Population pharmacokinetic models of anti-PD-1 mAbs in patients with multiple tumor types: A systematic review

Sex-Related Differences in Immunotherapy Toxicities: Insights into Dimorphic Responses

Significant sex-based differences exist in the immune system and antitumor immune responses, potentially leading to variations in both the efficacy and toxicity of anticancer immunotherapies. Women generally mount stronger innate and adaptive immune responses than men, which can result in more severe immune-related adverse events (irAEs) during treatments with immune checkpoint inhibitors (ICIs). However, the importance of sex dimorphism in the safety of cancer immunotherapy remains underexplored in clinical oncology, despite its profound implications for treatment outcomes. Our review highlights the critical influence of biological sex on pharmacokinetics, pharmacodynamics, and immune responses, shaping ICI efficacy and the prevalence, type, and severity of irAEs. Integrating sex as a critical variable in cancer treatment and clinical trial design is essential for personalizing therapeutic strategies, bridging existing knowledge gaps, and enhancing survival rates and quality of life for patients across genders.

Sex differences in the pharmacokinetics of anticancer drugs: a systematic review

BACKGROUND

In addition to the effect of body weight, a patient's sex can influence the pharmacokinetics (PK) of anticancer agents, and thereby their activity and safety. The magnitude and relevance of sex differences, however, are currently unclear.

METHODS

We carried out a systematic review of published studies (clinical, n ≥ 10) on Food and Drug Administration (FDA)-approved (on 31 January 2022) anticancer drugs (excluding hormonal agents), aiming to identify significant PK differences between male and female patients. A difference of ≥20% on PK parameters (clearance or trough concentration) was considered significant. The methodological quality was assessed using the National Institutes of Health study quality assessment tool. This systematic review was conducted according to the PRISMA2020 guidelines and a previously published protocol, which was registered in the PROSPERO database (number 291008).

RESULTS

Data on 99 anticancer agents (for a total of 1643 abstracts and European Medicines Agency/FDA documents) were screened. The final dataset included 112 articles and 8 European Medicines Agency/FDA documents. The median size of a study cohort was 445 patients (range: 12-6468 patients). Significant PK differences (>+20% in clearance or apparent clearance in women) were identified for 14 drugs, and potentially significant PK differences (due to conflicting reports) for another 8 drugs. None of the studies included sex-based summaries to assess whether the observed differences in PK may impact the efficacy or safety profile.

CONCLUSIONS

Significant sex differences in PK have been identified including commonly used drugs of different classes, such as 5-fluorouracil, doxorubicin, paclitaxel, regorafenib, atezolizumab, and temozolomide. The risk-benefit ratio for such anticancer drugs is likely to be improved by the development of sex-specific dosing strategies. Additional sex-based PK-pharmacodynamic analyses are recommended during dose optimisation and are to be conducted in line with the FDA Project Optimus guidance. They should be reported even if no association between the patients' sex and the activity and/or toxicity of an anticancer drug has been identified.

Model-informed drug development of envafolimab, a subcutaneously injectable PD-L1 antibody, in patients with advanced solid tumors

BACKGROUND AND OBJECTIVES

Envafolimab is the first and only globally approved subcutaneously injectable PD-L1 antibody for the treatment of instability-high (MSI-H) or DNA mismatch repair deficient (dMMR) advanced solid tumors in adults, including those with advanced colorectal cancer that has progressed after treatment with a fluoropyrimidine, oxaliplatin, and irinotecan. The aim of this investigation was to examine the pharmacokinetic and exposure-response (E-R) profile of envafolimab in patients with solid tumors to support the approval of fixed and alternative dose regimens.

METHODS

In this study, a population pharmacokinetic (PopPK) modeling approach will be employed to quantitatively evaluate intrinsic and extrinsic covariates. Additionally, PopPK-estimated exposure parameters were used to evaluate E-R relationship for safety and efficacy to provide a theoretical basis for recommending optimal treatment regimens. Simulations were performed on the dosing regimens of body weight-based regimen of 2.50 mg/kg QW, fixed dose 150 mg QW, and 300 mg Q2W for the selection of alternative dosing regimens. Data from 4 clinical studies (NCT02827968, NCT03101488, NCT03248843, and NCT03667170) were utilized.

RESULTS

The PopPK dataset comprised 182 patients with 1810 evaluable envafolimab concentration records. Finally, a one-compartment model incorporating first-order absorption, first-order linear elimination, and time-dependent elimination according to an Emax function was found to accurately describe the concentration-time data of envafolimab in patients with advanced solid tumors. Creatinine clearance and country were identified as statistically significant factors affecting clearance, but had limited clinical significance. A relative flat exposure-response relationship was observed between early measures of safety and efficacy to verify that no dose adjustment is required. Simulation results indicated that 2.50 mg/kg QW, 150 mg QW, and 300 mg Q2W regimen yield similar steady-state exposure.

CONCLUSIONS

No statistically significant difference was observed between weight-based and fixed dose regimens. Model-based simulation supports the adoption of a 150 mg weekly or 300 mg biweekly dosing regimen of envafolimab in the solid tumor population, as these schedules effectively balance survival benefits and safety risks.

A phase III study to access the safety and efficacy of prolgolimab 250 mg fixed dose administered every 3 weeks versus prolgolimab 1 mg/kg every 2 weeks in patients with metastatic melanoma (FLAT)

Background

Prolgolimab is the first Russian PD-1 inhibitor approved for the first-line treatment of unresectable or metastatic melanoma and advanced non-small cell lung cancer. It was approved in two weight-based regimens of 1 mg/kg Q2W and 3 mg/kg Q3W, but because of re-evaluation of weight-based dosing paradigm, studying of a fixed-dose regimen was considered perspective.

Methods

We conducted a multicenter, single-arm, open-label efficacy, pharmacokinetics, and safety study to obtain data that would allow the approval of the new flat dosing regimen of prolgolimab in patients with previously untreated unresectable or metastatic melanoma (BCD-100-8/FLAT, NCT05783882). The primary objective was to prove the non-inferiority of prolgolimab 250 mg Q3W versus prolgolimab 1 mg/kg Q2W for the treatment of patients with unresectable or metastatic melanoma in terms of ORR according to RECIST 1.1. Patients from the MIRACULUM study (BCD-100-2/MIRACULUM, NCT03269565) comprised a historical control group.

Results

One hundred fourteen patients received prolgolimab 250 mg Q3W, and 61 patients received prolgolimab (Prolgo) 1 mg/kg Q2W (historical control). Objective response was achieved by 33.3% [95% confidence interval (CI): 24.8, 42.8] of patients in the Prolgo 250 mg group compared with 32.8% (95% CI: 21.3, 46.0) of patients in the Prolgo 1 mg/kg group. Risk difference was 0.00, 95% CI (-0.12; NA), p = 0.0082. Both regimens were well tolerated, and safety profiles were comparable. The pharmacokinetic analysis (PK) showed that the regimen with the fixed dose of 250 mg Q3W was characterized by higher PK parameters. The immunogenicity study did not detect binding antibodies to prolgolimab in any of the subjects.

Conclusion

The obtained results showed that the selected fixed dosing regimen of prolgolimab 250 mg Q3W is characterized by efficacy and safety parameters comparable to that observed for the 1 mg/kg Q2W regimen.

Development and application of a population pharmacokinetic model repository for caffeine dose tailoring in preterm infants

BACKGROUND

Considerable interindividual variability for the pharmacokinetics of caffeine in preterm infants has been demonstrated, emphasizing the importance of personalized dosing. This study aimed to develop and apply a repository of currently published population pharmacokinetic (PopPK) models of caffeine in preterm infants to facilitate model-informed precision dosing (MIPD).

RESEARCH DESIGN AND METHODS

Literature search was conducted using PubMed, Embase, Scopus, and Web of Science databases. Relevant publications were screened, and their quality was assessed. PopPK models were reestablished to develop the model repository. Covariate effects were evaluated and the concentration-time profiles were simulated. An online simulation and calculation tool was developed as an instance.

RESULTS

Twelve PopPK models were finally included in the repository. Preterm infants' age and body size, especially the postnatal age and current weight, were identified as the most clinically critical covariates. Simulated blood concentration-time profiles across these models were comparable. Caffeine citrate-dose regimen should be adjusted according to the age and body size of preterm infants. The developed online tool can be used to facilitate clinical decision-making.

CONCLUSIONS

The first developed repository of PopPK models for caffeine in preterm infants has a wide range of potential applications in the MIPD of caffeine.

Population Pharmacokinetics and Exposure-Response Relationship of Zimberelimab in Chinese Patients with Advanced Tumors

This study aimed to establish a population pharmacokinetic (PopPK) model using data from 2 clinical trials of zimberelimab, evaluate the pharmacokinetics (PKs) of zimberelimab, explore the feasibility of 360 mg once every 3 weeks (Q3W) and 480 mg once every 4 weeks (Q4W) as alternative dosage regimens, and analyze the exposure-response relationship of the efficacy and safety of zimberelimab for advanced tumors. The PKs of zimberelimab were described using the 2-compartment model with time-dependent nonlinear elimination. The prediction-corrected visual predictive check was used to evaluate the model's predictive value on blood drug concentrations. In total, 2165 PK observations from 321 participants were included. The PopPK model demonstrated a high level of concordance between the observed data and the predicted values, indicative of a robust fit to the PK data of zimberelimab. The PK variables were similar for the 240 mg once every 2 weeks, 360 mg Q3W, and 480 mg Q4W regimens. No covariates significantly affecting the PK variables in the final model were found. The exposure variables of zimberelimab have no obvious correlations with efficacy and safety, and 360 mg Q3W and 480 mg Q4W are worthy of further study. This study establishes a PopPK model and analyzes the exposure-response relationship of zimberelimab, which helps to explore the potential for alternative dosing regimens and offers a foundation for optimizing therapeutic strategies for advanced cancer patients through simulation-based methods.

Phase I pharmacokinetic, safety, and preliminary efficacy study of tiragolumab in combination with atezolizumab in Chinese patients with advanced solid tumors

PURPOSE

Tiragolumab is an immunoglobulin G1 monoclonal antibody targeting the immune checkpoint T cell immunoreceptor with immunoglobulin and immunoreceptor ITIM domains. Targeting multiple immune pathways may improve anti-tumor responses. The phase I YP42514 study assessed the pharmacokinetics (PK), safety, and preliminary efficacy of tiragolumab plus atezolizumab in Chinese patients with advanced solid tumors.

METHODS

Adult patients from mainland China with Eastern Cooperative Oncology Group performance score 0/1, life expectancy of ≥ 12 weeks, and adequate hematologic/end organ function were eligible. Patients received tiragolumab 600 mg and atezolizumab 1200 mg intravenous every 3 weeks. Key endpoints were PK (serum concentrations of tiragolumab and atezolizumab) and safety. Results from this study were compared with the global phase I study, GO30103 (NCT02794571).

RESULTS

In this study, 20 patients received a median of five doses of tiragolumab plus atezolizumab. Median age was 57.5 years, 85.0% of patients were male and the most common tumor type was non-small cell lung cancer. Exposures in Chinese patients were comparable to the global GO30103 population: geometric mean ratio was 1.07 for Cycle 1 tiragolumab area under the concentration-time curve0-21 and 0.92 and 0.93 for Cycle 1 peak and trough atezolizumab exposure, respectively. Treatment-related adverse events were consistent across the Chinese and global populations. Two patients (10.0%) in this study achieved a partial response.

CONCLUSION

In this study, tiragolumab plus atezolizumab was tolerable and demonstrated preliminary anti-tumor activity. There were no meaningful differences in the PK or safety of tiragolumab plus atezolizumab between the Chinese and global populations.

CLINICAL TRIAL REGISTRATION NUMBER

China Clinical Trial Registry Identifier CTR20210219/YP42514. Date of registration 16 March 2021.

Population Pharmacokinetic Models of Venetoclax in Hematologic Malignancies: A Systematic Review

Several population pharmacokinetic (PPK) models of B cell lymphoma-2 (BCL-2) venetoclax (VEN) have been developed and published to characterize the influencing factors of pharmacokinetics in hematologic malignancies. This review described PPK models of VEN examining the magnitude and types of covariate effects in PK parameters, as well as identified areas that require further investigation in order to facilitate their use. Currently, there are six analyses on PPK models of VEN summarized in this review. Most analyses described the pharmacokinetics of VEN with a two-compartment model and all covariates are categorical. The median estimated apparent clearance (CL/F) was 446 L/Day and apparent volume of distribution of the central compartment (V2/F) was 114.5 L. The median IIV of CL/F reported was 39.5% and V2/F was 46.7%. Most commonly, CYP3A inhibitors, OATP1B3 inhibitors and rituximab co-administration were found to be significant covariates on CL/F. In addition, sex and population were influential covariates on V2/F. A detailed description of the characteristics of PPK models of VEN is provided in this review, as well as the effects of covariates on the PK parameters. For future development of the VEN PPK model, CYP3A inhibitors, rituximab co-administration, OATP1B1 transporter inhibitors, sex, population, and food might be considered. Further research and comprehensive investigations should be undertaken to explore reference ranges for therapeutic drug monitoring, define the potential role of patients with cerebrospinal fluid complications, and assess new or potential covariates. These endeavors will facilitate the development of personalized VEN therapy.

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

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