Press Release
10 February 2020

4basebio AG decides to increase the public share buyback offer volume from 2,056,452 to 5,230,726 shares

Heidelberg, Germany, and Cambridge, UK, 10 February 2020 - The management board of 4basebio AG (formerly Expedeon AG) (Frankfurt: 4BSB; ISIN: DE000A2YN801; Prime Standard) has decided today, to increase the original volume of the current public share buyback offer from 2,056,452 to 5,230,726 shares and thus to acquire up to 5,230,726 shares.

The acceptance period ends on 10 February 2020, 12:00 noon (local time Frankfurt am Main). If more than 5,230,726 shares are submitted for buyback under the offer, the declarations of acceptance will be considered in proportion to the ratio of the 5,230,726 shares to the total number of shares submitted for buyback by the shareholders.

David Roth, Chief Financial Officer of 4basebio AG, comments: "We very much appreciate the high acceptance of our buyback program which is intended to offer an attractive opportunity for our investors to realise value following our successful 120 million Euro deal earlier this year. 4basebio will benefit from the extension of the program and use the repurchased shares in advantage of the further corporate development - for example as consideration for the acquisition of companies or equity interests as part of our ongoing buy & build strategy."

Further details of the public buyback offer can be found in the offer document, which was published on 24 January 2020 on the Company's website () under the heading "News" and in the German Federal Gazette (Bundesanzeiger).

About 4basebio AG:

4basebio AG, formerly operating under the name of Expedeon AG, is an enabler of exciting advances in medical science and patient care. After divestment of its immunology and proteomics products portfolio on January 1 2020, the Company changed its name to 4basebio AG reflecting the enhanced focus on technologies and products centered around DNA. The Company will focus on DNA manufacturing to supply DNA products for therapeutic and other uses requiring large amounts of high-purity DNA, such as the fast-growing market of novel gene therapies and gene vaccines. Besides DNA manufacturing, 4basebio aims at providing research and diagnostic products based on its RNA reverse transcriptase, DNA polymerase and DNA primase enzymes, addressing the research tools and diagnostic products markets.

4basebio AG has offices in Germany, Spain, UK, and the US. The Company is listed on the Prime Standard segment of the Frankfurt Stock Exchange (Ticker: 4BSB; ISIN: DE000A2YN801; Note: Effective 21 January 2020, the ticker symbol for 4basebio AG was changed from EXNN to 4BSB.).

For further information, please contact:

4basebio AG
Dr. Heikki Lanckriet
CEO/CSO
Phone: 4
Email:
Investors' information: investors.4basebio.com

MC Services AG (Investor Relations and International Media Relations)

Julia Hofmann
Phone:
Email:

### This publication is intended for information only and constitutes neither an offer to sell nor an invitation to buy securities. Some statements included in this press release, relating neither to proven financial results nor other historical data, should be viewed as forward-looking, i.e. not definite. Such statements are mainly predictions of future results, trends, plans or goals. These statements should not be considered to be total guarantees since given their very nature they are subject to known and unknown risks and imponderability and can be affected by other factors as a consequence of which the actual results, plans and goals of 4basebio AG may deviate greatly from the established conclusions or implied predictions contained in such statements. 4basebio does not undertake to publicly update or revise these statements in the light of new information or future results or for any other reason. ###