Immune Checkpoint Inhibitors in Solid Organ Transplant Recipients With Advanced Skin Cancers-Emerging Strategies for Clinical Management

Use of immune checkpoint inhibitors (ICIs) in solid organ transplant recipients (SOTRs) with advanced skin cancers presents a significant clinical management dilemma. SOTRs and other immunosuppressed patients have been routinely excluded from ICI clinical trials with good reason: immune checkpoints play an important role in self- and allograft-tolerance and risk of acute allograft rejection reported in retrospective studies affects 10% to 65% of cases. These reports also confirm that cutaneous squamous cell carcinoma and melanoma respond to ICI therapy, although response rates are generally lower than those observed in immunocompetent populations. Prospective trials are now of critical importance in further establishing ICI efficacy and safety. However, based on current knowledge, we recommend that ICIs should be offered to kidney transplant recipients with advanced cutaneous squamous cell carcinoma, melanoma, or Merkel cell carcinoma if surgery and/or radiotherapy have failed. For kidney transplant recipients, this should be first line ahead of chemotherapy and targeted therapies. In SOTRs, the use of ICIs should be carefully considered with the benefits of ICIs versus risks of allograft rejection weighed up on a case-by-case basis as part of shared decision-making with patients. In all cases, parallel management of immunosuppression may be key to ICI responsiveness. We recommend maintaining immunosuppression before ICI initiation with a dual immunosuppressive regimen combining mammalian target of rapamycin inhibitors and either corticosteroids or calcineurin inhibitors. Such modification of immunosuppression must be considered in the context of allograft risk (both rejection and also its subsequent treatment) and risk of tumor progression. Ultimately, a multidisciplinary approach should underpin all clinical decision-making in this challenging scenario.

Cost-effectiveness analysis of cemiplimab vs pembrolizumab for treatment of advanced cutaneous squamous cell carcinoma

BACKGROUND: Most cutaneous squamous cell carcinomas (CSCCs) can be treated with surgical excision or radiation; however, approximately 1% of patients develop advanced disease. In 2018, the FDA approved cemiplimab-rwlc as the first programmed cell death-1 (PD-1) monoclonal antibody for the treatment of patients with metastatic CSCC or locally advanced CSCC who are not candidates for curative surgery or curative radiation. In June 2020, pembrolizumab, another PD-1 monoclonal antibody, was approved for the treatment of patients with recurrent or metastatic CSCC who are not candidates for curative surgery or radiation. We previously reported on the cost-effectiveness of cemiplimab vs historical standard of care for the treatment of advanced CSCC from a US perspective. OBJECTIVE: To estimate the cost-effectiveness of cemiplimab vs pembrolizumab for patients with advanced CSCC in the United States. METHODS: A "partitioned survival" framework was used to assess the cost-effectiveness of cemiplimab vs pembrolizumab. Clinical inputs were based on the most recent data cut of the phase 2 trials for cemiplimab (EMPOWER-CSCC-1; NCT02760498) and pembrolizumab (KEYNOTE-629). Progression-free survival and overall survival were extrapolated using parametric models until all patients had progressed or died. Health state utilities were derived from data collected in the EMPOWER-CSCC-1 trial. Costs included drug acquisition, drug administration, disease management, terminal care, and adverse events and were based on published 2020 US list prices. To assess model uncertainty, 1-way sensitivity and probabilistic sensitivity analyses (PSA) were conducted, alongside scenario analyses evaluating key modeling assumptions. RESULTS: In the base case, cemiplimab resulted in an incremental gain of 3.44 life-years (discounted) and incremental cost-effectiveness ratio (ICER) of $130,329 per quality-adjusted life-year (QALY) vs pembrolizumab. At a willingness-to-pay threshold of $150,000/QALY, PSA indicated a 71% probability that cemiplimab is cost-effective when compared with pembrolizumab. Scenario analysis resulted in ICERs ranging from $115,909 to $187,374. CONCLUSIONS: Findings suggest that cemiplimab is a cost-effective treatment for patients with advanced CSCC, compared with pembrolizumab. These results should be interpreted cautiously in the absence of head-to-head trials; however, in the absence of such data, these results can be used to inform health care decisions over resource allocation. DISCLOSURES: This study was supported by Regeneron Pharmaceuticals, Inc., and Sanofi. Paul, Cope, Keeping, Mojebi, and Ayers are employees of PRECISIONheor, which received funding to produce this work. Chen, Kuznik, and Xu are employees and stockholders of Regeneron Pharmaceuticals, Inc. Sasane is an employee and stockholder of Sanofi, Inc. Konidaris, Atsou, and Guyot are employees of Sanofi, Inc. The authors were responsible for all content and editorial decisions and received no honoraria related to the development of this publication.

Solid organ transplantation worsens the prognosis of patients with cutaneous squamous cell carcinoma of the head and neck region-Comparison between solid organ transplant recipients and immunocompetent patients

BACKGROUND

Cutaneous squamous cell carcinoma of the head and neck (CSCC-HN) appears to behave more aggressively in immunosuppressed patients. We aimed to investigate this hypothesis by comparing solid organ transplant recipients (SOTR) with CSCC-HN to immunocompetent patients.

METHODS

A retrospective comparative study was conducted for SOTR and immunocompetent patients who were treated for CSCC-HN.

RESULTS

A total of 177 SOTR and 157 immunocompetent patients with CSCC-HN were included. Lymph node metastases were more common in the SOTR group (9% vs 3%), and distant metastases occurred only in SOTR (3% of patients). SOTR had a higher rate of recurrences (19% vs 10%), which were mostly regional (7%) and distant (3%). The 2-year disease-specific survival of SOTR was lower (93% vs 100%).

CONCLUSIONS

SOTR with CSCC-HN has significantly worse outcomes compared to immunocompetent patients. Solid-organ transplantation should be regarded as a negative prognostic factor in patients with CSCC-HN.

Cisplatin influences the skin ion transport - An in vitro study

Platinum-based drugs, used in treating tumors, cause numerous undesirable effects in patients, like neuropathic pain, hypersensitivity, reddening, pruritus and rash. Changes in Na⁺ transport modify local osmolality and contribute to the initiation of hypersensitivity and allergy. They are also associated with stimulation of C-fibres and hyperalgesia. Cl^- transport is essential for regulation of sweat composition and the migration of immunocompetent cells. The aim of the conducted study was to assess the effect of a cisplatin solution on the electrophysiological parameters of the isolated rabbit skin specimens. The difference in transepithelial electrical potential (PD) and resistance (R) in stationary conditions and during 15 s mechanical-chemical stimulation (PDmin and PDmax), were measured. Measurement of R revealed that tissue samples were live, and their permeability to ions were stable. Control specimens had PD -0.22 mV (median). The PD of specimens treated by cisplatin was -0.55 mV (median), to for cisplatin and bumetanide 0 mV (median). Treatment with cisplatin did not change the continuous transport of Na⁺ and K⁺ ions, but did change that of Cl^- ions. Stimulation of samples with the transport blockers of Cl^-, Na⁺ and both induced repeatable and measurable reactions in the transport of the appropriate ions. It was shown that absorption of Na⁺ ions and release of Cl^- ions was intensified than in the untreated specimens. It was proven in the study that cisplatin influences the Na⁺ and Cl^- transport in the skin cells. Restoring the balance in ion flow can prevent side effects of use cisplatin-based drugs.

Immunotherapy and other systemic therapies for cutaneous SCC

Contrary to the impression that non-melanoma skin cancer is a banal and relatively trivial malignancy it causes about 1% of all cancer deaths. Cutaneous Squamous Cell carcinoma (CuSCC) make up a significant part of these deaths either from incurable loco-regional disease or metastatic disease. As is typical of the disease itself, these patients are often of advanced age, but the immunocompromised from organ transplantation or haematological malignancy are important populations. Systemic therapies have a long history in palliative therapy for CuSCC, but not a particularly extensively studied one. Cytotoxic chemotherapy is active with response rates derived from multiple small studies of 17-85%; as is often the case in solid tumour oncology responses are rarely durable. The Epidermal Growth Factor Receptor has been targeted with both small molecular inhibitors and monoclonal antibodies. Disease control rates of the order of 50-70% were seen but again durability remains an issue. Immunotherapy using interferon with retinoids also showed significant response rates in very small trials. The high rates of mutation seen in CuSCC and relationship with immunosuppression suggested that checkpoint inhibitors might be active. Checkpoint inhibition immunotherapy with PD-1 antibodies like cemiplimab have demonstrated response rates of the order of 40% and durability is encouraging: response duration was over a year in 75% of responders in the initial trial. We review the latest data with current immunotherapy drugs and consider the future directions such therapy may take us as well as the role of these therapies in special populations.

Identifying drug resistant cancer cells using microbubble well arrays

Drug resistance is a characteristic of tumor initiating cells that can give rise to metastatic disease. In this work we demonstrate the use of microbubble well arrays as a cell culture platform to enumerate and characterize drug resistant cells in a human derived tumorigenic squamous cell carcinoma cell line. The spherical architecture and compliant hydrophobic composition of the microbubble well favors single cell survival, clonal proliferation and formation of spheres that do not grow on standard tissue culture plastic and are resistant to cisplatin. Spheres form in isolation and in microbubble wells containing proliferating cells and to some degree they stain positive for common stem cell markers CD44 and CD133. Spheres are also observed in cellularized primary human tumors cultured in microbubble arrays. This proof-of-concept study illustrates the potential for microbubble array technology to enumerate cancer cells resistant to standard care drugs with the ability to test alternative drug combinations. This capability can be developed for designing patient specific treatment strategies. Recovery of drug-resistant cells will allow a more full characterization of their gene expression profile thereby expanding our fundamental knowledge and ability to develop new targets to fight metastatic disease.

Skin Cancers in Organ Transplant Recipients

Long-term utilization of immunosuppression in organ transplant recipients (OTRs) leads to decreased immune-mediated tumor surveillance and development of malignant tumors. A delicate balance needs to be maintained in the intensity of immunosuppression to keep the risk of malignancy low without jeopardizing life-saving graft function. OTRs are prone to developing skin cancers that exhibit unique epidemiologic, pathophysiologic, and prognostic characteristics. In this review, we discuss the most commonly reported skin cancers in OTRs: squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Kaposi sarcoma, Merkel cell carcinoma, and malignant melanoma (MM). Tumors in this high-risk population are aggressive and may respond poorly to standard therapies; however, new targeted therapies are promising. Checkpoint inhibitor antibodies have been used for treatment of cutaneous SCC, Merkel cell carcinoma, and MM; epidermal growth factor receptor inhibitors have been used for cutaneous SCC; hedgehog pathway inhibitors have been used for BCC; and BRAF and MEK inhibitors are being used increasingly in the management of MM. Guidelines for dermatologic screening are variable and primarily based on expert opinion. Prospective evidence-based trials by multidisciplinary groups are needed to better define surveillance schedules for pre- and posttransplant cutaneous malignancies.