Complete Remission of Basal Cell Carcinoma Following Treatment With Cemiplimab After 2 Years

PD-1 and PD-L1: architects of immune symphony and immunotherapy breakthroughs in cancer treatment

PD-1 (Programmed Cell Death Protein-1) and PD-L1 (Programmed Cell Death Ligand-1) play a crucial role in regulating the immune system and preventing autoimmunity. Cancer cells can manipulate this system, allowing them to escape immune detection and promote tumor growth. Therapies targeting the PD-1/PD-L1 pathway have transformed cancer treatment and have demonstrated significant effectiveness against various cancer types. This study delves into the structure and signaling dynamics of PD-1 and its ligands PD-L1/PD-L2, the diverse PD-1/PD-L1 inhibitors and their efficacy, and the resistance observed in some patients. Furthermore, this study explored the challenges associated with the PD-1/PD-L1 inhibitor treatment approach. Recent advancements in the combination of immunotherapy with chemotherapy, radiation, and surgical procedures to enhance patient outcomes have also been highlighted. Overall, this study offers an in-depth overview of the significance of PD-1/PD-L1 in cancer immunotherapy and its future implications in oncology.

Immunotherapy and Its Timing in Advanced Basal Cell Carcinoma Treatment

For patients with advanced basal cell carcinoma (BCC), including locally advanced or metastatic BCC not amenable to curative surgery or radiotherapy, hedgehog pathway inhibitors (HHI) vismodegib and sonidegib are approved as first-line systemic treatment. Results from clinical trials highlight that the overall discontinuation rate of HHI treatment varies from 88% to 92% with vismodegib and is approximately 92% with sonidegib, and half of patients will discontinue HHI after approximately 8 to 12 months. The main factors weighing in on the decision to discontinue HHI include efficacy (tumor response), adverse events and patient decision. In clinical practice, some of the patients that stop HHI may be re-evaluated if the tumor becomes amenable to surgery, or restart HHI at a later time, while others will need to switch to immunotherapy, depending on the reasons for HHI discontinuation. In this review, we revisit the therapeutic decisions considering a switch from HHI to immunotherapy with anti-PD-1 agent cemiplimab and we highlight the place of cemiplimab in the therapeutic ladder for patients with advanced BCC. We discuss the evidence on the efficacy and safety of anti-PD-1 agents as second-line systemic monotherapy, or in combination with other treatments, and the emergence of checkpoint immunotherapy as a neoadjuvant treatment.

Complete response of a large basosquamous carcinoma following treatment with cemiplimab and vismodegib

The anti-PD-1 antibody cemiplimab has demonstrated effectiveness in the setting of locally advanced basal cell carcinoma (BCC) and squamous cell carcinoma. We describe a case of a large, locally invasive basosquamous carcinoma, an aggressive type of BCC, invading the left sternocleidomastoid muscle with near compression of the left internal jugular vein producing a severe anaemia secondary to ulceration and chronic blood loss. The patient was initially started on vismodegib monotherapy but failed to respond. He was then started on cemiplimab in addition to vismodegib. Improvement was noted after one cycle. After 21 cycles of cemiplimab, the left shoulder ulcerated lesion was completely re-epithelialised. He remains in complete remission after 31 cycles of cemiplimab in addition to vismodegib.

Identifying Candidates for Immunotherapy among Patients with Non-Melanoma Skin Cancer: A Review of the Potential Predictors of Response

BACKGROUND

Non-melanoma skin cancer (NMSC) stands as an umbrella term for common cutaneous malignancies, including basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), together with rarer cutaneous cancers, such as Merkel cell carcinoma (MCC) and other forms of adnexal cancers. The majority of NMSCs can be successfully treated with surgery or radiotherapy, but advanced and metastatic stages may require systemic approaches such as immunotherapy with immune checkpoint inhibitors (ICIs).

SUMMARY

Since immunotherapy is not effective in all patients and can potentially lead to severe adverse effects, an important clinical question is how to properly identify those who could be suitable candidates for this therapeutic choice. In this paper, we review the potential features and biomarkers used to predict the outcome of ICIs therapy for NMSCs. Moreover, we analyze the role of immunotherapy in special populations, such as the elderly, immunocompromised patients, organ transplant recipients, and subjects suffering from autoimmune conditions.

KEY MESSAGES

Many clinical, serum, histopathological, and genetic features have been investigated as potential predictors of response in NMSCs treated with ICIs. Although this field of research is very promising, definitive, cost-effective, and reproducible biomarkers are still lacking and further efforts are needed to validate the suggested predictors in larger cohorts.

New Emerging Treatment Options for Advanced Basal Cell Carcinoma and Squamous Cell Carcinoma

Non-melanoma skin cancers, also known as keratinocyte tumors, have an increasing incidence worldwide, with basal cell carcinoma and squamous cell carcinoma being the most represented ones. Although surgery represents the gold-standard treatment for both tumors, some cases can progress to an advanced or a metastatic state and targeted therapy is required. Hedgehog signaling pathway has an important role in the development of basal cell carcinoma, and its inhibition is the key to new treatment options available for the treatment of locally advanced and metastatic basal cell carcinoma. Cutaneous squamous cell carcinoma is the second most frequent malignant skin cancer; when presenting in advanced or metastatic stage, alternative treatments are required; cemiplimab is a human monoclonal antibody directed against programmed cell death-1 receptor that acts by blocking T-cell inactivation and is the first drug approved for the treatment of adult patients with metastatic or locally advanced cutaneous squamous cell carcinoma. Studies evaluating pembrolizumab, ipilimumab and nivolumab as alternative treatments for advanced squamous cell carcinoma are still underway. Objective of this review is to analyze and discuss the novel therapies for advanced basal cell carcinoma and squamous cell carcinoma to obtain a sharper perspective of the available treatment options.

Current Perspectives in the Treatment of Locally Advanced Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common cancer in Caucasians, and its incidence continues to rise. Generally, BCCs have good outcomes when diagnosed and treated early. However, 1-10% of patients will develop advanced disease due to either delays in accessing treatment or aggressive tumors that may be refractory to treatment. Locally advanced basal cell carcinomas (laBCCs) are large, aggressive, or recurrent tumors that have the potential to invade surrounding tissues including bone, cartilage, nerve, and muscle. Treatment requires a multi-disciplinary approach where different modalities including surgery, radiation therapy, Hedgehog Pathway Inhibitors, and immunotherapy can be considered.

Differential expression of programmed cell death ligand 1 (PD-L1) and inflammatory cells in basal cell carcinoma subtypes

Few studies have evaluated programmed cell death ligand (PD-L1) expression and lymphocytic infiltrates in Basal Cell Carcinoma (BCC). The objectives of this study are to assess PD-L1 expression and markers of local immune response in nodular, superficial, and morpheaform BCC, and compare it to normal, sun-exposed skin from the periphery of intradermal nevi. This was a retrospective study that included three histological subtypes of BCCs, and sun-exposed skin from the periphery of dermal nevi as quality controls. Tissue microarrays (TMA) were constructed with subsequent staining of H&E and immunohistochemistry (IHC) for CD4, CD8, FOXP3 and PD-L1. Non-automated quantification of the infiltrate in the intratumoral and stromal compartments on TMAs was performed. A total of 115 BCC (39 nodular, 39 morpheaform, and 37 superficial) and 41 sun-exposed skin samples were included (mean age 65.4 years; 52.6% females). BCC showed higher expression of PD-L1 (5.4 vs 0.7%, p < 0.001), CD8 (29.8 vs 19.7%, p = 0.002), and FOXP3 (0.3 vs 0.06%, p = 0.022) compared to sun-exposed skin. There was a higher PD-L1 expression in nodular BCC compared with other subtypes. Low-risk BCC subtypes (superficial and nodular) exhibited more PD-L1 expression in intratumoral and stromal immune infiltrates as compared to high-risk BCC subtypes. As a limitation, no immune cells function was evaluated in this study, only the presence/absence of T-lymphocyte sub-populations was recorded. Substantial differences in both PD-L1 expression and lymphocytic infiltrates were found amongst the histological subtypes of BCC and sun-exposed skin. Highest PD-L1 expression was found in nodular BCCs which suggests a potentially targetable strategy in the treatment of this most common BCC subtype.