^Ad hoc announcement pursuant to Art. 53 LR

* A bondholder meeting will take place on May 6, 2024, to vote on proposals to

amend the terms of the outstanding convertible bonds maturing on July

17, 2024, including an extension of the maturity by six months.

Allschwil, Switzerland - April 23, 2024

Idorsia Ltd (SIX: IDIA) today announced that it has published an invitation to a

bondholder meeting for holders of its outstanding convertible bonds maturing on

July 17, 2024 (ISIN: CH0426820350) (the Bonds). At the meeting, the company i

proposing a change to the current terms of the Bonds to avoid potential

liquidity constraints in connection with the redemption of the Bonds.

Bondholders can access the invitation to the bondholder meeting at the following

link: www.idorsia.com/2024-bond (https://www.idorsia.com/investors/stock-

information/stock-overview/2024-bond)

André C. Muller, Chief Financial Officer, commented:

"Based on many interactions with some significant bondholders, we have decided

to adjust our initial proposal, by substantially reducing the conversion price

to CHF 6, extending the maturity date of the Bonds by six months, and

introducing a consent fee of 5 million shares. The requested approval of the new

terms of the Bonds by a majority of two thirds of the Bonds' aggregate principal

amount would avoid short-term liquidity constraints and should give the

additional time needed to negotiate and close additional collaborations that

could significantly extend the cash runway. I hope that all bondholders cast

their vote at the bondholder meeting and allow us to create mid- to long-term

value for all stakeholders."

For this purpose, Idorsia is calling a bondholder meeting in accordance with

articles 1164 et seqq. of the Swiss Code of Obligations (the Bondholder Meeting)

and proposes to the bondholders to modify the terms of the Bonds to, among

others, (i) amend the conversion price to CHF 6.00 (from currently CHF 33.95),

(ii) extend the maturity date by six months to January 17, 2025 and (iii) give

Idorsia the option to call the Bonds at par, in full or in part, at any time

upon giving ten trading days' notice.

As a consent fee for this transaction, the Issuer will deliver 5,000,000 Idorsia

shares to the bondholders once the amendment of the Bonds terms become

effective. In addition, Idorsia will commit to use proceeds from divestitures or

outlicensing transactions to repay the Bonds pursuant to the proposed amended

terms. The detailed, binding terms of the amendments and undertakings are set

out in the Bondholder invitation.

Idorsia's main investors, Jean-Paul and Martine Clozel, have expressed their

commitment to vote in favor of the proposals to amend the terms of the Bonds.

An Unaudited Financial Status as of March 31, 2024, required for the Bondholder

Meeting was made public on April 17, 2024 and is available on the company

website at the following link: www.idorsia.com/investors/financial-information

(http://www.idorsia.com/investors/financial-information)

Idorsia has appointed J.P. Morgan Securities plc to act as Dealer Manager for

the bondholder solicitation process.

Notes to the editor

About Idorsia

Idorsia Ltd is reaching out for more - We have more ideas, we see more

opportunities and we want to help more patients. In order to achieve this, we

will develop Idorsia into a leading biopharmaceutical company, with a strong

scientific core.

Headquartered near Basel, Switzerland - a European biotech-hub - Idorsia i

specialized in the discovery, development and commercialization of small

molecules to transform the horizon of therapeutic options. Idorsia has a 25-year

heritage of drug discovery, a broad portfolio of innovative drugs in the

pipeline, an experienced team of professionals covering all disciplines from

bench to bedside, and commercial operations in Europe and North America - the

ideal constellation for bringing innovative medicines to patients.

Idorsia was listed on the SIX Swiss Exchange (ticker symbol: IDIA) in June 2017

and has over 750 highly qualified specialists dedicated to realizing our

ambitious targets.

For further information, please contact

Andrew C. Wei

Senior Vice President, Head of Investor Relations & Corporate Communication

Idorsia Pharmaceuticals Ltd, Hegenheimermattweg 91, CH-4123 Allschwil

+41 58 844 10 10

investor.relations@idorsia.com (mailto:investor.relations@idorsia.com)

media.relations@idorsia.com (mailto:media.relations@idorsia.com)

www.idorsia.com (http://www.idorsia.com)

The above information contains certain "forward-looking statements", relating to

the company's business, which can be identified by the use of forward-looking

terminology such as "estimates", "believes", "expects", "may", "are expected

to", "will", "will continue", "should", "would be", "seeks", "pending" or

"anticipates" or similar expressions, or by discussions of strategy, plans or

intentions. Such statements include descriptions of the company's investment and

research and development programs and anticipated expenditures in connection

therewith, descriptions of new products expected to be introduced by the company

and anticipated customer demand for such products and products in the company'

existing portfolio. Such statements reflect the current views of the company

with respect to future events and are subject to certain risks, uncertaintie

and assumptions. Many factors could cause the actual results, performance or

achievements of the company to be materially different from any future results,

performances or achievements that may be expressed or implied by such forward-

looking statements. Should one or more of these risks or uncertaintie

materialize, or should underlying assumptions prove incorrect, actual result

may vary materially from those described herein as anticipated, believed,

estimated or expected.

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