173362 Proof 9 Saturday, December 7, 2019 20:44 THIS DOCUMENT IS IMPORTANT AND REQUIRES YOUR IMMEDIATE ATTENTION. IF YOU ARE IN ANY DOUBT ABOUT THE OFFER, THE CONTENTS OF THIS DOCUMENT OR THE ACTION YOU SHOULD TAKE, YOU ARE RECOMMENDED TO SEEK YOUR OWN INDEPENDENT FINANCIAL ADVICE FROM A STOCKBROKER, BANK MANAGER, SOLICITOR, ACCOUNTANT OR OTHER INDEPENDENT FINANCIAL ADVISER AUTHORISED UNDER THE FINANCIAL SERVICES AND MARKETS ACT 2000. IF YOU ARE OUTSIDE THE UNITED KINGDOM YOU SHOULD IMMEDIATELY CONSULT AN APPROPRIATELY AUTHORISED INDEPENDENT FINANCIAL ADVISER. If you have sold or otherwise transferred all your hVIVO Shares, please send this document and the accompanying documents (but not the accompanying Form of Acceptance), as soon as possible, to the purchaser or transferee or to the stockbroker, bank or other agent through whom the sale or transfer was effected for delivery to the purchaser or transferee. If you have sold or transferred only part of your holding of hVIVO Shares, you should retain these documents and consult the stockbroker, bank manager or other agent through whom the sale or transfer was effected. However, neither this document nor the Form of Acceptance should be distributed, forwarded or transmitted in or into any jurisdiction in which such an act would constitute a violation of the relevant laws in such jurisdiction. The distribution of this document or the Form of Acceptance in or into jurisdictions other than the United Kingdom may be restricted by the laws of those jurisdictions and therefore persons into whose possession this document comes should inform themselves about, and observe, any such restrictions. Failure to comply with any such restrictions may constitute a violation of the securities laws of any such jurisdiction. Application will be made for the Enlarged Open Orphan Share Capital to be admitted to trading on AIM. It is expected that, subject to the satisfaction of certain conditions, Admission will become effective and trading in the New Open Orphan Shares will commence at 8.00 a.m. on 17 January 2020. The issue of the New Open Orphan Shares is subject, inter alia, to the passing of the Merger Resolutions to be proposed at the Open Orphan General Meeting. This document should be read in conjunction with the accompanying Admission Document dated 9 December 2019 relating to Open Orphan and the New Open Orphan Shares. Recommended All-Equity Offer for Open Orphan plc to merge with hVIVO plc hVIVO Shareholders should carefully read the whole of this document and the information incorporated by reference. In particular, your attention is drawn to the letter from the Senior Independent hVIVO Director which is set out in Part I of this document and which contains, inter alia, the recommendation of the Independent hVIVO Directors to accept the Offer. THE PROCEDURE FOR ACCEPTANCE OF THE OFFER IS SET OUT ON PAGES 54 TO 57 OF THIS DOCUMENT AND, IN RESPECT OF hVIVO SHARES IN CERTIFICATED FORM, IN THE ACCOMPANYING FORM OF ACCEPTANCE. IF YOU HOLD hVIVO SHARES IN CERTIFICATED FORM THEN, TO ACCEPT THE OFFER, THE FORM OF ACCEPTANCE MUST BE COMPLETED AND RETURNED AS SOON AS POSSIBLE AND, IN ANY EVENT, SO AS TO BE RECEIVED BY EQUINITI BY POST AT CORPORATE ACTIONS, ASPECT HOUSE, SPENCER ROAD, LANCING, WEST SUSSEX, BN99 6DA NO LATER THAN 1.00 P.M. (LONDON TIME) ON 30 DECEMBER 2019. IF YOU HOLD hVIVO SHARES IN UNCERTIFICATED FORM THEN, TO ACCEPT THE OFFER, YOU SHOULD COMPLY WITH THE PROCEDURE FOR ACCEPTANCE SET OUT ON PAGES 16 TO 17 OF THIS DOCUMENT AND ENSURE THAT ACCEPTANCE IS MADE ELECTRONICALLY THROUGH CREST SO THAT THE TTE INSTRUCTION SETTLES NO LATER THAN 1.00 P.M. (LONDON TIME) ON 30 DECEMBER 2019. IF YOU ARE A CREST SPONSORED MEMBER, YOU MUST REFER TO YOUR CREST SPONSOR BEFORE TAKING ANY ACTION AS ONLY YOUR CREST SPONSOR WILL BE ABLE TO SEND THE NECESSARY TTE INSTRUCTIONS TO EUROCLEAR. Arden Partners plc, which, in the United Kingdom, is authorised and regulated by the Financial Conduct Authority, is acting exclusively for Open Orphan and no one else in connection with the Offer and will not be responsible to anyone other than Open Orphan for providing the protections afforded to clients of Arden nor for providing advice in relation to the Offer or any other matter or arrangement referred to in this document. MCF Ltd, which, in the United Kingdom, is authorised and regulated by the Financial Conduct Authority, is acting exclusively for hVIVO and no one else in connection with the Offer and will not be responsible to anyone other than hVIVO for providing the protections afforded to clients of MCF nor for providing advice in relation to the Offer or any other matter or arrangement referred to in this document. Numis Securities plc which, in the United Kingdom, is authorised and regulated by the Financial Conduct Authority, is acting exclusively for hVIVO and no one else in connection with this document and the matters referred to herein and will not be responsible to anyone other than hVIVO for providing the protections afforded to clients of Numis Securities plc nor for providing advice in relation to the contents of this document and the matters referred to herein. 173362 Proof 9 Saturday, December 7, 2019 20:44 IMPORTANT NOTICE The release, publication or distribution of this document in jurisdictions other than the United Kingdom may be restricted by law and therefore persons into whose possession this document comes should inform themselves about, and observe, any applicable restrictions or requirements. Any failure to comply with such restrictions may constitute a violation of the securities laws of any such jurisdiction. To the fullest extent possible, the companies involved in the Offer disclaim any responsibility or liability for the violation of such requirements by any person. This document has been prepared for the purposes of complying with English law, the Code, the Rules of the London Stock Exchange and the AIM Rules and the information disclosed may not be the same as that which would have been disclosed if this document had been prepared in accordance with the laws and regulations of any jurisdiction outside England and Wales. This document and the accompanying documents do not constitute an offer or form part of any offer or an invitation to purchase, subscribe for, sell or issue, any securities or a solicitation of any offer to purchase, subscribe for, sell or issue any securities pursuant to this document or otherwise in any jurisdiction in which such offer or solicitation is unlawful. This document does not comprise a prospectus or a prospectus equivalent document. The statements contained herein are made as at the date of this document, unless some other time is specified in relation to them, and service of this document shall not give rise to any implication that there has been no change in the facts set forth herein since such date. CAUTIONARY NOTE REGARDING FORWARD LOOKING STATEMENTS This document, including certain information incorporated by reference, contains certain forward-looking statements with respect to the financial condition, results of operations and business of Open Orphan or the Open Orphan Group and hVIVO or the hVIVO Group and certain plans and objectives of the hVIVO Board and the Open Orphan Board. These forward-looking statements can be identified by the fact that they do not relate to historical or current facts. Forward-looking statements often use words such as “anticipate”, “target”, “expect”, “estimate”, “intend”, “plan”, “goal”, “believe”, “will”, “may”, “should”, “would”, “could” or other words of similar meaning. These statements are based on assumptions and assessments made by the hVIVO Board and the Open Orphan Board in the light of their experience and their perception of historical trends, current conditions, expected future developments and other factors they believe appropriate. By their nature, forward-looking statements involve risk and uncertainty and the factors described in the context of such forward-looking statements in this document could cause actual results and developments to differ materially from those expressed in or implied by such forward-looking statements. Should one or more of these risks or uncertainties materialise, or should underlying assumptions prove incorrect, actual results may vary materially from those described in this document. Except as required by the FCA, the London Stock Exchange, the AIM Rules, the Code or any other applicable law, hVIVO and Open Orphan assume no obligation to update or correct the information contained in this document. INFORMATION FOR OVERSEAS SHAREHOLDERS The release, publication or distribution of this document in certain jurisdictions may be restricted by law. Persons who are not resident in the United Kingdom or who are subject to other jurisdictions should inform themselves of, and should observe, any applicable requirements. Any failure to comply with these requirements may constitute a violation of the securities laws of any such jurisdiction. To the fullest extent permitted by applicable law, the companies and persons involved in the Offer disclaim any responsibility or liability for the violation of such requirements by any person. Unless otherwise determined by Open Orphan or required by the Code, and permitted by applicable law and regulation, the Offer will not be made, directly or indirectly, in, into or from a jurisdiction where to do so would violate the laws in that jurisdiction and no person may accept the Offer by any such use, means, instrumentality or form within any jurisdiction if to do so would constitute a violation of the laws of that jurisdiction. Accordingly, copies of this document and all documents relating to the Offer are not being, and must not be, directly or indirectly, mailed or otherwise forwarded, distributed or sent in, into or from a jurisdiction where to do so would violate the laws in that jurisdiction, and persons receiving 2 173362 Proof 9 Saturday, December 7, 2019 20:44 this document and all documents relating to the Offer (including custodians, nominees and trustees) must not mail or otherwise distribute or send them in, into or from such jurisdictions where to do so would violate the laws in that jurisdiction.