Report on the review of condensed consolidated interim financial statements

Introduction

In accordance with the terms of our engagement, we have reviewed the condensed consolidated interim financial statements (consolidated balance sheet, consolidated statement of comprehensive income, consolidated statement of changes in equity, consolidated statement of cash flow and selected explanatory notes) of BB Biotech AG for the period ended 31 March 2023.

These condensed consolidated interim financial statements in accordance with International Accounting Standard 34 «Interim Financial Reporting» and article 14 of the Directive on Financial Reporting of the SIX Swiss Exchange are the responsibility of the Board of Directors whereas our responsibility is to issue a report on these condensed consolidated interim financial statements based on our review.

Scope of Review

We conducted our review in accordance with the Swiss Auditing Standard 910 (SAS 910) «Engagements to Review Financial Statements» and the International Standard on Review Engagements (ISRE) 2410 «Review of interim financial information performed by the independent auditor of the entity». This Standard requires that we plan and perform the review to obtain moderate assurance as to whether the condensed consolidated interim financial statements are free of material misstatements. A review is limited primarily to inquiries of company personnel and analytical procedures applied to financial data and thus provides less assurance than an audit. We have not performed an audit and accordingly, we do not express an audit opinion.

Conclusion

Based on our review, nothing has come to our attention that causes us to believe that the accompanying condensed consolidated interim financial statements do not give a true and fair view of all material respects of the net assets, the financial position and results of operations in accordance with International Accounting Standard 34 Interim Financial Reporting and article 14 of the Directive on Financial Reporting of the SIX Swiss Exchange.

Deloitte AG

Zurich, 19 April 2023

Deloitte AG, Pfingstweidstrasse 11, CH-8005 Zurich
Phone: +41 (0)58 279 60 00, Fax: +41 (0)58 279 66 00, www.deloitte.ch