EISAI : AIMS TO ADVANCE GASTROINTESTINAL CANCER TREATMENT WITH RESEARCH ACROSS MULTIPLE TUMOR TYPES AT ASCO GI 2023

No.23-08	January 18, 2023
	Eisai Co., Ltd.

EISAI AIMS TO ADVANCE GASTROINTESTINAL CANCER TREATMENT WITH RESEARCH

ACROSS MULTIPLE TUMOR TYPES AT ASCO GI 2023

Highlights Include an Update from the Dose Escalation Part of a Phase 1 Study Evaluating the Novel Anticancer Agent, E7386, in Advanced Solid Tumors Including Colorectal Cancer

Research from the LEAP (LEnvatinib And Pembrolizumab) Clinical Program May Provide New Information About Treating Patients with Unresectable Hepatocellular Carcinoma

Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, "Eisai") announced today the presentation of research across various types of gastrointestinal cancers during the 2023 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium (#GI23), which is taking place in-person in San Francisco, California and virtually from January 19-21.

Notable data include an update from the dose-escalation part of a Phase 1 Study evaluating E7386*1, a CREB-binding protein (CBP) / β-catenin interaction inhibitor, in patients with advanced solid tumors including colorectal cancer (NCT03833700; Abstract: #106). Based on these additional analyses, further investigation of safety, preliminary efficacy, pharmacokinetics and biomarker analyses of E7386 is ongoing using two dose levels in the expansion part.

Research from the LEAP (LEnvatinib And Pembrolizumab) clinical program includes a poster presentation featuring a health-related quality of life analysis from the Phase 3 LEAP-002 trial investigating the lenvatinib (LENVIMA®) plus pembrolizumab (KEYTRUDA®*2) combination versus lenvatinib plus placebo as a first- line treatment for patients with unresectable hepatocellular carcinoma (NCT03713593; Abstract: #506). Additional presentations on Eisai's oncology pipeline showcase Eisai's investigational compound, E7389- LF, a new liposomal formulation of eribulin, in combination with nivolumab in patients with solid tumors. Efficacy and safety were evaluated in expansion cohorts, including an esophageal cancer cohort (NCT04078295; Abstract: #337) and a gastric cancer cohort (NCT04078295; Abstract: #339).

"We are eager to share new data at the annual symposium where specialists in gastrointestinal cancers gather from all over the world, including findings from a Phase 1 study evaluating the novel investigational anticancer agent, E7386, in advanced solid tumors including colorectal cancer," said Dr. Takashi Owa, Chief Scientific Officer, Senior Vice President, Eisai Co., Ltd. "Our findings across colorectal, esophageal, gastric and liver cancer illustrate Eisai's commitment to further oncology research for people living with gastrointestinal cancers, who account for over one quarter of the global cancer incidence1."

In March 2018, Eisai and Merck (known as MSD outside the United States and Canada), through an affiliate, entered into a strategic collaboration for the worldwide co-development and co-commercialization of lenvatinib, both as monotherapy and in combination with Merck's anti-PD-1 therapy pembrolizumab. To

date, more than 10 trials have been initiated under the LEAP clinical program, which is evaluating the combination across multiple tumor types.

This release discusses investigational compounds and investigational uses for FDA-approved products. It is not intended to convey conclusions about efficacy and safety. There is no guarantee that any investigational compounds or investigational uses of FDA-approved products will successfully complete clinical development or gain FDA approval.

The full list of Eisai presentations is included below. The majority of abstracts are currently available on the ASCO website. The late-breaking abstracts will be released at the time of presentation during the symposium.

Cancer Type	Study/	Abstract Title	Abstract Type &
	Compound		Details
			(Pacific Standard Time)
Pipeline
		A phase 1 study of E7386, a CREB-binding	Poster Presentation
		Abstract #106
		protein (CBP)/β-catenin interaction inhibitor,
		January 21, 2023
	E7386	in patients (pts) with advanced solid tumors
	6:30-7:55 AM
		including colorectal cancer: updated dose-
		escalation part
		Gastric cancer (GC) cohort of a phase 2 trial	Poster Presentation
Solid Tumors	E7389-LF	Abstract #339
of E7389-LF (liposomal formulation of	January 19, 2023
		eribulin) in combination with nivolumab	12:00-1:30 PM
		The esophageal cancer cohort of a phase 2	Poster Presentation
		Abstract #337
	E7389-LF	trial of E7389‐LF (liposomal formulation of	January 19, 2023
		eribulin) + nivolumab	12:00-1:30 PM
LEAP clinical program
		First-line lenvatinib plus pembrolizumab plus	Poster Presentation
		Abstract #411
		chemotherapy versus chemotherapy in
		January 19, 2023
	LEAP-015	advanced/metastatic gastroesophageal
	12:00-1:30 PM
		adenocarcinoma: (LEAP-015): Safety run-in
Gastrointestinal		results (Encore presentation)
Cancers		Health-related quality of life (HRQoL) impact	Poster Presentation
		of lenvatinib (len) plus pembrolizumab	Abstract #506
	LEAP-002	(pembro) versus len plus placebo (pbo) as	January 20, 2023
	first-line (1L) therapy for advanced	12:00-1:30 PM
		hepatocellular carcinoma (aHCC): Phase 3
		LEAP-002 study
Real World Evidence
		Prevalence of historical medical conditions	Poster Presentation
		or comorbidities with potential role in clinical	Presentation #511
Gastrointestinal	Real-world	decision making related to suitability of	January 20, 2023
immuno-oncologic plus IV antiangiogenic	12:00-1:30 PM
Cancer	data
therapy in newly diagnosed first-line
		unresectable hepatocellular carcinoma in the
		United States

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[Notes to editors]

1. Eisai's Focus on Cancer

Eisai focuses on the development of anticancer drugs, targeting the tumor microenvironment (with experience and knowledge from existing in-house discovered compounds) and the driver gene mutation and aberrant splicing (leveraging RNA Splicing Platform) as areas (Ricchi) where real patient needs are still unmet, and where Eisai can aim to become a frontrunner in oncology. Eisai aspires to discover innovative new drugs with new targets and mechanisms of action from these Ricchi, with the aim of contributing to the cure of cancers.

*1 E7386 is created through collaboration research between Eisai and PRISM BioLab Co., Ltd. (Headquarters: Kanagawa)

*2 KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC., a subsidiary of Merck & Co., Inc., Rahway, N.J., U.S.A.

1. Melina A. et al. Global Burden of 5 Major Types of Gastrointestinal Cancer. Gastroenterology. 2020 July; 159(1): 335-349.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8630546/pdf/nihms-1758791.pdf

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