Accounting principles

12 Months Ended

Dec. 31, 2024

Accounting principles Note 4.1. Goodwill

Following initial recognition, goodwill is stated at cost less any accumulated impairment losses (see Note 4.4).

In respect of business combinations prior to January 1, 2020, in accordance with IFRS 1 exemption, goodwill is included on the basis

of its deemed cost, which represents the amount recorded under the prior basis of accounting, French GAAP, (“Previous GAAP”).

Note 4.2. Intangible assets

Pursuant to IAS 38—Intangible Assets, intangible assets acquired are recognized as assets on the statements of financial position at

their acquisition cost.

Licenses

Payments for separately acquired research and development are capitalized within “Other intangible assets” provided that they meet

the definition of an intangible asset: a resource that is (i) controlled by the Group, (ii) expected to provide future economic benefits for

the Group and (iii) identifiable (i.e., it is either separable or arises from contractual or legal rights). In accordance with paragraph 25 of

IAS 38—Intangible Assets, the recognition criterion relating to the likelihood of future economic benefits generated by the intangible

asset, is presumed to be achieved for research and development activities when they are acquired separately. In this context, amounts

paid to third parties in the form of initial payments or milestone payments relating to pharmaceutical specialties that have not yet

obtained a marketing authorization are recognized as intangible assets. These rights will be amortized on a straight-line basis, after

obtaining the marketing authorization, over their useful life. Unamortized rights (before marketing authorization) are subject to

impairment tests in accordance with the method defined in Note 4.4.

Research and development costs

Pursuant to IAS 38 – Intangible Assets, research costs are expensed in the period during which they are incurred. Development costs

are only recognized as intangible assets if the following criteria are met:

•it is technically feasible to complete the development of the project;

•it is the Group’s intention to complete the project and to utilize it;

•it has capacity to utilize the intangible asset;

•there is proof of the probability of future economic benefits associated with the asset

•there is availability of the technical, financial and other resources for completing the project; and

•there is a reliable evaluation of the development expenses.

The initial measurement of the asset is the sum of expenses incurred starting on the date on which the development project meets the

above criteria. Because of the risks and uncertainties related to regulatory authorizations and to the research and development process,

the Group believes that the six criteria stipulated by IAS 38 have not been fulfilled to date and the application of this principle has

resulted in all development costs being expensed as incurred in all periods presented.

Other intangible assets

Other intangible assets mainly consist of acquired software. Costs related to the acquisition of software licenses are recognized as

assets based on the costs incurred to acquire and set up the related software. Other intangible assets are amortized using the straight-

line method over a period of one year.

Note 4.3. Property, plant and equipment

Pursuant to IAS 16 – Property, Plant and Equipment, property, plant and equipment are recognized at their acquisition cost (purchase

price and directly attributable costs) or at their production cost by the Group, as applicable.

Property, plant and equipment are depreciated using the straight-line method over the estimated useful life of the asset. The principal

useful lives applied are as follows:



	DEPRECIATION PERIOD
Buildings
Office fixtures and fittings	3 years (1)
Equipment
Industrial materials and equipment	5 to 10 years
Technical facilities	5 to 10 years
Furniture and computer equipment:
Office equipment	5 to 10 years
IT equipment	3 years
Furniture	10 years

(1)Office fixtures and fittings estimated useful lives correspond to the Paris headquarters and Boston offices residual estimated

lease terms.

The useful lives of property, plant and equipment as well as any residual values are reviewed at each year-end and, in the event of a

significant change, the depreciation schedule is revised prospectively.

Note 4.4. Impairment of goodwill, intangible assets, property and plant and equipment

Goodwill and intangible assets not yet available for use are not amortized and are tested for impairment annually.

In addition, the Group assesses at the end of each reporting period whether there is an indication that intangible assets and property,

plant and equipment may be impaired. Pursuant to IAS 36—Impairment of Assets, criteria for assessing indication of loss in value may

notably include performance levels lower than forecast, a significant change in market data or the regulatory environment, or

obsolescence or physical damage of the asset not included in the amortization/depreciation schedule.

For the purpose of impairment testing, goodwill and intangible assets not yet available for use are allocated to each of the Group’s

CGUs expected to benefit from synergies arising from the business combination or from the use of the intangible assets.

An impairment loss is recognized when the carrying amount of a CGU, including the goodwill, exceeds the recoverable amount of the

CGU. The recoverable amount of a CGU is the higher of the CGU’s fair value less cost to sell and value-in-use. The total impairment

loss of a CGU is allocated first to reduce the carrying amount of goodwill allocated to the CGU and then to the other assets of the

CGU pro-rata on the basis of the carrying amount of each asset in the CGU.

An impairment loss on goodwill is not reversed in a subsequent period. Impairment losses on intangible assets and property, plant and

equipment shall be reversed subsequently if the impairment loss no longer exists or has decreased.

Note 4.5. Financial assets

Financial assets at amortized cost

Other financial assets (advances, loans and deposits granted to third parties and other short-term investments) and other receivables are

non-derivative financial assets with fixed or determinable payments that are not listed on an active market. They are initially

recognized at fair value plus transaction costs that are directly attributable to the acquisition or issue of the financial asset.

IFRS 9 – Financial Instruments requires an entity to recognize a loss allowance for expected credit losses on a financial asset at

amortized cost at each statement of financial position date. The amount of the loss allowance for expected credit losses equal to: (i) the

12—month expected credit losses or (ii) the full lifetime expected credit losses. The latter applies if credit risk has increased

significantly since initial recognition of the financial instrument.

Cash and cash equivalents

The Group classifies investments as cash equivalents in the statements of financial position and statements of cash flows when they

meet the conditions of IAS 7—Statement of Cash Flows, i.e., when they are:

•held in order to face short-term cash commitments; and

•short term and highly liquid assets at acquisition date, readily convertible into known amount of cash and not exposed to

any material risk of change in value.

Note 4.6. Share capital

Ordinary shares are classified in shareholders’ equity. Costs associated with the issuance of new shares are directly accounted for in

shareholders’ equity in diminution of issuance premium.

The Group’s own shares bought in the context of a brokering/liquidity agreement entered with an independent broker are presented as

a reduction of shareholders’ equity until their cancellation, their reissuance or their disposal.

Note 4.7. Share-based payments

Since its inception, the Group has established several plans for compensation settled in equity instruments in the form of founders’

share subscription warrants (“bons de souscription de parts de créateur d’entreprise” or “BCE”), share subscription warrants (“Bons de

souscription d’actions,” or “BSA”) and free shares (“Attributions gratuites d’actions,” or “AGA”), granted to its employees, corporate

officers and scientific consultants.

Pursuant to IFRS 2—Share-based Payment, these awards are measured at their fair value on the date of grant. The values of the equity

instruments are determined using the option pricing model (in particular, a Black and Scholes model for the BCE and BSA plans and a

Monte-Carlo simulation for the AGA plans which include market performance vesting conditions) based on the value of the

underlying equity instrument at grant date, the volatility observed in a sample of comparable listed companies and the estimated life of

the related equity instruments.

The Group recognizes the fair value of these awards as a share-based compensation expense over the period in which the related

services are received, i.e. over the vesting period, with a corresponding increase in shareholders’ equity. Share-based compensation is

recognized by installments in consistency with their graded vesting schedule, when applicable.

The amount recognized as an expense is adjusted to reflect the number of awards for which the related service and non-market

performance conditions are expected to be met, such that the amount ultimately recognized is based on the number of awards that meet

the related service and non-market performance conditions at the vesting date.

For share-based payment awards with market vesting conditions and non-vesting conditions, the grant-date fair value of the share-

based payment is measured to reflect such conditions and there is no true-up for differences between expected and actual outcome.

The measurement of the fair value of BSA, BCE and AGA incorporates the market-based vesting conditions and non-vesting

conditions as described in Note 4.16 “Use of judgments and estimates”.

Note 4.8. Financial liabilities

Note 4.8.1. Financial liabilities at amortized cost

Pursuant to IFRS 9 – Financial Instruments, the borrowings, the debt component of the Kreos / Claret OCABSA (classified as

convertible loan notes – see Compound instruments Compound instruments below) and Other financial liabilities (conditional

advances and royalty certificates) other than financial derivative liabilities are measured at amortized cost. They are initially

recognized at fair value and subsequently measured at amortized cost calculated using the effective interest rate (“EIR”) method. The

transaction costs that are directly attributable to the issue of the financial liability reduce that financial liability. These expenses are

then amortized over the lifetime of the liability, on the basis of the EIR. The EIR is the rate that exactly discounts estimated future

cash payments through the expected life of the financial liability to the amortized cost of a financial liability. Financial liabilities that

are due within one year are presented as current financial liabilities in the statements of financial position.

Royalty certificates

Royalty certificates meet the definition of financial liabilities. The Group concluded that they do not include embedded derivatives

related to the variability of royalties that are based on future net sales. In addition, the Group concluded that the prepayment options

were separate derivative instruments as their redemption price did not reimburse holders for an amount up to the approximate present

value of lost interest for the remaining term of the host contracts. However, their value at inception and subsequent dates is nil and has

no impact on the financial statements.

Royalty certificates are initially measured at fair value (refer to note 15.10 for valuation model applied). They are subsequently

measured at amortized cost calculated using the EIR method. The EIR is calculated based on future cash flows, which are estimated on

the basis of development and commercialization plans and budgets approved by the Board of Directors of the Group, and probability-

weighted to reflect the probability of success of clinical studies and any other uncertainty affecting them. If there is a change in the

timing or amount of estimated cash flows, then the gross carrying amount of the amortized cost of the financial liability is adjusted in

the period of change to reflect the revised actual and estimated cash flows, with a corresponding income or expense being recognized

in profit or loss. The revised gross carrying amount of the amortized cost of the financial liability is calculated by discounting the

future revised estimated cash flows at the original EIR.

Conditional advances and State guaranteed loan – “PGE”

Accounting treatment for conditional advances and the State-guaranteed loan (Prêt garanti par l'Etat, or "PGE") is set forth in Note 4.9.

Leases

Accounting treatment for lease liabilities is set forth in Note 4.12.

Note 4.8.2. Financial liabilities measured at fair value through profit or loss

Derivative instruments

BSA attached to Kreos 1 bonds, the conversion option of OCEANE, certain prepayment options of bonds, the Kreos / Claret warrants

and the Kreos / Claret Minimum Return Indemnifications ("MRI") are derivatives instruments. Derivatives are recognized initially at

fair value at the date the derivative contract is entered into and are subsequently remeasured to their fair value at each reporting date.

The resulting gain or loss from change in the fair value is recognized in profit or loss immediately, as financial expenses or income.

Hybrid instruments

OCEANE bonds and Heights convertible notes (whose characteristics are described in Note 15.2 and Note 15.5) are hybrid

instruments. A “hybrid contract” is a contract that includes both a non-derivative host contract and one or more embedded derivatives.

Embedded derivatives are required to be separated from the host contract (bifurcated) if: the economic characteristics and risks of the

embedded derivative are not closely related to those of the host, a separate instrument with the same terms as the embedded derivative

would meet the definition of a derivative, and the hybrid contract is not measured at fair value through profit or loss.

Separable embedded derivatives are required to be measured at fair value at each reporting date, with changes in fair value recognized

in profit or loss. The initial bifurcation of a separable embedded derivative does not result in any gain or loss being recognized.

Because the embedded derivative component is measured at fair value on initial recognition, the carrying amount of the host contract

on initial recognition is the difference between the carrying amount of the hybrid instrument and the fair value of the embedded

derivative. If the fair values of the hybrid instrument and host contract are more reliably measurable than that of the derivative

component - e.g. because of the availability of quoted market prices - then it may be acceptable to use those values to determine the

fair value of the derivative on initial recognition indirectly - i.e. as a residual amount.

The Heights convertible notes issued on August 24, 2023 included embedded derivatives as detailed in Note 15. The Group concluded

that these features were embedded derivatives that would modify the cash flows required under the contract and require to be

bifurcated from their host contract. The Group being unable to reliably value each embedded derivative at issuance date and on

subsequent reporting dates, it measured the whole hybrid instrument at fair value through profit or loss (“FVTPL”) as permitted by

IFRS 9. Instruments measured at FVTPL under these conditions are measured at their fair value on issuance and on subsequent

reporting dates, with changes in fair value recognized in profit or loss.

Compound instruments

The Kreos / Claret OCABSA are compound instruments (whose characteristics are described in Note 15.1). A “compound contract” is

a contract that includes both a debt component and an equity component. The debt component (excluding the conversion option and

the attached OCABSA warrants) is initially recognized at fair value and subsequently measured at amortized cost calculated using the

EIR method. The equity component corresponding to the conversion option and the attached OCABSA warrants is recorded in equity,

for the difference between the whole instrument’s fair value (its nominal value) and the standalone fair value of the debt component.

Fair value measurement

When measuring the fair value of an asset or a liability, the Company uses market observable data as far as possible. Fair values are

categorized into different levels in a fair value hierarchy based on the inputs used in the valuation techniques as follows:

•level 1: fair value calculated using quoted prices in an active market for identical assets and liabilities;

•level 2: fair value calculated using valuation techniques based on observable market data such as prices for assets and

liabilities or similar parameters quoted in an active market;

•level 3: fair value calculated using valuation techniques based in whole or in part on unobservable inputs such as prices

in an inactive market or a valuation based on multiples of unlisted securities.

See Note 12 Financial assets and liabilities, Note 15 Financial liabilities.

Note 4.9. Research tax credit, subsidies and conditional advances

Research tax credit

The Group benefits from the provisions of Article 244 quater B of the French General Tax Code relating to the French research tax

credit (“Crédit d’Impôt Recherche” or “CIR”). The CIR is granted to companies in order to encourage them to conduct technical and

scientific research. Companies that prove that they have expenditures which meet the required criteria (research expenditures located

in France or, since January 1, 2005, within the European Union or in another state that is a party to the Agreement on the European

Economic Area and has concluded a tax treaty with France that contains an administrative assistance clause) receive a tax credit that

can be used for the payment of the corporate tax due for the fiscal year in which the expenditures were made and the next three fiscal

years, or as applicable, companies may receive cash reimbursement for any excess portion at the three-year period following the fiscal

year of the expenditures. Only those companies meeting the EU definition of a small or medium-sized entity (“SME”) are eligible for

payment in cash of their research tax credit (to the extent not used to offset corporate tax payables) in the year following the request

for reimbursement. The expenditures taken into account for the calculation of the CIR involve only research expenses.

The CIR is presented under “Other operating income” in the statements of income (loss) as it is accounted for as a government grant

as defined in IAS 20 – Accounting for Government Grants and Disclosure of Government Assistance, and as “Other receivables and

assets” in the statement of financial position until its payment is received.

Subsidies

Subsidies are non-repayable grants received by the Group and recognized in the financial statements when there exists reasonable

assurance that the Group will comply with the conditions attached to the subsidies and the subsidies will be received.

Subsidies that are upfront payments are presented as deferred income and recognized through “Other operating income” for the

amount of the expenses incurred as part of the research program to which the subsidy relates.

A subsidy that is to be received either as compensation for expenses or for losses already incurred, or for immediate financial support

of the Group without associated future costs, is recognized in the Statements of income (loss) as “Other operating income” when there

exists reasonable assurance that the subsidies will be received.

Conditional advances and PGE

The Group receives conditional advances to finance at below market interest rate research and development projects. Due to the

innovative nature of its drug candidate development programs, the Group has benefited from certain sources of financial assistance

from Bpifrance. Bpifrance provides financial assistance and support to emerging French enterprises to facilitate the development and

commercialization of innovative technologies.

Funds received from Bpifrance in the form of conditional advances are recognized as financial liabilities, as the Group has a

contractual obligation to reimburse Bpifrance for such conditional advances in cash based on a repayment schedule. Each award of an

advance is made to help fund a specific development milestone. More tails on conditional advances are provided in Note 15.7.

Receipts or reimbursements of conditional advances are reflected as financing transactions in the statements of cash flows.

The difference between the present value of the advance at market rate (i.e., present value of contractual cash flows including principal

and interests, discounted using a market rate as effective interest rate in accordance with IFRS 9) and the amount received as cash

from the Bpifrance constitutes a subsidy within the meaning of IAS 20. Considering that these advances do not finance fixed assets,

these subsidies are presented as “Deferred income” in the statement of financial position and recognized in the statement of net income

(loss) as “Other operating income“ on a systematic basis over the periods in which the Group recognizes as expenses the related costs

for which the grants are intended to compensate.

The incremental interest expense resulting from the difference between (a) the market interest rate and the (b) below-market rate is

spread over the contractual period until the last repayment and recognized in the statement of income (loss) accordingly, using the EIR

method. In the event of a change in estimate of contractual cash flows due under the conditional advances, the Group recalculates the

book value of the debt resulting from the discounting of the anticipated new future cash flows at the initial EIR. The adjustment is

recognized in the statements of income (loss) for the period during which the modification is recognized.

In the statements of financial position, these conditional advances are recorded in “Other financial liabilities” as current or non-current

portion depending on their maturity. In the event Bpifrance waived the repayment of the advance, the corresponding liability is

derecognized and treated as a subsidy in the statements of income (loss).

The benefit resulting from the low interest of PGE loans is also recognized as a subsidy corresponding to the difference between the

present value of the PGE at market rate and the amount received as cash. The accounting treatment is therefore similar to the above-

mentioned accounting treatment for conditional advances. PGE are recorded in “Borrowings” as current or non-current portion

depending on their maturity.

Note 4.10. Employee benefits

The Group’s employees in France benefit from retirement benefits provided under French law, which consist in the following:

•compensation paid by the Group to employees upon their retirement (a defined benefit plan); and

•payments of retirement pensions by the social security agencies, which are financed by the contributions made by the

Group and employees. As they meet the definition of a defined contribution plan, the liabilities are presented as Tax and

employee-related payables in the statement of financial position.

In accordance with IAS 19 – Employee Benefits, the liability with respect to defined benefit plans is estimated by using the projected

credit unit method. According to this method, the cost of the retirement benefit is recognized in the statements of income (loss). The

retirement benefit commitments are valued at the current value of the estimated future payments, discounted using the market rate for

high quality corporate bonds with a term and currency that correspond to that estimated for the payment of the benefits. The Group

applied the decision of the IFRS IC, published on May 24, 2021, that concluded that, in the case that no rights were acquired in the

event of departure before retirement age and that the rights were capped after a certain number of years of seniority (“30 years”), the

commitment would only be recognized for the last 30 years of the employee’s career within the Group.

The difference between the amount of the provision at the beginning of a period and at the close of that period is recognized through

operating expenses for the portion representing the costs of services rendered and financial expenses for the net interest costs, and

through other comprehensive income (loss) for the portion representing the actuarial gains and losses due to changes in assumptions

and experience adjustments.

Note 4.11. Provisions

Provisions correspond to commitments resulting from litigation and various risks to which the Group may face in the context of its

operations. In accordance with IAS 37 – Provisions, Contingent Liabilities and Contingent Assets, a provision is recorded when the

Group has an obligation to a third party resulting from a past event that will likely result in an outflow of resources to the third party,

and for which future cash outflows may be estimated reliably. The amount recorded as a provision is an estimate of the expenditure

required to settle the obligation, discounted where necessary at year end. Contingent liabilities are not recognized, but are disclosed in

the notes to the financial statements unless the possibility of an outflow of economic resources is remote

Note 4.12. Leases

As lessee, the Group assesses whether a contract contains a lease at inception of a contract and upon the modification of a contract.

The Group elected to allocate the consideration in the contract to the lease and non-lease components on the basis of the relative

standalone price. The Group recognizes a right-of-use asset and a corresponding lease liability for all arrangements in which it is a

lessee, except for leases with a term of 12 months or less (short-term leases) and low-value leases (value of the underlying asset below

€5.0 thousand). For these short-term and low-value leases, the Group recognizes the lease payments as an operating expense on a

straight-line basis over the term of the lease.

The lease liability is initially measured at the present value of the future lease payments as from the commencement date of the lease

to the end of the lease term. The lease terms used by the Group reflect the non-cancellable terms of each contract, plus any extension

or termination options that the Group is reasonably certain to exercise or not exercise for all of the leases periods covered by the

extension options. The lease payments are discounted using the interest rate implicit in the lease or, if not readily determinable, the

Group incremental borrowing rate for the asset subject to the lease in the respective markets.

The Group remeasures the lease liability (and makes a corresponding adjustment to the related right-of-use asset) whenever there is a

change to the lease terms or expected payments under the lease, or a modification that is not accounted for as a separate lease. The

portion of the lease payments attributable to the repayment of lease liabilities and the portion attributable to payment of interests are

recognized in cash flows used in financing activities.

Right-of-use assets are initially recognized on the balance sheet at cost, which comprises the amount of the initial measurement of the

corresponding lease liability, adjusted for any lease payments made at or prior to the commencement date of the lease, any lease

incentives received and any initial direct costs incurred by the Group, and expected costs for obligations to dismantle and remove

right-of-use assets when they are no longer used.

Right-of-use assets are depreciated on a straight-line basis from the commencement date of the lease over the shorter of the useful life

of the right-of-use asset or the end of the lease term.

Right-of-use assets are assessed for impairment whenever there is an indication that the balance sheet carrying amount may not be

recoverable using cash flow projections.

Note 4.13. Translation of transactions denominated in foreign currency

Pursuant to IAS 21 – The Effects of Changes in Foreign Exchange Rates, transactions performed by the Group in currencies other than

their functional currency, which is the Euro, are translated at the prevailing exchange rate on the transaction date.

Trade receivables and payables and liabilities denominated in a currency other than the functional currency are translated at the

period-end exchange rate. Unrealized gains and losses arising on translation are recognized in net financial income / (loss).

Note 4.14. Current and deferred tax

Tax assets and liabilities for the current and prior periods are measured at the amount expected to be recovered from or paid to the

French tax authorities, using tax rates and tax laws enacted or substantively enacted at the end of the reporting period in accordance

with IAS 12 – Income Tax.

The income tax charge for the period comprises current tax due and the deferred tax charge. The tax expense is recognized in the

statement of income (loss) unless it relates to items recorded in other comprehensive income (loss) or directly in equity, in which case

the tax is also recorded in other comprehensive income (loss) or directly in equity.

Current taxes

The current tax expense is calculated based on taxable profit for the period, using tax rates enacted or substantively enacted at the

statement of financial position date. Considering the level of tax loss of the Group, no current tax expense is recognized.

Deferred taxes

Deferred taxes are recognized when there are temporary differences between the carrying amount of assets and liabilities in the

Group’s financial statements and the corresponding tax basis used to calculate taxable profit. Deferred taxes are not recognized if they

arise from the initial recognition of an asset or liability in a transaction other than a business combination which, at the time of the

transaction, does not affect either the accounting or the taxable profit (tax loss).

The Group applies the Amendments to IAS 12 – Deferred Tax related to Assets and Liabilities arising from a Single Transaction,

issued on May 7, 2021, and presents the deferred tax assets and liabilities arising from such transactions separately within Note 22 -

Income tax, rather than on a net basis. The Amendments have no impact on the Statements of financial position and the Statement of

comprehensive income (loss) for the periods presented.

Deferred tax assets

Deferred tax assets are recognized for all deductible temporary differences, unused tax losses and unused tax credits to the extent that

it is probable that the temporary difference will reverse in the foreseeable future and that taxable profit will be available against which

the deductible temporary difference, unused tax losses or unused tax credits can be utilized. See Note 4.16. Use of judgments and

estimates and Note 22. Income tax.

Note 4.15. Accounting of Prosynergia acquisition

From April 1, 2022 up until the merger completed on December 12, 2022, the Company owned a 100% ownership interest of

Prosynergia and as such, controlled Prosynergia. The Company had power over Prosynergia, was exposed or had rights to variable

returns from its involvement with the entity and had the ability to affect those returns through its power over the entity.

The financial statements of Prosynergia were therefore included in the consolidated financial statements of the Company from the date

control was obtained, i.e. April 1, 2022. Prosynergia was merged into the Company in December 12, 2022.

Considering that Prosynergia only owned patent rights but did not enter into any employee contract, research agreement, collaboration

agreement or out-licensed agreement, it did not meet the definition of a business under IFRS 3. Consequently, the acquisition cost of

this group of assets was allocated between the identifiable assets and liabilities acquired, pro rata to their respective fair values as of

April 1, 2022, without recognition of goodwill. For this purpose, the following approach was applied: first measurement of any

identifiable asset or liability initially measured at an amount other than cost in accordance with the applicable standards, deduction

from the cost of the group of assets of the amounts allocated to these assets and liabilities, and then allocation of the residual cost of

acquisition to the remaining identifiable assets and liabilities based on their relative fair values at the date of acquisition.

Also, the €1,400 thousand loan granted to Prosynergia in December 2021 was included in the acquisition cost to be allocated, since, in

substance, it was considered as a prepayment for the acquisition of the group of assets, which is repayable in cash in the event of non-

completion of the transaction.

The potential earn-out payment to be paid in the first half of 2023 was measured at fair value on April 1, 2022, for an amount of

€1,446 thousand, and included in the acquisition cost. This earn out could be triggered in the event the Group’s market capitalization

was in excess of €300 million (valued at certain specified record dates), a listing of the Group’s shares on Nasdaq or a merger and

acquisition transaction prior to March 31, 2023. The amount of the earn-out was equal to 1% of the difference between the Group’s

market capitalization and €300 million, subject to a maximum amount of €4.0 million. It was payable in the first half of 2023 if

conditions were met. No amount was payable in the event the Group’s market capitalization was lower than €300 million. The related

financial liability was subsequently remeasured to its fair value as of December 31, 2022 estimated to nil (see Note 15.9). The

remeasurement resulted in a financial income of €1,446 thousand over the year ended December 31, 2022.

As a consequence of the earn-out condition not being met on March 31, 2023, the related financial liability was derecognized.

The allocation of the acquisition cost is as follows:



(Amounts in thousands of euros)	Amount allocated as of April 1, 2022
Cash prepayment made in 2021 ........	325
Loan granted to Prosynergia in 2021	1,400
Cash payment made in 2022 .............	2,925
Acquisition fees (1) ...........................	466
Earn-out measured at fair value ........	1,446
Total acquisition cost allocated ......	6,562

Patents ...............................................	6,529
Cash and cash equivalents ................	42

Total assets ......................................	6,571

Total liabilities .................................	(9)

Total net assets ................................	6,562

(1)Of which €451 thousand were disbursed in 2021 and €15 thousand in 2022. Acquired cash amounts to €42 thousand.

The acquisition cost was mainly allocated to Prosynergia’s patents US 10,464,903 (filed on March 20, 2017 and granted on November

5, 2019), EP3 429 998 (filed on March 20, 2017 and granted on September 1, 2021) and continuation US 10,745,357 (filed on

November 1, 2019 and granted on August 18, 2020). All patents will expire in 2037.

These patents cover alternative synthesis process for obefazimod and a family of close chemical analogues. They also cover

alternative forms of obefazimod (salts thereof and crystalline forms of said salts), the pharmaceutical composition comprising them,

that could be of interest to the Company for future development.

Note 4.16. Use of judgments and estimates

In order to prepare financial statements in accordance with IFRS, estimates, judgments and assumptions were made by the Group’s

management which could affect the reported amounts of assets, liabilities, contingent liabilities, income and expenses.

These estimates are based on the assumption of going concern and are prepared in accordance with information available at the date

the financial statements were prepared. They are reviewed on an ongoing basis using past experience and various other factors

considered to be reasonable as the basis to measure the carrying amount of assets and liabilities. Estimates may be revised due to

changes in the underlying circumstances or subsequent to new information. Actual results may differ significantly from these

estimates in line with assumptions or different conditions.

This note provides an overview of the areas that involved a higher degree of judgement or complexity, and of items which are more

likely to be materially adjusted due to changes in estimates and assumptions. Detailed information about each of these estimates and

judgements is included in other notes together with information about the basis of calculation for each affected line item in the

financial statements.

•Recognition and measurement of impairment of CGUs. The main assumptions used for the impairment test include

(a) the amount of cash flows that are set on the basis of the development and commercialization plans and budgets

approved by Board of Directors, (b) assumptions related to the achievement of the clinical trials and the launch of the

commercialization, (c) the discount rate, (d) assumptions on risk related to the development and (e) for the

commercialization, selling price and volume of sales. The sensitivity analysis in respect of the recoverable amount of the

CGUs is presented in Note 6.

•Measurement of share-based payments granted to employees, corporate officers and scientific consultants, such as BCE,

BSA and AGA, which is based on actuarial models; these models require the use by the Group of certain calculation

assumptions such as the estimated vesting, the occurrence dates of a change of control or a M&A transaction dates, the

percentage of success (“POS”) of obefazimod, the expected volatility and maturity of the underlying equity instrument

(see Note 4.7 and Note 14),

•Fair value measurement at inception and after of derivative financial instruments resulting from (i) the warrants issued

concomitantly with the issuance of the straight and convertible bonds to Kreos on July 24, 2018 (or “Kreos 1”), (ii) the

prepayment option attached to the straight and convertible bonds issued to Kreos on October 2, 2020 (or “Kreos 2”), and

(iii) the prepayment option attached to the issuance of bond convertible into new or existing shares in July 30, 2021 (or

“OCEANE”) (see Notes 15), (iv) the Kreos / Claret BSA issued on August 21, 2023 and November 2, 2023, related to

tranches A-B and tranche C, respectively, and (v) the Kreos / Claret Minimum Return Indemnifications related to

tranches B and C, issued in March 2024 and June 2024, respectively.

•Fair value measurement of financial liabilities at inception (see Note 15), and after (for the Heights convertible notes

issued on August 24, 2023) measured at fair value at each reporting period, with fair value changed recognized in profit

or loss,

•Amortized cost measurement of royalty certificates, based on the following assumptions: (a) future cash flows, estimated

on the basis of development and commercialization plans and budgets approved by the Board of Directors and (b) the

effective interest rate. The sensitivity analysis in respect of the measurement of royalty certificates is presented in Note

15,

•Fair value measurement of the call option resulting from the equity line contracts entered into on September 30, 2019 (or

“Equity lines”) (see Note 13.2),

•Estimation of CIR, based on internal and external expenses, which meet the required criteria, incurred by the Group each

year (see Note 4.9),

•Recognition of deferred tax assets: availability of future taxable profit against which deductible temporary differences

and tax losses carried forward can be utilized and whether sufficient evidence exists (see Note 22).

•Recognition of deferred tax assets: tax deductibility of future royalty payments related to the royalty certificates issued in

September 2022 (see Notes 15 and 22).

•Determination of the terms of the leases, including whether the Group is reasonably certain to exercise extension and/or

termination options (see Note 15.8).

The main critical judgements made by the Group’s management impact the following items:

•Accounting treatment of specific conditions of share-based compensation plans (see Notes 4.7 and 14).

•Accounting treatment of the 2018 & 2020 Kreos 1 & 2 bonds, the 2021 OCEANE bonds, and the August 2023 Kreos /

Claret and Heights Financings (see Notes 4.8 and 15).