^Ad hoc announcement pursuant to Art. 53 LR

* The proposed consent fee will be increased to 8'000'000 Idorsia shares. All

other matters as proposed on April 23, 2024, remain unchanged.

* The bondholder meeting will take place on May 6, 2024, in order to vote on

the proposals published on April 23, 2024.

Allschwil, Switzerland - May 1, 2024

Idorsia Ltd (SIX: IDIA) today announced that in relation to the bondholder

meeting for holders of its outstanding convertible bonds maturing on July

17, 2024 (ISIN: CH0426820350) (the Bonds), Idorsia has improved the consent fee

to 8'000'000 Idorsia shares up from 5'000'000.

Other elements of the proposal published on April 23, 2024 such as the (i)

amendment to the conversion price to CHF 6.00 (from currently CHF?33.95), (ii)

extension of the maturity date by six months to January 17, 2025 and (iii)

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

time upon giving ten trading days' notice, remain unchanged. Bondholders can

access the invitation to the bondholder meeting and other documents in

connection with the bondholder meeting at the following link:

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


André C. Muller, Chief Financial Officer, commented:

"We have decided to improve our offered consent fee to 8 million Idorsia shares.

Based on interactions with some significant bondholders and the continued

support of Jean-Paul and Martine Clozel, we are confident to reach the required

two thirds majority of the Bonds' aggregate principal amount that will give us

the flexibility to secure other funding avenues and extend our cash runway."

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

the bondholder solicitation process.

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 is

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. Weiss

Senior Vice President, Head of Investor Relations & Corporate Communications

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's

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

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

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 uncertainties

materialize, or should underlying assumptions prove incorrect, actual results

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

estimated or expected.