129TiP: SAKK 16/14 – anti-PD-L1 antibody durvalumab (MEDI4736) in addition to neoadjuvant chemotherapy in patients with stage IIIA (N2) non-small cell lung cancer (NSCLC). A multicenter single-arm phase II trial

Frontiers and Opportunities: Highlights of the 2nd Annual Conference of the Chinese Antibody Society

Background

Programmed cell death 1 (PD-1) is an inhibitory immune checkpoint expressed on activatedT cells. Upon the formation of T cell receptor (TCR)-pMHC complexes, concomitant PD-1 ligation to its ligands programmed death-ligand 1 (PD-L1) or programmed death-ligand 2 (PD-L2) downregulates TCR signaling and effector function. Here we describe the preclinical characterization of Sintilimab, a fully human IgG4 antibody that potently blocks PD-1 interactions with PD-L1 and PD-L2.

Methods

The binding affinity and blockade function were detected by using surface plasmon resonance (SPR), Enzyme-linked immunosorbent assay (ELISA) and flow cytometry. The biology function properties were measured with luciferase assay and mixed lymphocyte reaction assay. In vivo anti-tumor function and preclinical pharmacokinetic (PK) were identified with human PD-1 transgenic mice and non-human primates separately.

Results

Sintilimab can specifically and strongly bind to human PD-1 (hPD-1) and cynomolgus PD-1 and the affinity of Sintilimab to human PD-1 was measured at 0.3 nm via surface SPR, and displayed slow dissociation kinetics. Sintilimab can block the interaction of PD-1 to PD-L1 and PD-L2 and induce high secretion levels of interferon (IFN)-γ and interleukin (IL)-2 in primary T cell assays. In humanized hPD-1 knock-in mouse models, Sintilimab showed potent anti-tumor activity and increased tumor-infiltrating CD8/CD4 T cell and CD8/ Treg ratios. Preclinical experimentation in non-human primates following a single intravenous infusion of Sintilimab at 1, 6 and 30 mg/kg presented with no signs of drug-related toxicity, and showed typical PK characteristics of an IgG antibody.

Conclusions

Sintilimab has desirable preclinical attributes that supports its clinical development for cancer treatment.

Durvalumab: a newly approved checkpoint inhibitor for the treatment of urothelial carcinoma

Until a recent introduction to checkpoint inhibitors, there were limited second-line chemotherapy options for urothelial carcinoma (UC) patients with disease progression after first-line, platinum-based treatment. Outcomes for patients with advanced disease over the past 30 years have highlighted a need for new and better therapy. In response to evolving interest, durvalumab (MEDI4736) was introduced as a potential treatment for advanced stages of UC. Durvalumab is a selective, high-affinity, human IgG1 kappa monoclonal antibody engineered with a triple mutation to reduce toxicity. This checkpoint inhibitor has shown promise in advanced UC and is currently the topic of much discussion in the cancer research community. This review article will explore the details surrounding durvalumab, while also giving a brief overview of additional immunotherapeutic agents utilized for UC.

The application and mechanism of PD pathway blockade for cancer therapy

Research in cancer therapeutics has achieved major progress in the understanding of the tumour-immunity cycle, which controls the delicate balance between the immune system and tumour. Identification of cancer cell T-cell inhibitory signals, including PD-L1, has generated novel insight into how to reinvigorate the patients' immune cells to respond to a variety of tumour types. PD-1 and PD-L1 (PD) inhibitory pathway blockade appears to a highly promising therapy and could accomplish durable anti-tumour responses with a reasonable toxicity profile. Some of the FDA-approved mAbs can reverse the negative regulators from tumour cells and antigen presenting cells of T-cell function to treat some cancer types by blocking the PD signalling pathway,especially advanced solid tumours. Emerging clinical data suggest that cancer immunotherapy will become a significant part of the clinical treatment of cancer.

Highlights on immune checkpoint inhibitors in non-small cell lung cancer

The treatment of advanced or refractory non-small cell lung cancer has been historically difficult owing to the lack of studies on effective systemic cure. The progress in lung cancer treatment has plateaued, necessitating new options for additional benefits. Immune checkpoint proteins are co-inhibitory factors that can diminish the antigen-specific immune responses by attenuating the regulatory role of cytotoxic T-lymphocyte-associated protein 4, programmed cell death-1, lymphocyte-activation gene 3, and T-cell immunoglobulin mucin-3. The therapeutic strategies targeting immune checkpoints mainly focus on the monoclonal antibody of these regulatory factors, which may facilitate clinical decision making. An enhanced understanding of the drug-resistance mechanisms and the therapeutic efficacy regulation will provide opportunities to improve the clinical outcomes of non-small cell lung cancer patients. Preclinical and clinical trials on these key immune-regulatory agents, which has heralded a new era in immuno-oncology in non-small cell lung cancer treatment, are currently in development.

Safety and effectiveness of localized lung resection combined with neoadjuvant chemotherapy in the treatment of stage I-II non-small cell lung cancer

This study was conducted to evaluate the safety and effectiveness of localized lung resection combined with neoadjuvant chemotherapy in the treatment of stage I-II non-small cell lung cancer (NSCLC). A total of 88 patients, who were admitted to our hospital for first diagnosis and treatment, were selected. The patients were divided into control group (n=40 cases) and observation group (n=48 cases) according to the last digit of the admission number. The control group was treated with minimally invasive localized lung resection by thoracoscope. The observation group underwent the same procedure combined with two cycles of systemic neoadjuvant chemotherapy before the surgery was adopted in the observation group. The effects of both treatments were compared. The operation time, intraoperative blood loss and postoperative drainage volume of observation group were significantly lower than those of the control group (P<0.05). The surgical resection rate and margin negative rate of observation group were higher than those of control group, while the occurrence rate of complications was lower than that of control group; results were statistically significant (P<0.05). The serum neutrophil gelatinase associated lipocalin (lipocalin-2/NGAL), matrix metalloproteinase-9 (MMP-9) and carcinoembryonic antigen (CEA) levels of two groups after the treatment were lower than those before; however, levels in the observation group exhibited a distinct decrease. The difference has statistical significance (P<0.05). The follow-up time of two groups was 3-38 months and the median time was 20.5 months. The tumor survival period of observation group was not prolonged, however, the survival rate and quality rate of life were enhanced; the difference has statistical significance (P<0.05). Localized lung resection combined with neoadjuvant chemotherapy can effectively improve the surgical effect of stage I-II NSCLC, prolong the survival period, enhance the survival rate, decrease the occurrence rate of complications and reduce the tumor related factors lipocalin-2, MMP-9 and CEA levels.