Kiadis Pharma N : 2nd Supplement February 2021

Kiadis Pharma N.V.

(a public limited liability company incorporated under the laws of the Netherlands with its registered seat in Amsterdam, the Netherlands)

Second Supplement to the Simplified Prospectus dated 5 June 2020

This supplement (the "Second Supplement") is published by Kiadis Pharma N.V. (the "Company", and together with its consolidated subsidiaries "Kiadis", "we", "our", "ours", "us" and similar terms).

This Supplement is a supplement to, and must be read in conjunction with, the simplified prospectus under the simplified disclosure regime for secondary issuances in accordance with Article 14 of Regulation (EU) 2017/1129 (the "Prospectus Regulation") dated 5 June 2020 (the Simplified Prospectus") that is constituted by (i) the specific registration document for secondary issuances of equity securities for the purpose of Articles 3 and 14 of the Prospectus Regulation that was prepared in accordance with the Prospectus Regulation and the rules promulgated thereunder, including Annex 3 of Commission Delegated Regulation (EU) 2019/980, and that was filed in English with, and was approved by the Netherlands Authority for the Financial Markets (Stichting Autoriteit Financiële Markten, "AFM") as competent authority under the Prospectus Regulation on 5 June 2020 (the "Simplified Registration Document"), supplemented by (ii) the specific securities note and summary for secondary issuances of equity securities for the purpose of Articles 3(3), 7 and 14 of the Prospectus Regulation that was prepared in accordance with the Prospectus Regulation and the rules promulgated thereunder, including Annex 12 of Commission Delegated Regulation (EU) 2019/980 and that was filed in English with, and was approved by the AFM as competent authority under the Prospectus Regulation on 5 June 2020 (the "Simplified Securities Note"), and that has been supplemented with the supplement within the meaning of Article 23 of the Prospectus Regulation that was prepared in accordance with the Prospectus Regulation and the rules promulgated thereunder, including Commission Delegated Regulation (EU) 2019/979, dated August 4, 2020 (the "First Supplement"), approved by the AFM in accordance with the Prospectus Regulation on such date.

This Second Supplement constitutes a supplement within the meaning of Article 23 of the Prospectus Regulation and was prepared in accordance with the Prospectus Regulation and the rules promulgated thereunder, including Commission Delegated Regulation (EU) 2019/979. This Supplement was filed in English with, and was approved by the AFM as competent authority under the Prospectus Regulation. The AFM has only approved this Second Supplement as meeting the standards of completeness, comprehensibility and consistency imposed by the Prospectus Regulation. Such an approval should not be considered as an endorsement of us in our capacity of issuer that is the subject of this Supplement or of our Shares. This Second Supplement will be notified to the Belgian Financial Services and Markets Authority (Autorité des services et marchés financiers, the "FSMA") for passporting in accordance with Article 25 of the Prospectus Regulation.

To the extent that there is any inconsistency between any statement in this Second Supplement and any other statement in the Simplified Prospectus, the statements in this Second Supplement will prevail. Potential investors should only rely on the information contained in the Simplified Prospectus as supplemented by this Second Supplement and any further supplements thereto within the meaning of Article 23 of the Prospectus Regulation, should such supplements be published.

Capitalized terms used but not (otherwise) defined herein are used as defined in the Simplified Prospectus.

The date of this Second Supplement is February 12, 2021 (the "Second Supplement Date").

AMENDMENTS AND ADDITIONS TO THE SIMPLIFIED PROSPECTUS

On November 2, 2020, we announced that we had entered into a definitive merger agreement under which Sanofi by means of a recommended public offer will offer to acquire all of our outstanding ordinary Shares at a price per Share of €5.45 in cash (cum dividend), representing an aggregate adjusted equity value on a fully diluted basis of approximately €308 million. The Management Board and Supervisory Board unanimously approve the intended transaction and recommend the offer to our Shareholders. The offer is subject to certain customary conditions and on December 9, 2020, we announced that the competition condition related to the offer had been satisfied. On January 14, 2021, we announced that we had drawn €20 million from the €27.7 million bridge loan facility that we entered into with Sanofi on January 13, 2021 to bridge our capital needs through the closing of the acquisition by Sanofi. On February 2, 2021 we announced that irrevocable commitments with Empery Asset Master Ltd., Empery Tax Efficient, LP and Empery Tax Efficient III, LP (jointly "Empery"), funds managed by Life Sciences Partners (jointly "Life Sciences Partners"), former Cytosen shareholders and option holders and Kreos Capital had been entered into, as a consequence of which as per the Second Supplement Date approximately 36.6% of the total number of issued and outstanding Shares on a fully diluted basis as at settlement of the offer is committed under the offer, subject to the offer being declared unconditional by Sanofi and the merger agreement not being terminated. On February 10, 2021, the AFM approved the offer memorandum (the "Offer Memorandum"), which was recognized by the FSMA on February 11, 2021. On February 12, 2021, Sanofi (via Sanofi Foreign Participations B.V. as offeror) launched the recommended public offer, and the Offer Memorandum and our position statement (the "Position Statement") were made generally available. The acceptance period will commence on February 15, 2021 and will expire on April 12, 2021, unless the acceptance period is extended. Completion of the offer is currently expected in the second quarter of 2021.

Furthermore, although it does not regard situations requiring a supplement specified in Commission Delegated Regulation (EU) 2019/979 nor situations which we consider to otherwise require a supplement pursuant to Article 23 of the Prospectus Regulation, the following is noted.



On August, 17, 2020, we announced a new research program, K-NK-ID101, that will focus on the development of K-NK cells as a treatment for COVID-19. This new program marks the start of broader application of our K-NK technology platform as a potential treatment, not only for cancer, but also for infectious diseases. In support of the K-NK-ID101 program, we have started collaborating with five premier Dutch institutions to study different anti-viral mechanisms of our K-NK cell therapy platform against SARS-CoV-2, the virus that caused the COVID-19 pandemic. The collaboration will study NK-cell biology in COVID-19 patients, the elimination of SARS-CoV-2 virus and virally infected cells by K-NK cells, and synergies between monoclonal antibodies, vaccines and K-NK cells.



On September 15, 2020, we announced that we had received $9.5 million in funding from the Advanced Regenerative Manufacturing Institute's (ARMI) BioFabUSA program, in partnership with the United States Department of Defense (DoD), to fund our K-NK-ID101 program. The funds from ARMI|BioFabUSA provides funding for our research on K-NK-ID101's activity and mode of action in COVID-19 treatment, including our Dutch research program announced on August 17, 2020. In addition, the funds will support a new Company-sponsored Phase I/IIa clinical trial that we plan to initiate in 2021 to evaluate K-NK-ID101 in COVID-19 and the scale up of GMP manufacturing. Additionally, we will collaborate with ARMI|BioFabUSA to establish large-scale manufacturing capacity for K-NK-ID101 in the US that can support theindustrialization of K-NK cell therapy. ARMI|BioFabUSA received funding from the United States Department of Defense (DoD) to advance large-scale manufacturing of engineered tissues and tissue-related technologies, including cell therapy.



On September 30, 2020, we announced our results for the six months ended June 30, 2020 and published our unaudited condensed consolidated interim financial statements for the six month period ended June 30, 2020.



On October 1, 2020, we announced that we had issued an amount of €5 million in convertible bonds to Kreos Capital in consideration for Kreos Capital waiving an equivalent amount under the Kreos Capital Facilities Agreements. As a result thereof, as per September 30, 2020 the outstanding amount under the Kreos Capital Facilities Agreements was lowered to €1.6 million.



On December 7, 2020, we announced that we had issued 267,012 Holdback Shares to the former CytoSen shareholders, increasing the number of outstanding Shares to 40,308,501.

In view of the above, with effect from the Second Supplement Date, the information appearing in, or incorporated by reference into, the Simplified Prospectus shall be supplemented and amended in the manner described below (references to page numbers are to the pages of the Simplified Registration Document or the Simplified Securities Note, as applicable):

1.

In paragraph 1.1 (Risks related to our financial position), in the risk factor headed

"We are dependent on external funding in the foreseeable future and require substantial additional funding to continue our operations including during the next twelve months. If we are unable to raise funding when needed or on acceptable terms, we could be forced to delay, reduce or terminate our development programs and may be unable to continue as a going concern and could ultimately go into insolvency." on page 3 of the Simplified Registration Document, the following amendments shall be made:

"We are dependent on external funding in the foreseeable future and require substantial additional funding to continue our operations including during the next twelve months. If we are unable to raise funding when needed or on acceptable terms, we could be forced to delay, reduce or terminate our development programs and may be unable to continue as a going concern and could ultimately go into insolvency.

As of December 31, 2019, we had cash and cash equivalents of €29.5 million and as of the Simplified Registration Document Date, we had cash and cash equivalents of approximately €22.7 million. As of the Second Supplement Date, we had cash and cash equivalents of approximately €30.232.2 million. Based on our operating plans, we believe that existing cash and cash equivalents will allow us to continue operating the business into the firstthird quarter of 2021. The fact that our working capital requirements for the next twelve months following the Simplified Registration Document Date require additional funds indicates the existence of a material uncertainty which may cast significant doubt about our ability to continue as a going concern. See also Note 2 of the consolidated financial statements for the financial year ended December 31, 2019 incorporated by reference in this Simplified Registration Document.

As we do not currently generate cash from product revenues to meet our current working capital requirements, we are dependent on the issuance and sale of equity and debt securities, debt financing arrangements and other funding sources, to continue financing our operations and to proceed with our current plans for clinical development and research. The fact that we discontinued our previous lead program ATIR101 may negatively impact our ability to attract additional funding. The potential consideration under our agreement with Aventis Inc., part of the Sanofi S.A. group of companies ("Sanofi"), of up to €857,5 million is contingent on achieving preclinical, clinical, regulatory and commercial milestones, and we will only be entitled to royalties if and when products resulting from the agreement have been approved and commercially sold - see also paragraph 4.8 below. Also, the impact of the coronavirus on capital markets as a whole already affects the availability, amount and type of financing and ultimately may impact our continuity - see also paragraph 1.2 below."

• 2. In paragraph 2.7 (Documents incorporated by reference and documents available) starting on page 46 of the Simplified Registration Document, the following amendments shall be made:

  "Kiadis Pharma N.V.'s articles of association (statuten) as they read on the Simplified Registration Document Date (the "Articles of Association") (the Dutch version and an English translation thereof (hyperlinked)) are incorporated by reference in this Simplified Registration Document. In addition, the Full Year Financial Statements (hyperlinked) and our unaudited condensed consolidated interim financial statements for the six month period ended June 30, 2020 (the "Interim Financials") (hyperlinked) are incorporated by reference in this Simplified Registration Document (hyperlinked)."

  "Copies of this Simplified Registration Document, the Full Year Financial Statements, the Interim Financials and the Articles of Association may be obtained free of charge for a period of twelve months following the Simplified Registration Document Date by sending a request in writing to us at Paasheuvelweg 25A, 1105 BP Amsterdam, the Netherlands and may also be obtained from our website atwww.kiadis.com."

• 3. In paragraph 3.1 (Selected consolidated historical financial information) starting on page 50 of the Simplified Registration Document, the following amendments shall be made:

  "Selected consolidated income statement data

€ in thousands, except per share data

For the six months endedFor the year endedJune 30 2020

2019

December 31 2019 2018

Revenues	-	-
Other income	-	-
Research and development	(13,751)	(16,247)	(43,043)	(17,468)
expenses
General and administrative	(6,265)	(9,487)	(30,191)	(7,733)
expenses
Total operating expenses	(20,016)	(25,734)	(73,234)	(25,201)
Operating loss	(19,867)	(25,734)	(73,234)	(25,201)
Interest income	-	1	-	-

Unaudited - 149

Audited

- -