NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OR REGULATIONS OF THAT JURISDICTION. THIS IS AN ANNOUNCE

NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION

IN WHOLE OR IN PART IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OR REGULATIONS

OF THAT JURISDICTION.

THIS IS AN ANNOUNCEMENT FALLING UNDER RULE

2.4 OF THE CITY CODE ON TAKEOVERS AND MERGERS ("THE CODE") AND DOES NOT CONSTITUTE AN ANNOUNCEMENT OF A FIRM INTENTION TO

MAKE AN OFFER UNDER RULE 2.7 OF THE CODE. THERE CAN BE NO CERTAINTY THAT AN OFFER WILL BE MADE.

THIS ANNOUNCEMENT CONSTITUTES INSIDE INFORMATION

AS STIPULATED UNDER THE MARKET ABUSE REGULATION (EU) NO. 596/2014, AS IT FORMS PART OF UK DOMESTIC LAW BY VIRTUE OF THE EUROPEAN

UNION (WITHDRAWAL) ACT 2018.

("Poolbeg" or the "Company")

Combination of Poolbeg and HOOKIPA Pharma Inc.

The boards of directors (each a "Board")

of HOOKIPA Pharma Inc. ("HOOKIPA") and Poolbeg Pharma plc ("Poolbeg") are pleased to announce that

they have entered into non-binding discussions for an all-share acquisition by HOOKIPA of Poolbeg (the "Potential Combination")

to create a strong clinical-stage biopharmaceutical company focused on developing and commercialising innovative medicines for critical

unmet medical needs, with a special focus on next-generation immunotherapies for the treatment of cancer and other serious diseases (the

The Potential Combination is intended to be implemented

by means of a scheme of arrangement under Part 26 of the Companies Act 2006.

that the Potential Combination would create a Nasdaq-listed Combined Group operated by a combined management team experienced in successfully

developing and commercializing medicines with a focus on execution and operational excellence. The Boards also believe the Potential Combination

would create a diversified clinical pipeline led by multi-KRAS targeting HB-700, a next generation immunotherapy potentially offering

additional treatment options for cancers with limited treatment options, and Phase 2-ready small molecule POLB 001, a potentially breakthrough

orally delivered preventative therapy for cancer immunotherapy-induced CRS, with potential value inflection points in areas of interest

in the pharmaceutical industry. Furthermore, the Boards expect the Potential Combination to bolster near-term clinical data catalysts,

with clinical data expected across multiple programmes over the next 24-months in large therapeutic areas with unmet medical needs. The

Combined Group would also have two partnered programmes with Gilead Sciences, Inc. ("Gilead"), offering the potential

of significant development and commercialisation milestones in addition to significant sales royalties (if either product is approved)

for the Combined Group's shareholders.

HOOKIPA is listed on the Nasdaq Capital Market

under the symbol HOOK and Poolbeg is listed on AIM under the symbol POLB.

Expected key terms of the Potential Combination

based on discussions to date comprise of:

by HOOKIPA of any firm offer under Rule 2.7 of the Code in respect of the Potential Combination is subject to the satisfaction or

waiver of a number of customary pre-conditions, including, amongst other things, the satisfactory completion of customary due diligence,

finalisation of the terms of the transaction, Board approvals of binding terms and sufficient prior expressions of interest from participants

in respect to the Fundraise. Before the announcement of any firm offer under Rule 2.7 of the Code, both HOOKIPA and Poolbeg intend

to engage with potential investors in the Fundraise, further details of which will be included in a separate presentation (the "Fundraise

Presentation"), which upon first use will be made available on HOOKIPA's website at www.ir.hookipapharma.com/potential-combination.

The Potential Combination would be subject to the approval of both HOOKIPA and Poolbeg shareholders and other conditions.

All discussions to date have been non-binding

and on a non-exclusive basis, and there can be no assurance that a firm offer will be made or that any transaction will be completed.

Information on HOOKIPA

HOOKIPA is a clinical-stage biopharmaceutical

company focused on developing next generation immunotherapies based on its proprietary arenavirus platform. HOOKIPA's product candidates

are designed to induce specific, robust and durable CD8+ T cells and antibodies to eliminate cancers and serious infectious diseases.

HOOKIPA's pipeline includes biological therapies for oncology, targeting human papillomavirus type 16-positive ("HPV16+")

cancers, KRAS mutated cancers, and other targets. In addition, HOOKIPA has partnered with Gilead to develop therapies that are intended

to provide functional cures for hepatitis B virus ("HBV") and human immunodeficiency virus-1 ("HIV").

HOOKIPA's next-generation vaccine platform is designed to supercharge immunity with its T cell activation platform based on work

of Nobel laureate and HOOKIPA co-founder, Rolf Zinkernagel. Further details of HOOKIPA's platform are set out in Appendix C.

Information on Poolbeg

Poolbeg is a clinical-stage

biopharmaceutical company focused on acquiring, developing and commercialising innovative medicines that will help improve the lives of

patients with rare and orphan diseases and where there is a high unmet medical need. Poolbeg's clinical programmes target large

addressable markets including cancer immunotherapy-induced Cytokine Release Syndrome ("CRS"), infectious disease,

and metabolic conditions such as obesity with the development of an oral GLP-1R agonist. Further details of Poolbeg's platform are

set out in Appendix C.

Important Takeover Code notes

There can be no certainty that any firm offer

will be made, even if the pre-conditions referred to above are satisfied or waived.

In accordance with Rule 2.4(c) of the

Code, HOOKIPA will be required, pursuant to Rule 2.6(a) of the Code, by no later than 5.00 p.m. on 30 January 2025,

to either announce a firm intention to make an offer for the Company, under Rule 2.7 of the Code, or announce that it does not intend

to make an offer for the Company, in which case the announcement will be treated as a statement to which Rule 2.8 of the Code applies.

The deadline can only be extended with the consent of the Panel in accordance with Rule 2.6(c) of the Code.

This announcement has been made with the approval

Pursuant to Rule 2.5 of the Code, HOOKIPA

reserves the right to introduce other forms of consideration and/or vary the mix or composition of consideration of any offer and vary

the transaction structure. HOOKIPA also reserves the right to amend the terms of any offer (including making the offer at a lower value,

whether by amending the Exchange Ratio or the HOOKIPA CVR Ownership Percentage or otherwise):

Prior to this announcement it has not been practical

for HOOKIPA to make enquiries of all persons acting in concert with it to determine whether any dealings in Poolbeg shares by such persons

give rise to a requirement under Rule 6 or Rule 11 of the Code for Poolbeg, if it were to make an offer, to offer any minimum

level, or particular form, of consideration. While neither HOOKIPA nor Poolbeg are aware of any such dealings, in accordance with Note

4 on Rule 2.4, any such details shall be announced as soon as practicable and in any event by no later than 16 January 2025.

Sources and bases of information

In this announcement, unless otherwise stated

or the context otherwise requires, the following bases and sources have been used:

HOOKIPA Shareholders will receive incremental

value in the form of a CVR instrument tied to HOOKIPA's HB-400, HB-500 and HB-200 programmes. More detail on these programmes and

their potential value to CVR holders is included below:

On a fully diluted basis, The HOOKIPA CVR Ownership

Percentage will be 55%, in the case of milestone payments related the HB-400 and HB-500 programmes, and 80%, in the case of proceeds of

a Disposition generated by the HB-200 programme, subject to the CVR Adjustment Mechanism outlined below:

HOOKIPA's existing immunotherapy focused

programmes and pipeline opportunities are detailed below. Further details on these programs are included in the Fundraise Presentation:

Poolbeg's existing platform

and pipeline opportunities are detailed below. Further details on these programmes are included in the Fundraise Presentation:

This announcement is not intended to, and does

not, constitute or form part of any offer, invitation or the solicitation of an offer to purchase, otherwise acquire, subscribe for, sell

or otherwise dispose of, any securities whether pursuant to this announcement or otherwise.

The distribution of this announcement in jurisdictions

outside the United Kingdom may be restricted by law and therefore persons into whose possession this announcement comes should inform

themselves about, and observe such restrictions. Any failure to comply with the restrictions may constitute a violation of the securities

law of any such jurisdiction.

Cavendish Capital Markets Limited ("Cavendish"),

which is authorised and regulated by the Financial Conduct Authority for investment business activities, is acting exclusively as financial

adviser to Poolbeg Pharma plc in relation to the matters set out in this announcement and is not acting for any other person in relation