Phase I study of the antiprogrammed cell death-1 Ab spartalizumab (PDR001) in Japanese patients with advanced malignancies

A phase 2 study of spartalizumab (PDR001) among patients with recurrent or metastatic esophageal squamous cell carcinoma (KCSG HN18-17, K-MASTER project 12)

Spartalizumab (PDR001) is a humanized IgG4 monoclonal antibody targeting programmed cell death protein 1 (PD-1). We conducted a single-arm, phase 2 trial to investigate the efficacy and safety of spartalizumab in patients with refractory esophageal squamous cell carcinoma (ESCC). Patients with histologically confirmed ESCC who experienced disease progression after platinum-based chemotherapy received 300 mg of intravenous spartalizumab every three weeks until disease progression or occurrence of unacceptable toxicity. The primary endpoint was centrally assessed objective response according to the Response Evaluation Criteria in Solid Tumors, version 1.1. Adverse events were closely monitored throughout the study. From March 2020 through April 2021, 44 patients with ESCC were enrolled. Of the 44 patients, the objective response rate was 20.5% (95% confidence interval: 8.5-32.4). With a median follow-up of 10.9 months, median progression-free survival and overall survival were 3.2 months and 11.2 months, respectively. In addition, the median duration of response was 24.7 months. The most common grade 3 or 4 adverse event was grade 3 dysphagia (eight [18%] patients). Biomarker analyses explored programmed cell death ligand 1 and CD20 as potential predictive markers for PD-1 blockade. Spartalizumab showed promising activity with a manageable safety profile, indicating its potential as a new treatment option for patients with refractory ESCC.

Trial registration

The trial was registered at ClinicalTrials.gov under the identifier NCT03785496.

Unresectable Hepatocellular Carcinoma: A Review of New Advances with Focus on Targeted Therapy and Immunotherapy

With an expected incidence of more than 1 million cases by 2025, liver cancer remains a problem for world health. With over 90% of cases, hepatocellular carcinoma (HCC) is the most prevalent kind of liver cancer. In this review, we presented the range of experimental therapeutics for patients with advanced HCC, the successes and failures of new treatments, areas for future development, the evaluation of dose-limiting toxicity in different drugs, and the safety profile in patients with liver dysfunction related to the underlying chronic liver disease. In addition to the unmet demand for biomarkers to guide treatment decisions and the burgeoning fields of immunotherapy and systemic therapy in hepatocellular carcinoma, the development of old and new drugs, including their failures and current advancements, has been reviewed. This review aims to evaluate the updated optimal clinical treatment of unresectable hepatocellular carcinomas in clinical practice, mainly through targeted therapy. Although surgical treatment can significantly enhance the survival probability of early and intermediate-stage patients, it is unsuitable for most HCC patients due to a lack of donors. Due to their severe toxicity, the few first-line anti-HCC drugs, such as sorafenib, are often reserved for advanced HCC patients for whom other therapies have failed. The second-line drugs are usually alternatives for patients with intolerance or resistance. Consequently, the ongoing growth of possible preclinical drugs and studies on miRNAs, lncRNAs, and numerous other signaling pathway targets for developing novel drugs may introduce additional treatment prospects for HCC.

Phase I study of the antiprogrammed cell death-1 Ab spartalizumab (PDR001) in Japanese patients with advanced malignancies

Spartalizumab is a humanized IgG4/κ mAb directed against human programmed cell death-1 (PD-1). In this phase I study, we investigated safety, pharmacokinetics, preliminary antitumor activity, and toxicity of spartalizumab in patients with advanced malignancies. Patients (n = 18) with a range of tumor types received spartalizumab i.v. at doses of 1, 3, and 10 mg/kg every 2 weeks until disease progression, unacceptable toxicity, or discontinuation at the discretion of the investigator or patient. Most patients (61%) had received five or more prior lines of therapy. No dose-limiting toxicities were reported and, hence, the maximum tolerated dose was 10 mg/kg or more. Pharmacokinetics in Japanese patients aligned with those reported in a global dose-escalation study. The safety profile was consistent with other approved anti-PD-1 mAbs; the most common drug-related adverse events were maculopapular rash (22%), followed by malaise and increased blood alkaline phosphatase (11% each). Partial responses were reported in two patients (11%), one with transitional cell carcinoma and the other with hepatocellular carcinoma. In conclusion, this study confirmed the safety of spartalizumab given at a dose of up to 10 mg/kg every 2 weeks in Japanese patients with cancers.

Phage Display Technology as a Powerful Platform for Antibody Drug Discovery

Antibody drugs with a high affinity and specificity are effective and safe for intractable diseases, such as cancers and autoimmune diseases. Furthermore, they have played a central role in drug discovery, currently accounting for eight of the top 20 pharmaceutical products worldwide by sales. Forty years ago, clinical trials on antibody drugs that were thought to be a magic bullet failed, partly due to the immunogenicity of monoclonal antibodies produced in mice. The recent breakthrough in antibody drugs is largely because of the contribution of phage display technology. Here, we reviewed the importance of phage display technology as a powerful platform for antibody drug discovery from various perspectives, such as the development of human monoclonal antibodies, affinity enhancement of monoclonal antibodies, and the identification of therapeutic targets for antibody drugs.