Successful treatment of multiple in-transit melanomas on the leg with intensity-modulated radiotherapy and immune checkpoint inhibitors: Report of two cases

Successful treatment of BRAF/MEK inhibitor-resistant advanced cutaneous melanoma with nivolumab plus ipilimumab combination therapy followed by intensity-modulated radiotherapy

BRAF kinase inhibitors in combination with MEK kinase inhibitors are among the most promising chemotherapeutic regimens for the treatment of advanced BRAF-mutant melanoma. Although the NCCN guideline for cutaneous melanoma recommended BRAF/MEK inhibitors as first-line therapies for unresectable BRAF-mutated melanoma, resistance to these drugs should be taken into account in real-world practice. Therefore, development of a protocol for BRAF/MEK inhibitor-resistant advanced melanoma is needed. In this report, a case of BRAF/MEK inhibitor-resistant advanced cutaneous melanoma that was successfully treated with nivolumab plus ipilimumab combination therapy followed by intensity-modulated radiotherapy (IMRT) is reported. In the present case, not only the locally irradiated lesion, but remote metastases including inguinal lymph nodes decreased after ipilimumab plus nivolumab followed by IMRT treatment leading to complete remission, suggesting that IMRT triggered an abscopal response. Moreover, immunohistochemical analysis showed increased CD3⁺ , CD4⁺ , and CD8⁺ T cells after radio-immunotherapy (RIT). This case suggests that RIT might break the tolerance in the tumor microenvironment and induce a systemic anti-melanoma immune response.

Melanoma and Immune Checkpoint Inhibitors

PURPOSE OF REVIEW

Prognosis of patients with advanced melanoma is dismal with a median overall survival of about 8 months and 5-year overall survival from a diagnosis of metastatic disease of roughly 10%. However, immune checkpoint inhibitors have brought indispensable benefits to melanoma patients. Here we will review the recent clinical efficacy and adverse events of immune checkpoint inhibitors for melanoma patients.

RECENT FINDINGS

The immune checkpoint inhibitors increase confirmed objective response and prolong progression-free and overall survival of the afflicted patients in association with maintaining their quality of life. Although diverse immune-related adverse events occur, most of them are manageable by appropriate immunomodulating agents. Clinical efficacy of immune checkpoint inhibitors continues even after discontinuation of drugs. Compared with conventional therapeutic options, the immune checkpoint inhibitors appear to prolong the survival of patients with advanced melanoma. Further clinical trials are warranted to determine whether their combinatory use with other treatment options may augment benefits or not.

Intensity-Modulated Radiotherapy Triggers Onset of Bullous Pemphigoid in a Patient with Advanced Melanoma Treated with Nivolumab

Since the efficacy of ipilimumab on nivolumab-resistant advanced melanoma is extremely low, additional supportive therapy for anti-PD-1 antibody therapy-resistant advanced melanoma is needed. Although several supportive therapies that enhance the antitumor immune response of anti-PD-1 antibodies have already been reported, unexpected immune-related adverse events were detected at the same time. In this report, we describe a patient with advanced melanoma treated with nivolumab followed by intensity-modulated radiotherapy, which might have triggered bullous pemphigoid (BP). Although several cases of BP developing in anti-PD-1 antibody-treated patients have already been reported, in this report, we shed light on the possible pathogenesis of BP developing in a patient treated with nivolumab through M2 macrophages.

Serum levels of soluble CD163 and CXCL5 may be predictive markers for immune-related adverse events in patients with advanced melanoma treated with nivolumab: a pilot study

Antibodies against PD-1, such as nivolumab and pembrolizumab, are widely used in the treatment of various cancers including advanced melanoma. The anti-PD-1 Ab significantly prolongs survival in patients with metastatic melanoma, and its administration in combination with local or systemic therapy may also lead to improved outcomes. Although anti-PD-1 Ab-based combined therapy might be effective for the treatment of advanced melanoma, the associated risk of irAEs is an important consideration. Therefore, being able to predict irAEs is of great interest to oncologists. The purpose of this study was to evaluate the value of using serum levels of sCD163 and CXCL5 to predict irAEs in patients with advanced melanoma who were administered nivolumab. To this end, we analyzed these serum levels in 46 cases of advanced melanoma treated with nivolumab. In addition, the tumor stroma was evaluated by immunohistochemistry and immunofluorescence. We measured the serum levels of sCD163 and CXCL5 on day 0 (immediately before nivolumab administration) and day 42. The serum absolute levels of sCD163 were significantly increased in patients who developed AEs (p = 0.0018). Although there was no significant difference in serum levels of CXCL5, the absolute value of CXCL5 could at least be a supportive marker for the increased absolute levels of serum sCD163. This study suggests that sCD163 and CXCL5 may serve as possible prognostic biomarkers for irAEs in patients with advanced melanoma treated with nivolumab.

Successful Treatment of Nivolumab-Resistant Multiple In-Transit Melanomas with Ipilimumab and Topical Imiquimod

Simultaneous or sequential, planned administration of ipilimumab could significantly enhance the antitumor effects of nivolumab in advanced melanoma patients. On the other hand, the efficacy of ipilimumab for nivolumab-resistant advanced melanoma is extremely poor. Therefore, additional supportive therapy for anti-PD-1 antibody therapy-resistant advanced melanoma has been widely investigated. In this report, we describe a case of multiple in-transit melanomas developing in a nivolumab-resistant patient successfully treated with ipilimumab in combination with imiquimod. Our present case suggested a possible therapy for nivolumab-resistant multiple in-transit melanomas using ipilimumab in combination with topical imiquimod.

Phase I study of nivolumab combined with IFN-β for patients with advanced melanoma

The efficacy of nivolumab is greater than that of other anti-melanoma drugs, so nivolumab-based combined therapies that enhance anti-tumor immune responses in patients with metastatic melanoma are of great interest to dermato-oncologists. As we have previously reported, IFN-β enhances the anti-tumor immune response of anti-PD-1 antibodies against B16F10 melanoma in vivo. To explore the potential of this property of IFN-β as part of a combination therapy for the treatment of metastatic melanoma patients, we performed a phase 1 trial, using a traditional rule-based 3 + 3 design, on patients with advanced melanoma. The nivolumab dose was fixed at 2 mg/kg, every 3 weeks. IFN-β was administered to three groups at doses of 1 million, 2 million, and 3 million units, respectively. Dose-limiting toxicities were defined as any grade 3-5 adverse events occurring between day 0 and day 42 that might possibly be related to nivolumab and IFN-β. Of the nine patients who received this combined therapy, none experienced dose-limiting toxicities, and all completed the treatment phase of the study. Patient follow-up continued for 6 months following the final treatment. There were two complete responses (22%) and one partial response (11%), all of which occurred in patients who had received monthly IFN-β immediately prior to the study. In this study, we determined the safe dose of IFN-β, when combined with nivolumab, to be 3 million units. To determine the efficacy of this combination therapy, further phase II trials are required.