Penpulimab: First Approval

Current trends in sensitizing immune checkpoint inhibitors for cancer treatment

Immune checkpoint inhibitors (ICIs) have dramatically transformed the treatment landscape for various malignancies, achieving notable clinical outcomes across a wide range of indications. Despite these advances, resistance to immune checkpoint blockade (ICB) remains a critical clinical challenge, characterized by variable response rates and non-durable benefits. However, growing research into the complex intrinsic and extrinsic characteristics of tumors has advanced our understanding of the mechanisms behind ICI resistance, potentially improving treatment outcomes. Additionally, robust predictive biomarkers are crucial for optimizing patient selection and maximizing the efficacy of ICBs. Recent studies have emphasized that multiple rational combination strategies can overcome immune checkpoint resistance and enhance susceptibility to ICIs. These findings not only deepen our understanding of tumor biology but also reveal the unique mechanisms of action of sensitizing agents, extending clinical benefits in cancer immunotherapy. In this review, we will explore the underlying biology of ICIs, discuss the significance of the tumor immune microenvironment (TIME) and clinical predictive biomarkers, analyze the current mechanisms of resistance, and outline alternative combination strategies to enhance the effectiveness of ICIs, including personalized strategies for sensitizing tumors to ICIs.

Progress in the clinical development of investigational systemic agents for recurrent and metastatic nasopharyngeal carcinoma

INTRODUCTION

Nasopharyngeal carcinoma (NPC) remains an endemic disease in certain parts of the world, with many patients presenting with advanced disease on diagnosis. Chemotherapy had remained the standard of care with minimal progress made until recent years. This review aims to provide an overview of recent significant breakthroughs and up-and-coming novel strategies in treating this deadly disease.

AREAS COVERED

This review focuses on the latest clinical development of promising investigational agents in the treatment of advanced NPC. These include anti-vascular agents, signaling pathways inhibitors and immunotherapy.

EXPERT OPINION

The addition of immune-checkpoint inhibitors (CPI) to platinum-based chemotherapy has undoubtedly changed the therapeutic landscape of R/M NPC in the first-line setting. This leaves much room for further research on the optimal treatment strategy in subsequent-line settings, likely including the addition of CPI to anti-vascular agents or novel CPI combinations, with or without chemotherapy as a backbone. Other potential approaches include optimal CPI maintenance therapy after first-line CPI-chemotherapy combination. Potential novel agents on the horizons are antibody-drug conjugates, bi-specific antibodies and signaling inhibitors, with several phase II/III studies currently underway.

Efficacy and safety of anlotinib plus penpulimab as second-line treatment for small cell lung cancer: A multicenter, open-label, single-arm phase II trial

BACKGROUND

Currently, the need for new therapeutic strategies involving programmed cell death protein-1 (PD-1) monoclonal antibodies in the second-line setting of small cell lung cancer (SCLC) is urgent. This study aimed to evaluate the efficacy and safety of anlotinib plus penpulimab as a second-line treatment for patients with SCLC who progressed after first-line platinum-based chemotherapy.

METHODS

This study included the patients from Cohort 4 of a single-arm, open-label, multicenter, phase II clinical trial. A safety run-in phase was performed under anlotinib (10/12 mg quaque die [QD], days 1-14) plus penpulimab (200 mg intravenously [IV], day 1) in a 21-day cycle, followed by the formal trial in which the patients received anlotinib (12 mg QD, days 1-14) plus penpulimab (200 mg IV, day 1) in a 21-day cycle. The primary endpoint of the safety run-in phase was safety. The primary endpoint of the formal trial phase was the objective response rate (ORR).

RESULTS

From April 28, 2020, to November 24, 2020, 21 patients were enrolled from 11 hospitals, including 2 in the safety run-in phase and 19 in the formal trial phase. In the formal trial phase, the ORR was 42.1% (8/19; 95% confidence interval [CI]: 17.7-66.6%). The median progression-free survival was 4.8 months (95% CI: 2.9-11.3 months), and the median overall survival was 13.0 months (95% CI: 4.6-not applicable [NA] months). The incidence of ≥grade 3 treatment-related adverse events (TRAEs) was 52.4% (11/21), and the incidence of treatment-related serious adverse events (AEs) was 28.6% (6/21). Two AE-related deaths occurred. The most common AEs were hypertension (57.1%, 12/21), hypothyroidism (42.9%, 9/21), and hypertriglyceridemia (38.1%, 8/21).

CONCLUSIONS

In patients with SCLC who progressed after first-line platinum-based chemotherapy, the second-line anlotinib plus penpulimab treatment demonstrates promising anti-cancer activity and a manageable safety profile, which warrants further investigation.

TRIAL REGISTRATION

No. NCT04203719, https://clinicaltrials.gov/.

HER2-Low Breast Cancer: Now and in the Future

Breast cancer is a heterogeneous disease, and its subtypes are characterized by hormone receptor and human epidermal growth factor receptor 2 (HER2) expression status. "HER2-low" tumors, which exhibit a low level of HER2 expression (immunohistochemistry 1+ or 2+ without gene amplification), were conventionally considered not amenable to anti-HER2 targeting agents based on the results of a phase III trial of trastuzumab. However, this perspective is being challenged by the emergence of novel anti-HER2 antibody-drug conjugates, such as trastuzumab-deruxtecan. These innovative therapies have demonstrated remarkable efficacy against HER2-low breast cancer, shedding new light on a previously overlooked category of breast cancer. Such promising results highlight the need for in-depth investigations of the biology and prognostic implications of HER2-low tumors. In this review, we comprehensively summarize the current evidence surrounding this topic and highlight areas that warrant further exploration and research in the future.

PD-1: A critical player and target for immune normalization

Immune system imbalances contribute to the pathogenesis of several different diseases, and immunotherapy shows great therapeutic efficacy against tumours and infectious diseases with immune-mediated derivations. In recent years, molecules targeting the programmed cell death protein 1 (PD-1) immune checkpoint have attracted much attention, and related signalling pathways have been studied clearly. At present, several inhibitors and antibodies targeting PD-1 have been utilized as anti-tumour therapies. However, increasing evidence indicates that PD-1 blockade also has different degrees of adverse side effects, and these new explorations into the therapeutic safety of PD-1 inhibitors contribute to the emerging concept that immune normalization, rather than immune enhancement, is the ultimate goal of disease treatment. In this review, we summarize recent advancements in PD-1 research with regard to immune normalization and targeted therapy.

First-line penpulimab combined with paclitaxel and carboplatin for metastatic squamous non-small-cell lung cancer in China (AK105-302): a multicentre, randomised, double-blind, placebo-controlled phase 3 clinical trial

BACKGROUND

Penpulimab is a novel programmed death (PD)-1 inhibitor. This study aimed to establish the efficacy and safety of first line penpulimab plus chemotherapy for advanced squamous non-small-cell lung cancer.

METHODS

This multicentre, randomised, double-blind, placebo-controlled, phase 3 clinical trial enrolled patients with locally advanced or metastatic squamous non-small-cell lung cancer from 74 hospitals in China. Eligible participants were aged 18-75 years, had histologically or cytologically confirmed locally advanced (stage IIIb or IIIc) or metastatic (stage IV) squamous non-small-cell lung cancer, were ineligible to complete surgical resection and concurrent or sequential chemoradiotherapy, had an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1, did not have previous systemic chemotherapy for locally advanced or metastatic non-small-cell lung cancer, and had one or more measurable lesions according to RECIST (version 1.1). Participants were randomly assigned (1:1) to receive intravenous penpulimab 200 mg or placebo (excipient of penpulimab injection), plus paclitaxel 175 mg/m2 and carboplatin AUC of 5 intravenously on day 1 every 3 weeks for four cycles, followed by penpulimab or placebo as maintenance therapy. Stratification was done according to the PD-L1 tumour proportion score (<1% vs 1-49% vs ≥50%) and sex (male vs female). The participants, investigators, and other research staff were masked to group assignment. The primary outcome was progression-free survival assessed by the masked Independent Radiology Review Committee in the intention-to-treat population and patients with a PD-L1 tumour proportion score of 1% or more (PD-L1-positive subgroup). The primary analysis was based on the intention-to-treat analysis set (ie, all randomly assigned participants) and the PD-L1-positive subgroup. The safety analysis included all participants who received at least one dose of study drug after enrolment. This trial was registered with ClinicalTrials.gov (NCT03866993).

FINDINGS

Between Dec 20, 2018, and Oct 10, 2020, 485 patients were screened, and 350 participants were randomly assigned (175 in the penpulimab group and 175 in the placebo group). Of 350 participants, 324 (93%) were male and 26 (7%) were female, and 347 (99%) were of Han ethnicity. In the final analysis (June 1, 2022; median follow-up, 24·7 months [IQR 0-41·4]), the penpulimab group showed an improved progression-free survival compared with the placebo group, both in the intention-to-treat population (median 7·6 months, 95% CI 6·8--9·6 vs 4·2 months, 95% CI 4·2-4·3; HR 0·43, 95% CI 0·33-0·56; p<0·0001) and in the PD-L1-positive subgroup (8·1 months, 5·7-9·7 vs 4·2 months, 4·1-4·3; HR 0·37, 0·27-0·52, p<0·0001). Grade 3 or worse treatment-emergent adverse events occurred in 120 (69%) 173 patients in the penpulimab group and 119 (68%) of 175 in the placebo group.

INTERPRETATION

Penpulimab plus chemotherapy significantly improved progression-free survival in patients with advanced squamous non-small-cell lung cancer compared with chemotherapy alone. The treatment was safe and tolerable. Penpulimab combined with paclitaxel and carboplatin is a new option for first-line treatment in patients with this advanced disease.

FUNDING

The National Natural Science Foundation of China, Shanghai Municipal Health Commission, Chia Tai Tianqing Pharmaceutical, Akeso.

Overview of tumor immunotherapy based on approved drugs

Tumor immunotherapy has become a new hotspot for cancer treatment. Various immunotherapies, such as immune checkpoint inhibitors, oncolytic viruses (OVs), cytokines, and cancer vaccines, have been used to treat tumors. They operate through different mechanisms, along with certain toxicities and side effects. Understanding the mechanisms by which immunotherapy modulates the immune system is essential for improving the efficacy and managing these adverse effects. This article discusses various currently approved cancer immunotherapy mechanisms and related agents approved by the Food and Drug Administration, the European Medicines Agency, and the Medicines and Medical Devices Agency. We also review the latest progress in immune drugs approved by the National Medical Products Administration, including monoclonal antibodies, cytokines, OVs, and chimeric antigen receptor-T cell therapy, to help understand the clinical application of tumor immunotherapy.

Immune checkpoint inhibitor-associated adrenal insufficiency in Chinese cancer patients: a retrospective analysis

PURPOSE

Immune checkpoint inhibitors (ICIs) are of great success in cancer therapy. This study aimed to identify adrenal insufficiency (AI) associated with immune checkpoint inhibitor (ICI) treatment in cancer patients receiving steroid replacement therapy and report the clinical characteristics of ICI-associated AI and concurrent immune-associated adverse events (irAEs).

METHODS

Patients prescribed cortisone acetate between January 2020 and March 2022 were reviewed to identify AI associated with ICI treatment. Data collected included indication of ICI (cancer type), drug characteristics, and outcomes.

RESULTS

A total of 101 patients were diagnosed with AI following treatment with ICIs. The median age was 64 years (range 22-83 years); 73.3% of the patients were male. Median time to develop primary AI and secondary AI after starting ICI therapy was 200.5 (35-280) days and 178 (16-562) days, respectively. Concurrent irAEs occurred in 67 (66.3%) patients and included 63 (62.4%) endocrine irAEs. Log-rank test showed that there was a trend toward higher likelihood of death at 120-day follow-up in patients initially receiving intravenous hydrocortisone compared with those receiving oral cortisone acetate after diagnosis of AI (p = 0.029).

CONCLUSION

This retrospective study comprehensively documented the clinical characterization of ICI-associated AI. Those initially receiving intravenous hydrocortisone after diagnosis of AI were associated with higher likelihood of death. Physicians should be aware of the variability of ICI-associated irAEs early in the treatment, early diagnoses, and timely management should be made.

Hot and cold tumors: Immunological features and the therapeutic strategies

The "hotness" or "coldness" of the tumors are determined by the information of the cancer cells themselves, tumor immune characteristics, tumor microenvironment, and signaling mechanisms, which are key factors affecting cancer patients' clinical efficacy. The switch mechanism of "hotness" and "coldness" and its corresponding pathological characteristics and treatment strategies are the frontier and hot spot of tumor treatment. How to distinguish the "hotness" or "coldness" effectively and clarify the causes, microenvironment state, and characteristics are very important for the tumor response and efficacy treatments. Starting from the concept of hot and cold tumor, this review systematically summarized the molecular characteristics, influencing factors, and therapeutic strategies of "hot and cold tumors," and analyzed the immunophenotypes, the tumor microenvironment, the signaling pathways, and the molecular markers that contribute to "hot and cold tumors" in details. Different therapeutic strategies for "cold and hot tumors" based on clinical efficacy were analyzed with drug targets and proteins for "cold and hot tumors." Furthermore, this review combines the therapeutic strategies of different "hot and cold tumors" with traditional medicine and modern medicine, to provide a basis and guidance for clinical decision-making of cancer treatment.

Therapeutic Targets of Monoclonal Antibodies Used in the Treatment of Cancer: Current and Emerging

Cancer is one of the leading global causes of death and disease, and treatment options are constantly evolving. In this sense, the use of monoclonal antibodies (mAbs) in immunotherapy has been considered a fundamental aspect of modern cancer therapy. In order to avoid collateral damage, it is indispensable to identify specific molecular targets or biomarkers of therapy and/or diagnosis (theragnostic) when designing an appropriate immunotherapeutic regimen for any type of cancer. Furthermore, it is important to understand the currently employed mAbs in immunotherapy and their mechanisms of action in combating cancer. To achieve this, a comprehensive understanding of the biology of cancer cell antigens, domains, and functions is necessary, including both those presently utilized and those emerging as potential targets for the design of new mAbs in cancer treatment. This review aims to provide a description of the therapeutic targets utilized in cancer immunotherapy over the past 5 years, as well as emerging targets that hold promise as potential therapeutic options in the application of mAbs for immunotherapy. Additionally, the review explores the mechanisms of actin of the currently employed mAbs in immunotherapy.

Bispecific antibody targeting TGF-β and PD-L1 for synergistic cancer immunotherapy

The PD-1/PD-L1 signaling pathway plays a crucial role in cancer immune evasion, and the use of anti-PD-1/PD-L1 antibodies represents a significant milestone in cancer immunotherapy. However, the low response rate observed in unselected patients and the development of therapeutic resistance remain major obstacles to their clinical application. Accumulating studies showed that overexpressed TGF-β is another immunosuppressive factor apart from traditional immune checkpoints. Actually, the effects of PD-1 and TGF-β pathways are independent and interactive, which work together contributing to the immune evasion of cancer cell. It has been verified that blocking TGF-β and PD-L1 simultaneously could enhance the efficacy of PD-L1 monoclonal antibody and overcome its treatment resistance. Based on the bispecific antibody or fusion protein technology, multiple bispecific and bifunctional antibodies have been developed. In the preclinical and clinical studies, these updated antibodies exhibited potent anti-tumor activity, superior to anti-PD-1/PD-L1 monotherapies. In the review, we summarized the advances of bispecific antibodies targeting TGF-β and PD-L1 in cancer immunotherapy. We believe these next-generation immune checkpoint inhibitors would substantially alter the cancer treatment paradigm, especially in anti-PD-1/PD-L1-resistant patients.

Radioiodine therapy in advanced differentiated thyroid cancer: Resistance and overcoming strategy

Thyroid cancer is the most prevalent endocrine tumor and its incidence is fast-growing worldwide in recent years. Differentiated thyroid cancer (DTC) is the most common pathological subtype which is typically curable with surgery and Radioactive iodine (RAI) therapy (approximately 85%). Radioactive iodine is the first-line treatment for patients with metastatic Papillary Thyroid Cancer (PTC). However, 60% of patients with aggressive metastasis DTC developed resistance to RAI treatment and had a poor overall prognosis. The molecular mechanisms of RAI resistance include gene mutation and fusion, failure to transport RAI into the DTC cells, and interference with the tumor microenvironment (TME). However, it is unclear whether the above are the main drivers of the inability of patients with DTC to benefit from iodine therapy. With the development of new biological technologies, strategies that bolster RAI function include TKI-targeted therapy, DTC cell redifferentiation, and improved drug delivery via extracellular vesicles (EVs) have emerged. Despite some promising data and early success, overall survival was not prolonged in the majority of patients, and the disease continued to progress. It is still necessary to understand the genetic landscape and signaling pathways leading to iodine resistance and enhance the effectiveness and safety of the RAI sensitization approach. This review will summarize the mechanisms of RAI resistance, predictive biomarkers of RAI resistance, and the current RAI sensitization strategies.

Advances in the structural characterization of complexes of therapeutic antibodies with PD-1 or PD-L1

Antibody-based immune checkpoint blockade (ICB)-based therapeutics have become effective clinical applications for cancers. Applications of monoclonal antibodies (mAbs) to de-activate the PD-1-PD-L1 pathway could effectively reverse the phenotype of depleted activated thymocytes (T cells) to recover their anti-tumoral activities. High-resolution structures of the complexes of the therapeutic monoclonal antibodies with PD-1 or PD-L1 have revealed the key inter-molecular interactions and provided valuable insights into the fundamental mechanisms by which these antibodies inhibit PD-L1-PD-1 binding. Each anti-PD-1 mAb exhibits a unique blockade mechanism, such as interference with large PD-1-PD-L1 contacting interfaces, steric hindrance by overlapping a small area of this site, or binding to an N-glycosylated site. In contrast, all therapeutic anti-PD-L1 mAbs bind to a similar area of PD-L1. Here, we summarized advances in the structural characterization of the complexes of commercial mAbs that target PD-1 or PD-L1. In particular, we focus on the unique characteristics of those mAb structures, epitopes, and blockade mechanisms. It is well known that the use of antibodies as anti-tumor drugs has increased recently and both PD-1 and PD-L1 have attracted substantial attention as target for antibodies derived from new technologies. By focusing on structural characterization, this review aims to aid the development of novel antibodies targeting PD-1 or PD-L1 in the future.

Role of histone methyltransferase SETDB1 in regulation of tumourigenesis and immune response

Epigenetic alterations are implicated in tumour immune evasion and immune checkpoint blockade (ICB) resistance. SET domain bifurcated histone methyltransferase 1 (SETDB1) is a histone lysine methyltransferase that catalyses histone H3K9 di- and tri-methylation on euchromatin, and growing evidence indicates that SETDB1 amplification and abnormal activation are significantly correlated with the unfavourable prognosis of multiple malignant tumours and contribute to tumourigenesis and progression, immune evasion and ICB resistance. The main underlying mechanism is H3K9me3 deposition by SETDB1 on tumour-suppressive genes, retrotransposons, and immune genes. SETDB1 targeting is a promising approach to cancer therapy, particularly immunotherapy, because of its regulatory effects on endogenous retroviruses. However, SETDB1-targeted therapy remains challenging due to potential side effects and the lack of antagonists with high selectivity and potency. Here, we review the role of SETDB1 in tumourigenesis and immune regulation and present the current challenges and future perspectives of SETDB1 targeted therapy.

Emerging PD-1/PD-L1 targeting immunotherapy in non-small cell lung cancer: Current status and future perspective in Japan, US, EU, and China

Non-small cell lung cancer (NSCLC), one of the deadliest types of cancers worldwide, has been the target of immunotherapy due to its high immune antigenicity. With the addition of immune-checkpoint inhibitors (ICIs), including anti-PD-1/PD-L1 antibodies, as an indispensable and powerful regimen for the treatment of this lethal disease, the median survival time for patients with stage IV NSCLC is approximately 2 years. In contrast, the response rate to ICIs remains less than 50%, even if the patients are selected using biomarkers such as PD-L1. Pharmaceutical companies have begun to develop additional anti-PD-1/PD-L1 antibodies to overcome resistance and are devising further immunotherapy combinations. More than 20 anti-PD-1/PD-L1antibodies have been approved or are currently in development. Numerous combination therapies are under development, and several combination therapies have provided positive results in randomized controlled trials. This review aimed to examine the current status of approved and investigational anti-PD-1/PD-L1antibodies for NSCLC in Japan, the United States, the European Union, and China. Further, this review discusses the challenges and future perspectives for developing new ICIs in alignment with the global developments in Japan.

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

Aims and background

A number of population pharmacokinetic (PPK) models of anti-programmed cell death-1 (PD-1) monoclonal antibodies (mAbs) in multiple tumor types have been published to characterize the influencing factors of their pharmacokinetics. This review described PPK models of anti-PD-1 mAbs that investigate the magnitude and types of covariate effects in PK parameters, provide a reference for building PPK models of other anti-PD-1 mAbs, and identify areas requiring additional research to facilitate the application of PPK models.

Methods

A systematic search for analyses of PPK models of eleven anti-PD-1 mAbs on the market that were carried out in humans was conducted using PubMed, Embase, and the Cochrane Library. The search covered the period from the inception of the databases to April 2022.

Results

Currently, there are fourteen analyses on PPK models of anti-PD-1 mAbs summarized in this review, including seven models that refer to nivolumab, four referring to pembrolizumab, one referring to cemiplimab, one referring to camrelizumab, and one referred to dostarlimab. Most analyses described the pharmacokinetics of anti-PD-1 mAbs with a two-compartment model with time-varying clearance (CL) and a sigmoidal maximum effect. The estimated CL and volume of distribution in the central (V_C) ranged from 0.179 to 0.290 L/day and 2.98 to 4.46 L, respectively. The median (range) of interindividual variability (IIV) for CL and V_C was 30.9% (8.7%–50.8%) and 29.0% (4.32%–40.7%), respectively. The commonly identified significant covariates were body weight (BW) on CL and V_C, and albumin (ALB), tumor type, sex, and performance status (PS) on CL. Other less assessed significant covariates included lactate dehydrogenase (LDH), immunoglobulin G (IgG), ipilimumab coadministration (IPICO) on CL, and body mass index (BMI), malignant pleural mesothelioma (MESO) on V_C.

Conclusion

This review provides detailed information about the characteristics of PPK models of anti-PD-1 mAbs, the effects of covariates on PK parameters, and the current status of the application of the models. ALB, BW, specific tumor type, sex, and PS should be considered for the future development of the PPK model of anti-PD-1 mAbs. Other potential covariates that were assessed less frequently but still have significance (e.g., LDH, IgG, and IPICO) should not be ignored. Thus, further research and thorough investigation are needed to assess new or potential covariates, which will pave the way for personalized anti-PD-1 mAbs therapy.

Autoimmune hemolytic anemia in patients with relapsed Hodgkin's lymphoma after treatment with penpulimab, a monoclonal antibody against programmed death receptor-1

In August 2021, penpulimab, an anti-programmed cell death 1 (PD-1) monoclonal antibody, was approved in China for the treatment of adult patients with relapsed or refractory classic Hodgkin's lymphoma who completed at least second-line chemotherapy. Penpulimab is currently in clinical trials in China and Australia for the treatment of nasopharyngeal cancer and non-small cell lung cancer. Several clinical studies have shown that penpulimab is safe and effective, and no immune-related adverse events (irAEs) above grade 3 were observed. A 60-year-old woman with relapsed Hodgkin's lymphoma developed nausea and fatigue after receiving penpulimab monotherapy (200 mg every 2 weeks). Ten days after the second injection, the patient's condition worsened, and biochemical test results confirmed autoimmune hemolytic anemia (AIHA), with a hemoglobin level of 70 g/L (normal range, 115-150 g/L), an unconjugated bilirubin level of 19.08 µmol/L (normal range, 0-17 µmol/L), and positive direct antiglobulin test (DAT) results. On the same day, we treated her with prednisone (2 mg/kg), but her hemoglobin level continued to decline to 51 g/L one day after hormone therapy, so she received an intravenous infusion of washed red blood cells and underwent plasmapheresis, which eventually resolved the AIHA. Considering that the hemoglobin level was < 65 g/L and the irAE was grade 4, penpulimab was discontinued, and the symptoms of AIHA disappeared. From this event, we know that severe AIHA can occur after penpulimab use similar to other PD-1 antibodies. In this case, plasmapheresis showed a good therapeutic effect and should be used as a supplementary means when hormonal and immunosuppressive therapies cannot provide rapid symptom relief. In addition, we recommend regular direct antiglobulin testing, as well as haptoglobin, lactate dehydrogenase and other hemolysis-related laboratory tests, in patients prescribed penpulimab and similar drugs for the early diagnosis and treatment of AIHA.