Characterization of the Anti–PD-1 Antibody REGN2810 and Its Antitumor Activity in Human PD-1 Knock-In Mice

Cemiplimab-Induced Hyperosmolar Hyperglycemic State With Concurrent Diabetic Ketoacidosis in a Patient Receiving Treatment for Cutaneous Squamous Cell Carcinoma

The immune checkpoint inhibitor (ICI) cemiplimab is a human monoclonal antibody used in the treatment of locally advanced and metastatic cutaneous squamous cell carcinoma (CSCC) not amenable to surgery or radiation therapy. Although cemiplimab shows excellent efficacy with a good tolerability profile, it can cause side effects, including potentially life-threatening endocrinopathies. We discuss the case of a 77-year-old Caucasian female with CSCC treated with only three cycles of cemiplimab who presented with altered mental status and was found to have severe hyperglycemia, hyperosmolarity, ketonemia, glucosuria, and ketonuria concerning for hyperosmolar hyperglycemic syndrome (HHS) with concurrent diabetic ketoacidosis (DKA). The patient made a rapid recovery in the hospital while on standard therapies for HHS/DKA and cemiplimab was discontinued upon discharge. While there have been reports of cemiplimab-induced DKA, to our knowledge, this is the first reported case of cemiplimab-induced HHS-DKA. This report aims to shed light on cemiplimab-induced HHS-DKA and to underscore the need to elucidate the molecular mechanisms underlying ICI-induced diabetes mellitus (ICI-DM).

Efficacy of Cemiplimab as Adjuvant or Neoadjuvant Therapy in the Treatment of Cutaneous Squamous Cell Carcinoma

INTRODUCTION

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer in the White population. Unfortunately, the prognosis of advanced cSCC is poor, and management can be challenging. Until recently, the choice of systemic medications was limited, and those that were available had modest efficacy. Cemiplimab is an anti-programmed cell-death protein 1 inhibitor and the first immunotherapeutic agent approved for the treatment of metastatic or locally advanced cSCC. The purpose of this study was to evaluate the efficacy of cemiplimab when used as adjuvant or neoadjuvant therapy in patients treated at our institution.

METHODS

A retrospective review of patients with locally advanced or metastatic cSCC who were treated with cemiplimab as adjuvant or neoadjuvant therapy at a single institution between February 2019 and November 2022 was performed. Response to treatment was objectively assessed based on Response Evaluation Criteria in Solid Tumors, version 1.1, criteria. The primary end point was objective response rate. Secondary endpoints included time to observed response, disease-control rate, progression-free survival, overall survival, and adverse effects of therapy.

RESULTS

A total of 6 patients were identified with a median age of 79 years (range, 51-90 years). Four patients had locally advanced cSCC, and 2 had distant metastasis. Cemiplimab was used as adjuvant therapy in 3 patients and neoadjuvant therapy in 2 patients. There was 1 patient in which it was used for limb salvage, who would have otherwise required an amputation. Objective response rate, complete response, and partial response were 66% (4 of 6), 33% (2 of 6), and 33% (2 pf 6), respectively. Average time to observed response was 2.9 months. Disease-control rate was 83% (5 of 6), and average progression-free survival was 10 months. Toxicity was reported in 2 patients, both of which were grade 1 severity.

CONCLUSIONS

Cemiplimab has established its utility in the treatment of advanced cSCC, demonstrating clinical efficacy while generally having a tolerable adverse effect profile. Our preliminary results suggest that cemiplimab has potential as an adjuvant or neoadjuvant therapy in combination with surgery for treatment of cSCC.

High response rate with extended dosing of cemiplimab in advanced cutaneous squamous cell carcinoma

BACKGROUND

Cemiplimab (Libtayo®), a human monoclonal immunoglobulin G4 antibody to the programmed cell death-1 receptor, is approved for the treatment of patients with advanced cutaneous squamous cell carcinoma (CSCC), who are not candidates for curative surgery or curative radiation, using an every-3-weeks (Q3W) dosing interval. Pharmacokinetic modeling indicated that Ctrough of extended intravenous dosing of 600 mg every 4 weeks (Q4W) would be comparable to the approved intravenous dosage of 350 mg Q3W. We examined the efficacy, pharmacokinetics, and safety of cemiplimab dosed Q4W.

METHODS

In this open-label, phase II trial (ClinicalTrials.gov identifier NCT02760498), the cohort of patients ≥18 years old with advanced CSCC received cemiplimab 600 mg intravenously Q4W for up to 48 weeks. Tumor measurements were recorded every 8 weeks. The primary endpoint was objective response rate by independent central review.

RESULTS

Sixty-three patients with advanced CSCC were treated with cemiplimab. The median duration of follow-up was 22.4 months (range: 1.0-39.8). An objective response was observed in 39 patients (62%; 95% CI: 48.8% to 73.9%), with 22% of patients (n=14) achieving complete response and 40% (n=25) achieving partial response. The most common treatment-emergent adverse events were diarrhea, pruritus, and fatigue.

CONCLUSIONS

Extended dosing of cemiplimab 600 mg intravenously Q4W exhibited substantial antitumor activity, rapid and durable responses, and an acceptable safety profile in patients with advanced CSCC. These results confirm that cemiplimab is a highly active therapy for advanced CSCC. Additional data would help ascertain the benefit-risk profile for the 600 mg intravenous dosing regimen compared with the approved regimen.

Genomic Profiling Reveals Immune-Related Gene Differences in Lung Cancer Patients Stratified by PD1/PDL1 Expression: Implications for Immunotherapy Efficacy

Lung cancer remains a leading cause of global cancer-related mortality, and the exploration of innovative therapeutic approaches, such as PD1/PDL1 immunotherapy, is critical. This study leverages comprehensive data from the Cancer Genome Atlas (TCGA) to investigate the differential expression of PD1/PDL1 in lung cancer patients and explores its implications. Clinical data, RNA expression, somatic mutations, and copy number variations of 1017 lung cancer patients were obtained from TCGA. Patients were categorized into high (HE) and low (LE) PD1/PDL1 expression groups based on mRNA levels. Analyses included differential gene expression, functional enrichment, protein-protein interaction networks, and mutational landscape exploration. The study identified 391 differentially expressed genes, with CD4 and PTPRC among the upregulated genes in the HE group. Although overall survival did not significantly differ between HE and LE groups, enrichment analysis revealed a strong association with immunoregulatory signaling pathways, emphasizing the relevance of PD1/PDL1 in immune response modulation. Notably, TP53 mutations were significantly correlated with high PD1/PDL1 expression. This study provides a comprehensive analysis of PD1/PDL1 expression in lung cancer, uncovering potential biomarkers and highlighting the intricate interplay between PD1/PDL1 and the immune response. The identified upregulated genes, including CD4 and PTPRC, warrant further investigation for their roles in the context of lung cancer and immunotherapy. The study underscores the importance of considering molecular heterogeneity in shaping personalized treatment strategies for lung cancer patients. Limitations, such as the retrospective nature of TCGA data, should be acknowledged.

Advances and challenges of first-line immunotherapy for non-small cell lung cancer: A review

The current use of immune checkpoint inhibitors (ICIs) for the treatment of lung cancer has dramatically changed the clinical strategy for metastatic non-small cell lung cancer (mNSCLC). As a result of great achievements in clinical trials, 6 programmed death-1 inhibitors (sintilimab, camrelizumab, tislelizumab, pembrolizumab, cemiplimab, and nivolumab), 2 programmed death-ligand 1 inhibitors (sugemalimab and atezolizumab), and 1 cytotoxic T lymphocyte-associated antigen-4 inhibitor (ipilimumab) have been approved as first-line treatment for mNSCLC by the US Food and Drug Administration. Recently, research on ICIs has shifted from a large number of second-line to first-line settings in clinical trials. Results from first-line trials have shown that almost all driver-negative mNSCLC are treated with ICIs and significantly prolong patient survival; however, the low response rate and adverse reactions to immunotherapy remain to be addressed. Here, we summarize the use of ICIs, including monotherapy and combination therapy, in the first-line treatment of mNSCLC in recent years and discuss the low response rate and adverse reactions of ICIs as well as the challenges and expectations for the first-line treatment of mNSCLC in the future.

Immunogenicity of Cemiplimab: Low Incidence of Antidrug Antibodies and Cut-Point Suitability Across Tumor Types

The immunogenicity of cemiplimab, a fully human immunoglobulin G4 monoclonal antibody directed against programmed cell death 1, was assessed in patients across multiple tumor types. The development of antidrug antibodies (ADAs) against cemiplimab was monitored using a validated bridging immunoassay. To identify ADA-positive samples in the assay, statistically determined cut points were established by analyzing baseline clinical study samples from a mixed population of different tumor types, and this validation cut point was used to assess immunogenicity in all subsequent studies. Regulatory guidance requires that ADA assay cut points be verified for appropriateness in different patient populations. Thus, for the cemiplimab ADA assay, we evaluated whether each new oncology population was comparable with the validation population used to set the cut point. Assay responses from 2393 individual serum samples from 8 different tumor types were compared with the validation population, using established statistical methods for cut-point determination and comparison, with no significant differences observed. Across tumor types, the immunogenicity of cemiplimab was low, with an overall treatment-emergent ADA incidence rate of 1.9% and 2.5% at intravenous dose regimens of 3 mg/kg every 2 weeks and 350 mg every 3 weeks, respectively. Moreover, no neutralizing antibodies to cemiplimab were detected in patients with ADA-positive samples, and there was no observed impact of cemiplimab ADAs on pharmacokinetics. Study-specific cut points may be required in some diseases, such as immune and inflammatory diseases; however, based on this analysis, in-study cut points are not required for each new oncology disease indication for cemiplimab.

First-line cemiplimab monotherapy and continued cemiplimab beyond progression plus chemotherapy for advanced non-small-cell lung cancer with PD-L1 50% or more (EMPOWER-Lung 1): 35-month follow-up from a mutlicentre, open-label, randomised, phase 3 trial

BACKGROUND

Cemiplimab provided significant survival benefit to patients with advanced non-small-cell lung cancer with PD-L1 tumour expression of at least 50% and no actionable biomarkers at 1-year follow-up. In this exploratory analysis, we provide outcomes after 35 months' follow-up and the effect of adding chemotherapy to cemiplimab at the time of disease progression.

METHODS

EMPOWER-Lung 1 was a multicentre, open-label, randomised, phase 3 trial. We enrolled patients (aged ≥18 years) with histologically confirmed squamous or non-squamous advanced non-small-cell lung cancer with PD-L1 tumour expression of 50% or more. We randomly assigned (1:1) patients to intravenous cemiplimab 350 mg every 3 weeks for up to 108 weeks, or until disease progression, or investigator's choice of chemotherapy. Central randomisation scheme generated by an interactive web response system governed the randomisation process that was stratified by histology and geographical region. Primary endpoints were overall survival and progression free survival, as assessed by a blinded independent central review (BICR) per Response Evaluation Criteria in Solid Tumours version 1.1. Patients with disease progression on cemiplimab could continue cemiplimab with the addition of up to four cycles of chemotherapy. We assessed response in these patients by BICR against a new baseline, defined as the last scan before chemotherapy initiation. The primary endpoints were assessed in all randomly assigned participants (ie, intention-to-treat population) and in those with a PD-L1 expression of at least 50%. We assessed adverse events in all patients who received at least one dose of their assigned treatment. This trial is registered with ClinicalTrials.gov, NCT03088540.

FINDINGS

Between May 29, 2017, and March 4, 2020, we recruited 712 patients (607 [85%] were male and 105 [15%] were female). We randomly assigned 357 (50%) to cemiplimab and 355 (50%) to chemotherapy. 284 (50%) patients assigned to cemiplimab and 281 (50%) assigned to chemotherapy had verified PD-L1 expression of at least 50%. At 35 months' follow-up, among those with a verified PD-L1 expression of at least 50% median overall survival in the cemiplimab group was 26·1 months (95% CI 22·1-31·8; 149 [52%] of 284 died) versus 13·3 months (10·5-16·2; 188 [67%] of 281 died) in the chemotherapy group (hazard ratio [HR] 0·57, 95% CI 0·46-0·71; p<0·0001), median progression-free survival was 8·1 months (95% CI 6·2-8·8; 214 events occurred) in the cemiplimab group versus 5·3 months (4·3-6·1; 236 events occurred) in the chemotherapy group (HR 0·51, 95% CI 0·42-0·62; p<0·0001). Continued cemiplimab plus chemotherapy as second-line therapy (n=64) resulted in a median progression-free survival of 6·6 months (6·1-9·3) and overall survival of 15·1 months (11·3-18·7). The most common grade 3-4 treatment-emergent adverse events were anaemia (15 [4%] of 356 patients in the cemiplimab group vs 60 [17%] of 343 in the control group), neutropenia (three [1%] vs 35 [10%]), and pneumonia (18 [5%] vs 13 [4%]). Treatment-related deaths occurred in ten (3%) of 356 patients treated with cemiplimab (due to autoimmune myocarditis, cardiac failure, cardio-respiratory arrest, cardiopulmonary failure, septic shock, tumour hyperprogression, nephritis, respiratory failure, [n=1 each] and general disorders or unknown [n=2]) and in seven (2%) of 343 patients treated with chemotherapy (due to pneumonia and pulmonary embolism [n=2 each], and cardiac arrest, lung abscess, and myocardial infarction [n=1 each]). The safety profile of cemiplimab at 35 months, and of continued cemiplimab plus chemotherapy, was generally consistent with that previously observed for these treatments, with no new safety signals INTERPRETATION: At 35 months' follow-up, the survival benefit of cemiplimab for patients with advanced non-small-cell lung cancer was at least as pronounced as at 1 year, affirming its use as first-line monotherapy for this population. Adding chemotherapy to cemiplimab at progression might provide a new second-line treatment for patients with advanced non-small-cell lung cancer.

FUNDING

Regeneron Pharmaceuticals and Sanofi.

Isatuximab in combination with cemiplimab in patients with relapsed/refractory multiple myeloma: A phase 1/2 study

BACKGROUND

Given the incurable nature of multiple myeloma (MM), efforts are made to improve the efficacy of anti-CD38 monoclonal antibodies via combinations with other potentially synergistic therapies. This Phase 1/2 trial (NCT03194867) was designed to determine whether cemiplimab (anti-PD-1) enhances the anti-myeloma activity of isatuximab (anti-CD38) in patients with relapsed and refractory multiple myeloma (RRMM), to confirm the feasibility of the combination, determine its efficacy, and further evaluate its safety.

METHODS

Patients received isatuximab 10 mg/kg once weekly for 4 weeks followed by every 2 weeks (Isa), or isatuximab 10 mg/kg plus cemiplimab 250 mg every 2 (Isa + CemiQ2W) or every 4 weeks (Isa + CemiQ4W).

RESULTS

Overall, 106 patients with RRMM treated with a median of 4 prior lines were included; 25.5% had high-risk cytogenetics, 63.2% were refractory to proteasome inhibitors and immunomodulatory agents, 26.4% were previously exposed to daratumumab, and 84.0% were refractory to their last treatment line. There were no major changes in the safety or pharmacokinetic profile of isatuximab with the addition of cemiplimab. As assessed by investigators, four patients (11.8%) in the Isa arm, nine patients (25.0%) in the Isa + CemiQ2W arm, and eight patients (22.2%) in the Isa + CemiQ4W arm were responders. Though response rates were numerically higher in cemiplimab-containing arms, differences were not statistically significant and did not translate to improved progression-free or overall survival after a median follow-up of 9.99 months.

CONCLUSION

Our results suggest a marginal benefit by adding cemiplimab to isatuximab, despite demonstration of target engagement, without additional observed safety issues.

Classic and new strategies for the treatment of advanced melanoma and non-melanoma skin cancer

Advanced melanoma and non-melanoma skin cancers (NMSCs) are burdened with a dismal prognosis. To improve the survival of these patients, studies on immunotherapy and target therapies in melanoma and NMSCs are rapidly increasing. BRAF and MEK inhibitors improve clinical outcomes, and anti-PD1 therapy demonstrates better results than chemotherapy or anti-CTLA4 therapy in terms of the survival of patients with advanced melanoma. In recent years, the combination therapy of nivolumab plus ipilimumab has gained ground in studies for its survival and response rate benefits in patients with advanced melanoma. In addition, neoadjuvant treatment for stages III and IV melanoma, either as monotherapy or combination therapy, has recently been discussed. Another promising strategy evaluated in recent studies is the triple combination of anti-PD-1/PD-L1 immunotherapy and anti-BRAF plus anti-MEK targeted therapy. On the contrary, in advanced and metastatic BCC, successful therapeutic strategies, such as vismodegib and sonidegib, are based on the inhibition of aberrant activation of the Hedgehog signaling pathway. In these patients, anti-PD-1 therapy with cemiplimab should be reserved as the second-line therapy in case of disease progression or poor response. In patients with locally advanced or metastatic SCC, who are not candidates for surgery or radiotherapy, anti-PD1 agents such as cemiplimab, pembrolizumab, and cosibelimab (CK-301) have shown significant results in terms of response rate. PD-1/PD-L1 inhibitors, such as avelumab, have also been used in Merkel carcinoma, achieving responses in half of the patients with advanced disease. The latest prospect emerging for MCC is the locoregional approach involving the injection of drugs that can stimulate the immune system. Two of the most promising molecules used in combination with immunotherapy are cavrotolimod (a Toll-like receptor 9 agonist) and a Toll-like receptor 7/8 agonist. Another area of study is cellular immunotherapy with natural killer cells stimulated with an IL-15 analog or CD4/CD8 cells stimulated with tumor neoantigens. Neoadjuvant treatment with cemiplimab in CSCCs and nivolumab in MCCs has shown promising results. Despite the successes of these new drugs, the new challenges ahead will be to select patients who will benefit from these treatments based on biomarkers and parameters of the tumor microenvironment.

Cost-effectiveness of cemiplimab plus chemotherapy versus chemotherapy for the treatment of advanced non-small cell lung cancer

Background

In patients with advanced non-small cell lung cancer (aNSCLC), cemiplimab plus chemotherapy prolonged overall survival (OS) and progression-free survival (PFS) significantly compared to chemotherapy alone. The cost-effectiveness of these drugs is still uncertain. The aim of this study is to assess the cost-effectiveness of cemiplimab plus chemotherapy compared with chemotherapy for the treatment of aNSCLC from the third-party payer perspective in the United States.

Materials and methods

The cost-effectiveness of cemiplimab with chemotherapy versus chemotherapy for the treatment of aNSCLC was evaluated using a partitioned survival model containing three mutually incompatible health states. The clinical characteristics and outcomes used in the model were gathered from EMPOWER-Lung 3 trial. We have conducted deterministic one-way sensitivity analysis and probabilistic sensitivity analysis in order to evaluate the robustness of the model. The primary outcomes considered were the costs, life-years, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratio (ICER), incremental net health benefits (INHB), and incremental net monetary benefits (INMB).

Results

Treatment of aNSCLC with cemiplimab plus chemotherapy increased efficacy by 0.237 QALYs and was associated with an increased total cost of $50,796 compared to chemotherapy alone, resulting in an ICER of $214,256/QALY gained. At a WTP threshold of $150,000/QALY, the INHB of cemiplimab plus chemotherapy was 0.203 QALYs and the INMB was $304,704 compared to chemotherapy alone. The probabilistic sensitivity analysis revealed that there was only a 0.04% chance that cemiplimab with chemotherapy would be cost-effective at a WTP threshold of $150,000/QALY. The performance of model was mainly determined by the price of cemiplimab, according to a one-way sensitivity analysis.

Conclusions

From the third-party payer perspective, cemiplimab combined chemotherapy is unlikely to be a cost-effective option for the treatment of aNSCLC at the WTP threshold of $150,000/QALY in the United States.

The Current Treatment Landscape of Cutaneous Squamous Cell Carcinoma

Non-melanoma skin cancers (NMSCs) are the most common form of skin cancer worldwide. The global incidence of cutaneous squamous cell carcinoma (CSCC) is rising, with an estimated 2.4 million cases diagnosed in 2019. Chronic exposure to ultraviolet (UV) radiation is a major risk factor for developing CSCC. Most early-stage CSCCs are treated successfully with surgery or radiotherapy; however, locally advanced or metastatic disease can be associated with significant morbidity or mortality. Recently, the treatment paradigm for advanced CSCC has been revolutionised by the introduction of immunotherapy, which can achieve a response rate of approximately 50% with durable cancer control, and significant improvement in quality of life. With the regulatory approval of programmed death-1 (PD-1)-targeting drugs since 2018, immunotherapy is now recognised as the standard of care for first-line systemic therapy in advanced or metastatic CSCC.

The High-Resolution Structure Reveals Remarkable Similarity in PD-1 Binding of Cemiplimab and Dostarlimab, the FDA-Approved Antibodies for Cancer Immunotherapy

Multiple tumors have responded well to immunotherapies, which use monoclonal antibodies to block the immune checkpoint proteins and reactivate the T-cell immune response to cancer cells. Significantly, the anti-PD-1 antibodies pembrolizumab and nivolumab, which were approved in 2014, have revolutionized cancer therapy, demonstrating dramatic improvement and longer duration. The US FDA authorized the third anti-PD-1 medication, cemiplimab, in 2018 for use in patients with cutaneous squamous cell carcinoma. To further understand the molecular mechanism of the antibody drug, we now reveal the intricate structure of PD-1 in complex with the cemiplimab Fab at a resolution of 1.98 Å. The cemiplimab-PD-1 interaction preoccupies the space for PD-L1 binding with a greater binding affinity than the PD-1/PD-L1 interaction, which is the basis for the PD-1 blocking mechanism. The structure reveals that cemiplimab and dostarlimab are significantly similar in PD-1 binding, although the precise interactions differ. A comparative investigation of PD-1 interactions with the four FDA-approved antibodies reveals that the BC, C'D, and FG loops of PD-1 adopt distinct conformations for optimal interaction with the antibodies. The structural characteristics in this work could be helpful information for developing more potent anti-PD-1 biologics against cancer.

Population pharmacokinetics modeling and exposure-response analyses of cemiplimab in patients with recurrent or metastatic cervical cancer

A population pharmacokinetic (PopPK) model was previously developed for cemiplimab in patients with solid tumors, including advanced cutaneous squamous cell carcinoma (CSCC). Here, we update the existing PopPK model and characterize exposure-response relationships using efficacy and safety data obtained in patients with recurrent or metastatic cervical cancer (R/M CC). To improve model stability and robustness of the existing PopPK model in 1062 patients, the random-effect error model was revised, and structural covariates were removed from the base model to be tested in the covariate analysis. The updated model was used for external validation of cemiplimab pharmacokinetics (PK) in patients with R/M CC on cemiplimab monotherapy (350 mg every 3 weeks intravenously) from a phase III study (NCT03257267). Exposure-response relationships for cemiplimab efficacy (overall survival [OS], progression-free survival [PFS], duration of response [DOR], objective response rate [ORR]), and safety (immune-related adverse events [irAEs]) were analyzed in 295 patients with R/M CC from the aforementioned study. The updated PopPK model showed improved stability with 94.8% successful bootstrap runs vs. 47.6% in the prior model. Cemiplimab exposure was similar across tumor types, including basal cell carcinoma, CSCC, and non-small cell lung cancer. External validation showed the updated model adequately described cemiplimab PK in patients with R/M CC. In exposure-response efficacy analyses, Cox proportional hazard modeling (CPHM) showed no trend between exposure and OS, Kaplan-Meier plots showed no trend between exposure and PFS or DOR, and logistic regression analyses conducted on ORR showed no exposure-response relationship. In exposure-response safety analyses, CPHM showed no trend between exposure and irAEs.

Molecular Mechanisms and Targeted Therapies of Advanced Basal Cell Carcinoma

Among human cutaneous malignancies, basal cell carcinoma is the most common. Solid advances in unveiling the molecular mechanisms of basal cell carcinoma have emerged in recent years. In Gorlin syndrome, which shows basal cell carcinoma predisposition, identification of the patched 1 gene (PTCH1) mutation was a dramatic breakthrough in understanding the carcinogenesis of basal cell carcinoma. PTCH1 plays a role in the hedgehog pathway, and dysregulations of this pathway are known to be crucial for the carcinogenesis of many types of cancers including sporadic as well as hereditary basal cell carcinoma. In this review, we summarize the clinical features, pathological features and hedgehog pathway as applied in basal cell carcinoma. Other crucial molecules, such as p53 and melanocortin-1 receptor are also discussed. Due to recent advances, therapeutic strategies based on the precise molecular mechanisms of basal cell carcinoma are emerging. Target therapies and biomarkers are also discussed.

Pembrolizumab vs cemiplimab for the treatment of advanced non-small cell lung cancer with PD-L1 expression levels of at least 50%: A network meta-analysis and cost-effectiveness analysis

Background

Pembrolizumab and cemiplimab have been approved as treatment for advanced non-small-cell lung cancer (NSCLC) with high programmed death ligand-1 (PD-L1) expression. This study aimed to evaluate the cost-effectiveness of pembrolizumab compared with that of cemiplimab in the treatment of advanced NSCLC with high PD-L1 expression from a societal perspective in the United States.

Materials and methods

Cost-effectiveness analysis integration of the network meta-analysis framework was performed using data from the EMPOWER-Lung 1, KEYNOTE 024, and KEYNOTE 042 phase 3 randomized clinical trials. A network meta-analysis including 2289 patients was constructed, and the Markov and partitioned survival (PS) models were used to assess the cost-effectiveness of pembrolizumab compared with that of cemiplimab for the treatment of high PD-L1 expression (≥50% of tumor cells). The time horizon was 10 years. The main outcomes were overall costs, incremental cost-effectiveness ratios (ICERs), quality-adjusted life-years (QALYs), life-years, incremental net health benefits (INHB), and incremental net monetary benefits (INMB). The robustness of the model was verified using one-way and probabilistic sensitivity analyses, and subgroup analyses were conducted.

Results

Treatment of advanced NSCLC with high PD-L1 expression with pembrolizumab achieved 0.093 QALYs and was associated with an incremental cost of $10,657 compared with cemiplimab, yielding an ICER of $114,246/QALY. The ICER in the PS model was similar to that in the Markov model, with a difference of $3,093/QALY. At a willingness-to-pay (WTP) threshold of $100,000/QALY, INHB, and INMB of pembrolizumab were -0.013 QALYs and -$1,329, respectively, and the probability of cemiplimab was 51% when compared with pembrolizumab. When the WTP threshold increased to $150,000/QALY, the INHB and INMB of pembrolizumab were 0.022 QALYs and $3,335, respectively, and the probability of pembrolizumab was 51.85%. One-way sensitivity analysis indicated that the models were sensitive to pembrolizumab and cemiplimab costs. Subgroup analysis revealed that treatment with pembrolizumab was related to a higher INHB in several subgroups, including patients with brain metastases at baseline.

Conclusion

Our findings suggest that the WTP threshold should be considered when choosing between cemiplimab and pembrolizumab to treat advanced NSCLC with high PD-L1 expression. Reducing the cost of pembrolizumab may lead to valuable outcomes.

Emerging immune checkpoint inhibitors for the treatment of non-small cell lung cancer

INTRODUCTION

Over the last decade, immune checkpoint inhibitors (ICIs) have impacted on the standard therapy for patients with non-small cell lung cancer (NSCLC). ICIs first showed efficacy in patients with advanced disease who had progressed after chemotherapy, later reaching the first-line therapy context alone, in combination with chemotherapy, and/or with dual-immunotherapy regimens.

AREAS COVERED

Most of their benefit is, however, restricted to just 20% of patients due to primary or emergence of acquired resistance. In this review, we will describe the role of new emerging ICIs in the current panorama of NSCLC therapeutic approaches, not only in metastatic disease but also in locally advanced stage disease, with specific focus on those drugs under investigation in Phase 2/3 clinical trials.

EXPERT OPINION

Several new ICIs are now under investigation to optimize NSCLC patient management; these are usually used in combination with other well-known agents, such as 'traditional' ICIs and chemotherapy, or with other newly developed drugs. Identification of better biomarkers will provide personalized treatment approaches to overcome patient-specific immune resistance.

Cemiplimab and Cutaneous Squamous Cell Carcinoma: From Bench to Bedside

Non-melanoma skin cancers (NMSCs) are the most common cancer in fair-skinned individuals with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) being the most common subtype. While BCC has historically been the most common NMSC, SCC is increasing in incidence relative to BCC. SCC has a very poor prognosis with advanced local infiltration or when it achieves a metastatic state with around 50% of patients with locally advanced disease relapsing with an average overall survival of 10–13 months for patients with recurrent or metastatic disease.

The pathogenesis of cutaneous SCC (cSCC) is multifactorial, and many studies have also described in detail the strong link between tumour apoptosis, DNA repair mechanism deficiencies, and developing cSCC. Patients with TP53 mutations are more susceptible to develop cSCC, thus highlighting the importance of cell cycle regulation and also pointing towards the potential therapeutic targets within.

This review illustrates the role of the programmed death receptor-1 (PD-1) inhibitor cemiplimab in treating advanced and metastatic cSCC not suitable to surgical excision and describes its development in the context of the translational research paradigm from preclinical studies to its licenced implementation in clinical care and beyond.

Evolution of Preclinical Characterization and Insights into Clinical Pharmacology of Checkpoint Inhibitors Approved for Cancer Immunotherapy

Cancer immunotherapy has significantly advanced the treatment paradigm in oncology, with approvals of immuno‐oncology agents for over 16 indications, many of them first line. Checkpoint inhibitors (CPIs) are recognized as an essential backbone for a successful anticancer therapy regimen. This review focuses on the US Food and Drug Administration (FDA) regulatory approvals of major CPIs and the evolution of translational advances since their first approval close to a decade ago. In addition, critical preclinical and clinical pharmacology considerations, an overview of the pharmacokinetic and dose/regimen aspects, and a discussion of the future of CPI translational and clinical pharmacology as combination therapy becomes a mainstay of industrial immunotherapy development and in clinical practice are also discussed.

Comparative Efficacy and Safety of Anti-PD-1/PD-L1 for the Treatment of Non-Small Cell Lung Cancer: A Network Meta-Analysis of 13 Randomized Controlled Studies

Objective

The present network meta-analysis (NMA) was conducted to summarize the direct and indirect evidence of common programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitors including avelumab, atezolizumab, cemiplimab, nivolumab, and pembrolizumab for the treatment of non-small cell lung cancer (NSCLC) patients and further to determine the optimal therapeutic regimen.

Methods

We performed a systematic literature search to identify all potentially eligible studies in PubMed, Embase, and the Cochrane Library until August 7, 2021. The primary outcome was overall survival (OS), and the second outcome was treatment-related adverse events (TRAEs). We used random-effects model to conduct direct and network meta-analyses, which were performed by using RevMan 5.3 and R version 3.6.1, respectively.

Results

Direct meta-analysis suggested that atezolizumab, cemiplimab, nivolumab, or pembrolizumab significantly improved OS compared with chemotherapy (CT), and NMA further established that atezolizumab [hazard ratio (HR), 0.77; 95% CrI, 0.62-0.96], nivolumab (HR, 0.75; 95% CrI, 0.62-0.93), or pembrolizumab (HR, 0.71; 95% Credible interval (Crl), 0.57-0.89) significantly and cemiplimab (HR, 0.68; 95% CrI, 0.46-1.02) numerically improved OS compared with CT. Meanwhile, NMA also indicated that cemiplimab was numerically superior to other PD-1/PD-L1 agents. Moreover, avelumab, atezolizumab, cemiplimab, nivolumab, and pembrolizumab were found to have fewer TRAEs compared with CT in direct meta-analysis, which were supported by the results from the NMA. Meanwhile, surface under the cumulative ranking curve (SUCRA) and ranking probability suggested that cemiplimab provided the most favorable balance between efficacy and safety, with the first ranking for the OS.

Conclusions

Based on available evidence, cemiplimab may have the most favorable risk-benefit ratio for NSCLC patients compared with other common therapeutic management. However, future research with a large-scale, high-quality, and mature follow-up is needed to further determine which agents should be preferentially selected for NSCLC patients due to the limitations of our NMA and variations of eligible studies in treatment line and PD-L1 status.

Molecular Mechanisms of Cutaneous Squamous Cell Carcinoma

Non-melanoma skin cancers are cutaneous malignancies representing the most common form of cancer in the United States. They are comprised predominantly of basal cell carcinomas and squamous cell carcinomas (cSCC). The incidence of cSCC is increasing, resulting in substantial morbidity and ever higher treatment costs; currently in excess of one billion dollars, per annum. Here, we review research defining the molecular basis and development of cSCC that aims to provide new insights into pathogenesis and drive the development of novel, cost and morbidity saving therapies.

PD-1 N58-Glycosylation-Dependent Binding of Monoclonal Antibody Cemiplimab for Immune Checkpoint Therapy

Immune checkpoint therapy (ICT) with a monoclonal antibody (MAb) against programmed cell death protein 1 (PD-1) is a powerful clinical treatment for tumors. Cemiplimab is a human IgG4 antibody approved in 2018 and is the first MAb proven to be effective for locally advanced basal cell carcinoma. Here, we report the crystal structure of cemiplimab bound to PD-1 and the effects of PD-1 N-glycosylation on the interactions with cemiplimab. The structure of the cemiplimab/PD-1 complex shows that cemiplimab mainly binds to PD-1 with its heavy chain, whereas the light chain serves as the predominant region to compete with the binding of PD-L1 to PD-1. The interaction network of cemiplimab to PD-1 resembles that of camrelizumab (another PD-1-binding MAb), and the N58 glycan on the BC loop of PD-1 may be involved in the interaction with cemiplimab. The binding affinity of cemiplimab with PD-1 was substantially decreased with N58-glycan-deficient PD-1, whereas the PD-1/PD-L1 blocking efficiency of cemiplimab was attenuated upon binding to the N58-glycosylation-deficient PD-1. These results indicate that both the binding and blocking efficacy of cemiplimab require the N58 glycosylation of PD-1. Taken together, these findings expand our understanding of the significance of PD-1 glycosylation in the interaction with cemiplimab.

Infrequent liver injury from cemiplimab in patients with advanced cutaneous squamous cell carcinoma

Aim: To describe the incidence and outcomes of liver injury in patients with advanced cutaneous squamous cell carcinoma (cSCC) receiving cemiplimab. Methods: Charts of cSCC patients receiving cemiplimab between 28 September 2018 and 14 July 2020 were reviewed. Liver injury was determined using laboratory criteria, and causality assessment was completed. Results: Of 39 cemiplimab-treated patients, four (10.3%) developed liver injury. Two cases of hepatotoxicity were attributed to immune-mediated liver injury caused by cemiplimab and the two other cases were attributed to other causes. The four patients with liver injury had tumor responses and survival similar to those of the patients without liver injury. Conclusion: Liver injury arising during cemiplimab therapy is mild and infrequent in cSCC patients. Due to its favorable safety profile, cemiplimab should be considered in patients with cSCC and pre-existing liver disease.

Neoadjuvant cemiplimab for resectable hepatocellular carcinoma: a single-arm, open-label, phase 2 trial

BACKGROUND

Surgical resection of early stage hepatocellular carcinoma is standard clinical practice; however, most tumours recur despite surgery, and no perioperative intervention has shown a survival benefit. Neoadjuvant immunotherapy has induced pathological responses in multiple tumour types and might decrease the risk of postoperative recurrence in hepatocellular carcinoma. We aimed to evaluate the clinical activity of neoadjuvant cemiplimab (an anti-PD-1) in patients with resectable hepatocellular carcinoma.

METHODS

For this single-arm, open-label, phase 2 trial, patients with resectable hepatocellular carcinoma (stage Ib, II, and IIIb) were enrolled and received two cycles of neoadjuvant cemiplimab 350 mg intravenously every 3 weeks followed by surgical resection. Eligible patients were aged 18 years or older, had confirmed resectable hepatocellular carcinoma, an Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate liver function. Patients were excluded if they had metastatic disease, if the surgery was not expected to be curative, if they had a known additional malignancy requiring active treatment, or if they required systemic steroid treatment or any other immunosuppressive therapy. After resection, patients received an additional eight cycles of cemiplimab 350 mg intravenously every 3 weeks in the adjuvant setting. The primary endpoint was significant tumour necrosis on pathological examination (defined as >70% necrosis of the resected tumour). Secondary endpoints included delay of surgery, the proportion of patients with an overall response, change in CD8+ T-cell density, and adverse events. Tumour necrosis and response were analysed in all patients who received at least one dose of cemiplimab and completed surgical resection; safety and other endpoints were analysed in the intention-to-treat population. Patients underwent pre-treatment biopsies and blood collection throughout treatment. This trial is registered with ClinicalTrials.gov (NCT03916627, Cohort B) and is ongoing.

FINDINGS

Between Aug 5, 2019, and Nov 25, 2020, 21 patients were enrolled. All patients received neoadjuvant cemiplimab, and 20 patients underwent successful resection. Of the 20 patients with resected tumours, four (20%) had significant tumour necrosis. Three (15%) of 20 patients had a partial response, and all other patients maintained stable disease. 20 (95%) patients had a treatment-emergent adverse event of any grade during the neoadjuvant treatment period. The most common adverse events of any grade were increased aspartate aminotransferase (in four patients), increased blood creatine phosphokinase (in three), constipation (in three), and fatigue (in three). Seven patients had grade 3 adverse events, including increased blood creatine phosphokinase (in two patients) and hypoalbuminaemia (in one). No grade 4 or 5 events were observed. One patient developed pneumonitis, which led to a delay in surgery by 2 weeks.

INTERPRETATION

This report is, to our knowledge, the largest clinical trial of a neoadjuvant anti-PD-1 monotherapy reported to date in hepatocellular carcinoma. The observed pathological responses to cemiplimab in this cohort support the design of larger trials to identify the optimal treatment duration and definitively establish the clinical benefit of preoperative PD-1 blockade in patients with hepatocellular carcinoma.

FUNDING

Regeneron Pharmaceuticals.

Immunotherapy (Cemiplimab)-Induced Bullous Pemphigoid: A Possible Pitfall in 18F-FDG PET/CT

ABSTRACT

A 78-year-old man with multiple squamous cell carcinomas of the skin underwent 18F-FDG-PET/CT for restaging after 4 cycles of cemiplimab. The scan showed new disseminated FDG-avid skin lesions. Dermatologic examination and biopsy revealed bullous pemphigoid. Discontinuation of cemiplimab and treatment with corticosteroids led to clinical improvement, after which treatment with cemiplimab was resumed. A broad spectrum of inflammatory adverse events can occur in patients treated with immune checkpoint inhibitors, and FDG avidity of these lesions may mimic metastases. Knowledge of such imaging pitfalls is essential for interpreting 18F-FDG-PET/CT, particularly if they occur in the same organ as the primary tumor.

Update on Management Recommendations for Advanced Cutaneous Squamous Cell Carcinoma

Simple Summary

Cutaneous squamous cell carcinoma (cSCC) is the second most common form of skin cancer, which predominantly occurs on the head and neck. Early detection and treatment of primary tumours is crucial to limit progression and local invasion of deep tissues. While high-risk markers of poor prognosis have been identified, factors predicting regional control or survival remain uncertain. Therefore, diagnosis and management of cSCC should be performed individually, considering patient’s clinicopathological profile and the best available treatment options. Surgical excision, radiotherapy, and/or systemic treatments can be selected depending on patient’s status and tumour stage. Considering that a more comprehensive assessment will be provided by a multidisciplinary team, we aimed to generate a practical document that may assist oncologists and dermatologists on the prognosis, diagnosis, management, and follow-up of patients with advanced cSCC.

Abstract

Cutaneous squamous cell carcinoma (cSCC) is the second most common form of skin cancer, the incidence of which has risen over the last years. Although cSCC rarely metastasizes, early detection and treatment of primary tumours are critical to limit progression and local invasion. Several prognostic factors related to patients’ clinicopathologic profile and tumour features have been identified as high-risk markers and included in the stratification scales, but their association with regional control or survival is uncertain. Therefore, decision-making on the diagnosis and management of cSCC should be made based on each individual patient’s characteristics. Recent advances in non-invasive imaging techniques and molecular testing have enhanced clinical diagnostic accuracy. Surgical excision is the mainstay of local treatment, whereas radiotherapy (RT) is recommended for patients with inoperable disease or in specific circumstances. Novel systemic treatments including immunotherapies and targeted therapies have changed the therapeutic landscape for cSCC. The anti-PD-1 agent cemiplimab is currently the only FDA/EMA-approved first-line therapy for patients with locally advanced or metastatic cSCC who are not candidates for curative surgery or RT. Given the likelihood of recurrence and the increased risk of developing multiple cSCC, close follow-up should be performed during the first years of treatment and continued long-term surveillance is warranted.

Cemiplimab plus chemotherapy versus chemotherapy alone in non-small cell lung cancer: a randomized, controlled, double-blind phase 3 trial

First-line cemiplimab (anti-programmed cell death-1 (PD-1)) monotherapy has previously shown significant improvement in overall survival (OS) and progression-free survival (PFS) versus chemotherapy in patients with advanced non-small cell lung cancer (aNSCLC) and PD-ligand 1 (PD-L1) expression ≥50%. EMPOWER-Lung 3 ( NCT03409614 ), a double-blind, placebo-controlled, phase 3 study, examined cemiplimab plus platinum-doublet chemotherapy as first-line treatment for aNSCLC, irrespective of PD-L1 expression or histology. In this study, 466 patients with stage III/IV aNSCLC without EGFR, ALK or ROS1 genomic tumor aberrations were randomized (2:1) to receive cemiplimab 350 mg (n = 312) or placebo (n = 154) every 3 weeks for up to 108 weeks in combination with four cycles of platinum-doublet chemotherapy (followed by pemetrexed maintenance as indicated). In total, 57.1% (266/466 patients) had non-squamous NSCLC, and 85.2% (397/466 patients) had stage IV disease. The primary endpoint was OS. The trial was stopped early per recommendation of the independent data monitoring committee, based on meeting preset OS efficacy criteria: median OS was 21.9 months (95% confidence interval (CI), 15.5-not evaluable) with cemiplimab plus chemotherapy versus 13.0 months (95% CI, 11.9-16.1) with placebo plus chemotherapy (hazard ratio (HR) = 0.71; 95% CI, 0.53-0.93; P = 0.014). Grade ≥3 adverse events occurred with cemiplimab plus chemotherapy (43.6%, 136/312 patients) and placebo plus chemotherapy (31.4%, 48/153 patients). Cemiplimab is only the second anti-PD-1/PD-L1 agent to show efficacy in aNSCLC as both monotherapy and in combination with chemotherapy for both squamous and non-squamous histologies.

Diabetic ketoacidosis as a hallmark of autoimmune diabetes occurring after two cycles of cemiplimab

INTRODUCTION

Clinical indications of immune checkpoint inhibitors have expanded to a variety of malignancies. Nearly 50% of patients with advanced cutaneous squamous cell carcinoma, respond to the programmed-death 1 inhibitor cemiplimab. To date, insulin-dependent diabetes mellitus has been documented with the use of several immune checkpoint inhibitors but not cemiplimab.

CASE REPORT

We report herein the first case of a patient with cutaneous squamous cell carcinoma who developed diabetic ketoacidosis and insulin-dependent diabetes mellitus following only two cycles of cemiplimab. A score of 6 on the Naranjo nomogram makes the causality relationship between cemiplimab use and the insulin-dependent diabetes mellitus probable.

MANAGEMENT AND OUTCOME

The patient's developed diabetic ketoacidosis was managed with intravenous fluids and intravenous insulin, with a prompt resolution. Cemiplimab was discontinued, and the patient was discharged on long-acting and short-acting insulin therapy, with a follow-up with endocrinology.

DISCUSSION/CONCLUSIONS

The mechanism by which cemiplimab caused insulin-dependent diabetes mellitus is most likely due to lack of endogenous insulin production in the setting of immune-mediated loss of pancreatic beta-cells. Patients may benefit from fasting blood glucose monitoring and early immune checkpoint inhibitor discontinuation where elevated serum glucose is detected.

Cemiplimab for the treatment of advanced cutaneous squamous cell carcinoma

INTRODUCTION

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent malignant skin cancer, with an increasing worldwide incidence. Cemiplimab is a human monoclonal antibody directed against programmed cell death-1 receptor that acts by blocking T-cell inactivation. It is the first drug approved for the treatment of adult patients with metastatic or locally advanced cutaneous squamous cell carcinoma who are not candidates for curative surgery or curative radiation.

AREAS COVERED

The aim of this review is to analyze the mechanism of action, including pharmacokinetic and pharmacodynamic properties, clinical efficacy, safety, and tolerability of cemiplimab for squamous cell carcinoma.

EXPERT OPINION

The introduction of immune checkpoint inhibitors has revolutionized the therapeutic scenario of advanced skin cancers. Many challenges regarding the use of cemiplimab for locally advanced and metastatic CSCC still exist. The use of combination treatments, including the association of different immune checkpoint inhibitors, could be a strategy to increase treatment response, reducing the possibility of therapeutic failure. Also, different schemes of treatment or dose adjustments should be considered in order to reduce toxicity, avoiding treatment discontinuation and increasing patient´s quality of life.

Cemiplimab in advanced cutaneous squamous cell carcinoma

Cemiplimab, a high-affinity, highly potent human monoclonal antibody that binds to the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) receptor, is the only drug to attain Food and Drug Administration (FDA) approval and marketing authorization from the European Commission for use in patients with metastatic and locally advanced cutaneous squamous cell carcinoma (CSCC) who are not candidates for curative surgery or curative radiation therapy as a first- or later-line treatment. In pivotal phase II clinical testing, cemiplimab showed rapid and substantial antitumor efficacy and acceptable safety. This systematic review was aimed at evaluating the efficacy and safety of cemiplimab in patients with advanced CSCC. To this end, I reviewed EMBASE, MEDLINE, PubMed, and clinical trial registries/databases by using the following keywords alone or in combination: "cemiplimab," "Libtayo," "cutaneous squamous cell carcinoma," "REGN2810," and "SER439684." Cemiplimab showed clinical efficacy and considerable safety and was associated with low rates of treatment discontinuation (7%) and death (3%). However, the current recommendation is primarily based on only phase II clinical testing due to the absence of an approved comparator agent.

Immune Checkpoint Inhibitors for Advanced Cutaneous Squamous Cell Carcinoma: A Systematic Review with Meta-Analysis

BACKGROUND

Results of early trials led to FDA approval of immune checkpoint inhibitors (ICIs) for advanced and recurrent/metastatic (R/M) cutaneous squamous cell carcinoma (CSCC). Updated data from these trials are pending and extent of survival outcomes is undetermined.

OBJECTIVE

The aim of this study was to assess the efficacy of ICIs in advanced CSCC, comprising locally advanced (LA), locoregionally advanced (LR), and recurrent or metastatic (R/M) disease.

PATIENTS AND METHODS

A systematic review of four databases (PubMed, Scopus, OVID, Cochrane) and meta-analysis of proportions was performed. Phase I and II prospective clinical trials were included.

RESULTS

Six trials evaluating cemiplimab (n = 3) and pembrolizumab (n = 3) were eligible for inclusion. Overall survival (OS) was not reached at data-cutoff. Pooled analysis of 392 patients demonstrated that ICIs conferred an objective response rate (ORR) of 42.43% (95% CI 37.53-47.45) and disease control rate (DCR) of 58.05% (95% CI 53.04-62.95). Patients with LR or distant metastatic lesions achieved equivalent ORRs and DCRs. Duration of response (DOR) was not reached in all trials and 92% of all responders continued to have therapeutic response at data cut-off. Tolerability was favorable, with only 27.12% (95% CI 10.89-47.38) of patients experiencing grade ≥ 3 adverse events.

CONCLUSION

Surgical treatment of CSCC remains the guideline-based standard of care for curative intent of local, LA, and LR disease. ICIs demonstrate promising results for LA, LR, and R/M CSCC not amenable to surgery. Endpoints assessing survival and durability of response have not been reached, warranting additional trials exploring neoadjuvant or adjuvant therapy in combination with local treatment.

A HER2 target antibody drug conjugate combined with anti-PD-(L)1 treatment eliminates hHER2+ tumors in hPD-1 transgenic mouse model and contributes immune memory formation

PURPOSE

Disitamab vedotin (RC48) is an HER2-directed antibody-drug conjugate, emerging as an effective strategy for cancer therapy, which not only enhances antitumor immunity in previous animal models but also improves clinical outcomes for patients such as with gastric cancer, urothelium carcinoma, and HER2 low-expressing breast cancer. Here, we explore the combination therapeutic efficacy of this novel HER2-targeting ADC with immune checkpoint inhibitors in a human HER2-expressing syngeneic breast cancer model.

METHODS

The human HER2+ cancer cell line is constructed by stable transfection and individual clones were isolated by single-cell sorting. Flow cytometry was performed to determine its binding activity. Cytotoxic effect was determined using an MTT assay with the supplement of RC48. Human PD-1 transgenic mice were used to analyze the in vivo antitumor effects of the ADC and its combination therapy with PD-1/PD-L1 antibody.

RESULTS

The combination of RC48 and PD-1/PD-L1 immune checkpoint inhibition significantly enhanced tumor suppression and antitumor immunity. Tumor rejection in the synergistic groups was accompanied by massive T cell infiltration and immune marker activation. Furthermore, the combination therapy promoted immunological memory formation in the tumor eradication animals, protecting them from tumor rechallenge.

CONCLUSION

A novel HER2-targeting ADC combined with immune checkpoint inhibitors can achieve remarkable effects in mice and elicit long-lasting immune protection in a hHER2+ murine breast cancer model. This study provides insights into the efficacy of RC48 therapeutic activity and a rationale for potential therapeutic combination strategies with immunotherapy.

Case Report: Autoimmune Pemphigus Vulgaris in a Patient Treated With Cemiplimab for Multiple Locally Advanced Cutaneous Squamous Cell Carcinoma

BACKGROUND

Pemphigus vulgaris (PV) is a rare and severe autoimmune blistering disorder affecting the skin and mucous membranes, characterized by the production of autoantibodies against two desmosomal adhesion proteins, desmoglein 1 and 3. In patients with advanced squamous cell carcinoma of the skin unfit for surgery and radiotherapy, immune check-point inhibitors, including the anti-Programmed Death-1 (PD-1) agent cemiplimab have been successfully employed proving relevant clinical outcomes. Cemiplimab is a monoclonal antibody capable of inhibiting PD-1 signalling that has recently been approved for the treatment of patients with metastatic or locally advanced cutaneous squamous cell carcinoma. Although the peculiar setting of advanced CSCC involving elderly patients, rare and unusual skin immune-related adverse events such as PV could be observed in cemiplimab treated patients.

CASE REPORT

A 95-year-old man without a history of autoimmune disease was treated with cemiplimab for multiple and advanced squamous cell carcinomas of the head obtaining a complete response to therapy. After seven cycles of cemiplimab administered every 21 days, the patient developed a mucocutaneous blistering eruption. Clinical diagnosis of PV was suspected on the basis of the diffuse involvement of trunk and extremities with large blisters and necrotic eschar. It was carried out an ELISA test, that showed high level of circulating antibodies against desmoglein 1, thus confirming the diagnosis of PV. For this reason, cemiplimab infusion was discontinued and complete resolution of skin lesions was obtained using oral prednisone 0,8 mg/kg/daily for four weeks. Once remission was achieved, a maintenance dose of 10 mg/day was administered, observing a good control of bullous disease and low value of desmoglein 1. Response to CSCC persisted also during cemiplimab discontinuation, until obtaining a complete remission still persisting at 9 months after the last cycle of therapy.

CONCLUSION

The case we observed is the first description of PV revealed from cemiplimab therapy, thus suggesting that cemiplimab could allow the arise of underlying autoimmune PV, through a mechanism both T and B-cell-mediated.

Integrated analysis of a phase 2 study of cemiplimab in advanced cutaneous squamous cell carcinoma: extended follow-up of outcomes and quality of life analysis

Background

To provide pooled longer term data from three groups of a phase 2 study of cemiplimab in patients with advanced cutaneous squamous cell carcinoma (CSCC), and to determine duration of response (DOR) and impact on quality of life (QoL).

Methods

Patients received cemiplimab 3 mg/kg every 2 weeks (group 1, metastatic CSCC [mCSCC], n=59; group 2, locally advanced CSCC, n=78) or cemiplimab 350 mg every 3 weeks (group 3, mCSCC, n=56). Primary endpoint was objective response rate (ORR) per independent central review (ICR). QoL was repeatedly measured at day 1 of each treatment cycle (groups 1 and 2: 8 weeks; group 3: 9 weeks).

Results

Median duration of follow-up was 15.7 months. Overall, ORR per ICR was 46.1% (95% CI: 38.9% to 53.4%). Complete response (CR) rates were 20.3%, 12.8%, and 16.1% for groups 1, 2, and 3, respectively. Median time to CR was 11.2 months. Among patients with partial response or CR, the estimated proportion of patients with ongoing response at 12 months from the first objective response was 87.8% (95% CI: 78.5% to 93.3%), with median DOR not reached. Kaplan-Meier estimated probability of overall survival (OS) was 73.3% (95% CI: 66.1% to 79.2%) at 24 months, with median OS not reached. Global Health Status (GHS)/QoL improvements were observed as early as cycle 2 and were significantly improved and durable until last assessment. Kaplan-Meier estimate of median time to first clinically meaningful improvement for pain was 2.1 (95% CI: 2.0 to 3.7) months and was significantly improved in responders versus non-responders (p<0.0001).

Conclusions

This is the largest (n=193) clinical dataset for a programmed cell death-1 inhibitor against advanced CSCC, confirming the sustained substantial clinical activity of cemiplimab in these patients, including new findings of improved CR rates over time, increasing DOR, and durable pain control and GHS/QoL improvement.

Trial registration number

ClinicalTrials.gov Registry (NCT02760498), https://clinicaltrialsgov/ct2/show/NCT02760498.

Neutralization of PD-L2 is Essential for Overcoming Immune Checkpoint Blockade Resistance in Ovarian Cancer

PURPOSE

Ovarian cancer represents a major clinical hurdle for immune checkpoint blockade (ICB), with reported low patient response rates. We found that the immune checkpoint ligand PD-L2 is robustly expressed in patient samples of ovarian cancers and other malignancies exhibiting suboptimal response to ICB but not in cancers that are ICB sensitive. Therefore, we hypothesize that PD-L2 can facilitate immune escape from ICB through incomplete blockade of the PD-1 signaling pathway.

EXPERIMENTAL DESIGN

We engineered a soluble form of the PD-1 receptor (sPD-1) capable of binding and neutralizing both PD-L2 and PD-L1 with ×200 and ×10,000 folds improvement in binding affinity over wild-type PD-1 leading to superior inhibition of ligand-mediated PD-1 activities.

RESULTS

Both in vitro and in vivo analyses performed in this study demonstrated that the high-affinity sPD-1 molecule is superior at blocking both PD-L1- and PD-L2-mediated immune evasion and reducing tumor growth in immune-competent murine models of ovarian cancer.

CONCLUSIONS

The data presented in this study provide justification for using a dual targeting, high-affinity sPD-1 receptor as an alternative to PD-1 or PD-L1 therapeutic antibodies for achieving superior therapeutic efficacy in cancers expressing both PD-L2 and PD-L1.

Cost-Effectiveness Analysis of Cemiplimab Versus Chemotherapy as First-Line Treatment in Advanced NSCLC with PD-L1 Expression Levels of at Least 50

INTRODUCTION

Cemiplimab may significantly increase overall survival in the first-line treatment of advanced non-small cell lung cancer (NSCLC) with a PD-L1 level of at least 50%. Therefore, there is a need to consider the cost-effectiveness of using this therapy for this indication.

METHODS

This Markov model was built to estimate the cost and effectiveness of cemiplimab vs. chemotherapy in the first-line treatment of advanced NSCLC based on the data from the EMPOWER-Lung 1 trial. Life-years (LYs), quality-adjusted LYs (QALYs) and lifetime costs were estimated. One-way and probabilistic sensitivity analyses were performed to evaluate the model uncertainty. Additional subgroup analyses were performed.

RESULTS

Treatment of advanced NSCLC with cemiplimab added 0.546 QALYs (1.492 LYs) and resulted in an incremental cost of $22,069.804 compared with chemotherapy, which was associated with an incremental cost-effectiveness ratio of $40,390.412 per QALY gained. The results of one-way sensitivity analysis found that the cost of cemiplimab was the most sensitive factor in our study. The probabilistic sensitivity analysis showed that the probability of cemiplimab being cost-effective was 100%. The subgroup analysis demonstrated that high PD-L1 expression (≥ 90%, > 60 to < 90% and ≥ 50 to ≤ 60%) also kept the incremental cost-effectiveness stable at $63,415.2450 per QALY, $61,896.446 per QALY and $-71,921.259 per QALY.

CONCLUSION

From the perspective of US payers, cemiplimab is cost-effective in the first-line treatment of advanced NSCLC at the willingness-to-pay threshold of $150,000 per QALY.

Population pharmacokinetic characteristics of cemiplimab in patients with advanced malignancies

Cemiplimab, a human monoclonal antibody targeting programmed cell death-1 (PD-1) receptor, demonstrated antitumor activity in patients with advanced malignancies and a safety profile comparable to other anti-PD-1 therapies. This population pharmacokinetics (PopPK) analysis of cemiplimab included 11,178 pharmacokinetics (PK) observations from 548 patients pooled from a first-in-human study (Study 1423; NCT02383212) in advanced malignancies and a Phase 2 study (Study 1540; NCT02760498) in advanced cutaneous squamous cell carcinoma (CSCC). Most patients (80.3%) received cemiplimab 3 mg/kg every 2 weeks (Q2W) intravenously (IV). A PopPK model was developed by evaluating two-compartment linear models with an empirical non-linear function describing time-varying change in cemiplimab clearance and covariates that improved goodness-of-fit. PopPK simulations were used to describe cemiplimab exposure generated by a fixed 350 mg every 3 weeks (Q3W) IV dose regimen. PopPK modeling showed that a two-compartment model with zero-order IV infusion rate and first-order elimination rate well described individual concentrations of cemiplimab. Although several covariates, including baseline body weight and albumin concentrations, had a modest impact on cemiplimab exposure, the magnitude of influence was within the typical observed PK variability of approximately 30%. Based on PopPK simulation results, the 350 mg Q3W dose regimen was selected for further studies in advanced malignancies, including advanced CSCC. Similarity in observed cemiplimab exposure at the fixed 350 mg Q3W and the weight-based 3 mg/kg Q2W dose regimens confirmed this fixed dose selection. A robust PopPK model was developed to describe cemiplimab concentrations and supported use of the fixed 350 mg Q3W IV dose regimen.

Preclinical characterization of dostarlimab, a therapeutic anti-PD-1 antibody with potent activity to enhance immune function in in vitro cellular assays and in vivo animal models

Inhibitors of programmed cell death protein 1 (PD-1) and its ligand (PD-L1) have dramatically changed the treatment landscape for patients with cancer. Clinical activity of anti-PD-(L)1 antibodies has resulted in increased median overall survival and durable responses in patients across selected tumor types. To date, 6 PD-1 and PD-L1, here collectively referred to as PD-(L)1, pathway inhibitors are approved by the US Food and Drug Administration for clinical use. The availability of multiple anti-PD-(L)1 antibodies provides treatment and dosing regimen choice for patients with cancer. Here, we describe the nonclinical characterization of dostarlimab (TSR-042), a humanized anti-PD-1 antibody, which binds with high affinity to human PD-1 and effectively inhibits its interaction with its ligands, PD-L1 and PD-L2. Dostarlimab enhanced effector T-cell functions, including cytokine production, in vitro. Since dostarlimab does not bind mouse PD-1, its single-agent antitumor activity was evaluated using humanized mouse models. In this model system, dostarlimab demonstrated antitumor activity as assessed by tumor growth inhibition, which was associated with increased infiltration of immune cells. Single-dose and 4-week repeat-dose toxicology studies in cynomolgus monkeys indicated that dostarlimab was well tolerated. In a clinical setting, based on data from the GARNET trial, dostarlimab (Jemperli) was approved for the treatment of adult patients with mismatch repair–deficient recurrent or advanced endometrial cancer that had progressed on or following prior treatment with a platinum-containing regimen. Taken together, these data demonstrate that dostarlimab is a potent anti-PD-1 receptor antagonist, with properties that support its continued clinical investigation in patients with cancer.

Immune checkpoint inhibitors for brain metastases in non-small-cell lung cancer: from rationale to clinical application

Brain metastases (BM) is common in non-small-cell lung cancer (NSCLC) patients. Immune checkpoint inhibitors (ICIs) have gradually become a routine treatment for NSCLC BM patients. Currently, three PD-1 inhibitors (pembrolizumab, nivolumab and cemiplimab), one PD-L1 inhibitor (atezolizumab) and one CTLA-4 inhibitor (ipilimumab) have been approved for the first-line treatment of metastatic NSCLC. It is still controversial whether PD-L1, tumor infiltrating lymphocytes, and tumor mutation burden can be used as predictive biomarkers for immune checkpoint inhibitors in NSCLC patients with BM. In addition, clinical data on NSCLC BM were inadequate. Here, we review the theoretical basis and clinical data for the application of ICIs in the therapy of NSCLC BM.

Tumor-targeted CD28 bispecific antibodies enhance the antitumor efficacy of PD-1 immunotherapy

Monoclonal antibodies that block the programmed cell death 1 (PD-1) checkpoint have revolutionized cancer immunotherapy. However, many major tumor types remain unresponsive to anti-PD-1 therapy, and even among responsive tumor types, most of the patients do not develop durable antitumor immunity. It has been shown that bispecific antibodies activate T cells by cross-linking the TCR/CD3 complex with a tumor-specific antigen (TSA). The class of TSAxCD3 bispecific antibodies have generated exciting results in early clinical trials. We have recently described another class of "costimulatory bispecifics" that cross-link a TSA to CD28 (TSAxCD28) and cooperate with TSAxCD3 bispecifics. Here, we demonstrate that these TSAxCD28 bispecifics (one specific for prostate cancer and the other for epithelial tumors) can also synergize with the broader anti-PD-1 approach and endow responsiveness-as well as long-term immune memory-against tumors that otherwise do not respond to anti-PD-1 alone. Unlike CD28 superagonists, which broadly activate T cells and induce cytokine storm, TSAxCD28 bispecifics display little or no toxicity when used alone or in combination with a PD-1 blocker in genetically humanized immunocompetent mouse models or in primates and thus may provide a well-tolerated and "off the shelf" combination approach with PD-1 immunotherapy that can markedly enhance antitumor efficacy.

Development of humanized mouse with patient-derived xenografts for cancer immunotherapy studies: A comprehensive review

Immunotherapy has revolutionized cancer treatment, however, not all tumor types and patients are completely responsive to this approach. Establishing predictive pre-clinical models would allow for more accurate and practical immunotherapeutic drug development. Mouse models are extensively used as in vivo system for biomedical research. However, due to the significant differences between rodents and human, it is impossible to translate most of the findings from mouse models to human. Pharmacological development and advancing personalized medicine using patient-derived xenografts relies on producing mouse models in which murine cells and genes are substituted with their human equivalent. Humanized mice (HM) provide a suitable platform to evaluate xenograft growth in the context of a human immune system. In this review, we discussed recent advances in the generation and application of HM models. We also reviewed new insights into the basic mechanisms, pre-clinical evaluation of onco-immunotherapies, current limitations in the application of these models as well as available improvement strategies. Finally, we pointed out some issues for future studies.

Preclinical models and technologies to advance nanovaccine development

The remarkable success of targeted immunotherapies is revolutionizing cancer treatment. However, tumor heterogeneity and low immunogenicity, in addition to several tumor-associated immunosuppression mechanisms are among the major factors that have precluded the success of cancer vaccines as targeted cancer immunotherapies. The exciting outcomes obtained in patients upon the injection of tumor-specific antigens and adjuvants intratumorally, reinvigorated interest in the use of nanotechnology to foster the delivery of vaccines to address cancer unmet needs. Thus, bridging nano-based vaccine platform development and predicted clinical outcomes the selection of the proper preclinical model will be fundamental. Preclinical models have revealed promising outcomes for cancer vaccines. However, only few cases were associated with clinical responses. This review addresses the major challenges related to the translation of cancer nano-based vaccines to the clinic, discussing the requirements for ex vivo and in vivo models of cancer to ensure the translation of preclinical success to patients.

Fixed Dose of Cemiplimab in Patients with Advanced Malignancies Based on Population Pharmacokinetic Analysis

Introduction

This study outlined cemiplimab intravenous (IV) dosing strategy to move from body weight (BW)-based 3 mg/kg every-2-week (Q2W) dosing in first-in-human study (study 1423; NCT02383212) to fixed 350 mg every-3-week (Q3W) dosing, utilizing population pharmacokinetics (PopPK) modeling and simulations, and supported by a limited dataset from a phase 2 study (study 1540; NCT02760498).

Methods

Cemiplimab concentration data from a total of 505 patients were pooled from study 1423 in advanced malignancies and study 1540 in advanced cutaneous squamous cell carcinoma (CSCC). All patients received weight-based cemiplimab dose (1, 3, 10 mg/kg Q2W or 3 mg/kg Q3W) except 4% who received 200 mg Q2W. A linear two-compartment PopPK model incorporating covariates that improved goodness-of-fit statistics was developed to compare cemiplimab exposure at 350 mg Q3W versus 3 mg/kg Q2W. Upon availability, observed cemiplimab concentration at 350 mg Q3W in study 1540 was then compared with the simulated values.

Results

Post hoc estimates of cemiplimab exposure and variability (505 patients; weight range 30.9–156 kg; median 76.1 kg) at steady state were found to be similar at 350 mg Q3W and 3 mg/kg Q2W. Effect of BW on cemiplimab exposure was described by exposure versus BW plots and at extreme BW. Overlay of individual observed cemiplimab concentrations in 51 patients with metastatic CSCC on simulated concentration–time profiles in 2000 patients at 350 mg Q3W confirmed cemiplimab exposure similarity and demonstrated the robustness of dose optimization based on PopPK modeling and simulations.

Conclusions

Cemiplimab 350 mg Q3W is being further investigated in multiple indications.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01638-5.

Humanized Mouse Models for the Advancement of Innate Lymphoid Cell-Based Cancer Immunotherapies

Innate lymphoid cells (ILCs) are a branch of the immune system that consists of diverse circulating and tissue-resident cells, which carry out functions including homeostasis and antitumor immunity. The development and behavior of human natural killer (NK) cells and other ILCs in the context of cancer is still incompletely understood. Since NK cells and Group 1 and 2 ILCs are known to be important for mediating antitumor immune responses, a clearer understanding of these processes is critical for improving cancer treatments and understanding tumor immunology as a whole. Unfortunately, there are some major differences in ILC differentiation and effector function pathways between humans and mice. To this end, mice bearing patient-derived xenografts or human cell line-derived tumors alongside human genes or human immune cells represent an excellent tool for studying these pathways in vivo. Recent advancements in humanized mice enable unparalleled insights into complex tumor-ILC interactions. In this review, we discuss ILC behavior in the context of cancer, the humanized mouse models that are most commonly employed in cancer research and their optimization for studying ILCs, current approaches to manipulating human ILCs for antitumor activity, and the relative utility of various mouse models for the development and assessment of these ILC-related immunotherapies.

Tolerability and antitumor activity of cemiplimab, a human monoclonal anti-PD-1, as monotherapy in patients with pretreated non-small cell lung cancer (NSCLC): Data from the Phase 1 NSCLC expansion cohort

OBJECTIVES

Blockade of programmed cell death-1 (PD-1) and its ligand (PD-L1) has transformed the treatment of NSCLC. In a first-in-human, Phase 1, dose escalation and cohort expansion study, cemiplimab, a monoclonal antibody directed against PD-1, was evaluated for the treatment of patients with advanced solid tumors (NCT02383212). Here, we report results in patients with advanced NSCLC from the dose expansion cohort.

MATERIALS AND METHODS

Immune-checkpoint inhibitor naive patients with advanced NSCLC (stage III/IV), irrespective of PD-L1 status, who had progressed after, or were refractory to first- or later-line therapy were enrolled and received cemiplimab 200 mg every 2 weeks intravenously for up to 48 weeks. Primary study objectives were to assess safety and tolerability, and to evaluate clinical activity of cemiplimab.

RESULTS

Twenty patients with NSCLC were enrolled. Median age was 64.0 years (range: 50-82); 65.0 % were male; 80.0 % had an ECOG performance status of 1; 60.0 % had a histology of adenocarcinoma. Median number of prior lines of systemic therapy was 2 (range: 1-4). Median duration of follow-up was 7.0 months (range: 1.0-18.2). All patients experienced ≥1 treatment-emergent adverse event (TEAE) of any grade. Most common TEAEs were arthralgia, asthenia, cough, and dyspnea (each 4/20; 20.0 %). Grade ≥3 TEAEs occurred in 60.0 % (12/20) of patients. Of patients with measurable disease per independent central review (ICR), five had partial response (PR), four had stable disease (SD) and 10 had progressive disease. Objective response rate (ORR; complete response + PR) was 25.0 % (95 % CI: 8.7-49.1 %). Duration of response exceeded 8 months in four of the five responding patients at the time of data cut-off (April 30, 2019). The disease control rate per ICR (ORR + SD) was 50.0 % (95 % CI: 27.2-72.8 %).

CONCLUSION

Cemiplimab showed an acceptable safety profile and demonstrated antitumor activity in pretreated patients with NSCLC.

Cemiplimab monotherapy for first-line treatment of advanced non-small-cell lung cancer with PD-L1 of at least 50%: a multicentre, open-label, global, phase 3, randomised, controlled trial

BACKGROUND

We aimed to examine cemiplimab, a programmed cell death 1 inhibitor, in the first-line treatment of advanced non-small-cell lung cancer with programmed cell death ligand 1 (PD-L1) of at least 50%.

METHODS

In EMPOWER-Lung 1, a multicentre, open-label, global, phase 3 study, eligible patients recruited in 138 clinics from 24 countries (aged ≥18 years with histologically or cytologically confirmed advanced non-small-cell lung cancer, an Eastern Cooperative Oncology Group performance status of 0-1; never-smokers were ineligible) were randomly assigned (1:1) to cemiplimab 350 mg every 3 weeks or platinum-doublet chemotherapy. Crossover from chemotherapy to cemiplimab was allowed following disease progression. Primary endpoints were overall survival and progression-free survival per masked independent review committee. Primary endpoints were assessed in the intention-to-treat population and in a prespecified PD-L1 of at least 50% population (per US Food and Drug Administration request to the sponsor), which consisted of patients with PD-L1 of at least 50% per 22C3 assay done according to instructions for use. Adverse events were assessed in all patients who received at least one dose of the assigned treatment. This study is registered with ClinicalTrials.gov, NCT03088540 and is ongoing.

FINDINGS

Between June 27, 2017 and Feb 27, 2020, 710 patients were randomly assigned (intention-to-treat population). In the PD-L1 of at least 50% population, which consisted of 563 patients, median overall survival was not reached (95% CI 17·9-not evaluable) with cemiplimab (n=283) versus 14·2 months (11·2-17·5) with chemotherapy (n=280; hazard ratio [HR] 0·57 [0·42-0·77]; p=0·0002). Median progression-free survival was 8·2 months (6·1-8·8) with cemiplimab versus 5·7 months (4·5-6·2) with chemotherapy (HR 0·54 [0·43-0·68]; p<0·0001). Significant improvements in overall survival and progression-free survival were also observed with cemiplimab in the intention-to-treat population despite a high crossover rate (74%). Grade 3-4 treatment-emergent adverse events occurred in 98 (28%) of 355 patients treated with cemiplimab and 135 (39%) of 342 patients treated with chemotherapy.

INTERPRETATION

Cemiplimab monotherapy significantly improved overall survival and progression-free survival compared with chemotherapy in patients with advanced non-small-cell lung cancer with PD-L1 of at least 50%, providing a potential new treatment option for this patient population.

FUNDING

Regeneron Pharmaceuticals and Sanofi.

HX008: a humanized PD-1 blocking antibody with potent antitumor activity and superior pharmacologic properties

Through reactivating tumor-infiltrating lymphocytes, therapeutics targeting programmed cell death protein 1 (PD-1) demonstrate impressive clinical efficacy in the treatment of multiple cancers. In this report, we characterize HX008, a humanized IgG4S228P anti-PD-1 monoclonal antibody with an engineered Fc domain, in a series of in vitro assays and in vivo studies. In vitro, HX008 binds to human PD-1 with high affinity and potently suppresses the interaction of PD-1 with PD-L1 and PD-L2. The lack of detectable binding to complement C1q and Fc gamma receptor III-a (FcγRIIIa) suggested that HX008 maintained reduced antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. A comparable enhancement of cytokine production and NFAT-driven luciferase expression in cell-based assays confirmed that HX008 could promote T-cell function as effectively as Nivolumab. In vivo antitumor activity studies were carried out within two special tumor models: 1) the MiXeno model with an adoptive transfer of human peripheral blood mononuclear cells into HCC827 xenograft mice; and 2) HuGEMM with human PD-1 gene knock-in syngeneic MC38-bearing mice. In both models, HX008 significantly inhibits tumor growth and shows an effective antitumor response comparable to approved anti-PD-1 drugs. Furthermore, in a pharmacokinetics study performed in cynomolgus monkeys, HX008 induced no immune-related adverse events when administered at 10 mg/kg. Although some anti-drug antibody effects were observed in the primate PK study, the safety and favorable pharmacokinetics demonstrated in human clinical trials validate HX008 as a suitable candidate for cancer immunotherapy. Taken together, our studies provide a fairly thorough characterization of HX008 and strong support for its further clinical research and application.

Preclinical PET imaging with the novel human antibody 89Zr-DFO-REGN3504 sensitively detects PD-L1 expression in tumors and normal tissues

Background

Programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) blocking antibodies including cemiplimab have generated profound clinical activity across diverse cancer types. Tumorous PD-L1 expression, as assessed by immunohistochemistry (IHC), is an accepted predictive marker of response to therapy in some cancers. However, expression is often dynamic and heterogeneous, and therefore not reliably captured by IHC from tumor biopsies or archival samples. Thus, there is significant need for accurate whole-body quantification of PD-L1 levels.

Methods

We radiolabeled the novel human anti-PD-L1 antibody REGN3504 with zirconium-89 (⁸⁹Zr) using the chelator p-SCN-Bn-Deferoxamine to enable non-invasive immuno-positron emission tomography (immuno-PET) of PD-L1 expression. PET imaging assessed the localization of ⁸⁹Zr-REGN3504 to multiple human tumor xenografts. Mice genetically humanized for PD-1 and PD-L1 were used to assess the biodistribution of ⁸⁹Zr-REGN3504 to normal tissues and the estimated human radiation dosimetry of ⁸⁹Zr-REGN3504 was also determined. Pharmacokinetics of REGN3504 was assessed in monkeys.

Results

Clear localization of ⁸⁹Zr-REGN3504 to human tumor xenografts was observed via PET imaging and ex vivo biodistribution studies demonstrated high (fourfold to sixfold) tumor:blood ratios. ⁸⁹Zr-REGN3504 specifically localized to spleen and lymph nodes in the PD-1/PD-L1 humanized mice. ⁸⁹Zr-REGN3504 immuno-PET accurately detected a significant reduction in splenic PD-L1 positive cells following systemic treatment with clodronate liposomes. Radiation dosimetry suggested absorbed doses would be within guidelines for other ⁸⁹Zr radiolabeled, clinically used antibodies. Pharmacokinetics of REGN3504 was linear.

Conclusion

This work supports the clinical translation of ⁸⁹Zr-REGN3504 immuno-PET for the assessment of PD-L1 expression. Future clinical studies will aim to investigate the utility of ⁸⁹Zr-REGN3504 immuno-PET for predicting and monitoring response to anti-PD-1 therapy.