HLA-A*02 TESTING USING ONE LAMBDA*S SECORE CDX HLA SEQUENCING SYSTEM IN DAIICHI SANKYO*S FIRST-IN-HUMAN STUDY OF DS-2243a IN PARTICIPANTS WITH ADVANCED SOLID TUMORS

This Clinical Performance Study is defined as an interventional performance
study per Article 2 (46) Regulation (EU) 2017/746. The investigational SeCore*
CDx HLA Sequencing System (henceforth referred to as the Device) will be used
to provide human leukocyte antigen (HLA) allele test results to aid in the
eligibility determination of patients associated with the interventional
medicinal product clinical trial DS2243-054. Minimally invasive specimen
collection via venipuncture is performed for the purpose of this Clinical
Performance Study

The primary objective of this Clinical Performance Study is to utilize the
Device for performance evaluation to detect HLA-A Locus alleles as part of the
eligibility criteria for patients to receive an experimental medicinal product
under the DS2243-054 first in human clinical trial.

The Device for performance evaluation will be used to directly sequence DNA
samples purified from collected Whole Blood specimens to specifically detect
Target Alleles, HLA-A*02:01, A*02:02, A*02:03, A*02:04, A*02:05, A*02:06,
A*02:09, A*02:10, or A*02:11, in patients diagnosed with advanced (metastatic
or unresectable) SS or MRCLS as well as metastatic or unresectable locally
advanced Adenocarcinoma/Squamous cell carcinoma type NSCLC (Ad/Sq) or
Urothelial Carcinoma (UC).

The safety and efficacy clinical performance characteristics of the Device for
performance evaluation used in this study are evaluated based on the endpoint
of the corresponding medicinal product clinical trial.

The secondary objectives of this Clinical Performance Study are to conduct the
following exploratory evaluations and develop descriptive statistics on the
following attributes:
• Operational characteristics of the Device for performance in a clinical study
setting.
• Determine prevalence of the Target Alleles in the participant population.
• Gather feedback on the implementation of the Device for performance
evaluation from DSI.

The Clinical Performance Study involves the HLA testing of prospective
venipuncture whole blood specimen collection under the DS2243-054 medicinal
product clinical trial protocol from consented patients, who are at least 18
years of age diagnosed with advanced (metastatic or unresectable) SS, MRCLS as
well as metastatic or unresectable locally advanced NSCLC Ad/Sq or UC. Patient
recruitment, specimen collection, and shipment will occur at and be managed by
approximately five DSI investigator sites within the USA and European Union
participating in the DS-2243-054 clinical trial. As DSI intends to enroll
approximately 150 participants into the medicinal product clinical trial, the
expected overall screening sample size should be approximately 650 patients.

Upon receipt of the specimen at the One Lambda Inc.*s internal investigator
testing site, specimen accessioning, processing into DNA, and sample testing
will be managed and conducted by the testing site. DNA sample testing to
determine patient HLA Target Allele status will be performed using the
investigational and performance evaluation use only Device.

The HLA test results will be generated by the Device and reported back to DSI
and their investigator sites for continued patient eligibility determination
for the DS2243-054 medicinal product clinical trial.

Please refer to the protocol.