— APL1101 Advances into Clinical Development toward Initiation of the Phase I First-in-Human Trial —
Atransen Pharma Ltd. (“APL”; Headquarters: Osaka; CEO: Tomoyuki Asano) announces that it submitted the clinical trial notification for the Japanese Phase I/IIa clinical trial of APL1101, an orally administered small-molecule inhibitor targeting LAT1 (L-type amino acid transporter 1), to the Pharmaceuticals and Medical Devices Agency (“PMDA”) on 9th October 2026. The statutory 30-day investigation associated with the notification was completed on 9th November 2026.
This milestone marks the transition of APL1101, APL’s lead development program, from late-stage preclinical development into clinical development.
Clinical Trial Design and Positioning
The planned study is a Phase I/IIa clinical trial consisting of a Phase I First-in-Human (“FIH”) portion followed by a Phase IIa portion.
The Phase I FIH portion will enroll patients with advanced solid tumors and is planned to evaluate APL1101 administered orally once daily, with dose escalation conducted in 28-day treatment cycles. The principal objectives are to evaluate safety, tolerability, pharmacokinetics (“PK”), and pharmacodynamics (“PD”).
Subject to the data generated in the Phase I portion, the Phase IIa portion is planned to evaluate the preliminary efficacy, safety, and tolerability of APL1101 in selected solid tumors. The decision to proceed to the Phase IIa portion and the detailed tumor types to be evaluated will be determined based on the results of the Phase I portion and the Company’s development strategy.
With completion of the 30-day investigation, the statutory 30-day period required under Japan’s clinical trial notification process for this Phase I/IIa trial has been fulfilled. APL will proceed with the remaining preparations in coordination with the participating medical institutions, ethics review committees, and other relevant parties, with the initial goal of initiating the Phase I FIH portion.
Completion of the 30-day investigation does not constitute approval or authorization of APL1101 or of the clinical trial by the PMDA. It also does not establish the efficacy or safety of APL1101. APL1101 remains an investigational, unapproved drug product.
Development Characteristics of APL1101
APL1101 is Atransen’s proprietary small-molecule drug candidate targeting LAT1, a transporter involved in the transport of essential amino acids in cancer cells.
Based on the concept of “locking inhibition,” Atransen is developing APL1101 with the aim of selectively inhibiting LAT1-mediated amino-acid transport and creating a new oral treatment option for solid tumors with elevated LAT1 expression.
The development program incorporates the following features:
- An orally administered, once-daily dosing strategy
- Dose escalation in 28-day treatment cycles
- A patient-selection strategy
- Evaluation of biomarkers
- A Japan-first FIH strategy designed to inform subsequent U.S. and global development
Future Development and Global Strategy
APL plans first to generate safety, tolerability, PK, and PD data in Japanese patients through the Phase I FIH portion. The Company will then seek to establish clinical proof of concept for the LAT1-targeted therapeutic approach through the Phase IIa portion.
Data generated in Japan are expected to inform the Company’s future clinical development plan in the United States and its broader global development strategy. APL plans to engage in discussions with the U.S. Food and Drug Administration (“FDA”) regarding the U.S. development plan for APL1101.
This announcement relates to the planned Japanese Phase I/IIa trial and does not indicate that a clinical trial may be initiated in the United States or that the FDA has reached any conclusion regarding APL1101.
APL will continue to advance the clinical development of APL1101 and engage with relevant domestic and international parties regarding potential financing, co-development, licensing, and other strategic partnership opportunities.
Relationship to the AMED Program
The development of APL1101 is being advanced with support from AMED startup ecosystem strengthening program, with the objective of transitioning the program from nonclinical development into clinical development and obtaining the clinical POC.
APL intends to leverage the research, manufacturing, regulatory, and clinical development capabilities established through the program to advance APL1101 toward potential implementation in Japan and other markets.
About Atransen Pharma Ltd.
Company: Atransen Pharma Ltd.
Headquarters: Osaka, Japan
Representative: Tomoyuki Asano, Chief Executive Officer
Business: Research and development of novel oncology therapeutics
Website: https://www.atransen.com/
Contact: admin@atransen.com
Forward-Looking Statements
This release contains forward-looking statements regarding APL1101’s development plans, anticipated timing of trial initiation, potential transition to the Phase IIa portion, tumor types, discussions with the FDA, and potential strategic partnerships. These statements are based on information available to Atransen as of the date of this release and are subject to change due to discussions with regulatory authorities, ethics review committees, participating medical institutions, clinical data, financing, development costs, and other factors.