Advanced Cutaneous Squamous Cell Carcinoma Research Articles

Clinical and histopathological features of advanced cutaneous squamous cell carcinoma with varying responses to cemiplimab.

Most patients with unresectable locally advanced cutaneous squamous cell carcinoma (cSCC) benefit from cemiplimab, but some do not respond. Our study aims to identify clinical and histopathological features predicting response to cemiplimab. We analyzed 15 patients treated with cemiplimab, assessing clinical, demographic, histopathological, and immunohistochemical characteristics and correlating them with treatment response. Furthermore, effectiveness and safety were evaluated in our cohort. Our cohort included 12 males and 3 females, with a mean age of 78.1years. The majority of tumors, accounting for 66.7%, were located in the head and neck region. Treatment was well-tolerated, with only one grade3 colitis. There was no correlation between immune-related adverse events and treatment response. Non-responders were younger (69.4 vs. 82.5years). A history of hematological malignancy correlated with poorer response. High mitotic rate, poor tumor differentiation, high vimentin and p53, and low E-cadherin expression were associated with worse response. Conversely, higher intratumoral inflammatory infiltrate density, presence of necrotic areas, and lower mismatch repair-protein staining correlated with better response. Cemiplimab is a safe and effective therapy, particularly in elderly patients. Well-differentiated tumors with low proliferative index, intratumoral inflammatory infiltrate, and tumor necrosis may predict better clinical response.

Neoadjuvant Atezolizumab in Patients With Surgically Resectable Advanced Cutaneous Squamous Cell Carcinoma

PURPOSE To evaluate the feasibility of administering three doses of neoadjuvant atezolizumab before curative surgical resection in patients with advanced cutaneous squamous cell carcinoma (cSCC). PATIENTS AND METHODS This single-arm phase II trial included patients with cSCC of the head and neck with stage III or IV disease, or stage II lesions for which standard therapy would incur an unacceptable morbidity. Patients received up to three doses of atezolizumab at a fixed dose of 1,200 mg every 21 days before undergoing surgical resection. The primary end point was the percentage of patients able to complete three doses of therapy and be eligible for surgical resection without discontinuation due to toxicity or progression. Secondary end points included unconfirmed RECIST 1.1 response rate, pathological response rate (major and complete pathological response), and safety and tolerability of atezolizumab. RESULTS Twenty patients were enrolled and treated. Sixteen (80%) of 20 patients completed three doses of atezolizumab, and all patients were eligible for surgical resection. A pathological complete response was seen in seven (35%; 95% CI, 15.4 to 59.2) patients, and a major pathological response (<10% viable tumor) was seen in four (20%; 95% CI, 5.7 to 43.7) patients. RECIST responses were seen in eight (40%; 95% CI, 19.1 to 64.0) patients, and one (5%) patient progressed. Grade 3 or higher adverse events were seen in one (5%) patient who developed pneumonitis after the first dose of atezolizumab. CONCLUSION Neoadjuvant atezolizumab is feasible and well tolerated in patients with advanced cSCC and results in a high rate of major and complete pathological responses.

"Response to Sajid et al. “Response to Valerio Nardone et al.’s “Previous radiotherapy increases the efficacy of cemiplimab in the treatment of locally advanced and metastatic cutaneous squamous cell carcinoma: Aretrospective analysis.”

"Response to Sajid et al. “Response to Valerio Nardone et al.’s “Previous radiotherapy increases the efficacy of cemiplimab in the treatment of locally advanced and metastatic cutaneous squamous cell carcinoma: Aretrospective analysis.”

Cutaneous Squamous Cell Carcinoma in Patients with Solid-Organ-Transplant-Associated Immunosuppression.

The management of advanced cutaneous squamous cell carcinoma (CSCC) has been revolutionized by the introduction of immunotherapy. Yet, successful treatment with immunotherapy relies on an adequate antitumor immune response. Patients who are solid-organ transplant recipients (SOTRs) have a higher incidence of CSCC compared to the general population. This review discusses the current knowledge of epidemiology, pathophysiology, and management of patients with CSCC who are immunocompromised because of their chronic exposure to immunosuppressive medications to prevent allograft rejection. First, we discuss the prognostic impact of immunosuppression in patients with CSCC. Next, we review the risk of CSCC development in immunosuppressed patients due to SOT. In addition, we provide an overview of the biological immune disruption present in transplanted immunosuppressed CSCC patients. We discuss the available evidence on the use of immunotherapy and provide a framework for the management approach with SOTRs with CSCC. Finally, we discuss potential novel approaches that are being investigated for the management of immunosuppressed patients with CSCC.

A phase 2 open-label study of cemiplimab in patients with advanced cutaneous squamous cell carcinoma (EMPOWER-CSCC-1): Final long-term analysis of groups 1, 2, and 3, and primary analysis of fixed-dose treatment group 6

BackgroundIn the phase 2 EMPOWER-CSCC-1 study (NCT02760498), cemiplimab demonstrated antitumor activity against metastatic (mCSCC) and locally advanced cutaneous squamous cell carcinoma (laCSCC). ObjectivesTo report final analysis of weight-based cemiplimab in mCSCC and laCSCC (Groups 1 and 2), fixed-dose cemiplimab in mCSCC (Group 3), and primary analysis of fixed-dose cemiplimab in mCSCC/laCSCC (Group 6). MethodsPatients received cemiplimab (3 mg/kg intravenously [IV] every 2 weeks [Groups 1 and 2]) or cemiplimab (350 mg IV [Groups 3 and 6]) every 3 weeks. The primary endpoint was objective response rate (ORR). Duration of response (DOR) and progression-free survival (PFS) are presented per protocol, according to post-hoc sensitivity analyses that only include the period of protocol-mandated imaging assessments. ResultsAt 42.5 months, ORR for Groups 1–3 (n=193) was 47.2%, estimated 12-month DOR was 88.3%, and median PFS was 26.0 months. At 8.7 months, ORR for Group 6 (n=165 patients) was 44.8%; median DOR and median PFS were not reached. Serious treatment-emergent adverse event rates (grade ≥3) were Groups 1–3: 31.1% and Group 6: 34.5%. LimitationsNon-randomized study, non-survival primary endpoint. ConclusionEMPOWER-CSCC-1 provides the largest prospective data on long-term efficacy and safety for anti-programmed cell death-1 therapy in advanced CSCC.

940TiP INTerpath-007: A phase II/III, adaptive, randomized study of neoadjuvant and adjuvant pembrolizumab (pembro) with V940 (mRNA-4157) for treatment of resectable locally advanced (LA) cutaneous squamous cell carcinoma (cSCC)

940TiP INTerpath-007: A phase II/III, adaptive, randomized study of neoadjuvant and adjuvant pembrolizumab (pembro) with V940 (mRNA-4157) for treatment of resectable locally advanced (LA) cutaneous squamous cell carcinoma (cSCC)

Successful Use of Cemiplimab in a Very Elderly Patient With Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinoma (SCC) is a common skin cancer with significant morbidity and mortality, particularly in advanced stages. Treatment options for metastatic cutaneous SCC in very elderly patients are limited due to concerns about treatment tolerability and potential adverse effects. We report the case of a 90-year-old female patient with metastatic cutaneous SCC who was treated with cemiplimab, a monoclonal antibody (m-Ab) against programmed cell death protein 1 (PD-1), in combination with radiotherapy. The patient received cemiplimab for a limited period, during which time she demonstrated significant clinical improvement without severe adverse events. Radiotherapy was performed as a locoregional treatment with the aim to enhance immunotherapy efficacy. This case highlights the feasibility and effectiveness of cemiplimab in very elderly patients with metastatic cutaneous SCC. Despite the common apprehensions regarding the use of immunotherapy in this age group, our patient tolerated cemiplimab well, and the combination with radiotherapy proved beneficial. This suggests that even in very elderly patients, short-term use of cemiplimab, in conjunction with locoregional treatments such as radiotherapy, can be a viable and successful therapeutic approach. Cemiplimab, even in combination with radiotherapy, can be effectively and safely administered to very elderly patients with metastatic cutaneous SCC. This case supports the consideration of immunotherapy, even for a limited duration, as a practical option in the management of advanced cutaneous SCC in elderly patients, expanding the potential treatment strategies for this population.

Overexpression of CCL-20 and CXCL-8 genes enhances tumor escape and resistance to cemiplimab, a programmed cell death protein-1 (PD-1) inhibitor, in patients with locally advanced and metastatic cutaneous squamous cell carcinoma

ABSTRACT Cemiplimab has demonstrated relevant clinical activity in cutaneous squamous cell carcinoma (cSCC) but mechanisms of primary and acquired resistance to immunotherapy are still unknown. We collected clinical data from locally advanced and/or metastatic cSSC patients treated with cemiplimab in two Italian University centers. In addition, gene expression analysis by using Nanostring Technologies platform to evaluate 770 cancer- and immune-related genes on 20 tumor tissue samples (9 responders and 11 non-responders to cemiplimab) was performed. We enrolled 81 patients with a median age of 82 years. After 16.4 months of median follow-up, 12- and 24-months PFS were 53% and 42%, respectively; while 12- and 24-months OS were 71% and 61%, respectively. Treatment was well tolerated. Overall response rate (ORR) was 58%, with a disease control rate (DCR) of 77.8%. The difference between genes expressed in responder versus non-responder patient samples was substantial, particularly for genes involved in immune system regulation. Cemiplimab-resistant tumors were associated with over-expression of CCL-20 and CXCL-8. Cemiplimab confirmed efficacy and safety data in real-life cSCC patients. Overexpression of CCL-20 and CXCL-8 could represent biomarkers of lack of response to immunotherapy.

Real-World Experience With Cemiplimab in Advanced Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most common nonmelanoma skin cancer in Canada. However, few real-world reports exist on the treatment of refractory locally advanced (LA) and metastatic cSCC with cemiplimab to date. The objective of this study was to characterize the demographic and clinical outcomes of advanced cSCC patients on cemiplimab in a real-world setting. Retrospective analysis of adult patients with refractory LA and metastatic cSCC treated with cemiplimab at the London Regional Cancer Program in Canada. Patient demographics and treatment characteristics were reported, as well as Kaplan-Meier estimates of progression-free survival (PFS) and overall survival (OS). Forty patients were included in this study. Sixteen (40%) had LA disease and 24 (60%) had metastatic disease. Median treatment duration was 3.5 months (range: 0.6-29.4 months). Kaplan-Meier analyses of the entire study population revealed that the median OS was not reached [NR; 95% confidence interval (CI) 9.1 months-NR], but median PFS was 11.5 months (95% CI 7.0 months-NR). A total of 25% of patients experienced at least one adverse event from cemiplimab. Reasons for treatment discontinuation were death from any cause (25%), disease progression (15%), cemiplimab adverse events (5%), and other causes (15%). The 12 month estimates of OS and PFS were lower than pivotal phase I and II clinical trials. However, toxicity was tolerable. Cemiplimab remains a safe and effective therapy in patients with refractory LA and metastatic cSCC disease.

Adverse events in cemiplimab therapy for locally advanced or metastatic cutaneous squamous cell carcinoma: A global propensity-matched retrospective cohort study

Adverse events in cemiplimab therapy for locally advanced or metastatic cutaneous squamous cell carcinoma: A global propensity-matched retrospective cohort study

Therapeutic Approaches for Non-Melanoma Skin Cancer: Standard of Care and Emerging Modalities.

Skin cancer encompasses a range of cutaneous malignancies, with non-melanoma skin cancers (NMSCs) being the most common neoplasm worldwide. Skin exposure is the leading risk factor for initiating NMSC. Ultraviolet (UV) light induces various genomic aberrations in both tumor-promoting and tumor-suppressing genes in epidermal cells. In conjunction with interactions with a changed stromal microenvironment and local immune suppression, these aberrations contribute to the occurrence and expansion of cancerous lesions. Surgical excision is still the most common treatment for these lesions; however, locally advanced or metastatic disease significantly increases the chances of morbidity or death. In recent years, numerous pharmacological targets were found through extensive research on the pathogenic mechanisms of NMSCs, leading to the development of novel treatments including Hedgehog pathway inhibitors for advanced and metastatic basal cell carcinoma (BCC) and PD-1/PD-L1 inhibitors for locally advanced cutaneous squamous cell carcinoma (cSCC) and Merkel cell carcinoma (MCC). Despite the efficacy of these new drugs, drug resistance and tolerability issues often arise with long-term treatment. Ongoing studies aim to identify alternative strategies with reduced adverse effects and increased tolerability. This review summarizes the current and emerging therapies used to treat NMSC.

Neoadjuvant Immunotherapy in Non-melanoma Skin Cancers of the Head and Neck.

Neoadjuvant immunotherapy will change the standard of care for advanced resectable cutaneous squamous cell carcinoma (cSCC) and possibly other non-melanoma skin cancers. With pathological complete response rates around 50% for cSCC in early studies, neoadjuvant therapy allows patients the possibility of significant reduction in tumor size, de-escalation of adjuvant therapy, and improved long-term outcomes. Patients must be carefully selected to ensure that there is a margin of safety with respect to resectability, such that if a tumor progresses on neoadjuvant therapy, there remains a curative surgical option that is acceptable to the patient. The optimal treatment paradigm is an area of active research, with many researchers questioning whether adjuvant therapy, or even local therapy, is necessary in patients who seem to have a complete response. The ability to predict who will respond will become even more critical to answer, as a significant number of patients do not want to risk their disease progressing, especially in cosmetically sensitive areas of the head and neck. Recent studies in melanoma show promise for improved response rates using combination therapies, and these strategies may apply to cSCC as well. The use of LAG-3 inhibitors or mRNA vaccine technology may further improve the utility of neoadjuvant strategies.

Recurrence Patterns of Advanced Cutaneous Squamous Cell Carcinoma of the Head and Neck.

The objective of this study was to describe risk factors and recurrence patterns that can guide the creation of evidence-based surveillance guidelines for advanced cutaneous squamous cell carcinoma of the head and neck. This was a single-institution retrospective case series. High-volume academic head and neck surgical oncology practice. Patients who underwent surgery for cutaneous squamous cell carcinoma of the head and neck staged Brigham and Women's Hospital T2b and T3 from 2003 to 2023 were reviewed. Patient demographics, clinicopathologic history, cancer data, treatment, and outcomes were abstracted. Disease-free survival and risk factors for recurrence were described. A total of 183 patients were included. Fifty-six (30.6%) experienced recurrence. This included local recurrence in 21 (11.5%), regional in 21 (13.3%), and distant in 11 (6%). The majority of regional and distant recurrences occurred within 1 year of surgery. The majority of disease recurrence occurs in the first 1 to 2 years following surgical excision of advanced-stage cutaneous squamous cell carcinoma of the head and neck. Close surveillance and frequent imaging within those years are critical to catch subclinical and distant diseases.

Previous radiotherapy increases the efficacy of cemiplimab in the treatment of locally advanced and metastatic cutaneous squamous cell carcinoma: A retrospective analysis

BackgroundCemiplimab, a PD-1 inhibitor approved in 2018 for patients with locally advanced or metastatic cutaneous squamous cell carcinoma (cSCC) who are ineligible for curative therapies, lacks clarity regarding the optimal patient selection despite its known efficacy. ObjectiveThis retrospective study aims to assess the real-world treatment patterns and outcomes in patients with cSCC at our institution. MethodsA retrospective analysis of consecutively treated patients with cemiplimab for cSCC was conducted. Progression-Free Survival (PFS) and Overall Survival (OS) were evaluated alongside clinical-pathologic characteristics. Results45 patients were included, of which 73.3% were male with a median age of 77 years. After 18 months of median follow-up median PFS and OS were not reached with a mean of 21.3 months ± 2.2 months and 25.3 ± 2.1 months, respectively. Univariate and multivariate analyses revealed significant correlations only between PFS and previous radiotherapy (p-values: 0.043 and 0.046, respectively).Limitations: limitations include its retrospective nature, the low number of patients analyzed and the potential for inherent biases. ConclusionsThe study reveals a significant association between prior radiotherapy and improved PFS in cemiplimab-treated cSCC, suggesting the potential for combining radiotherapy with cemiplimab. Further exploration of this combined approach is warranted.

Impact of cemiplimab treatment duration on clinical outcomes in advanced cutaneous squamous cell carcinoma

Treatment duration with checkpoint inhibitors must be optimized to prevent unjustified toxicity, but evidence for the management of cutaneous squamous cell carcinoma is lacking. A retrospective study was performed to evaluate the survival of patients with cutaneous squamous cell carcinoma (CSCC) who discontinued cemiplimab due to different causes and without progression. Among 95 patients with CSCC who received cemiplimab, 22 (23%) patients discontinued immunotherapy due to causes other than progression, such as comorbidities, toxicity, complete response or lack of compliance (group that discontinued before censoring [DBC]), then 73 patients had standard treatment scheduled (STS). The overall survival was 25.2 months (95% CI: 8.9–29.4) in STS group and 28.3 months (95% CI: 12.7–28.3) in the DBC group; deaths for all causes were 11/22 (50%) in the DBC group and 34/73 (46.6%) in the STS group (p = 0.32). 10/22 (45.4%) subjects died due to CSCC in the DBC after discontinuation and 34/73 (46.6%) in the STS group, and the difference between groups was not significant (p = 0.230). Duration of treatment was significantly lower in subjects with stable disease versus those with complete or partial response (16.9, 30.6 and 34.9 months, respectively; p = 0.004). Among the 22 STS patients, 12 received cemiplimab for less than 12 months (10 [83%] died) and 10 for at least 12 months (1 [10%] died). Our observation, finding no outcome difference between DBC and STS groups, suggests that ICI treatment after one year might expose patients to further treatment related events without efficacy advantages.Graphical abstract

Using serial 18F-FDG PET/CT PERCIST response to predict responses to immune check point inhibitors in patients with advanced cutaneous squamous cell carcinoma.

9548 Background: The role of serial 18F-FDG-PET/CT imaging in predicting long term efficacy of PD-1 targeted immune checkpoint inhibitor (ICI) in advanced cutaneous squamous cell carcinoma (cSCC) is unknown. This study aims to correlate PET PERCIST response with time to progressive disease. Methods: This was a single-centre retrospective study of patients treated with ICI for advanced cSCC who had baseline and serial FDG-PET/CT within 4-months of commencement of ICI. PERCST 1.0 was calculated by two radiologists independently and classified into complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease (PMD). The primary endpoint was time to progression from commencement of ICI. Progression was determined by a multidisciplinary team combining clinical and radiological assessments. Results: Of the 242 patients treated with ICI for advanced cSCC during 2018-2023, 83 (34%) patients had a serial FDG PET. Of these, 53 patients met the inclusion criteria of ≤4-months from ICI to second PET. CMR (54.7%), PMR (15.1%), SMD (11.3%) and PMD (18.9%) were seen as initial responses by PERCST 1.0. With a median follow-up of 8-months (1-55), progressive disease as determined by the multidisciplinary team was observed in 11 patients (21%). For these 11 patients, the 4-month PERCST 1.0 response was measured as CMR (n=1), PMR (N=1), SMD (N=2) and PMD (N=7). The median TTP was significantly higher in CMR/ PMR vs SMD/PMD (55 vs 4-Months, P<0.001). At data cut off, 94.6% (N=35) of patients with a 4-month PET PERCST 1.0 CMR/ PMR assessment did not progress clinically. Clinical response was maintained at a minimum of 12-months in 94.7% (n=18) of those responding. Conclusions: Rate of CMR and PMR in advanced cSCC is high with ICI. Early PET CMR/ PMR appears to predict long term durable responses. Incorporation of PET/CT into the assessment of response in cSCC may help guide treatment decisions by early identification of those patients not responding to ICI.

Primary immunotherapy monotherapy (PRIMO) in locally advanced cutaneous squamous cell carcinoma.

9585 Background: Neoadjuvant immunotherapy is a potential curative approach to patients with locally advanced cutaneous squamous cell carcinoma (cSCC) that offers an attractive alternative to traditional, often morbid surgery and/or radiation. In this study, we report our initial institutional experience treating patients with primary immunotherapy monotherapy (PRIMO) and reserving surgery or radiation for progression only. Methods: Patients with primary or recurrent locally advanced cSCC (AJCC 8 T3-4 or node positive or in-transit metastases) in whom surgical resection and/or definitive radiation were deemed excessively morbid or futile and were treated with PRIMO were included in an IRB-approved database. Patients were treated with IV cemiplimab (350mg q 3week) or pembrolizumab (200mg q3week or 400 q6week). Complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) was scored according to iRECIST criteria. Kaplan Meier analysis was used to estimate overall survival (OS) and progression free survival (PFS). Univariate analysis (UVA) for PD was performed using Chi square for categorical variables and Kruskal-Wallis for continuous variables. Results: This study included 36 patients treated between 2017-2023, with a median age of 80 (61-96), and a median follow up of 13.5 months (8-20.5). Most patients had lesions on the head and neck (32; 88.9%), recurrent disease (26; 72.2%), and T3/4N0 disease (20; 55.6%), while 18 patients (50.0%) had nodal disease or in-transit metastases. Cemiplimab was used in 31 patients (86.1%) while pembrolizumab was used for 5 patients (13.9%). Twelve patients (33.3%) stopped PRIMO due to an immune-related adverse event (irAE). 1 and 2yr OS and 1 and 2yr PFS were 76%, 64%, 72% and 51%, respectively. Best initial response to PRIMO was a CR in 15 (41.7%), PR in 14 (38.9%), SD in 3 (8.3%) and PD in 4 (11.1%) patients. All 3 lesions (100%) with SD and 3/14 lesions (21.4%) with PR ultimately progressed with a median duration of response of only 3 months (2.0-6.8), while all 15 lesions (100%) with a CR and 11/14 lesions with a PR (78.5%) remain controlled at last follow up with a median duration of response of 15.5 months (8.8 – 23.3) (p<0.001). The median duration of months of ongoing response after the completion of PRIMO was 11 (0-57). The median number of treatment cycles was 14 (2-36) in all patients, and 16 (2-36) in the 26 patients that did not progress. The only variable significantly associated with PD on UVA was the lack of irAE; 10/26 (38.5%) patients who did not have an irAE experienced PD, while 0/12 patients (0%) who had an irAE experienced PD (p=0.035). Conclusions: The use of PRIMO for locally advanced cSCC produces impressive response rates that appear durable without any additional therapy. This attractive alternative to the emerging neoadjuvant paradigm deserves prospective validation with longer term follow up.

A phase 2 study of de-escalation in resectable, locally advanced cutaneous squamous cell carcinoma (cSCC) with the use of neoadjuvant pembrolizumab: De-Squamate.

9514 Background: Neoadjuvant anti-Programmed Death therapy has shown a 64% complete or major pathological response rate in patients (pts) with resected stage II-IV(M0) cSCC. The De-Squamate study (NCT05025813) evaluated the feasibility of a risk adapted surgical de-escalation approach guided by clinical, radiological and pathological response in resectable cSCC pts of all sites receiving neoadjuvant pembrolizumab. Methods: This multi-centre, open-labelled, non-randomised, single-arm phase 2 study evaluated the response of neoadjuvant Pembrolizumab for 4 cycles administered IV 200mg Q3W in immunocompetent pts with Stage II-IV (M0) resectable cSCC. Pts underwent CT/MRI and 18F-FDG-PET imaging at baseline and following completion of neoadjuvant pembrolizumab. In those with a complete metabolic response, mapping biopsies of target site(s) were performed and if negative for residual SCC (clinical complete response [CCR]), surgery and post operative radiation therapy (PORT) were omitted. Patients with clinical or radiological residual disease/ positive mapping biopsy underwent surgical resection. PORT was de-escalated if there was a pathological complete response (PCR - no residual tumour cells) or major pathological response (MPR - less than or equal to 10% viable tumour cells). Pts proceeded to 13 cycles of maintenance Pembrolizumab. The primary endpoint was the combined rate of PCR, MPR and CCR following neoadjuvant Pembrolizumab and secondary endpoint includes treatment de-escalation and safety. Results: All 27 patients were enrolled and received a minimum of 2 cycles of neoadjuvant Pembrolizumab. The primary endpoint was observed in 17 patients (63%, 95% CI: 42-80), comprised of PCR (15%), MPR (0%) and CCR (48%). De-escalation of both surgery and PORT was achieved in 48% and a further 15% avoided PORT alone. With a minimum follow up of 6 months, no pts with PCR/MPR/CCR recurred. Investigator assessed treatment-related adverse events ≥ grade 3 was seen in 2 patients (7%). Conclusions: Pembrolizumab led to a high rate of PCR and CCR in resectable cSCC. The de-squamate study design effectively selected pts for surgical and PORT de-escalation and demonstrated a sustained response in this cohort. Clinical trial information: NCT05025813 .

Case series: Outcomes of immunotherapy in locally advanced and metastatic cutaneous squamous cell carcinoma in Lakes and Waikato region.

e21529 Background: Cutaneous squamous cell carcinomas (CSCC) have an incidence of 425 per 100,000 in New Zealand (1). 5% progress to locally advanced or metastatic disease. Immunotherapy is unfunded for this indication despite excellent response and safety profile (2). The objective was to evaluate real world outcomes of patients who managed to access immunotherapy. Methods: Review of referrals to medical oncology in the Lakes & Waikato region between 1 August 2017 to 31 August 2022 with unresectable locally advanced or metastatic CSCC who had immunotherapy. Patients who were not referred to medical oncology, could not afford immunotherapy and/or unsuitable for a clinical trial were excluded from analysis. Results: 13/15 (86.7%) reviewed were male. Mean age was 71. 7 were locally advanced and 8 were metastatic. 14 self-funded pembrolizumab (11 first line, 3 second line). 1 accessed immunotherapy via a trial. 12 (80%) had significant responses; 3 achieved a complete response and 9 achieved a partial response. Median duration of response was not reached, with a median number of 18 cycles delivered. Median follow up was 23.8 months. 9 (60%) remain alive with ongoing response. 6 died on treatment; 3 from non-malignancy and non-treatment related causes. No Grade IV toxicities were observed. Grade III transaminitis was seen in one patient. Grade I-II toxicities seen in 11 (73.3%), including arthralgia (26.7%), fatigue (20%), transaminitis (13.3%), rash (20%), hypothyroidism (6.7%), diarrhoea (6.7%) and dyspnoea (6.7%). Conclusions: Despite an elderly & comorbid cohort, immunotherapy resulted in durable responses and excellent safety profile, highlighting the unmet need for immunotherapy funding in New Zealand. More understanding is required around the different responses to anti-PD1 therapies for the same malignancy type. (1) Pondicherry A, et al. The burden of non-melanoma skin cancers in Auckland, New Zealand. Australas J Dermatol. 2018 Aug; 59(3):210-213 (2) Hughes B, et al. Pembrolizumab for locally advanced and recurrent/metastatic cutaneous squamous cell carcinoma (KEYNOTE-629 study): an open-label, nonrandomized, multicentre, phase II trial. Ann Oncol. 2021;32(10):1276-1285.

Pathologic response rates to neoadjuvant pembrolizumab in locally advanced (LA) resectable cutaneous squamous cell carcinoma (cSCC).

9591 Background: Cutaneous squamous cell carcinoma (cSCC) is the second commonest cutaneous malignancy, accounting for 20% of cutaneous malignancies and 75% of non-melanoma skin cancer deaths. Anti-PD-1 is approved in unresectable and metastatic cSCC, and is associated with high rates of pathologic response in resectable locally advanced (LA) cSCC. We conducted a phase II single-arm neoadjuvant trial of pembrolizumab (P) in patients with PD-1 naïve resectable LA cSCC. Methods: Patients with AJCC/UICC ≥T3 (or T2 with ≥2 BWH high-risk features) and/or N+ disease were eligible. Patients received 2 cycles of P (200mg Q3W) prior to definitive surgery, and 15 cycles post-surgery (NCT04808999). The primary endpoint was pathologic complete response (pCR, defined as 0% residual viable tumor, RVT) per independent central pathology review. Key secondary endpoints included incidence of adverse events (AEs), recurrence-free survival (RFS), overall survival (OS), safety and unbiased spatial biomarkers. A selected panel of multiplex immunofluorescence imaging biomarkers were used by PredxBio Inc.’s computational pipeline to reveal spatial intratumor heterogeneity in the tumor microenvironment (TME). Results: Thirty patients were enrolled and received at least 1 cycle of P. The median age was 79 (59-93) years and patients were predominantly male (77%). One patient withdrew consent prior to surgery. Three patients died prior to definitive surgery: 2 from COVID-19, a third from a NSTEMI possibly related to P. Of the 26 response-evaluable patients, AJCC/UICC stage at baseline was high-risk T2, T3, N1, and N2 in 2 (8%), 12 (46%), 9 (34.5%), and 3 (11.5%) patients, respectively. We observed pCR in 15 (57%), pathologic partial response (pPR, 10% < %RVT <50%) in 2 (8%) and pathologic non-response (pNR, >50%RVT) in 8 (31%) patients. One patient is pending surgery. Postoperative radiotherapy (RT) was de-escalated in 54% of the patients (14/15 in pCR). Median RFS was 13 (pCR) versus 10.5 (non-pCR) months. One Grade 5 (NSTEMI) and two Grade 3 (hepatitis, colitis) treatment-related AEs were observed. Computational analysis identifies key spatial interactions between PDL-1+/CD68+ cells implicated in response to P. Conclusions: Neoadjuvant P is efficacious in resectable LA cSCC with a high pCR rate (57%). Three deaths were observed, including 2 unrelated to treatment and 1 possible Grade 5 cardiac irAE, reflecting the inherent risks of perioperative therapy in this patient population. RT was de-escalated in 93% of pCR patients. No relapse events in pCR patients. Spatial interactions between PDL-1+ cells and CD68+ macrophages have a role in therapeutic response and will be detailed along with other spatial analyses of the TME compartment that have an impact on outcomes. Clinical trial information: NCT04808999 .