DISCUVA LIMITED Index to Financial Statements Statement of Financial Position as at

Report of Independent Auditors

To the Director of Discuva Limited

accompanying financial statements of Discuva Limited, which comprise the statement of financial position as of December 23, 2017, and the related statements of comprehensive income, of cash flows and of changes in equity for the period

Management s Responsibility for the Financial Statements

Management is responsible for the preparation and fair presentation of the financial statements in accordance with the International Financial Reporting

Standards as issued by the International Accounting Standards Board; this includes the design, implementation, and maintenance of internal control relevant to the preparation and fair presentation of financial statements that are free from material

misstatement, whether due to fraud or error.

Auditors Responsibility

Our responsibility is to express an opinion on the financial statements based on our audit. We conducted our audit in accordance with auditing standards

generally accepted in the United States of America. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free from material misstatement.

An audit involves performing procedures to obtain audit evidence about the amounts and disclosures in the financial statements. The procedures selected depend

on our judgment, including the assessment of the risks of material misstatement of the financial statements, whether due to fraud or error. In making those risk assessments, we consider internal control relevant to the Company s preparation and

fair presentation of the financial statements in order to design audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the Company s internal control. Accordingly,

we express no such opinion. An audit also includes evaluating the appropriateness of accounting policies used and the reasonableness of significant accounting estimates made by management, as well as evaluating the overall presentation of the

financial statements. We believe that the audit evidence we have obtained is sufficient and appropriate to provide a basis for our audit opinion.

In our opinion, except for the exclusion of

comparative information as discussed in Note 1, the financial statements referred to above present fairly, in all material respects, the financial position of Discuva Limited as of December 23, 2017, and the results of its operations and

its cash flows for the period then ended in accordance with the International Financial Reporting Standards as issued by the International Accounting Standards Board.

As discussed in Note 1, the

accompanying financial statements do not include comparative figures for the prior year as required by IAS 1 Presentation of Financial Statements . In our opinion, inclusion of comparative figures is necessary to obtain a proper

understanding of the current period s financial statements. The purpose of these financial statements is to meet the reporting requirements of Rule 3-05 of Regulation

S-X of Securities and Exchange Commission (SEC).

/s/ PricewaterhouseCoopers LLP

Reading, United Kingdom

Statement of Financial Position

At December 23, 2017

The accompanying notes form an integral part of these Financial Statements.

Statement of Comprehensive Income

For the period from April 1, 2017 to December 23, 2017

The accompanying notes form an integral part of these Financial Statements.

Statement of Cash Flows

For the period from April 1, 2017 to December 23, 2017

The accompanying notes form an integral part of these Financial Statements.

Statement of Changes in Equity

Period ended December 23, 2017

The accompanying notes form an integral part of these Financial Statements.

Ordinary shares and share premium

When ordinary shares

are issued, the nominal value of the shares is credited to ordinary shares. Any premium paid above the nominal value is credited to the share premium reserve.

Share-based payment reserve

The share-based payment

reserve arises as the expense of issuing new potentially dilutive share options is recognized over time (share option grants). The reserve reduces as share options vest and are exercised.

The revaluation reserve arises when

an asset s carrying amount is increased as a result of a revaluation. The revaluation reserve is transferred directly to retained earnings when the asset is derecognized.

On December 22, 2017, the Directors

passed a special resolution to cancel the paid up capital to the extent of 0.99 of each of the preferred shares of 1.00 nominal value in the capital of the Company. As a consequence, 3,255,000 was transferred to the

Company s retained earnings, increasing the Company s distributable reserves. A corresponding amount has been debited to other reserves as the underlying fair value of the debt associated with the preference shares was not reduced by the

earnings records the accumulated profits and losses, as well as any transfers from other reserves, of the Company since inception of the business.

Notes to the Financial Statements

1. Basis of accounting

The principal accounting policies

adopted by Discuva Limited (the Company ) in the preparation of these financial statements are set out below.

Basis of preparation

The financial statements have been prepared in accordance with International Financial Reporting Standards and IFRS Interpretations Committee interpretations

( IFRS ) as issued by the IASB. The Financial Statements have been prepared on a going concern basis and under the historical cost convention. These financial statements were authorized by the Director of Discuva Limited on May 15,

The consolidated financial statements of Discuva Limited as of and for the period ended December 23, 2017 have been prepared in accordance

with International Financial Reporting Standards as issued by the International Accounting Standards Board (IFRS) except that the consolidated financial information do not include comparative figures for the prior period as required by IAS 1

Presentation of Financial Statements . The purpose of these financial statements is to meet the reporting requirements of Rule 3-05 of Regulation S-X of

Securities and Exchange Commission (SEC).

The financial information in these financial statements has been prepared on a going concern basis which assumes that the Company will continue in operational

existence for the foreseeable future.

On December 23, 2017, Summit Therapeutics plc ( Summit ) completed a transaction to acquire the

Company. The Director believes that preparing the financial statements on the going concern basis is appropriate due to the financial support of the new ultimate parent company. The Director has received confirmation that Summit intends to support

the Company for at least one year after these financial statements are signed.

The preparation of the financial statements, in conformity with IFRS, requires the use of estimates and assumptions that affect the reported amounts of assets

and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Although these estimates are based on management s best knowledge of the amount, event or actions, actual

results may ultimately differ from those estimates. The areas involving a higher degree of judgement or complexity, or areas where assumptions and estimates are significant to the consolidated financial statements are disclosed in Note 2

Critical accounting judgements and key sources of estimation uncertainty .

Revenue is measured at the fair value of the consideration received or receivable and represents amounts receivable for goods and services provided in the

normal course of business net of value added tax and other sales-related taxes. The Company recognizes revenue when (i) the amount can be reliably measured; (ii) when it is probable that future economic benefits will flow to the Company;

and (iii) when specific criteria have been met for each of the Company s activities.

non-refundable, upfront payments are assessed as to whether they relate to the provision of a license or development service. Upfront payments classified as the provision of a license are recognized in full

immediately while revenue related to further research and development services are initially reported as deferred revenue on the Statement of Financial Position and are recognized as revenue over the research term or development period.

Intangible fixed assets are stated at

historic cost less amortization. Amortization is calculated to write off the cost of intangible fixed assets in equal instalments over their estimated useful lives as follows:

1. Basis of accounting (continued)

Impairment of assets

At each period end date the Company

reviews the carrying amount of its tangible and intangible assets to determine whether there is any indication that those assets have suffered an impairment loss. For the purposes of assessing impairment, assets are grouped at the lowest levels for

which there are separately identifiable cash flows (cash-generating units).

An impairment loss is recognized for the amount by which the asset s or

cash-generating unit s carrying amount exceeds its recoverable amount. The recoverable amount is the higher of fair value, reflecting market conditions, less costs to sell, and the value in use based on an internal discounted cash flow

evaluation. Impairment losses recognized for cash-generating units is charged pro rata to the other assets in the cash generating unit. All assets are subsequently reassessed for indications as to whether an impairment loss previously recognized may

Property, plant and equipment

Property, plant and equipment are stated at historic cost less depreciation except for buildings. Historic cost comprises the purchase price plus any

incidental costs of acquisition and commissioning. Buildings are accounted for under the revaluation model and are depreciated over their estimated useful lives. Buildings are revalued with sufficient regularity to ensure that the carrying amount

does not differ materially from the fair value at the end of the reporting period. Increases in the carrying amount arising on revaluation of buildings are credited to other comprehensive income and shown as a revaluation reserve in equity.

Depreciation is calculated to write off the cost, less residual value, of property, plant and equipment in equal annual installments over their estimated

useful lives as follows:

in respect of operating leases are charged to the Statement of Comprehensive Income on a straight-line basis over the terms of the leases.

Other operating income includes income received and recognized from government agencies,

non-government and not for profit organizations and which are accounted for in accordance with IAS 20, Accounting for Government Grants and Disclosure of Government Assistance .

Also included in other operating income are service recharges. Service recharges are due from related parties and are calculated at arm s length and

recognized in the period the expenditure is incurred.