Review of the Clinical Pharmacokinetics, Efficacy and Safety of Pembrolizumab

Development of a recombinant human IgG1 monoclonal antibody against the TRBV5-1 segment of the T cell receptor for the treatment of mature T cell neoplasms

Background

Mature T-cell neoplasms arise from the neoplastic transformation of a single T lymphocyte, and all cells in a neoplastic clone share the same V segment in the beta chain of the T-cell receptor (TCR). These segments may represent an innovative target for the development of targeted therapies.

Methods

A specific V segment of the TCR beta chain (TRBV5-1) was analyzed using bioinformatic tools, identifying three potential antigenic peptides. One of these peptides, selected for synthesis, was used to screen a library of human single-chain variable fragments (scFv) through phage display. One fragment demonstrated high affinity and specificity for the antigen and was used to produce a human monoclonal antibody of the IgG1 class.

Results

Surface plasmon resonance (SPR) studies confirmed the high affinity of the monoclonal antibody for the antigen in the nanomolar range. Flow cytometry analysis on patients' samples demonstrated that the antibody, conjugated with a fluorochrome, selectively binds to tumor T lymphocytes expressing TRBV5-1, without binding to other lymphocytes or blood cell components.

Conclusions

The development of fully human IgG1 monoclonal antibodies targeting specific V segments of the TCR beta chain represents a potential therapeutic option for patients with mature T-cell neoplasms.

Cardiovascular adverse events and immune-related adverse events associated with PD-1/PD-L1 inhibitors for head and neck squamous cell carcinoma (HNSCC)

While some literature has provided limited information about the potential cardiovascular risk and immune-related adverse events (irAEs) risk associated with PD-1/PD-L1 inhibitors in the treatment of Head and Neck Squamous Cell Carcinoma (HNSCC), the exact relevance is still uncertain. To assess the pharmacovigilance (PV), constituent ratio, severity, and reaction outcomes of major adverse cardiovascular events (MACE) and immune-related adverse events (irAEs) related to PD-1/PD-L1 inhibitors for HNSCC reported to the United States Food and Drug Administration Adverse Event Reporting System (FAERS). We analyzed reports of cardiovascular adverse events and irAEs associated with drug therapy for HNSCC submitted to FAERS from the 1st quarter 2015 to the 3rd quarter of 2023. Three PD-1/PD-L1 inhibitors were identified: nivolumab, pembrolizumab and durvalumab. Our primary composite endpoint was the PV of MACE and irAEs related to PD-1/PD-L1 inhibitors in the treatment of HNSCC, and the secondary endpoint was PV of other cardiovascular events. The software implemented was STATA 17.0 MP. 19,372 suspected drug-adverse event reports related to drug treatment in patients with HNSCC were identified, of which 916 reports were cardiovascular events, including 555 reports of MACE and 361 reports of other cardiovascular events. The PV signal regarding MACE was detected in durvalumab (PRR  = 2.12, 95% CI: 1.24-3.61; χ2  = 7.71; ROR  = 2.19, 95% CI: 1.24-3.86; IC  = 1.01; IC025  = 0.07) but not in nivolumab and pembrolizumab. The constituent ratio of MACE in all adverse events caused by nivolumab (OR  = 0.38, 95% CI: 0.19-0.73) and pembrolizumab (OR  = 0.48, 95% CI: 0.23-0.99) was significantly decreased, compared with durvalumab. A PV signal about other cardiovascular events was detected in durvalumab (PRR  = 3.04, 95% CI: 1.73-5.31; χ2  = 16.13; ROR  = 3.15, 95% CI: 1.74-5.70; IC  = 1.46; IC025  = 0.48), but it was not detected in nivolumab or pembrolizumab. The constituent ratio of other cardiovascular events in all adverse events caused by nivolumab (OR  = 0.25, 95% CI: 0.13-0.48) and pembrolizumab (OR  = 0.40, 95% CI: 0.20-0.80) was significantly decreased, compared with durvalumab. The constituent ratio of other cardiovascular events in all adverse events caused by nivolumab (OR  = 0.61, 95% CI: 0.38-0.99) was significantly decreased, compared with pembrolizumab. There were 40 cases of hypertension. A PV signal about hypertension was detected in pembrolizumab (PRR  = 3.72, 95% CI: 1.87-7.43; χ2  = 15.99; ROR  = 3.75, 95% CI: 1.87-7.51; IC  = 1.53, IC025  = 0.45), but it was not detected in nivolumab. The constituent ratio of hypertension in all adverse events caused by nivolumab (OR  = 0.09, 95% CI: 0.09-0.39) was significantly decreased, compared with pembrolizumab. There were 737 cases of irAEs. A PV signal about irAEs was detected in nivolumab (PPR  = 1.27, 95% CI: 1.05-1.53; χ2  = 6.38; ROR  = 1.28, 95% CI: 1.06-1.56; IC  = 0.29, IC025  = -0.00) and pembrolizumab (PPR  = 2.20, 95% CI: 1.79-2.71; χ2  = 56.55; ROR  = 2.31, 95% CI: 1.84-2.88; IC  = 1.03; IC025  = 0.68), but it was not detected in durvalumab. The constituent ratio of irAEs in all adverse events caused by nivolumab (OR  = 0.58, 95% CI: 0.44-0.76) significantly decreased, compared with pembrolizumab. By comparing the PV signals, constituent ratio, severity, and reaction outcome of the three drugs, we suppose that nivolumab can be used as the safest PD-1/PD-L1 inhibitor for HNSCC.

Acute pancreatitis associated with pembrolizumab-induced hypertriglyceridemia

INTRODUCTION

Acute pancreatitis (AP) following drug-induced hypertriglyceridemia is a rare clinical phenomenon. Immune checkpoint inhibitors have revolutionized treatment for a variety of solid organ and hematological malignancies. Pembrolizumab is a programmed cell death receptor-1 (PD-1) inhibitor that has shown promising responses in many advanced cancers. However, a constellation of immune-related adverse events has also been described. There are reports of pembrolizumab-induced hypertriglyceridemia, but AP as a result of this side effect remains an exceedingly rare clinical sequela.

CASE REPORT

We delineate a case of a patient with stage IVB non-small-cell lung cancer who developed progressive abdominal pain and nausea following administration of pembrolizumab for four months. Laboratory studies revealed increased serum lipase and triglyceride levels at 12,562 IU/L and 16,901 mg/dL, respectively. The diagnosis of AP was made based on the revised Atlanta classification criteria. After ruling out alternative causes, pembrolizumab-induced hypertriglyceridemia was considered the likely etiology of AP.

MANAGEMENT AND OUTCOME

The patient was transferred to the medical intensive care unit for close monitoring. Treatment was initiated with intravenous fluids, pain medications, and an insulin infusion. However, her hypertriglyceridemia levels remained persistently elevated, necessitating therapeutic apheresis. She recovered well with no complications after triglyceride apheresis.

DISCUSSION

AP following pembrolizumab-associated hypertriglyceridemia remains a rare clinicopathologic entity. Given the widespread clinical use of immune checkpoint inhibitors, knowledge of such rare adverse events is crucial. Evaluation of serum triglyceride levels before and after initiating pembrolizumab therapy may be mandated, especially in patients with metabolic comorbidities.

Eculizumab for myasthenic exacerbation during treatment with immune-checkpoint inhibitors

OBJECTIVE

To test the complement inhibitor eculizumab in the treatment of MG exacerbation during therapy with the immune-checkpoint inhibitor (ICI) pembrolizumab, avoiding its discontinuation, which could be detrimental to oncologic course.

METHODS

A 76-year-old male with non-thymomatous generalized anti-AchR + MG (MGFA class IVB), during treatment with pembrolizumab for colorectal cancer, developed a severe myasthenic exacerbation, refractory to steroids and IvIg. Eculizumab was started, without pembrolizumab discontinuation. The patient was prospectively followed using MGFA, MG Activities of Daily Living (MG-ADL), Quantitative MG (QMG), MG Composite (MGC), and MG Quality of Life 15 (MG-QOL-15).

RESULTS

After an 18-week follow-up, the patient presented a progressive improvement in scores on all scales, achieving a MGFA class IIIB. The percentage improvement was 40% in MG-ADL, 36% in MG Composite, and about 30% in QMG. Bulbar symptoms improved by about 70% in MG-ADL and MG Composite and 40% in QMG. Eculizumab was well tolerated and pembrolizumab regularly continued, with a good control of cancer progression.

DISCUSSION

Eculizumab potentially offers a mechanism-based treatment of MG in patients under anti-programmed cell death protein 1 (PD-1) agents, without interfering with their mechanism of action and avoiding their discontinuation. Larger case series deserve to be evaluated.

Clinical benefit of pembrolizumab in treatment of first line non-small cell lung cancer: a systematic review and meta-analysis of clinical characteristics

OBJECTIVE

Pembrolizumab has become an integral first line therapeutic agent for non-small cell lung cancer (NSCLC), but its potential predictive role in clinical and molecular characteristics remains to be clarified. Accordingly, we performed a systematic review and meta-analysis to evaluate the clinical benefit of pembrolizumab in treatment of first line NSCLC and to select individuals with the greatest potential benefit from pembrolizumab therapy, in order to obtain a more accurate treatment of NSCLC in immunotherapy.

METHODS

Mainstream oncology datasets and conferences were searched for randomized clinical trials (RCTs) published before August 2022. RCTs involved individuals with first line NSCLC treated with pembrolizumab monotherapy or in combination with chemotherapy. Two authors independently selected the studies, extracted data, and assessed the risk of bias. The basic characteristics of the included studies were recorded, along with 95 percent confidence intervals (CI) and hazard ratios (HR) for all patients and subgroups. The primary endpoint was overall survival (OS), and secondary endpoints was progression-free survival (PFS). Pooled treatment data were estimated using the inverse variance-weighted method.

RESULTS

Five RCTs involving 2,877 individuals were included in the study. Pembrolizumab-based therapy significantly improved OS (HR 0.66; CI 95%, 0.55-0.79; p < 0.00001) and PFS (HR 0.60; CI 95%, 0.40-0.91; p = 0.02) compared with chemotherapy. OS was substantially enhanced in individuals aged < 65 years (HR 0.59; CI 95%, 0.42-0.82; p = 0.002), males (HR 0.74; CI 95%, 0.65-0.83; p < 0.00001), with a smoking history (HR 0.65; CI 95%, 0.52-0.82; p = 0.0003), with PD-L1 tumor proportion score (TPS) < 1% (HR 0.55; CI 95%, 0.41-0.73; p < 0.0001) and TPS ≥ 50% (HR 0.66; CI 95%, 0.56-0.76; p < 0.00001), but not in individuals aged ≥ 75 years (HR 0.82; CI 95%, 0.56-1.21; p = 0.32), females (HR 0.57; CI 95%, 0.31-1.06; p = 0.08), never smokers (HR 0.57; CI 95%, 0.18-1.80; p = 0.34), or with TPS 1-49% (HR 0.72; CI 95%, 0.52-1.01; p = 0.06). Pembrolizumab significantly prolonged OS in NSCLC patients, regardless of histology type (squamous or non-squamous NSCLC), performance status (PS) (0 or 1), and brain metastatic status (all p < 0.05). Subgroup analysis revealed that pembrolizumab combined with chemotherapy had more favorable HR values than pembrolizumab monotherapy in improving the OS of individuals with different clinical and molecular features.

CONCLUSION

Pembrolizumab-based therapy is a valuable option for first line treating advanced or metastatic NSCLC. Age, sex, smoking history and PD-L1 expression status can be used to predict the clinical benefit of pembrolizumab. Cautiousness was needed when using pembrolizumab in NSCLC patients aged ≥ 75 years, females, never smokers, or in patients with TPS 1-49%. Furthermore, pembrolizumab in combination with chemotherapy may be a more effective treatment regimen.

Efficacy of first-line systemic treatment regimens for recurrent/metastatic head and neck squamous cell carcinoma: a network meta-analysis

PURPOSE

To evaluate the efficacy on overall survival (OS) and progression-free survival (PFS) of the first-line systemic therapy regimens on 6-, 12-, 18-, 24-, and 30 months in recurrent/metastatic head and neck squamous cell carcinoma (R/M-HNSCC) and figure out the best regimen.

METHODS

PubMed, Embase, The Cochrane Library, Scopus, and Google Scholars were systematically searched for studies in regard to the first-line systemic regimens for R/M-HNSCC from inception to March 2022. Odds ratios (ORs) were generated for dichotomous variants by network meta-analysis. The primary endpoint was OS, and the second endpoint was PFS. The software implemented was STATA 17.0 MP.

RESULTS

Eventually, 18 studies with 5298 patients and 12 first-line systematic regimens were enrolled. immunotherapy + chemotherapy (OR = 2.30, 95% CI 1.60-3.31) and single immunotherapy (OR = 1.91, 95% CI 1.33-2.76) were significantly superior to the EXTREME on OS at 30th month. Meantime, immunotherapy + chemotherapy (SUCRA = 87.7%) has the highest ranking. TPEx (OR = 1.61, 95% CI 1.05-2.48) showed significantly better efficacy compared with EXTREME on PFS at 12th month. Simultaneously, TPEx (SUCRA = 87.1%) had the highest ranking and was the long-lasting first-echelon regimen both in OS and PFS from a longitudinal perspective. It should be noted that EXTREME included platinum-based chemotherapy + fluorouracil + cetuximab, TPEx included docetaxel + cisplatin + cetuximab.

CONCLUSION

Considering the efficacy, safety, compliance, and economic profiles collectively, one of the standard first-line regimens, literally TPEx should be recommended as the best choice for R/M-HNSCC. Furthermore, more head-to-head trials are needed to confirm those findings.

Analysis of the clinical characteristics of pembrolizumab-induced bullous pemphigoid

Background

Pembrolizumab, a programmed cell death protein 1 checkpoint inhibitor, is a novel drug used to treat a variety of advanced malignancies. However, it can also result in many immune-related adverse events, with cutaneous toxicities being the most frequent. Regarding pembrolizumab-induced skin adverse reactions, bullous pemphigoid (BP) has the worst effects on quality of life. Recently, there have been more and more reports of BP incidents resulting from pembrolizumab therapy in patients with cancer. This study aimed to define the clinical characteristics, diagnosis and management of pembrolizumab-induced BP and identify potential differences between classical BP and pembrolizumab-induced BP.

Methods

Case reports, case series, and case analyses of pembrolizumab-induced BP up to 10 December 2022 were collected for retrospective analysis.

Results

Our study included 47 patients (33 males and 14 females) from 40 studies. The median age was 72 years (range 42-86 years). The median time to cutaneous toxicity was 4 months (range 0.7-28 months), and the median time to bullae formation was 7.35 months (range 0.7-32 months). The most common clinical features were tense bullae and blisters (85.11%), pruritus (72.34%), and erythema (63.83%) on the limbs and trunk. In 20 of the 22 cases tested, the serum anti-BP180 autoantibodies were positive. However, in 10 cases (91.90%, 10/11) the circulating autoantibodies of anti-BP230 were negative. 40 patients had skin biopsies and the skin biopsy revealed subepidermal bullae or blister eosinophil infiltration in 75.00% of patients with pembrolizumab-induced BP, 10.00% of patients with lymphocyte infiltration and 20.00% of patients with neutrophil infiltration. There were 20 patients (50%) with eosinophilic infiltration around the superficial dermis vessels, 8 patients (20.00%) with lymphocyte infiltration around the superficial dermis vessels, and 4 patients (10.00%) with neutrophil infiltration around the superficial dermis vessels. Direct immunofluorescence detected linear immunoglobulin G (IgG) IgG and/or complement C3 along the dermo-epidermal junction in 36 patients (94.74%) with BP. IgG positivity was detected by indirect immunofluorescence in 81.82% of patients with BP. All patients were in complete remission (95.65%,44/46) or partial remission (4.35%, 2/46) of BP, whereas 9/46 patients had a relapse or refractory. The majority of patients achieved BP remission after discontinuation of pembrolizumab with a combination of topically and systemically administered steroid treatments, or other medications. The median duration of BP remission was 2 months (range 0.3-15 months).

Conclusion

A thorough diagnosis of pembrolizumab-induced BP should be made using clinical signs, biochemical markers, histopathological and immunopathological tests. Pembrolizumab-induced BP had similar clinical characteristics to classic BP. Temporary or permanent discontinuation of pembrolizumab therapy may be required in patients with perbolizumab-induced BP depending on the severity of BP and the response to medication. Pembrolizumab-induced BP may be effectively treated using topical and systemic steroid treatments in combination with other medications (e.g., doxycycline, niacinamide, dapsone, rituximab, intravenous immunoglobulins, dupilumab, cyclophosphamide, methotrexate, mycophenolate mofetil, and infliximab). Clinicians should provide better management to patients with BP receiving pembrolizumab to prevent progression and ensure continuous cancer treatment.