Regulatory Review of New Therapeutic Agents

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.

Assessment of Drugs Approved by Public Knowledge-Based Applications (Kouchi-shinsei) During the Last Two Decades in Japan

Public knowledge‐based application (“Kouchi‐shinsei” in Japanese) is unique to Japan, implemented to eliminate the off‐label use of unapproved indications, dosages, and administrations because of drug lag. The guidance for public knowledge‐based application was issued in 1999. This study comprehensively investigated the trends of items approved by public knowledge‐based application in Japan during the last 2 decades. Prescription drugs approved from January 2000 to December 2019 were surveyed. In Japan, 1,855 drugs were approved within the target survey period. Among them, 219 (11.8%) were approved by public knowledge‐based application. Considering the changes in the number of items approved by public knowledge‐based application over the years, the number of items approved in 2000 was 7, reaching a maximum of 34 items in 2011, and decreased after that, 8 items were approved in 2019. The regulatory characteristics of drugs approved by public knowledge‐based application and those of other drugs were compared. By public knowledge‐based application, more anticancer and pediatric drugs were approved (P < 0.001), and only one drug for orphan diseases was approved (P < 0.001). In addition, the review time of public knowledge‐based applications was significantly shorter than that of normal applications regardless of time point. The approval system using public knowledge‐based application began in 2000, following issuance of the “Guidance for off‐label use of prescription drugs.” Furthermore, the approved items were mostly drugs for cancer, infectious diseases, and pediatric drugs. We anticipate the promotion of public knowledge‐based application to accommodate the approval of drugs for orphan diseases.

Evolving Landscape of New Drug Approval in Japan and Lags from International Birth Dates: Retrospective Regulatory Analysis

The Pharmaceuticals and Medical Devices Agency (PMDA) has approved hundreds of new drugs in recent years. We retrospectively analyzed the new drugs approved in Japan from 2008 to 2019, and identify the first-in-world approvals and clarify the current drug lag. The new drug and the drug lag were defined as a drug with a new active substance and a difference between the approval date in Japan and the international birth date, respectively. Among 400 new drugs approved in Japan during the last 12 years, 80 (20.0%) were first approved in Japan, and 320 were outside Japan (the United States: 202, 50.5%; Europe: 82, 20.5%; other regions: 36, 9.0%). Of these, 45 new drugs have not yet been approved outside Japan, and the remaining 355 have been globally approved in Japan and overseas. The number of new drug approvals were the largest in oncology followed by metabolic/endocrine and infectious diseases. The median drug lags (year) among all 400 new drugs and 355 new drugs with global approvals were 4.3 and 4.7 in the first tertile (2008-2011), 1.5 and 2.6 in the second tertile (2012-2015), and reduced to 1.3 and 2.2 in the third tertile (2016-2019), respectively. Substantial drug lag remains in neurology, psychiatry, and therapeutic areas where the number of new drug approvals was relatively small. Collectively, one-fifth of the new drugs approved in Japan are first-in-world approvals. Drug lag has been greatly decreased, although it still exists.

Safety and Evidence of Off-Label Use of Approved Drugs at the National Cancer Center Hospital in Japan

PURPOSE

In Japan, for pharmaceutical products to be covered by public medical insurance, their efficacy and safety must first be confirmed in clinical trials. To our knowledge, this study is the first investigation into the off-label use of pharmaceutical products at a high-volume cancer treatment center in Japan. The objective of this study is to explore the framework necessary for future pharmaceutical development and regulatory approval in the field of oncology by surveying the frequency of and indications for off-label use of pharmaceutical products at the National Cancer Center Hospital in Tokyo, Japan.

MATERIALS AND METHODS

The pharmaceutical products used off-label in daily practice from 2003 to 2015 at the National Cancer Center Hospital were retrospectively examined based on applications that had been submitted to an internal review committee requesting off-label use.

RESULTS

A total of 1,390 applications were submitted during the study period. The most frequently used supporting documents were the results of phase II trials, followed by case series and phase III trials. The cancer most frequently treated with off-label drugs was sarcoma (15.1%), followed by urologic cancer (9.2%) and GI cancer (7.6%).

CONCLUSION

As reported in previous studies, pharmaceutical products were generally used off-label for the treatment of rare cancers, for which large-scale clinical trials are difficult to conduct. Continued discussion of the types of frameworks that are needed to guide pharmaceutical development is necessary.

MASTER KEY Project: Powering Clinical Development for Rare Cancers Through a Platform Trial

For rare cancers, challenges in establishing standard therapies are greater than those for major cancers, and effective methods are needed. MASTER KEY Project is a multicenter study based in Japan, with two main parts: prospective registry study and multiple clinical trials. Advanced rare cancers, cancers of unknown primary origin, and those with rare tissue subtypes of common cancers are targeted. The registry study accumulates highly reliable consecutive data that can be used for future drug development. The multiple trials are conducted simultaneously, targeting either a specific biomarker or a rare tumor type of interest. The first interim data set from the registry part presented here shows the prevalence of genetic abnormalities, response rates, survival rates, and clinical trial enrollment rates. From May 2017 to April 2019, 560 patients (mean age = 53) were enrolled in the project. Frequent cancer types included soft tissue sarcomas, neuroendocrine tumors, and central nervous system tumors. Among the 528 patients with assessable data, 69% (364/528) had next‐generation sequencing tests, with 48% (176/364) harboring an “actionable” alteration. Seventy‐one (13%) patients have been enrolled in one of the clinical trials, with an accrual rate of 3.94 patients/month. A descriptive analysis of biomarker‐directed or non‐biomarker‐directed treatment survival was performed. This project is expected to accelerate development of treatments for rare cancers and show that comprehensive platform trials are an advantageous strategy.