Funding to accelerate clinical progression of Iksuda’s pipeline of new generation of antibody drug
conjugates, targeting tumours with high unmet need.

Investment round led by Korean-based Mirae Asset Capital and Celltrion.

Iksuda Therapeutics (Iksuda), the developer of a new generation of
antibody drug conjugates (ADCs) with raised therapeutic index, today announced it has completed a
US $47 million (circa GB £34 million) financing round, co-led by Mirae Asset Capital and its
subsidiaries, Celltrion and Premier Partners, with the Company being advised by Ashfords LLP. The
funding will support the advancement of Iksuda’s lead ADC assets and expansion of its payload and
conjugation platform technologies.

Iksuda’s lead pre-clinical candidate, IKS03, is a best-in-class CD19-targeted ADC candidate for B-cell
cancers. The investment will enable progression of IKS03 to first-in-human phase 1 clinical trials. It
will also be used to accelerate the Company’s earlier-stage programmes including IKS04 and IKS012
to IND filing.

Iksuda’s ADC programmes target tumours that currently have limited treatment options and high
relapse rates. The Company’s drug development pipeline is centred on the improved safety and
efficacy conferred by tumour activated, prodrug payloads in combination with stable conjugation
technologies, including its proprietary novel PermaLink® platform. Iksuda’s research-stage pipeline
utilises its proprietary Protein Alkylating (ProAlk) tumour-activated payload platform, recently licensed
from Göttingen University1. The novel mode of action for the ProAlk tuneable payload series differs
from the field’s primary focus of intra- or DNA inter-strand cross-linking, conferring benefits against
drug and tumour resistance mechanisms, and enabling the development of more powerful, more
tolerable ADCs.

Dr Dave Simpson, Chief Executive Officer, Iksuda Therapeutics, said: “This is a transformational
investment milestone for Iksuda, enabling us to focus on the progression of our industry-leading ADC
programmes and bring them to the clinic, whilst supporting our commercial growth. The funding not
only reflects the potential of our technologies, but also the unmatched expertise of the Iksuda team.
We are grateful for the support of this group of investors and delighted to welcome them to the team.”

Ji Kwang Chung, Investor, Mirae Asset Capital, commented: “We have been highly impressed
with Iksuda’s approach and progress to date, and with the Company’s leadership. We are delighted to
lead this investment round, and to contribute to enabling the team to progress its very promising
pipeline of ADC candidates.”

Woosung, Kee, CEO, Celltrion Inc., added: “By pursuing tumours that are resistant to current
treatment approaches, Iksuda is extending the boundaries of ADC technology, and consequently the
treatment options for patients. This ideally complements Celltrion’s drive to pioneer uncharted areas
of innovative therapies, incorporating unique and successful next-generational approaches that
promote health and welfare globally. We have been very impressed with Iksuda’s progress to date
and look forward to working together to support their mission.”

Iksuda Therapeutics closes $47 million financing round | Iksuda Therapeutics