 until disease progression or unacceptable toxic effects.

Main Outcomes and Measures

The primary end point was objective response rate as assessed by investigators according to the Response Evaluation Criteria In Solid Tumors (version 1.1). Secondary end points included progression-free survival, time to response, duration of response, disease control rate, overall survival, and safety.

Results

A total of 50 patients (32 men [64%]; median age, 57 years [IQR, 52-62 years]) were enrolled and received treatment. The median follow-up duration was 13.4 months (IQR, 9.6-16.2 months). The objective response rate was 64.0% (32 of 50; 95% CI, 49.2%-77.1%). The median time to response and duration of response were 2.7 months (IQR, 0.9-2.9 months) and 17.5 months (95% CI, 12.0 to not reached), respectively. The disease control rate was 88.0% (44 of 50; 95% CI, 75.7%-95.5%). The estimated median progression-free survival was 18.4 months (95% CI, 10.6 to not reached). The median overall survival was not reached. The most common grade 3 or 4 treatment-related adverse events were increased gamma-glutamyltransferase levels (15 [30%]), decreased neutrophil count (11 [22%]), increased conjugated bilirubin levels (10 [20%]), and increased aspartate aminotransferase levels (10 [20%]). No treatment-related deaths occurred.

Conclusions and Relevance

The findings of this nonrandomized clinical trial suggest that camrelizumab plus apatinib and temozolomide may be a potential first-line treatment option for patients with advanced acral melanoma, which warrants further validation in a randomized clinical trial.

Trial Registration

ClinicalTrials.gov Identifier: NCT04397770.

Glioblastoma-on-a-chip construction and therapeutic applications

Glioblastoma (GBM) is the most malignant type of primary intracranial tumor with a median overall survival of only 14 months, a very poor prognosis and a recurrence rate of 90%. It is difficult to reflect the complex structure and function of the GBM microenvironment in vivo using traditional in vitro models. GBM-on-a-chip platforms can integrate biological or chemical functional units of a tumor into a chip, mimicking in vivo functions of GBM cells. This technology has shown great potential for applications in personalized precision medicine and GBM immunotherapy. In recent years, there have been efforts to construct GBM-on-a-chip models based on microfluidics and bioprinting. A number of research teams have begun to use GBM-on-a-chip models for the investigation of GBM progression mechanisms, drug candidates, and therapeutic approaches. This review first briefly discusses the use of microfluidics and bioprinting technologies for GBM-on-a-chip construction. Second, we classify non-surgical treatments for GBM in pre-clinical research into three categories (chemotherapy, immunotherapy and other therapies) and focus on the use of GBM-on-a-chip in research for each category. Last, we demonstrate that organ-on-a-chip technology in therapeutic field is still in its initial stage and provide future perspectives for research directions in the field.

Immune checkpoint inhibitor-based therapy for advanced acral and mucosal melanoma

Acral melanoma (AM) and mucosal melanomas (MM) are rare clinical subtypes of melanoma. AM and MM are etiologically, biologically, and molecularly distinct from cutaneous melanoma (CM). Despite the recent development of immune checkpoint inhibitors (ICIs) for the treatment of advanced CMs, the true therapeutic efficacy of ICIs for these rare subtypes remains unclear. Since these subtypes are rare, especially in the Caucasian population, their biological features and corresponding novel therapies are underexplored than those of CM. Even in the larger phase III clinical trials for ICIs, the sample size of patients with AM and MM is limited. Consequently, establishment of standard of care for advanced AM and MM has been challenging. This review covers current update and overview on clinical efficacy of ICIs and ICI-based therapy for advanced AM and MM, based mainly on the reported clinical trials, prospective observational studies, and retrospective studies, to provide a better understanding of the current landscape of this field. In addition, we discuss the future direction of treatment for those rare clinical subtypes, focusing on issues relevant to dermatology and medical oncology.

Future prospects for cancer immunotherapy using induced pluripotent stem cell-derived dendritic cells or macrophages

Cancer immunotherapy is now the first-line treatment for many unresectable cancers. However, it remains far from a complete cure for all patients. Therefore, it is necessary to develop innovative methods for cancer immunotherapy, and immune cell therapy could be an option. Currently, several institutions are attempting to generate immune cells from induced pluripotent stem cells (iPSCs) for use in cancer immunotherapy. A method for generating dendritic cells (DCs) and macrophages (MPs) from iPSC has been established. iPSC-derived DCs (iPS-DCs) can activate T cells via antigen presentation, and iPSC-derived macrophages (iPS-MPs) attack cancer. Since iPSCs are used as the source, genetic modification is easy, and various immune functions, such as the production of anti-tumour cytokines, can be added. Furthermore, when iPS-DCs and iPS-MPs are immortalized, cost reduction through mass production is theoretically possible. In this review, the achievements of cancer research using iPS-DCs and iPS-MPs are summarized, and the prospects for the future are discussed.

Immunotherapy for Melanoma: The Significance of Immune Checkpoint Inhibitors for the Treatment of Advanced Melanoma

Therapeutic options for treating advanced melanoma have progressed rapidly in recent decades. Until 6 years ago, the regimen for treating advanced melanoma consisted mainly of cytotoxic agents such as dacarbazine and type I interferons. Since 2014, anti-programmed cell death 1 (PD1) antibodies have been recognized as anchor drugs for treating advanced melanoma, with or without additional combination drugs such as ipilimumab, but the efficacies of these immunotherapies are not fully satisfactory. In this review, we describe the development of the currently available anti-PD1 Abs-based immunotherapies for advanced melanoma, focusing on their efficacy and immune-related adverse events (AEs), as well as clinical trials still ongoing for the future treatment of advanced melanoma.