Tokyo, Japan, November 28, 2017 -- Kyowa Hakko Kirin Co., Ltd. (Tokyo: 4151 President and CEO:

Nobuo Hanai, “Kyowa Hakko Kirin”) today announces that the U.S. Food and Drug Administration

(FDA) has accepted for review the Biologics License Application (BLA) for mogamulizumab to

treat Cutaneous T-cell Lymphoma (CTCL) in patients who have received at least one prior

systemic therapy, and has granted Priority Review status.

This BLA is supported by the data from the MAVORIC (Mogamulizumab anti-CCR4 Antibody

Versus ComparatOR In CTCL) study, the largest global randomized clinical trial of systemic

therapy in CTCL.

The FDA has granted mogamulizumab Priority Review status, which is available to drugs that

would be significant improvements in the safety or effectiveness of the treatment, diagnosis, or

prevention of serious conditions when compared to standard applications. The Prescription Drug

User Fee Act (PDUFA) action date for the BLA is June 4, 2018.

“I am delighted that the FDA accepted the BLA for mogamulizumab with Priority Review and this

is another significant achievement for our subsidiary, Kyowa Kirin Pharmaceutical Development,”

said Mitsuo Satoh, Ph.D., Executive Officer, Vice President Head of R&D Division of Kyowa Hakko

Kirin. “We will keep working with Regulatory Authorities such as FDA to make it available to

patients with CTCL in the US as soon as possible.”

Mogamulizumab was first approved in Japan in 2012 for other hematological malignancies and in

2014 for use in CTCL. FDA has granted Breakthrough Therapy Designation status to

mogamulizumab for the treatment of Mycosis Fungoides (MF) and Sézary Syndrome (SS), in

patients who have received at least one prior systemic therapy. MF and SS are the most common

subtypes of CTCL.

The Kyowa Hakko Kirin Group companies strive to contribute to the health and well-being of

people around the world by creating new value through the pursuit of advances in life sciences

and technologies.

About Mogamulizumab

Mogamulizumab is a humanized monoclonal antibody (mAb) directed against CC chemokine

receptor 4 (CCR4), which is frequently expressed on leukemic cells of certain hematologic

malignancies including CTCL. Mogamulizumab was produced using Kyowa Hakko Kirin’s

proprietary POTELLIGENT®

 platform, which is associated with enhanced antibody-dependent

cellular cytotoxicity (ADCC).

About MAVORIC

MAVORIC is a Phase 3 open-label, multi-center, randomized study of mogamulizumab versus

active comparator in patients with MF and SS who have failed at least one prior systemic

treatment. The study was conducted in the US, Europe, Japan and Australia, and randomized 372

patients.