LAUSANNE, Switzerland, October 29, 2026
ADC Therapeutics SA has announced an important regulatory and commercial development for ZYNLONTA® (loncastuximab tesirine-lpyl) in Japan. The company’s Japanese licensing partner, Tanabe Pharma Corporation, submitted a marketing authorization application to Japan’s Ministry of Health, Labour and Welfare (MHLW) on October 29, 2026, seeking approval to treat adults with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) who have received two or more previous lines of systemic therapy. The submission is supported by encouraging results from a Japanese Phase 1/2 clinical bridging study evaluating ZYNLONTA as a single-agent treatment. In a separate development, Tanabe Pharma entered into an exclusive sublicensing agreement with Nippon Shinyaku Co., Ltd. for the commercialization of ZYNLONTA in Japan. These developments represent progress in the potential introduction of the antibody-drug conjugate into the Japanese oncology market and strengthen ADC Therapeutics’ international commercialization strategy.
Tanabe Pharma Submits Japanese Marketing Authorization Application
The marketing authorization application is based on clinical evidence from the Japanese Phase 1/2 MT-2111-A-101 bridging study, which evaluated ZYNLONTA monotherapy in Japanese patients with relapsed or refractory DLBCL. This regulatory submission seeks approval for patients whose disease has returned after treatment or has not responded adequately to previous therapies. DLBCL is an aggressive type of non-Hodgkin lymphoma that develops from B lymphocytes and can progress rapidly without effective treatment. Patients whose disease relapses or becomes refractory after multiple treatment regimens often face limited therapeutic options, creating a need for additional targeted treatments. Tanabe Pharma originally entered into an exclusive licensing agreement with ADC Therapeutics in January 2022 to develop and commercialize ZYNLONTA in Japan. Under the current sublicensing arrangement, Tanabe Pharma will continue to lead development activities and remain responsible for obtaining Japanese regulatory approval under the submitted application. The filing is an important regulatory milestone, but the medicine must still undergo review by the Japanese authorities before any marketing authorization decision is made.
Japanese Phase 2 Results Demonstrate Clinical Activity
The Japanese Phase 2 portion of the MT-2111-A-101 study reported an overall response rate (ORR) of 58.1%, including a complete response rate of 41.9%. The median duration of response had not been reached at a median follow-up of 15.21 months, indicating that the available follow-up had not yet established the median time for which responses lasted. The findings were presented at the Japanese Society of Hematology meeting and were reported to be consistent with results from the global pivotal LOTIS-2 study. ADC Therapeutics also stated that no new safety concerns were identified in the Japanese study. These findings provide clinical support for the regulatory application and offer information about treatment activity in the Japanese patient population. ZYNLONTA is a CD19-directed antibody-drug conjugate (ADC) designed to deliver a cytotoxic drug payload to cancer cells expressing the CD19 protein. After binding to CD19 on the target cell, the ADC is internalized, allowing enzymes inside the cell to release its pyrrolobenzodiazepine (PBD) payload. This targeted delivery approach is intended to direct the cancer-killing component toward malignant B cells. The Japanese study results are encouraging, although the reported response rates should not be interpreted as proof of long-term survival benefit.
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Nippon Shinyaku to Support Commercialization in Japan
The exclusive sublicensing agreement between Tanabe Pharma and Nippon Shinyaku brings additional Japanese hematology and oncology commercialization expertise to the potential launch of ZYNLONTA. Nippon Shinyaku has an established commercial and field medical presence in Japan and experience introducing innovative therapies developed by international pharmaceutical companies. The partnership is intended to support market preparation and commercialization if Japanese regulatory approval is obtained. ADC Therapeutics CEO Ameet Mallik described the developments as an important step toward expanding ZYNLONTA’s global reach and potentially making the treatment available to more patients with B-cell malignancies. The company, headquartered in Lausanne, Switzerland, focuses on the development and commercialization of antibody-drug conjugates. ZYNLONTA has previously received accelerated approval from the U.S. FDA and conditional approval from the European Commission for certain adults with relapsed or refractory DLBCL after two or more lines of systemic therapy.
The Japanese filing and sublicensing agreement mark significant progress in the product’s international development. Regulatory review, potential approval and the first commercial sale in Japan remain important upcoming milestones. If authorized, ZYNLONTA could provide another treatment option for eligible patients with heavily pretreated DLBCL. The outcome of the Japanese regulatory assessment will determine the next stage of its introduction in this market.
Source: ADC Therapeutics press release
