Verona Pharma (VRNA) 20-F 27 Feb 20 2019 FY Annual report (foreign) Financial data

DEI

DEI	12 Months Ended
	Dec. 31, 2019shares
Document Information [Abstract]
Document Type	20-F
Document Annual Report	true
Document Transition Report	false
Document Shell Company Report	false
Entity Filer Category	Accelerated Filer
Document Fiscal Year Focus	2019
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Period Focus	FY
Entity Registrant Name	Verona Pharma PLC
Entity Central Index Key	0001657312
Current Fiscal Year End Date	--12-31
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Number of shares outstanding (in shares)	105,326,638

CONSOLIDATED STATEMENT OF FINAN

CONSOLIDATED STATEMENT OF FINANCIAL POSITION - GBP (£) £ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Non-current assets:
Goodwill	£ 441	£ 441
Intangible assets	2,757	2,618
Property, plant and equipment	43	21
Right-of-use assets	971
Total non-current assets	4,212	3,080
Current assets:
Prepayments and other receivables	2,770	2,463
Current tax receivable	7,396	4,499
Short term investments	7,823	44,919
Cash and cash equivalents	22,934	19,784
Total current assets	40,923	71,665
Total assets	45,135	74,745
Capital and reserves attributable to equity holders:
Share capital	5,266	5,266
Share premium	118,862	118,862
Share-based payment reserve	10,364	7,923
Accumulated loss	(100,627)	(68,633)
Total equity	33,865	63,418
Current liabilities:
Derivative financial instrument	895	2,492
Lease liability	460
Trade and other payables	8,261	7,733
Total current liabilities	9,616	10,225
Non-current liabilities:
Assumed contingent liability	1,103	996
Non-current lease liability	491
Deferred income	60	106
Total non-current liabilities	1,654	1,102
Total equity and liabilities	£ 45,135	£ 74,745

CONSOLIDATED STATEMENT OF COMPR

CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Profit or loss [abstract]
Research and development costs	£ (33,476)	£ (19,294)	£ (23,717)
General and administrative costs	(7,607)	(6,297)	(6,039)
Operating loss	(41,083)	(25,591)	(29,756)
Finance income	2,351	2,783	7,018
Finance expense	(474)	(1,325)	(2,465)
Loss before taxation	(39,206)	(24,133)	(25,203)
Taxation — credit	7,265	4,232	4,706
Loss for the year	(31,941)	(19,901)	(20,497)
Other comprehensive income / (loss):
Exchange differences on translating foreign operations	(33)	38	(29)
Total comprehensive loss attributable to owners of the Company	£ (31,974)	£ (19,863)	£ (20,526)
Loss per ordinary share — basic and diluted (pence per share)	£ (30.3)	£ (18.9)	£ (23.4)

CONSOLIDATED STATEMENT OF CASH

CONSOLIDATED STATEMENT OF CASH FLOWS - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash used in operating activities:
Loss before taxation	£ (39,206)	£ (24,133)	£ (25,203)
Finance income	(2,351)	(2,783)	(7,018)
Finance expense	474	1,325	2,465
Share-based payment charge	2,441	2,901	2,919
Increase in prepayments and other receivables	(484)	(640)	(161)
Increase in trade and other payables	449	531	5,363
Depreciation of property, plant, equipment and right of use asset	398	8	7
Unrealised FX gains/ losses	(8)	0	0
Amortization of intangible assets	106	90	116
Cash used in operating activities	(38,181)	(22,701)	(21,512)
Cash inflow from taxation	4,361	4,590	816
Net cash used in operating activities	(33,820)	(18,111)	(20,696)
Cash flow from investing activities:
Interest received	887	883	128
Purchase of plant and equipment	(38)	(13)	(9)
Payment for patents and computer software	(244)	(255)	(208)
Purchase of short term investments	(7,940)	(59,700)	(54,465)
Maturity of short term investments	45,134	64,366	5,085
Net cash generated from / (used in) investing activities	37,799	5,281	(49,469)
Cash flow used in financing activities:
Gross proceeds from the April 2017 Global Offering	0	0	70,032
Transaction costs on April 2017 Global Offering	0	0	(6,786)
Repayment of finance lease liabilities	(426)
Net cash (used in) / generated from financing activities	(426)	0	63,246
Net increase / (decrease) in cash and cash equivalents	3,553	(12,830)	(6,919)
Cash and cash equivalents at the beginning of the year	19,784	31,443	39,785
Effect of exchange rates on cash and cash equivalents	(403)	1,171	(1,423)
Cash and cash equivalents at the end of the year	£ 22,934	£ 19,784	£ 31,443

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - GBP (£) £ in Thousands	Total	Share Capital	Share Premium	Share-based Payment Reserve	Total Accumulated Losses
Beginning balance (Previously stated [member]) at Dec. 31, 2016	£ 34,469	£ 2,568	£ 58,526	£ 2,103	£ (28,728)
Loss for the year	(20,497)				(20,497)
Exchange differences on translating foreign operations	(29)				(29)
Total comprehensive loss for the year	(20,526)				(20,526)
New share capital issued	70,325	2,677	67,648
Transaction costs on share capital issued	(7,453)		(7,453)
Share options exercised during the year	147	6	141
Share-based payments	2,919			2,919
Ending balance at Dec. 31, 2017	80,365	5,251	118,862	5,022	(48,770)
Loss for the year	(19,901)				(19,901)
Exchange differences on translating foreign operations	38				38
Total comprehensive loss for the year	(19,863)				(19,863)
New share capital issued	15	15	0
Share-based payments	2,901			2,901
Ending balance (Previously stated [member]) at Dec. 31, 2018	63,418	5,266	118,862	7,923	(68,633)
Ending balance at Dec. 31, 2018	63,418
Loss for the year	(31,941)				(31,941)
Exchange differences on translating foreign operations	(33)				(33)
Total comprehensive loss for the year	(31,974)				(31,974)
Share-based payments	2,441			2,441
Ending balance at Dec. 31, 2019	£ 33,865	£ 5,266	£ 118,862	£ 10,364	£ (100,627)

General information

General information	12 Months Ended
	Dec. 31, 2019
Disclosure of notes and other explanatory information [Abstract]
General information	General information Verona Pharma plc and its subsidiaries (the "Company") are a clinical-stage biopharmaceutical group focused on developing and commercializing innovative therapeutics for the treatment of respiratory diseases with significant unmet medical needs. The Company is a public limited company, which is dual listed on the AIM, a market of the London Stock Exchange, and The Nasdaq Global Market ("Nasdaq"). The company is incorporated and domiciled in the United Kingdom. The address of the registered office is 1 Central Square, Cardiff, CF10 1FS, United Kingdom. The Company has two subsidiaries, Verona Pharma Inc. and Rhinopharma Limited ("Rhinopharma"), both of which are wholly owned. The Company listed its American Depositary Shares ("ADS") on Nasdaq in April 2017 ("the 2017 Global Offering"). The ADSs trade on The Nasdaq the symbol “VRNA” and Verona Pharma’s ordinary shares trade on AIM under the symbol “VRP”.

Accounting policies

Accounting policies	12 Months Ended
	Dec. 31, 2019
Disclosure of changes in accounting policies, accounting estimates and errors [Abstract]
Accounting policies	Accounting policies A summary of the principal accounting policies, all of which have been applied consistently throughout the year, is set out below. Basis of preparation The consolidated financial statements of the Company have been prepared in accordance with International Financial Reporting Standards ("IFRSs") as issued by the International Accounting Standards Board and IFRS Interpretations Committee applicable to companies reporting under IFRS. The consolidated financial statements have been prepared under the historical cost convention, with the exception of derivative financial instruments which have been measured at fair value. The preparation of financial statements in conformity with IFRS requires the use of certain critical accounting estimates. It also requires management to exercise its judgment in the process of applying the Company's accounting policies. The areas involving a higher degree of judgment or complexity, or areas where assumptions and estimates are significant to the consolidated financial statements are disclosed in note 4. Going concern The Company has incurred recurring losses since inception, including net losses of £31.9 million , £19.9 million and £20.5 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. In addition, as of December 31, 2019 , the Company had an accumulated loss of £100.6 million . The Company expects to continue to generate operating losses for the foreseeable future. As of the issuance date of the annual consolidated financial statements, the Company expects that its cash and cash equivalents, would be sufficient to fund its operating expenses and capital expenditure requirements for at least 12 months from the issuance date of these annual consolidated financial statements. Accordingly, the consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. The Company intends to initiate its Phase 3 program for the maintenance treatment of COPD once it believes it has alignment with the FDA on its planned design for the Phase 3 clinical program. The Company will require significant additional funding to initiate and complete this Phase 3 program and will need to secure the required capital to fund the program. The Company will seek additional funding through public or private financings, debt financing, collaboration or licensing agreements and other arrangements. However, there is no guarantee that the Company will be successful in securing additional finance on acceptable terms, or at all, and should the Company be unable to raise sufficient additional funds it will be required to defer the initiation of Phase 3 clinical trials, until such funding can be obtained. This could also force the Company to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, or pursue alternative development strategies that differ significantly from its current strategy, which could have a material adverse effect on the Company’s business, results of operations and financial condition. Business combination The Company applies the acquisition method to account for business combinations. The consideration transferred for the acquisition of a subsidiary is the fair value of the assets transferred, the liabilities incurred to the former owners of the acquiree and the equity interests issued by the Company. The consideration transferred includes the fair value of any asset or liability resulting from a contingent consideration arrangement. The excess of the cost of acquisition over the fair value of the Company's share of the identifiable net assets acquired is recorded as goodwill. Goodwill arising on acquisitions is capitalized and is subject to an impairment review, both annually and when there are indications that the carrying value may not be recoverable. Identifiable assets acquired and liabilities and contingent liabilities assumed in a business combination are measured initially at their fair values at the acquisition date. Acquisition-related costs are expensed as incurred and included in administrative expenses. Basis of consolidation These consolidated financial statements include the financial statements of Verona Pharma plc and its wholly owned subsidiaries Verona Pharma, Inc. and Rhinopharma. The acquisition method of accounting was used to account for the acquisition of Rhinopharma. Inter-company transactions, balances and unrealized gains on transactions between group companies are eliminated. Verona Pharma Inc. and Rhinopharma adopt the same accounting policies as the Company. Foreign currency translation Items included in the Company's consolidated financial statements are measured using the currency of the primary economic environment in which the entity operates ("the functional currency"). The consolidated financial statements are presented in pounds sterling ("£"), which is the functional and presentational currency of the Company. Transactions in foreign currencies are recorded using the rate of exchange ruling at the date of the transaction. Monetary assets and liabilities denominated in foreign currencies are translated using the rate of exchange ruling at the balance sheet date and the gains or losses on translation are included in the Consolidated Statement of Comprehensive Income. Non-monetary items that are measured in terms of historical cost in a foreign currency are translated using the exchange rates at the dates of the original transactions. Non-monetary items measured at fair value in a foreign currency are translated using the exchange rates at the date when the fair value was determined. The assets and liabilities of foreign operations are translated into pounds sterling at the rate of exchange ruling at the balance sheet date. Income and expenses are translated at weighted average exchange rates for the period. The exchange differences arising on translation for consolidation are recognized in Other Comprehensive Income. Cash and cash equivalents Cash and cash equivalents includes cash in hand, deposits held at call with banks and other short-term highly liquid investments with original maturities of three months or less. Deferred taxation Deferred tax is provided in full, using the liability method, on temporary differences arising between the tax bases of assets and liabilities and their carrying amounts in the consolidated financial statements. Deferred tax is determined using tax rates and laws that have been enacted or substantially enacted by the balance sheet date and expected to apply when the related deferred tax is realized or the deferred liability is settled. Deferred tax assets are recognized to the extent that it is probable that the future taxable profit will be available against which the temporary differences can be utilized. Research and development costs Capitalization of expenditure on product development commences from the point at which technical feasibility and commercial viability of the product can be demonstrated and the Company is satisfied that it is probable that future economic benefits will result from the product once completed. No such costs have been capitalized to date. Expenditure on research and development activities that do not meet the above criteria is charged to the Consolidated Statement of Comprehensive Income as incurred. Property, plant and equipment Property, plant and equipment are stated at cost, net of depreciation and any provision for impairment. Cost includes the original purchase price of the asset and the costs attributable to bringing the asset to its working condition for its intended use. Depreciation is calculated to write off the cost less their estimated residual values, on a straight-line basis over the expected useful economic lives of the assets concerned. The principal annual periods used for this purpose are: Computer hardware 3 years Intangible assets and goodwill (a) Goodwill Goodwill arises on the acquisition of subsidiaries and represents the excess of the consideration transferred over the fair value of the identifiable net assets acquired. (b) Patents Patent costs associated with the preparation, filing, and obtaining of patents are capitalized and amortized on a straight-line basis over the estimated useful lives of ten years . (c) Computer software Amortization is calculated so as to write off the cost less estimated residual values, on a straight-line basis over the expected useful economic life of two years. (d) In-process research & development ("IP R&D") The IP R&D asset acquired through a business combination, that had not reached technical feasibility, was initially recognized at fair value. Subsequent movements in the assumed contingent liability (see 2.12) that relate to changes in estimated cashflows or probabilities of success are recognized as additions to the IP R&D asset that it relates to. There were no changes in estimated cashflows or probabilities of success in the years ended 31 December, 2019, or 2018. This is a change in accounting policy as prior to January 1, 2019, movements in the assumed contingent liability were taken to the Statement of Comprehensive Income (see note 2.17). As a result of the change in accounting policy £484 thousand was restated from Accumulated Loss to the IP R&D asset. The asset is subject to impairment testing until completion, abandonment of the project or when the research findings are commercialized through a revenue generating project. The Company determines whether intangible assets are impaired on an annual basis or when there is an indication of impairment. Impairment of intangible assets, goodwill and non-financial assets The Company holds intangible assets relating to acquired IP R&D, patent costs and goodwill. Goodwill and intangible assets are tested annually for impairment or if there is an indication of impairment. The Company is a single cash generating unit ("CGU") so all intangibles are allocated to the Company as one CGU. As at 31 December, 2019, and 2018 the Company carried out impairment reviews with reference to its market capitalization. At points during the year ended 31 December 2019, the Company's market capitalization was less than its net assets. As a result, the Company carried out an impairment review by forecasting expected sales of ensifentrine, delivered by nebulizer for the maintenance treatment of chronic COPD, and associated costs. This cashflow forecast was then discounted to its net present value to demonstrate that the value in use of the ensifentrine was greater than the Company's net assets. The Company was required to make various estimates and assumptions as inputs for this model including, but not limited to: • market size and product acceptance by clinicians, patients and reimbursement bodies; • gross and net selling price; • costs of manufacturing, product distribution and marketing support; • costs of the Company's overhead; • size and make up of a sales force; • probabilities of success; and • discount rate. Employee Benefits (a) Pension The Company operates defined contribution pension schemes for its employees. Contributions payable for the year are charged to the Consolidated Statement of Comprehensive Income. The Company has no further liability once the contributions have been paid. (b) Bonus plans The Company recognizes a liability and an expense for bonus plans if contractually obligated or if there is a past practice that has created a constructive liability. Share-based payments The Company operates a number of equity-settled, share-based compensation schemes. The fair value of share based payments is determined using the Black-Scholes model and requires several assumptions and estimates as disclosed in note 17. The fair value of share-based payments under these schemes is expensed on a straight-line basis over the share based payments' vesting periods, based on the Company's estimate of shares that will eventually vest. Provisions Provisions are recognized when the Company has a present legal or constructive liability as a result of past events, it is probable that an outflow of resources will be required to settle the liability, and the amount can be reliably estimated. Provisions are measured at the present value of the expenditures expected to be required to settle the liability using a pre-tax rate that reflects current market assessments of the time value of money and the risks specific to the liability. Assumed contingent liability related to the business combination In 2006 the Company acquired Rhinopharma and assumed contingent liabilities owed to Vernalis Pharmaceuticals Limited which was subsequently acquired by Ligand Pharmaceuticals, Inc. (“Ligand”). The Company refers to the assignment and license agreement as the Ligand Agreement. Ligand assigned to the Company all of its rights to certain patents and patent applications relating to ensifentrine and related compounds (the "Ligand Patents") and an exclusive, worldwide, royalty-bearing license under certain Ligand know-how to develop, manufacture and commercialize products (the "Licensed Products") developed using Ligand Patents, Ligand know-how and the physical stock of certain compounds. The assumed contingent liability comprises a milestone payment on obtaining the first approval of any regulatory authority for the commercialization of a Licensed Product, low to mid-single digit royalties based on the future sales performance of all Licensed Products and a portion equal to a mid-twenty percent of any consideration received from any sub-licensees for the Ligand Patents and for Ligand know-how. The liability was initially recognized at fair value and subsequently measured at amortized cost. The assumed contingent liability is estimated as the expected value of the milestone payment and royalty payments. This expected value is based on estimated future royalties payable, derived from sales forecasts, and an assessment of the probability of success using standard market probabilities for respiratory drug development. The risk-weighted value of the assumed contingent arrangement is discounted back to its net present value applying an effective interest rate of 12% . Royalties payable are based on the future sales performance so the amount payable is unlimited. Sales that may be achieved are difficult to predict and subject to estimate, which is inherently uncertain. The assumed contingent liability is accounted for as a liability and its value is measured at amortized cost using the effective interest rate method, and is re-measured for changes in estimated cash flows or when the probability of success changes. Remeasurements relating to changes in estimated cash flows and probabilities of success are recognized in the IP R&D asset it relates to ("see 2.7"). This is a change in accounting policy for the year ended December 1, 2019 (see 2.17). The unwind of the discount is recognized in finance expense. Financial instruments — initial recognition and subsequent measurement The Company classifies a financial instrument, or its component parts, as a financial liability, a financial asset or an equity instrument in accordance with the substance of the contractual arrangement and the definitions of a financial liability, a financial asset and an equity instrument. A financial instrument is any contract that gives rise to a financial asset of one entity and a financial liability or equity instrument of another entity. (a) Financial assets, initial recognition and measurement and subsequent measurement The Company has no financial assets recorded at fair value through profit or loss ("FVPTL"). All assets are initially recognized initially at fair value plus transaction costs and subsequently measured at amortized cost using the effective interest method. (b) Financial liabilities, initial recognition and measurement and subsequent measurement Financial liabilities are classified as measured at amortized cost or FVTPL. The Company's warrants are classified as FVTPL and fair value gains and losses are recognized in profit or loss. Other financial liabilities are initially recognized at fair value and subsequently measured at amortized cost using the effective interest method. Interest expense and foreign exchange gains and losses are recognized in profit or loss. Any gain or loss on derecognition is also recognized in profit or loss. The Company's financial liabilities include trade and other payables, the Company's warrants and the assumed contingent liability. (c) Derivative financial instruments Derivatives are initially recognized at fair value on the date a derivative contract is entered into and are subsequently re-measured at fair value at the end of each reporting date. The Company holds one type of derivative financial instrument, the warrants, as explained in Note 2.14. The full fair value of the derivative is classified as a non-current liability when the warrants are exercisable in more than 12 months and as a current liability when the warrants are exercisable in less than 12 months. Changes in fair value of a derivative financial liability when related to a financing arrangement are recognized in the Consolidated Statement of Comprehensive Income within Finance Income or Finance Expense. arrants Warrants issued by the Company to investors as part of a share subscription are compound financial instruments where the warrant meets the definition of a financial liability. The financial liability component is initially measured at fair value in the Consolidated Statement of Financial Position. Equity is measured at the residual between the subscription price for the entire instrument and the liability component. The financial liability component is remeasured. Equity is not remeasured. Short Term Investments Short term investments include fixed term deposits held at banks with original maturities between three months and a year. They are classified as loans and receivables and are measured at amortized cost using the effective interest method. Transaction costs Qualifying transaction costs might be incurred in anticipation of an issuance of equity instruments and may cross reporting periods. The entity defers these costs on the balance sheet until the equity instrument is recognized. Deferred costs are subsequently reclassified as a deduction from equity when the equity instruments are recognized, as the costs are directly attributable to the equity transaction. If the equity instruments are not subsequently issued, the transaction costs are expensed. Any costs not directly attributable to the equity transaction are expensed. Transaction costs that relate to the issue of a compound financial instrument are allocated to the liability and equity components of the instrument in proportion to the allocation of proceeds. Where the liability component is held at fair value through profit or loss, the transaction costs are expensed to the Consolidated Statement of Comprehensive Income. For liabilities held at amortized cost, transaction costs are deducted from the liability and subsequently amortized. The amount of transaction costs accounted for as a deduction from equity in the period is disclosed separately in accordance with International Accounting Standard (“IAS 1”). Investments in subsidiaries Investments in subsidiaries are shown at cost less any provision for impairment. New standards, amendments and interpretations adopted by the Company The following standard has been adopted by the Company for the first time for the financial year beginning on or after January 1, 2019: ▪ IFRS 16 "Leases" The Company adopted IFRS 16 on January 1, 2019, and, as a consequence, changed its accounting policies. See note 2.17. New standards, amendments and interpretations issued but not effective for the financial year beginning January 1, 2019 and not early adopted There are no IFRS standards or interpretations not yet effective that would be expected to have a material impact on the Group.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2019
Disclosure of detailed information about financial instruments [abstract]
Financial Instruments	Financial Instruments Financial Risk Factors The Company's activities have exposed it to a variety of financial risks: market risk (including currency risk and interest rate risk), credit risk, and liquidity risk. The Company's overall risk management program is focused on preservation of capital and the unpredictability of financial markets and has sought to minimize potential adverse effects on the Company's financial performance and position. (a) Currency risk Foreign currency risk reflects the risk that the Company's net assets will be negatively impacted due to fluctuations in exchange rates. The Company has not entered into foreign exchange contracts to hedge against gains or losses from foreign exchange fluctuations. The summary data about the Company's exposure to currency risk is as follows. Figures are the pound sterling values of balances in each currency: December 31, 2019 December 31, 2018 GBP USD EUR GBP USD EUR £'000s £'000s £'000s £'000s £'000s £'000s Cash and cash equivalents 18,517 4,399 18 11,293 8,470 21 Short term Investments 6,316 1,507 — 19,850 25,069 — Trade and other payables 3,226 4,306 728 2,872 4,329 532 Sensitivity Analysis A reasonably possible strengthening or weakening of the Euro or U.S. dollar against pounds sterling as of December 31, 2019 and 2018 would have affected the measurement of the financial instruments denominated in a foreign currency (excluding the assumed contingent liability). The following table shows how a movement in a currency would give rise to a profit or (loss) and a corresponding entry in equity. Profit or loss and equity Strengthening Weakening December 31, 2019 £'000s £'000s EUR (5% movement) (36 ) 36 USD (5% Movement) 80 (80 ) December 31, 2018 £'000s £'000s EUR (5% movement) (26 ) 26 USD (5% Movement) 1,461 (1,461 ) Foreign currency denominated trade payables are short term in nature (generally 30 to 45 days). The Company has a U.S. operation, the net assets of which are exposed to foreign currency translation risk. Estimated cashflows relating to the assumed contingent liability are predominantly denominated in US dollars. In the years ended December 31, 2019, and 2018, movements in foreign exchange rates were not material and no sensitivity analysis is therefore provided. (b) Credit risk Credit risk reflects the risk that the Company may be unable to recover contractual receivables. As the Company is still in the development stage no policies are currently required to mitigate this risk. For banks and financial institutions, only independently rated parties with a minimum rating of "B+" are accepted. The Directors recognize that this is an area in which they may need to develop specific policies should the Company become exposed to further financial risks as the business develops. As of December 31, 2019 , and December 31, 2018 , cash and cash equivalents and short term investments were placed at the following banks: Cash and Cash Equivalents Year ended December 31, 2019 Credit rating Year ended December 31, 2018 Credit rating £'000 £'000 Banks Royal Bank of Scotland 1 A1 150 A1 Lloyds Bank 8,355 Aa3 15,862 Aa3 Citibank 6,529 Aa3 3,135 A1 Barclays 1,968 A1 449 A2 Wells Fargo 111 Aa1 188 Aa1 Close Brothers 5,970 Aa3 — — Total 22,934 19,784 Short Term Investments Year ended December 31, 2019 Credit Year ended December 31, 2018 Credit £'000 £'000 Banks Royal Bank of Scotland 5,616 A1 9,186 A1 Lloyds Bank — Aa3 1,567 Aa3 Standard Chartered — A1 15,450 A1 Citibank — Aa3 7,053 A1 Barclays 2,207 A1 11,663 A2 Total 7,823 44,919 (c) Management of capital The Company considers capital to be its equity reserves. At the current stage of the Company's life cycle, the Company's objective in managing its capital is to ensure funds raised meet the research and operating requirements until the next development stage of the Company's suite of projects. The Company ensures it is meeting its objectives by reviewing its Key Performance Indicators to ensure the research activities are progressing in line with expectations, costs are controlled and unused funds are placed on deposit to conserve resources and increase returns on surplus cash held. (d) Interest rate risk As of December 31, 2019 , the Company had cash deposits of £22.9 million ( 2018 : £19.8 million ) and short term investments of £7.8 million ( 2018 : £44.9 million). The rates of interest received during 2019 ranged between 0.0% and 2.87% . A 0.25% increase in interest rates would not have a material impact on finance income. The Company's exposure to interest rate risk, which is the risk that the interest received will fluctuate as a result of changes in market interest rates on classes of financial assets and financial liabilities, was as follows: December 31, 2019 December 31, 2018 Floating interest rate Fixed interest rate Floating interest rate Fixed interest rate £'000s £'000s £'000s £'000s Financial asset Cash deposits 10,006 12,928 15,082 4,702 Short Term Investments — 7,823 — 44,919 Total 10,006 20,751 15,082 49,621 (e) Liquidity risk The Company periodically prepares working capital forecasts for the foreseeable future, allowing an assessment of the cash requirements of the Company, to manage liquidity risk. The following table provides an analysis of the Company's financial liabilities. The carrying value of all balances approximates to their fair value. The Company's maturity analysis for the derivative financial instrument from the issue of warrants is given in note 18. LESS THAN 1 YEAR BETWEEN 1 AND 2 YEARS BETWEEN 2 AND 5 YEARS OVER 5 YEARS £'000s £'000s £'000s £'000s At December 31, 2019 Trade payables 1,455 — — — Accruals 6,806 — — — Lease liability 476 557 — — Assumed contingent liability (1) — — — 1,807 Total 8,737 557 — 1,807 • This table includes the undiscounted amount of the assumed contingent liability. See note 20. LESS THAN 1 YEAR BETWEEN 1 AND 2 YEARS BETWEEN 2 AND 5 YEARS OVER 5 YEARS £'000s £'000s £'000s £'000s At December 31, 2018 Trade payables 2,839 — — — Other payables 12 — — — Accruals 4,882 — — — Assumed contingent liability (1) — — — 1,807 Total 7,733 — — 1,807 (1) This table includes the undiscounted amount of the assumed contingent liability. See note 20. Fair value estimation The carrying amounts of cash and cash equivalents, receivables, accounts payable and accrued liabilities approximate to fair value due to their short-term nature. The carrying amount of the assumed contingent liability approximates to fair value as the underlying assumptions are currently similar. For financial instruments that are measured in the Consolidated Statement of Financial Position at fair value, IFRS 7 requires disclosure of fair value measurements by level of the following fair value measurement hierarchy: ▪ Quoted prices (unadjusted) in active markets for identical assets or liabilities (level 1); ▪ Inputs other than quoted prices included within level 1 that are observable for the asset or liability, either directly or indirectly (level 2); and ▪ Inputs for the asset or liability that are not based on observable market data (level 3). For the year ended December 31, 2019 , and 2018 , fair value adjustments to financial instruments measure at fair value through profit and loss resulted in the recognition of finance income of £ 1.6 million in 2019 and a finance loss of £1.2 million in 2018 . The fair value of financial instruments that are not traded in an active market is determined by using valuation techniques. These valuation techniques maximize the use of observable market data where it is available and rely as little as possible on entity specific estimates. If all significant inputs required to ascertain the fair value of an instrument are observable, the instrument is included in level 2. If one or more of the significant inputs are not based on observable market data, the instrument is included in level 3. Level 3 Total £'000s £'000s At December 31, 2019 Derivative financial instrument 895 895 Total 895 895 Movements in Level 3 items during the years ended December 31, 2019 , and 2018 are as follows: Derivative financial instrument 2019 2018 £'000s £'000s At January 1 2,492 1,273 Fair value adjustments recognized in profit and loss (1,597 ) 1,219 At December 31 895 2,492 Further details relating to the derivative financial instrument are set out in notes 4 and 18 of these financial statements. In determining the fair value of the derivative financial instrument, the Company applied the Black Scholes model; key inputs include the share price at reporting date, estimations on timelines, volatility and risk-free rates. These assumptions and the impact of changes in these assumptions, where material, are disclosed in note 18. Change in liabilities arising from financing activities The Company has provided a reconciliation so that changes in liabilities arising from financing activities, including both changes arising from cash flows and non-cash changes can be evaluated. 2019 Derivative financial instrument £'000s At January 1 2,492 Fair value adjustments - non cash (1,597 ) At December 31 895 See note 18 for information relating to the derivative financial instrument. 2019 Lease liability £'000s At January 1 316 Capitalization of rental leases - non cash 1,061 Payment of lease liability - cash (426 ) At December 31 951 See note 14 and note 2.17 for information relating to the capitalized leases.

Critical accounting estimates a

Critical accounting estimates and judgments	12 Months Ended
	Dec. 31, 2019
Disclosure of changes in accounting policies, accounting estimates and errors [Abstract]
Critical accounting estimates and judgments	Critical accounting estimates and judgments The preparation of financial statements in conformity with IFRS requires the use of accounting estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Although these estimates are based on management's best knowledge of current events and actions, actual results ultimately may differ from those estimates. IFRS also requires management to exercise its judgment in the process of applying the Company's accounting policies. The areas involving a higher degree of judgment or complexity, or areas where assumptions and estimates are significant to the consolidated financial statements are as follows: (a) Assumed contingent liability The Company has a material liability for the future payment of royalties and milestones associated with contractual liabilities on ensifentrine, acquired as part of the acquisition of Rhinopharma. The estimation of the amounts and timing of future cashflows requires the forecast of royalties payable and the estimation of the likelihood that the regulatory approval milestone will be achieved (see notes 2.12 and 20). The estimates for the assumed contingent liability are based on a discounted cash flow model. Key estimates included the calculation of deferred consideration are: ▪ development, regulatory and marketing risks associated with progressing the product to market approval in key target territories; ▪ market size and product acceptance by clinicians, patients and reimbursement bodies; ▪ gross and net selling price; ▪ launch of competitive products; ▪ probabilities of success; and ▪ time to crystallization of contingent consideration. When there is a change in the expected cash flows or probabilities of success, the assumed contingent liability is re-measured with the change in value recognized in the IP R&D asset it relates to. This is a change in accounting policy for the year ended December 1, 2019 (see 2.17). The assumed contingent liability is measured at amortized cost with the discount unwinding in finance expense throughout the year. Actual outcomes could differ significantly from the estimates made. The Company has judged that the probabilities of success will change when it moves from one stage of clinical development to another. Management have determined that, for the purposes of assessing probabilities of success, the Company will move from Phase 2 to Phase 3 after an End of Phase 2 Meeting with the Food and Drug Administration ("FDA") in the US that provides confidence over ensifentrine's historical development program and planned Phase 3 program. A remeasurement of the liability at this time is likely to result in a significant increase in both the liability and the corresponding IP R&D asset.The Company has previously announced that it expects to meet with the FDA in the first half of 2020. The Company notes that there is no guarantee that the meeting will take place in the timeframe anticipated or that there will be a successful outcome. Should the probabilities of success and estimates of cash flows change there will be a material increase in the assumed contingent liability and corresponding IP R&D asset. The amount will be dependent on feedback from the FDA and the probabilities of success applied. Should the Company determine that it has moved from Phase 2 to Phase 3 then the value of the liability could increase by between £15 million and £30 million ; the increase in the value of the liability will give rise to an approximately equivalent increase in the value of the IP R&D asset, as described further in Note 2.7. The value of the assumed contingent liability as of December 31, 2019 amounted to £1.1 million . ( 2018 : £1.0 million ). (b) Valuation of the Derivative Financial Liability In July 2016, the Company issued 31,115,926 units to new and existing investors at the placing price of £1.4365 per unit. Each unit comprises one ordinary share and one warrant. The warrants entitle the investors to subscribe for in aggregate a maximum of 12,401,262 ordinary shares. In accordance with IAS 32 and the Company’s accounting policy, as disclosed in note 2.14, the Company classified the warrants as a derivative financial liability to be presented on the Company's Consolidated Statement of Financial Position. The fair value of these warrants is determined by applying the Black-Scholes model. Assumptions are made on inputs such as term, volatility and risk free rate in order to determine the fair value per warrant. For further details see note 18.

Earnings per share

Earnings per share	12 Months Ended
	Dec. 31, 2019
Disclosure of earnings per share [Abstract]
Earnings per share	Earnings per share Basic loss per ordinary share of 30.3p ( 2018 : 18.9p and 2017 : 23.4 p) for the Company is calculated by dividing the loss for the year ended December 31, 2019 by the weighted average number of ordinary shares in issue of 105,326,638 as of December 31, 2019 ( 2018 : 105,110,504 and 2017 : 87,748,031 ). Potential ordinary shares are not treated as dilutive as the entity is loss making and such shares would be anti-dilutive.

Segmental reporting

Segmental reporting	12 Months Ended
	Dec. 31, 2019
Disclosure of entity's operating segments [Abstract]
Segmental reporting	Segmental reporting The Company’s activities are covered by one operating and reporting segment: Drug Development. There have been no changes to management’s assessment of the operating and reporting segment of the Company during the year. All non-current assets are based in the United Kingdom.

Operating loss

Operating loss	12 Months Ended
	Dec. 31, 2019
Analysis of income and expense [abstract]
Operating loss	Operating loss Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Operating Loss is stated after charging / (crediting): Research and development costs: Employee benefits (note 8) 4,688 3,360 3,435 Amortization of patents (note 12) 102 85 111 Legal, professional consulting and listing fees 537 161 331 Other research and development expenses 28,149 15,688 19,840 Total research and development costs 33,476 19,294 23,717 General and administrative costs: Employee benefits (note 8) 3,093 3,240 2,857 Legal, professional consulting and listing fees 2,155 1,296 2,045 Amortization of computer software (note 12) 4 5 5 Depreciation of property, plant and equipment (note 13) 16 8 7 Depreciation of right-of-use assets (note 14) 382 — — Operating lease charge — land and buildings — 384 294 Loss / (gain) on variations in foreign exchange rate 345 (9 ) 36 Other general and administrative expenses 1,612 1,373 795 Total general and administrative costs 7,607 6,297 6,039 Operating loss 41,083 25,591 29,756

Directors' emoluments and staff

Directors' emoluments and staff costs	12 Months Ended
	Dec. 31, 2019
Analysis of income and expense [abstract]
Directors' emoluments and staff costs	Directors' emoluments and staff costs Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 The average number of employees (excluding directors) of the Company during the year: Research and development 13 7 7 General and administrative 9 7 5 Total 22 14 12 Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Aggregate emoluments of directors: Salaries and other short-term employee benefits 850 830 897 Social security costs 112 94 103 Incremental payment for additional services 26 26 — Other pension costs 10 10 17 Total directors' emoluments 998 960 1,017 Share-based payment charge 925 1,337 1,037 Directors' emoluments including share-based payment charge 1,923 2,297 2,054 Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Aggregate executive officers costs: Wages and salaries 1,150 857 864 Social security costs 98 83 81 Share-based payment charge 751 769 1,332 Other pension costs 21 19 17 Total executive officers costs 2,020 1,728 2,294 Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Aggregate other staff costs: Wages and salaries 2,788 1,622 1,272 Social security costs 265 150 101 Share-based payment charge 765 795 550 Other pension costs 46 34 21 Total other staff costs 3,864 2,601 1,944 The Company considers key management personnel to comprise directors and executive officers. The Company operates defined contribution pension schemes for its employees and executive director. The total pension cost during the year ended December 31, 2019 was £77 thousand ( 2018 : £63 thousand and 2017 : £ 55 thousand ). There were no prepaid or accrued contributions to the scheme at December 31, 2019 ( 2018 and 2017 : £ nil ).

Finance income and expense

Finance income and expense	12 Months Ended
	Dec. 31, 2019
Analysis of income and expense [abstract]
Finance income and expense	Finance income and expense Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Finance income: Interest received on cash balances 754 861 345 Foreign exchange gain on translating foreign currency denominated balances — 1,922 — Fair value adjustment on derivative financial instruments (note 18) 1,597 — 6,650 Other Income — — 23 Total finance income 2,351 2,783 7,018 Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Finance expense: Fair value adjustment on derivative financial instruments (note 18) — 1,219 — Interest on discounted lease liability 50 — — Foreign exchange loss on translating foreign currency denominated balances 305 — 2,392 Unwinding of discount factor related to the assumed contingent arrangement (note 20) 119 106 73 Total finance expense 474 1,325 2,465

Taxation

Taxation	12 Months Ended
	Dec. 31, 2019
Disclosure of income tax [Abstract]
Taxation	Taxation Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Analysis of tax credit for the year Current tax: U.K. tax credit (7,250 ) (4,290 ) (5,006 ) U.S. tax charge 56 30 306 Adjustment in respect of prior periods (71 ) 28 (6 ) Total tax credit (7,265 ) (4,232 ) (4,706 ) The difference between the total tax shown above and the amount calculated by applying the standard rate of tax to the loss before tax is as follows: Factors affecting the tax credit for the year Loss on ordinary activities before taxation (39,206 ) (24,133 ) (25,203 ) Multiplied by standard rate of corporation tax of 19% (2018: 19% and 2017: 19.25%) (7,449 ) (4,585 ) (4,852 ) Effects of: Non-deductible expenses 515 540 675 Fair value adjustment on derivative financial instruments (303 ) 232 (1,280 ) Research and development incentive (3,119 ) (1,846 ) (2,116 ) Temporary differences not recognized (6 ) (3 ) (2 ) Difference in overseas tax rates 16 8 136 Tax losses carried forward not recognized 3,152 1,394 2,739 Adjustment in respect of prior periods (71 ) 28 (6 ) Total tax credit (7,265 ) (4,232 ) (4,706 ) U.K. corporation tax is charged at 19% ( 2018 : 19.00% and 2017 : 19.25% ) and U.S. federal and state tax at 27.6% ( 2018 : 27.6% and 2017 : 35% ). The following tables represent deferred tax balances recognized in the Consolidated Statement of Financial Position. There were no movements in either the deferred tax asset or the deferred tax liability. As at December 31, 2019 As at December 31, 2018 £'000s £'000s Deferred tax assets 332 250 Deferred tax liabilities (332 ) (250 ) Net balances — — The deferred tax liability relates to the difference between the accounting and tax bases of the IP R&D intangible asset. A deferred tax asset relating to UK tax losses has been recognized and offset against the liability. Factors that may affect future tax charges The Company has U.K. tax losses available for offset against future profits in the United Kingdom. However an additional deferred tax asset has not been recognized in respect of such items due to uncertainty of future profit streams. As of December 31, 2019 , the unrecognized deferred tax asset at 17% is estimated to be £ 9.27 million ( 2018 : £6.65 million at 17% ).

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2019
Disclosure of detailed information about intangible assets [abstract]
Goodwill	Goodwill As of December 31, 2019 As of December 31, 2018 £'000s £'000s Goodwill at January 1 and December 31 441 441 Goodwill represents the excess of the purchase price over the fair value of the net assets acquired in connection with the acquisition of Rhinopharma in September 2006. Goodwill is not amortized, but is tested annually for impairment. The Company has one CGU so goodwill is tested for impairment together with its intangible assets. It was tested with reference to the Company's market capitalization as of December 31, 2019 , the date of testing of IP R&D and goodwill impairment. The market capitalization of the Company was approximately £65.3 million as of December 31, 2019 , ( 2018 : 92.2 million ) compared to the Company's net assets of £33.9 million ( 2018 : £ 63.4 million ). Therefore, no impairment was required. The Company notes that after the reduction in its share price since December 31, 2018, and before the increase by December 31, 2019, at various points in the three months to March 31, 2019, the market value of the Company was less than its net book value. The Company therefore carried out an impairment review as at March 31, 2019. From market research the Company assessed, among other inputs, potential patient numbers from likely physician prescribing patterns, price points, the time from possible launch to peak sales, script rejection, attrition rates and probability of success. The Company also carried out a sensitivity analysis on key assumptions and assessed that a reasonable change in these assumptions would not lead to the value in use falling below net book value. Consequently, management determined that the Company's value in use exceeded the carrying value of the Company's assets and that no impairment was required. At various other points in the year ended December 31, 2019, the market value of the Company was less than its net book value. Consequently, management re-performed the impairment review quarterly, and identified no changes to market conditions, the competitive landscape, market research insights or other factors that would change its conclusions. As a result, management determined that the Company's value in use exceeded the carrying value of the Company's assets and that no impairment was required at those dates.

Intangible assets

Intangible assets	12 Months Ended
	Dec. 31, 2019
Disclosure of detailed information about intangible assets [abstract]
Intangible assets	Intangible assets IP R&D Computer software Patents Total £'000s £'000s £'000s £'000s Cost At January 1, 2018 (Restated) 1,953 11 727 2,691 Additions — 4 251 255 Disposals — — (6 ) (6 ) At December 31, 2018 (Restated) 1,953 15 972 2,940 Accumulated amortization At January 1, 2018 — 6 232 238 Charge for year — 5 85 90 Disposals — — (6 ) (6 ) At December 31, 2018 — 11 311 322 Net book value At December 31, 2018 (Restated) 1,953 4 661 2,618 IP R&D Computer software Patents Total £'000s £'000s £'000s £'000s Cost At January 1, 2019 1,953 15 972 2,940 Additions — 3 242 245 At December 31, 2019 1,953 18 1,214 3,185 Accumulated amortization At January 1, 2019 — 11 311 322 Charge for year — 4 102 106 At December 31, 2019 — 15 413 428 Net book value At December 31, 2019 1,953 3 801 2,757 Intangible assets comprise patents, computer software and an IP R&D asset that arose on the acquisition of Rhinopharma and investment in patents to protect ensifentrine. The IP R&D asset acquired through the business combination was initially recognized at fair value. Subsequent movements in the assumed contingent liability that relate to changes in estimated cash flows or probabilities of success are recognized as additions to the IP R&D asset that it relates to. This is a change in accounting policy (see note 2.17). The asset is not amortized and is tested annually for impairment. Patents are amortized over a period of ten years and are tested annually for impairment. Intangible assets are tested for impairment with goodwill, as the Company has only one CGU. See note 11 for information about the impairment review.

Property, plant and equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2019
Disclosure of detailed information about property, plant and equipment [abstract]
Property, plant and equipment	Property, plant and equipment Computer hardware Total £'000s £'000s Cost At January 1, 2018 26 26 Additions 13 13 At December 31, 2018 39 39 Accumulated depreciation At January 1, 2018 10 10 Charge for the year 8 8 At December 31, 2018 18 18 Net book value At December 31, 2018 21 21 Computer hardware Total £'000s £'000s Cost At January 1, 2019 39 39 Additions 38 38 At December 31, 2019 77 77 Accumulated depreciation At January 1, 2019 18 18 Charge for the year 16 16 At December 31, 2019 34 34 Net book value At December 31, 2019 43 43

Right-of-use assets - property

Right-of-use assets - property leases Right-of-use assets - property leases	12 Months Ended
	Dec. 31, 2019
Disclosure of leases [Abstract]
Right-of-use assets - property leases	Right-of-use assets - property leases The right-of-use asset relates to rented office space in London and New York where the Company generally enters in to leases for terms of less than three years. Before the adoption of IFRS 16 these leases were classified as operating leases. The Consolidated Statement of Financial Position shows the following amounts relating to leases: Year ended December 31, 2019 As of January 1, 2019* £'000s £'000s Right-of-use assets Right-of-use assets 971 326 971 326 Lease liabilities Current (460 ) (316 ) Non Current (491 ) — (951 ) (316 ) Additions to the right-of-use assets were £ 1,047,000 and were recognized when the Company was reasonably certain to extend the leases. The additions related to both of the Company's office locations, both of which agreements have similar terms and conditions. To calculate the value of the lease liabilities the Company applied a discount rate of 8% . The leases end in 2021 and 2022 and include options to extend them. The Company has determined it is not yet reasonably certain to operate the option to extend the leases and so has recognized lease payments only to these points in its calculation of the lease liabilities. The right-of-use lease assets are depreciated over the term of the leases. The Consolidated Statement of Comprehensive Income includes the following amounts relating to leases: Year ended December 31, 2019 Year ended December 31, 2018 £'000s £'000s Depreciation charge of right-of-use assets Right-of-use assets (382 ) — (382 ) — Interest expense (including finance cost) 50 — Expense relating to short-term leases (included in general and administrative expenses) 78 — The total cash outflow for leases in 2019 was £ 492,000 .

Prepayments and other receivabl

Prepayments and other receivables	12 Months Ended
	Dec. 31, 2019
Subclassifications of assets, liabilities and equities [abstract]
Prepayments and other receivables	Prepayments and other receivables As of December 31, 2019 As of December 31, 2018 £'000s £'000s Prepayments 1,309 1,362 Other receivables 1,461 1,101 Total prepayments and other receivables 2,770 2,463 The prepayments balance includes prepayments for insurance and clinical activities.

Share Capital

Share Capital	12 Months Ended
	Dec. 31, 2019
Disclosure of share capital, reserves and other equity interest [Abstract]
Share Capital	Share Capital The movements in the Company's share capital are summarized below: Date Description Number of shares Share Capital amounts in £'000s January 1, 2018 105,017,401 5,251 August 9, 2018 Vesting of RSUs 58,112 3 September 20, 2018 Vesting of RSUs 251,125 12 As at December 31, 2018 105,326,638 5,266 As at December 31, 2019 105,326,638 5,266 The total number of authorized ordinary shares, with a nominal value of £0.05 each, is 200,000,000 (share capital of £10,000,000 ). All 105,326,638 ordinary shares at December 31, 2019 are allotted, unrestricted, called up and fully paid. All issued shares rank pari passu. During 2018, the Company issued 309,237 ordinary shares upon vesting of employee restricted share units.

Share-based payments charge

Share-based payments charge	12 Months Ended
	Dec. 31, 2019
Disclosure of share-based payment arrangements [Abstract]
Share-based payments charge	Share-based payments charge The Company operates various share based payment incentive schemes for its staff. In accordance with IFRS 2 "Share Based Payments," the cost of equity-settled transactions is measured by reference to their fair value at the date at which they are granted. Where equity-settled transactions were entered into with third party service providers, fair value is determined by reference to the value of the services provided. For other equity-settled transactions fair value is determined using the Black-Scholes model. The cost of equity-settled transactions is recognized over the period until the award vests. No expense is recognized for awards that do not ultimately vest. At each reporting date, the cumulative expense recognized for equity-based transactions reflects the extent to which the vesting period has expired and the number of awards that, in the opinion of the Directors at that date, will ultimately vest. The costs of equity-settled share-based payments to employees are recognized in the Statement of Comprehensive Income, together with a corresponding increase in equity during the vesting period. During the twelve months ended December 31, 2019 , the Company recognized a share-based payment expense of £ 2.44 million ( 2018 : £ 2.90 million ). The charge is included within both general and administrative costs as well as in research and development costs and represents the current year's allocation of the expense for relevant share options. The Company operates an Unapproved Share Option Scheme under which options were issued before 31 December 2016. The Company also operates a tax efficient EMI Option Scheme under which options were issued before 31 December 2016. In 2017 the Company commenced the 2017 Incentive Award Plan under which the Company grants share options and Restricted Stock Units ("RSUs") to employees and directors. Since 2017 options are issued with an exercise price at the share price the evening before the date of issue. They vest over terms of one to four years. RSUs also vest over terms of one to four years . In the year ended December 31, 2019, the Company modified the terms of all the RSUs issued prior January 1, 2019, to include a market based performance condition. The Company's share price must be maintained above £2 for thirty days for the RSUs to vest, in addition to the existing service condition. The RSUs vest after a five year term irrespective of whether the £2 market condition was met. This modification did not result in an increase in the fair value of the RSUs. The RSUs issued in the year ended December 31, 2019, also include the same market condition and five year term. In the year ended December 31, 2019 , under the 2017 Incentive Award Plan, the Company granted 5,569,050 ( 2018 : 2,090,847 ) share options and 740,496 RSUs ( 2018 : 273,390 ). The total fair values of the options and RSUs were estimated using the Black-Scholes option-pricing model for equity-settled transactions and amounted to £ 2.25 million ( 2018 : £ 2.32 million ). The cost is amortized over the vesting period of the options and RSUs on a straight-line basis.The following assumptions were used for the Black-Scholes valuation of share options and RSUs granted in 2018 and 2019 . For the options granted under the Unapproved Scheme the table indicates the ranges used in determining the fair-market values, aligning with the various dates of the underlying grants. The volatility is calculated using historical weekly averages of the Company's share price over a period that is in line with the expected life of the options and RSUs. Issued in 2018 Unapproved Restricted Stock Units Options granted 2,090,847 273,390 Risk-free interest rate 1.08% - 1.22% 1.08% - 1.22% Expected life of options 5.5 - 7 years 5.5 - 7 years Annualized volatility 69.88% -71.35% 69.88% -71.35% Dividend rate 0.00 % 0.00 % Vesting period 1 to 4 years 1 to 4 years Issued in 2019 Unapproved Restricted Stock Units Options granted 5,569,050 740,496 Risk-free interest rate 0.39% - 0.82% 0.76% - 0.82% Expected life of options 5.5 - 7 years 5.5 - 7 years Annualized volatility 67.98% - 69.71% 63.82% - 69.71% Dividend rate 0.00 % 0.00 % Vesting period 1 to 4 years 1 to 4 years The Company had the following share options movements in the year ended December 31, 2019 : Year of issue Exercise At January 1, 2019 Options granted Options forfeited Options expired At December 31, 2019 Expiry date 2012 2.50 - 7.50 99,993 — — — 99,993 June 1, 2022 2013 2 99,990 — — (19,998 ) 79,992 April 15, 2023 2013 2.00 159,999 — — — 159,999 July 29, 2023 2014 1.75 109,998 — — — 109,998 May 15, 2024 2014 1.75 49,998 — — — 49,998 May 15, 2024 * 2015 1.25 41,997 — — — 41,997 January 29, 2025 * 2015 1.25 549,999 — — — 549,999 January 29, 2025 2016 2 240,000 — — — 240,000 February 2, 2026 2016 2.00 21,996 — — — 21,996 February 2, 2026 * 2016 1.80 676,664 — — — 676,664 August 3, 2026 2016 1.89 299,997 — — — 299,997 September 13, 2026 2016 2.04 300,000 — — — 300,000 September 16, 2026 2017 1.32 - 1.525 4,093,164 — — — 4,093,164 April 26, 2027 2018 1.46 2,008,319 — (34,614 ) — 1,973,705 March 8, 2028 2019 570.00 — 3,903,050 (87,356 ) — 3,815,694 March 29, 2029 2019 595.00 — 346,000 — — 346,000 June 11, 2029 2019 457.00 — 100,000 — — 100,000 August 22, 2029 2019 0.436 — 720,000 — — 720,000 November 6, 2029 2019 445.00 — 500,000 — — 500,000 November 26, 2029 Total 8,752,114 5,569,050 (121,970 ) (19,998 ) 14,179,196 * Options granted under the EMI Scheme. The Company had the following RSU movements in the year ended December 31, 2019 : Year of issue Exercise At January 1, 2019 Units Units Units At December 31, 2019 Expiry date 2017 729,987 — — — 729,987 April 26, 2027 2018 132,486 — — — 132,486 March 8, 2028 2019 740,496 — — 740,496 March 29, 2027 Total 862,473 740,496 — — 1,602,969 Outstanding and exercisable share options by scheme as of December 31, 2019 : Plan Outstanding Exercisable Weighted average exercise price in £ for Outstanding Weighted average exercise price in £ for Exercisable Unapproved 13,965,212 5,552,293 1.12 1.55 EMI 213,984 213,984 3.06 3.06 Total 14,179,196 5,766,277 1.15 1.61 As of December 31, 2019 there were no restricted share options exercisable ( 2018 : nil ) and there is no exercise price for restricted share options. The options outstanding at December 31, 2019 had a weighted average remaining contractual life of 7.7 years ( 2018 : 8.0 years ). For 2018 and 2019 , the number of options granted and expired and the weighted average exercise price of options were as follows: Number of options Weighted average exercise price (£) At January 1, 2018 7,527,458 1.53 Options granted in 2018: Employees 1,222,089 1.46 Directors 868,758 1.46 Options forfeited in the year (799,524 ) 1.43 Options expired in the year (66,667 ) 1.75 At December 31, 2018 8,752,114 1.53 Exercisable at December 31, 2018 3,542,884 1.66 Number of options Weighted average exercise price (£) At January 1, 2019 8,752,114 1.53 Options granted in 2019: Employees 4,042,106 0.55 Directors 1,526,944 0.53 Options forfeited in the year (121,970 ) 0.82 Options expired in the year (19,998 ) 2.00 At December 31, 2019 14,179,196 1.15 Exercisable at December 31, 2019 5,766,277 1.60 The following table shows the number of RSUs issued, exercised and forfeited in 2018. The fair value of each unvested RSU at grant date was £1.46 . Number of At January 1, 2018 1,052,236 Granted: Employees 136,404 Directors 136,986 RSUs vested in the year (309,237 ) RSUs forfeited in the year (153,916 ) At December 31, 2018 862,473 The following table shows the number of RSUs issued in 2019. There were no RSUs forfeited, canceled or vested in 2019. The fair value of each unvested RSU granted in 2019 was £0.57 . Number of At January 1, 2019 862,473 Granted: Employees 474,072 Directors 266,424 RSUs vested in the year — RSUs forfeited in the year — At December 31, 2019 1,602,969

Warrants

Warrants	12 Months Ended
	Dec. 31, 2019
Disclosure of share capital, reserves and other equity interest [Abstract]
Warrants	Derivative financial instrument On July 29, 2016, the Company issued 31,115,926 units to new and existing investors at the placing price of £1.4365 per unit. Each unit comprises one ordinary share and one warrant. The warrant holders can subscribe for 0.4 of an ordinary share at a per share exercise price of £ 1.7238 . The warrant holders can opt for a cashless exercise of their warrants, whereby the warrant holders can choose to exchange the warrants held for reduced number of warrants exercisable at nil consideration. The reduced number of warrants is calculated based on a formula considering the share price and the exercise price of the warrants. The warrants are therefore classified as a derivative financial liability, since their exercise could result in a variable number of shares to be issued. The warrants entitled the investors to subscribe for, in aggregate, a maximum of 12,401,262 shares. The warrants can be exercised until May 2, 2022. In the year ended December 31, 2019 , no warrants were forfeited ( 2018 : nil ). The table below presents the assumptions in applying the Black-Scholes model to determine the fair value of the warrants. As of December 31, 2019 As of December 31, 2018 Shares available to be issued under warrants 12,401,262 12,401,262 Exercise price £ 1.7238 £ 1.7238 Risk-free interest rate 0.540 % 0.760 % Expected term to exercise 2.34 years 3.34 years Annualized volatility 65.56 % 60.72 % Dividend rate 0.00 % 0.00 % As per the reporting date, the Company updated the underlying assumptions and calculated a fair value of these warrants amounting to £0.9 million . The variance of £(1.6) million is recorded as finance income in the Consolidated Statement of Comprehensive Income. Derivative financial instrument Derivative financial instrument 2019 2018 £'000s £'000s At January 1 2,492 1,273 Fair value adjustments recognized in profit or loss (1,597 ) 1,219 At December 31 895 2,492 For the amount recognized at December 31, 2019 , the effect when the following parameter deviates up or down is presented in the below table. Volatility (up / down 10% pts) £'000s Variable up 1,306 Base case, reported fair value 895 Variable down 535

Trade and other payables

Trade and other payables	12 Months Ended
	Dec. 31, 2019
Subclassifications of assets, liabilities and equities [abstract]
Trade and other payables	Trade and other payables As of December 31, 2019 As of December 31, 2018 £'000s £'000s Trade payables 1,455 2,839 Other payables — 12 Accruals 6,806 4,882 Total trade and other payables 8,261 7,733

Assumed contingent obligation r

Assumed contingent obligation related to the business combination	12 Months Ended
	Dec. 31, 2019
Disclosure of other provisions, contingent liabilities and contingent assets [Abstract]
Assumed contingent obligation related to the business combination	Assumed contingent liability related to the business combination The value of the assumed contingent liability as of December 31, 2019 is £1.1 million ( 2018 : £1.0 million ). The increase in value of the assumed contingent liability during 2019 amounted to £0.1 million ( 2018 : £0.1 million ). The assumed contingent liability relates to the acquisition, in 2006, of rights to certain patents and patent applications relating to ensifentrine and related compounds under which the Company is obliged to pay royalties to Ligand (see 2.12). The assumed contingent liability is measured at the expected value of the milestone payment and royalty payments. This expected value is based on estimated future royalties payable, derived from sales forecasts, and an assessment of the probability of success using standard market probabilities for respiratory drug development. The risk-weighted value of the assumed contingent arrangement is discounted back to its net present value applying an effective interest rate of 12% . The assumed contingent liability is accounted for as a liability and its value is measured at amortized cost using the effective interest rate method, and is re-measured for changes in estimated cash flows or when the probability of success changes. Re-measurements relating to changes in estimated cash flows and probabilities of success are recognized in the IP R&D asset it relates to ("see 2.7"). This is a change in accounting policy for the year ended December 1, 2019 (see 2.17). The unwind of the discount is recognized in finance expense. The Company considers that probabilities of success will change when it moves from one stage of clinical development to another. See note 4 for a further discussion of this. 2019 2018 £'000s £'000s January 1 996 875 Impact of changes in foreign exchange rates (12 ) 15 Unwinding of discount factor 119 106 December 31 1,103 996 There is no material difference between the fair value and carrying value of the financial liability. For the amount recognized as at December 31, 2019 , of £ 1,103 thousand , the effect if underlying assumptions were to deviate up or down is presented in the following table (assuming the probability of success does not change): Discount rate (up / down 1 % pt) Revenue (up / down 10 % pts) £'000s £'000s Variable up 1,067 1,135 Base case, reported fair value 1,103 1,103 Variable down 1,141 1,071

Related parties transactions an

Related parties transactions and other shareholder matters	12 Months Ended
	Dec. 31, 2019
Disclosure of related party [Abstract]
Related parties transactions and other shareholder matters	Related parties transactions and other shareholder matters (i) Related party transactions The Directors have authority and responsibility for planning, directing and controlling the activities of the Company and they therefore comprise key management personnel as defined by IAS 24, ("Related Party Disclosures"). Directors and key management personnel remuneration is disclosed in note 8. (ii) Other shareholder matters The Company has entered into the following arrangements with parties who are significant shareholders of the Company, though they are not classed as related parties. The Company entered into relationship agreements with Vivo Ventures Fund VII, L.P., Vivo Ventures VII Affiliates Fund, L.P., Vivo Ventures Fund VI, L.P., Vivo Ventures VI Affiliates Fund, L.P. (collectively, "Vivo Capital"), Orbimed Private Investments VI L.P. ("Orbimed") and Abingworth Bioventures VI L.P. ("Abingworth"). As agreed in these relationship agreements, the above parties invested in the Company as part of the July 2016 Placement, and the Company agreed to appoint representatives designated by Vivo Capital, OrbiMed and Abingworth to the board of directors, who are Dr. Mahendra Shah, Mr. Rishi Gupta, and Dr. Andrew Sinclair. The appointment rights within the relationship agreement with Arix and Arthurian terminated on closing of the Global Offering on April 26, 2017. Dr Cunningham agreed to continue to serve on the Company's board of directors as an independent director. The respective appointment rights under the remaining relationship agreements will automatically terminate upon (i) Vivo Capital, OrbiMed or Abingworth (or any of their associates), as applicable, ceasing to beneficially hold 6.5% of the issued ordinary shares, or (ii) the ordinary shares ceasing to be admitted to AIM. Piers Morgan, Chief Financial Officer of the Company, and his spouse purchased 88,415 ordinary shares in total for £53 thousand from the market in the year ended December 31, 2019 (2018: £ nil ). Dr. Jan-Anders Karlsson, Chief Executive Officer of the Company, purchased 3,250 ordinary shares for £5 thousand from the market in the year ended December 31, 2018. There was no similar transaction as at December 31, 2019. Dr. David Ebsworth, Chairman of the Company, purchased 247,600 ordinary shares for £124 thousand from the market in the year ended December 31, 2019 (2018: £14 thousand ). At December 31, 2018, there was a receivable of £126 thousand due from one director and two key management personnel relating to tax due on RSUs that vested in the year ended December 31, 2018. This receivable was repaid, together with interest at a rate of 3.9% per annum, by March 6, 2019. There was no such balance as at December 31, 2019. In the year ended December 31, 2019 , a director provided consultancy services for £ 26 thousand ( 2018 : £ 26 thousand ).

Events after the reporting date

Events after the reporting date Events after the reporting date	12 Months Ended
	Dec. 31, 2019
Disclosure of events after reporting period [Abstract]
Events after the reporting date	Events after the reporting date On February 3, 2020, the Company announced the appointment of David Zaccardelli as chief executive officer with effect from February 1, 2020, following the retirement of Jan-Anders Karlsson, PhD. The Company also announced the appointment of Mark Hahn as chief financial officer with effect from March 1, 2020, as successor to Piers Morgan.

Accounting policies (Policies)

Accounting policies (Policies)	12 Months Ended
	Dec. 31, 2019
Disclosure of changes in accounting policies, accounting estimates and errors [Abstract]
Going concern	Going concern
Business combination	Business combination The Company applies the acquisition method to account for business combinations. The consideration transferred for the acquisition of a subsidiary is the fair value of the assets transferred, the liabilities incurred to the former owners of the acquiree and the equity interests issued by the Company. The consideration transferred includes the fair value of any asset or liability resulting from a contingent consideration arrangement. The excess of the cost of acquisition over the fair value of the Company's share of the identifiable net assets acquired is recorded as goodwill. Goodwill arising on acquisitions is capitalized and is subject to an impairment review, both annually and when there are indications that the carrying value may not be recoverable. Identifiable assets acquired and liabilities and contingent liabilities assumed in a business combination are measured initially at their fair values at the acquisition date. Acquisition-related costs are expensed as incurred and included in administrative expenses.
Basis of consolidation	Basis of consolidation These consolidated financial statements include the financial statements of Verona Pharma plc and its wholly owned subsidiaries Verona Pharma, Inc. and Rhinopharma. The acquisition method of accounting was used to account for the acquisition of Rhinopharma. Inter-company transactions, balances and unrealized gains on transactions between group companies are eliminated. Verona Pharma Inc. and Rhinopharma adopt the same accounting policies as the Company.
Foreign currency translation	Foreign currency translation Items included in the Company's consolidated financial statements are measured using the currency of the primary economic environment in which the entity operates ("the functional currency"). The consolidated financial statements are presented in pounds sterling ("£"), which is the functional and presentational currency of the Company. Transactions in foreign currencies are recorded using the rate of exchange ruling at the date of the transaction. Monetary assets and liabilities denominated in foreign currencies are translated using the rate of exchange ruling at the balance sheet date and the gains or losses on translation are included in the Consolidated Statement of Comprehensive Income. Non-monetary items that are measured in terms of historical cost in a foreign currency are translated using the exchange rates at the dates of the original transactions. Non-monetary items measured at fair value in a foreign currency are translated using the exchange rates at the date when the fair value was determined. The assets and liabilities of foreign operations are translated into pounds sterling at the rate of exchange ruling at the balance sheet date. Income and expenses are translated at weighted average exchange rates for the period. The exchange differences arising on translation for consolidation are recognized in Other Comprehensive Income.
Cash and cash equivalents	Cash and cash equivalents Cash and cash equivalents includes cash in hand, deposits held at call with banks and other short-term highly liquid investments with original maturities of three months or less.
Deferred taxation	Deferred taxation Deferred tax is provided in full, using the liability method, on temporary differences arising between the tax bases of assets and liabilities and their carrying amounts in the consolidated financial statements. Deferred tax is determined using tax rates and laws that have been enacted or substantially enacted by the balance sheet date and expected to apply when the related deferred tax is realized or the deferred liability is settled. Deferred tax assets are recognized to the extent that it is probable that the future taxable profit will be available against which the temporary differences can be utilized.
Research and development costs	Research and development costs Capitalization of expenditure on product development commences from the point at which technical feasibility and commercial viability of the product can be demonstrated and the Company is satisfied that it is probable that future economic benefits will result from the product once completed. No such costs have been capitalized to date. Expenditure on research and development activities that do not meet the above criteria is charged to the Consolidated Statement of Comprehensive Income as incurred.
Property, plant and equipment	Property, plant and equipment Property, plant and equipment are stated at cost, net of depreciation and any provision for impairment. Cost includes the original purchase price of the asset and the costs attributable to bringing the asset to its working condition for its intended use. Depreciation is calculated to write off the cost less their estimated residual values, on a straight-line basis over the expected useful economic lives of the assets concerned.
Intangible assets and goodwill	Intangible assets and goodwill (a) Goodwill Goodwill arises on the acquisition of subsidiaries and represents the excess of the consideration transferred over the fair value of the identifiable net assets acquired. (b) Patents Patent costs associated with the preparation, filing, and obtaining of patents are capitalized and amortized on a straight-line basis over the estimated useful lives of ten years . (c) Computer software Amortization is calculated so as to write off the cost less estimated residual values, on a straight-line basis over the expected useful economic life of two years. (d) In-process research & development ("IP R&D") The IP R&D asset acquired through a business combination, that had not reached technical feasibility, was initially recognized at fair value. Subsequent movements in the assumed contingent liability (see 2.12) that relate to changes in estimated cashflows or probabilities of success are recognized as additions to the IP R&D asset that it relates to. There were no changes in estimated cashflows or probabilities of success in the years ended 31 December, 2019, or 2018. This is a change in accounting policy as prior to January 1, 2019, movements in the assumed contingent liability were taken to the Statement of Comprehensive Income (see note 2.17). As a result of the change in accounting policy £484 thousand was restated from Accumulated Loss to the IP R&D asset. The asset is subject to impairment testing until completion, abandonment of the project or when the research findings are commercialized through a revenue generating project. The Company determines whether intangible assets are impaired on an annual basis or when there is an indication of impairment.
Impairment of intangible assets, goodwill and non-financial asset	Impairment of intangible assets, goodwill and non-financial assets The Company holds intangible assets relating to acquired IP R&D, patent costs and goodwill. Goodwill and intangible assets are tested annually for impairment or if there is an indication of impairment. The Company is a single cash generating unit ("CGU") so all intangibles are allocated to the Company as one CGU. As at 31 December, 2019, and 2018 the Company carried out impairment reviews with reference to its market capitalization. At points during the year ended 31 December 2019, the Company's market capitalization was less than its net assets. As a result, the Company carried out an impairment review by forecasting expected sales of ensifentrine, delivered by nebulizer for the maintenance treatment of chronic COPD, and associated costs. This cashflow forecast was then discounted to its net present value to demonstrate that the value in use of the ensifentrine was greater than the Company's net assets. The Company was required to make various estimates and assumptions as inputs for this model including, but not limited to: • market size and product acceptance by clinicians, patients and reimbursement bodies; • gross and net selling price; • costs of manufacturing, product distribution and marketing support; • costs of the Company's overhead; • size and make up of a sales force; • probabilities of success; and • discount rate.
Employee Benefits	Employee Benefits (a) Pension The Company operates defined contribution pension schemes for its employees. Contributions payable for the year are charged to the Consolidated Statement of Comprehensive Income. The Company has no further liability once the contributions have been paid. (b) Bonus plans The Company recognizes a liability and an expense for bonus plans if contractually obligated or if there is a past practice that has created a constructive liability.
Share-based payments	Share-based payments The Company operates a number of equity-settled, share-based compensation schemes. The fair value of share based payments is determined using the Black-Scholes model and requires several assumptions and estimates as disclosed in note 17. The fair value of share-based payments under these schemes is expensed on a straight-line basis over the share based payments' vesting periods, based on the Company's estimate of shares that will eventually vest.
Provisions	Provisions Provisions are recognized when the Company has a present legal or constructive liability as a result of past events, it is probable that an outflow of resources will be required to settle the liability, and the amount can be reliably estimated. Provisions are measured at the present value of the expenditures expected to be required to settle the liability using a pre-tax rate that reflects current market assessments of the time value of money and the risks specific to the liability.
Assumed contingent obligation related to the business combinations	Assumed contingent liability related to the business combination In 2006 the Company acquired Rhinopharma and assumed contingent liabilities owed to Vernalis Pharmaceuticals Limited which was subsequently acquired by Ligand Pharmaceuticals, Inc. (“Ligand”). The Company refers to the assignment and license agreement as the Ligand Agreement. Ligand assigned to the Company all of its rights to certain patents and patent applications relating to ensifentrine and related compounds (the "Ligand Patents") and an exclusive, worldwide, royalty-bearing license under certain Ligand know-how to develop, manufacture and commercialize products (the "Licensed Products") developed using Ligand Patents, Ligand know-how and the physical stock of certain compounds. The assumed contingent liability comprises a milestone payment on obtaining the first approval of any regulatory authority for the commercialization of a Licensed Product, low to mid-single digit royalties based on the future sales performance of all Licensed Products and a portion equal to a mid-twenty percent of any consideration received from any sub-licensees for the Ligand Patents and for Ligand know-how. The liability was initially recognized at fair value and subsequently measured at amortized cost. The assumed contingent liability is estimated as the expected value of the milestone payment and royalty payments. This expected value is based on estimated future royalties payable, derived from sales forecasts, and an assessment of the probability of success using standard market probabilities for respiratory drug development. The risk-weighted value of the assumed contingent arrangement is discounted back to its net present value applying an effective interest rate of 12% . Royalties payable are based on the future sales performance so the amount payable is unlimited. Sales that may be achieved are difficult to predict and subject to estimate, which is inherently uncertain. The assumed contingent liability is accounted for as a liability and its value is measured at amortized cost using the effective interest rate method, and is re-measured for changes in estimated cash flows or when the probability of success changes. Remeasurements relating to changes in estimated cash flows and probabilities of success are recognized in the IP R&D asset it relates to ("see 2.7"). This is a change in accounting policy for the year ended December 1, 2019 (see 2.17). The unwind of the discount is recognized in finance expense. Accounting for the assumed contingent liability As discussed in note 2.12, in 2006 the Company acquired Rhinopharma and assumed contingent liabilities owed to Vernalis Pharmaceuticals Limited which was subsequently acquired by Ligand Pharmaceuticals, Inc. ("Ligand"). Ligand assigned to the Company all of its rights to certain patents and patent applications relating to ensifentrine and related compounds and an exclusive, worldwide, royalty-bearing license to develop, manufacture and commercialize products. The assumed contingent liability comprises a milestone payment on obtaining the first approval of any regulatory authority and royalties based on the future sales of ensifentrine. The initial fair value of the assumed contingent liability was estimated as the expected value of the milestone payment and royalty payments. This expected value is based on estimated future royalties payable, derived from sales forecasts, an assessment of the probability of success using standard market probabilities for respiratory drug development discounted to net present value applying an effective interest rate of 12% . The assumed contingent liability is accounted for as a liability and its value is measured at amortized cost using the effective interest rate method, and is re-measured for changes in estimated cash flows or when the probability of success changes. Up to the year ended December 31, 2018, movements in the liability relating to re-measurements of cash flows or changes in the probabilities of success were taken to the Consolidated Statement of Comprehensive Income. During the year ended December 31, 2019, the Company reviewed the accounting for this item and has determined that these movements in the liability will now be recognized in the cost of the corresponding asset. The corresponding asset is the intangible IP R&D asset. The Company believes that this change in accounting policy results in the Consolidated Financial Statements providing a more relevant and reliable view of its financial position and performance because without an adjustment to the IP R&D asset on the re-measurement of the liability, the cost of the asset would not be fairly reflected on the Consolidated Statement of Financial Position. The Consolidated Statement of Financial Position more faithfully represents the financial position of the Company if the intangible asset is adjusted by any re-measurement of the liability for changes in estimated cash flows, to give a fairer reflection of the cost of the intangible asset. The Company has reviewed the International Financial Reporting Interpretations Committee ("IFRIC") discussion of accounting for variable payments made for the purchase of an intangible asset that is not part of a business combination that concluded that it was too broad for it to address within the confines of existing IFRS standards. As a result, practice in this area is mixed and many pharmaceutical companies follow a cost accumulation model. The Company also noted that adjusting the cost of the asset when a liability is remeasured for changes in estimated cash flows is consistent with the guidance in IFRIC 1 for decommissioning liabilities and IFRS 16 for lease liabilities. There were no such re-measurements of the liability in the years ended December 31, 2019, 2018 and 2017. Movements in the liability in these periods related to the unwinding of the discount and movements in exchange rates. IAS 8 requires opening balance of each affected component of equity to be adjusted for the earliest prior period presented and the other comparative amounts disclosed for each prior period presented as if the new accounting policy had always been applied.
Financial instruments — initial recognition and subsequent measurement	Financial instruments — initial recognition and subsequent measurement The Company classifies a financial instrument, or its component parts, as a financial liability, a financial asset or an equity instrument in accordance with the substance of the contractual arrangement and the definitions of a financial liability, a financial asset and an equity instrument. A financial instrument is any contract that gives rise to a financial asset of one entity and a financial liability or equity instrument of another entity. (a) Financial assets, initial recognition and measurement and subsequent measurement The Company has no financial assets recorded at fair value through profit or loss ("FVPTL"). All assets are initially recognized initially at fair value plus transaction costs and subsequently measured at amortized cost using the effective interest method. (b) Financial liabilities, initial recognition and measurement and subsequent measurement Financial liabilities are classified as measured at amortized cost or FVTPL. The Company's warrants are classified as FVTPL and fair value gains and losses are recognized in profit or loss. Other financial liabilities are initially recognized at fair value and subsequently measured at amortized cost using the effective interest method. Interest expense and foreign exchange gains and losses are recognized in profit or loss. Any gain or loss on derecognition is also recognized in profit or loss. The Company's financial liabilities include trade and other payables, the Company's warrants and the assumed contingent liability. (c) Derivative financial instruments Derivatives are initially recognized at fair value on the date a derivative contract is entered into and are subsequently re-measured at fair value at the end of each reporting date. The Company holds one type of derivative financial instrument, the warrants, as explained in Note 2.14. The full fair value of the derivative is classified as a non-current liability when the warrants are exercisable in more than 12 months and as a current liability when the warrants are exercisable in less than 12 months. Changes in fair value of a derivative financial liability when related to a financing arrangement are recognized in the Consolidated Statement of Comprehensive Income within Finance Income or Finance Expense.
Warrants	arrants Warrants issued by the Company to investors as part of a share subscription are compound financial instruments where the warrant meets the definition of a financial liability. The financial liability component is initially measured at fair value in the Consolidated Statement of Financial Position. Equity is measured at the residual between the subscription price for the entire instrument and the liability component. The financial liability component is remeasured. Equity is not remeasured.
Short Term Investments	Short Term Investments Short term investments include fixed term deposits held at banks with original maturities between three months and a year. They are classified as loans and receivables and are measured at amortized cost using the effective interest method.
Transaction costs	Transaction costs Qualifying transaction costs might be incurred in anticipation of an issuance of equity instruments and may cross reporting periods. The entity defers these costs on the balance sheet until the equity instrument is recognized. Deferred costs are subsequently reclassified as a deduction from equity when the equity instruments are recognized, as the costs are directly attributable to the equity transaction. If the equity instruments are not subsequently issued, the transaction costs are expensed. Any costs not directly attributable to the equity transaction are expensed. Transaction costs that relate to the issue of a compound financial instrument are allocated to the liability and equity components of the instrument in proportion to the allocation of proceeds. Where the liability component is held at fair value through profit or loss, the transaction costs are expensed to the Consolidated Statement of Comprehensive Income. For liabilities held at amortized cost, transaction costs are deducted from the liability and subsequently amortized. The amount of transaction costs accounted for as a deduction from equity in the period is disclosed separately in accordance with International Accounting Standard (“IAS 1”).
Investments in subsidiaries	Investments in subsidiaries are shown at cost less any provision for impairment.
New standards, amendments and interpretations adopted by the Group	New standards, amendments and interpretations adopted by the Company The following standard has been adopted by the Company for the first time for the financial year beginning on or after January 1, 2019: ▪ IFRS 16 "Leases" The Company adopted IFRS 16 on January 1, 2019, and, as a consequence, changed its accounting policies. See note 2.17.
New standards, amendments and interpretations issued but not effective for the financial year beginning January 1, 2016 and not early adopted	New standards, amendments and interpretations issued but not effective for the financial year beginning January 1, 2019 and not early adopted There are no IFRS standards or interpretations not yet effective that would be expected to have a material impact on the Group.

Accounting policies (Tables)

Accounting policies (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of changes in accounting policies, accounting estimates and errors [Abstract]
Description of property, plant and equipment useful life	The principal annual periods used for this purpose are: Computer hardware 3 years
Disclosure of changes in accounting estimates	The following table is a summary of the restatement: Financial statement line item As reported Adjustment for the change in accounting policy As adjusted January 1, 2017 £'000s £'000s £'000s Accumulated loss 28,728 (484 ) 28,244 Intangible assets - IP R&D 1,469 484 1,953
Disclosure of additional information about leasing activities for lessee	£'000s Lease commitments (including prepayments) disclosed as at December 31, 2018 600 Less: adjustments relating to prepaid lease payments (28 ) Lease commitments as at December 31, 2018 572 Discounted using the group’s incremental borrowing rate 526 Less: short-term leases recognized on a straight-line basis as expense (210 ) Lease liability recognized as at January 1, 2019 316 The Consolidated Statement of Comprehensive Income includes the following amounts relating to leases: Year ended December 31, 2019 Year ended December 31, 2018 £'000s £'000s Depreciation charge of right-of-use assets Right-of-use assets (382 ) — (382 ) — Interest expense (including finance cost) 50 — Expense relating to short-term leases (included in general and administrative expenses) 78 —

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of detailed information about financial instruments [abstract]
Summary quantitative data about entity's exposure to risk	The summary data about the Company's exposure to currency risk is as follows. Figures are the pound sterling values of balances in each currency: December 31, 2019 December 31, 2018 GBP USD EUR GBP USD EUR £'000s £'000s £'000s £'000s £'000s £'000s Cash and cash equivalents 18,517 4,399 18 11,293 8,470 21 Short term Investments 6,316 1,507 — 19,850 25,069 — Trade and other payables 3,226 4,306 728 2,872 4,329 532
Disclosure of effect of changes in foreign exchange rates	A reasonably possible strengthening or weakening of the Euro or U.S. dollar against pounds sterling as of December 31, 2019 and 2018 would have affected the measurement of the financial instruments denominated in a foreign currency (excluding the assumed contingent liability). The following table shows how a movement in a currency would give rise to a profit or (loss) and a corresponding entry in equity. Profit or loss and equity Strengthening Weakening December 31, 2019 £'000s £'000s EUR (5% movement) (36 ) 36 USD (5% Movement) 80 (80 ) December 31, 2018 £'000s £'000s EUR (5% movement) (26 ) 26 USD (5% Movement) 1,461 (1,461 )
Disclosure of cash and cash equivalents and short term investments	As of December 31, 2019 , and December 31, 2018 , cash and cash equivalents and short term investments were placed at the following banks: Cash and Cash Equivalents Year ended December 31, 2019 Credit rating Year ended December 31, 2018 Credit rating £'000 £'000 Banks Royal Bank of Scotland 1 A1 150 A1 Lloyds Bank 8,355 Aa3 15,862 Aa3 Citibank 6,529 Aa3 3,135 A1 Barclays 1,968 A1 449 A2 Wells Fargo 111 Aa1 188 Aa1 Close Brothers 5,970 Aa3 — — Total 22,934 19,784 Short Term Investments Year ended December 31, 2019 Credit Year ended December 31, 2018 Credit £'000 £'000 Banks Royal Bank of Scotland 5,616 A1 9,186 A1 Lloyds Bank — Aa3 1,567 Aa3 Standard Chartered — A1 15,450 A1 Citibank — Aa3 7,053 A1 Barclays 2,207 A1 11,663 A2 Total 7,823 44,919
Disclosure of financial instruments by type of interest rate	he Company's exposure to interest rate risk, which is the risk that the interest received will fluctuate as a result of changes in market interest rates on classes of financial assets and financial liabilities, was as follows: December 31, 2019 December 31, 2018 Floating interest rate Fixed interest rate Floating interest rate Fixed interest rate £'000s £'000s £'000s £'000s Financial asset Cash deposits 10,006 12,928 15,082 4,702 Short Term Investments — 7,823 — 44,919 Total 10,006 20,751 15,082 49,621
Disclosure of maturity analysis of undiscounted cash outflows to repurchase derecognised financial assets or amounts payable to transferee in respect of transferred assets	The following table provides an analysis of the Company's financial liabilities. The carrying value of all balances approximates to their fair value. The Company's maturity analysis for the derivative financial instrument from the issue of warrants is given in note 18. LESS THAN 1 YEAR BETWEEN 1 AND 2 YEARS BETWEEN 2 AND 5 YEARS OVER 5 YEARS £'000s £'000s £'000s £'000s At December 31, 2019 Trade payables 1,455 — — — Accruals 6,806 — — — Lease liability 476 557 — — Assumed contingent liability (1) — — — 1,807 Total 8,737 557 — 1,807 • This table includes the undiscounted amount of the assumed contingent liability. See note 20. LESS THAN 1 YEAR BETWEEN 1 AND 2 YEARS BETWEEN 2 AND 5 YEARS OVER 5 YEARS £'000s £'000s £'000s £'000s At December 31, 2018 Trade payables 2,839 — — — Other payables 12 — — — Accruals 4,882 — — — Assumed contingent liability (1) — — — 1,807 Total 7,733 — — 1,807 (1) This table includes the undiscounted amount of the assumed contingent liability. See note 20.
Disclosure of fair value measurement of assets	Level 3 Total £'000s £'000s At December 31, 2019 Derivative financial instrument 895 895 Total 895 895
Disclosure of fair value measurement of liabilities	Level 3 Total £'000s £'000s At December 31, 2019 Derivative financial instrument 895 895 Total 895 895 2019 Derivative financial instrument £'000s At January 1 2,492 Fair value adjustments - non cash (1,597 ) At December 31 895 See note 18 for information relating to the derivative financial instrument. 2019 Lease liability £'000s At January 1 316 Capitalization of rental leases - non cash 1,061 Payment of lease liability - cash (426 ) At December 31 951
Disclosure of significant unobservable inputs used in fair value measurement of liabilities	Movements in Level 3 items during the years ended December 31, 2019 , and 2018 are as follows: Derivative financial instrument 2019 2018 £'000s £'000s At January 1 2,492 1,273 Fair value adjustments recognized in profit and loss (1,597 ) 1,219 At December 31 895 2,492

Operating loss (Tables)

Operating loss (Tables)	12 Months Ended
	Dec. 31, 2019
Analysis of income and expense [abstract]
Description of operating loss	Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Operating Loss is stated after charging / (crediting): Research and development costs: Employee benefits (note 8) 4,688 3,360 3,435 Amortization of patents (note 12) 102 85 111 Legal, professional consulting and listing fees 537 161 331 Other research and development expenses 28,149 15,688 19,840 Total research and development costs 33,476 19,294 23,717 General and administrative costs: Employee benefits (note 8) 3,093 3,240 2,857 Legal, professional consulting and listing fees 2,155 1,296 2,045 Amortization of computer software (note 12) 4 5 5 Depreciation of property, plant and equipment (note 13) 16 8 7 Depreciation of right-of-use assets (note 14) 382 — — Operating lease charge — land and buildings — 384 294 Loss / (gain) on variations in foreign exchange rate 345 (9 ) 36 Other general and administrative expenses 1,612 1,373 795 Total general and administrative costs 7,607 6,297 6,039 Operating loss 41,083 25,591 29,756

Directors' emoluments and sta_2

Directors' emoluments and staff costs (Tables)	12 Months Ended
	Dec. 31, 2019
Analysis of income and expense [abstract]
Disclosure of information about employees	Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 The average number of employees (excluding directors) of the Company during the year: Research and development 13 7 7 General and administrative 9 7 5 Total 22 14 12 Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Aggregate emoluments of directors: Salaries and other short-term employee benefits 850 830 897 Social security costs 112 94 103 Incremental payment for additional services 26 26 — Other pension costs 10 10 17 Total directors' emoluments 998 960 1,017 Share-based payment charge 925 1,337 1,037 Directors' emoluments including share-based payment charge 1,923 2,297 2,054 Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Aggregate executive officers costs: Wages and salaries 1,150 857 864 Social security costs 98 83 81 Share-based payment charge 751 769 1,332 Other pension costs 21 19 17 Total executive officers costs 2,020 1,728 2,294 Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Aggregate other staff costs: Wages and salaries 2,788 1,622 1,272 Social security costs 265 150 101 Share-based payment charge 765 795 550 Other pension costs 46 34 21 Total other staff costs 3,864 2,601 1,944

Finance income and expense (Tab

Finance income and expense (Tables)	12 Months Ended
	Dec. 31, 2019
Analysis of income and expense [abstract]
Disclosure of finance income	Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Finance income: Interest received on cash balances 754 861 345 Foreign exchange gain on translating foreign currency denominated balances — 1,922 — Fair value adjustment on derivative financial instruments (note 18) 1,597 — 6,650 Other Income — — 23 Total finance income 2,351 2,783 7,018
Disclosure of finance expense	Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Finance expense: Fair value adjustment on derivative financial instruments (note 18) — 1,219 — Interest on discounted lease liability 50 — — Foreign exchange loss on translating foreign currency denominated balances 305 — 2,392 Unwinding of discount factor related to the assumed contingent arrangement (note 20) 119 106 73 Total finance expense 474 1,325 2,465

Taxation (Tables)

Taxation (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of income tax [Abstract]
Disclosure of major tax components	Year ended December 31, 2019 Year ended December 31, 2018 Year ended December 31, 2017 £'000s £'000s £'000s Analysis of tax credit for the year Current tax: U.K. tax credit (7,250 ) (4,290 ) (5,006 ) U.S. tax charge 56 30 306 Adjustment in respect of prior periods (71 ) 28 (6 ) Total tax credit (7,265 ) (4,232 ) (4,706 ) The difference between the total tax shown above and the amount calculated by applying the standard rate of tax to the loss before tax is as follows: Factors affecting the tax credit for the year Loss on ordinary activities before taxation (39,206 ) (24,133 ) (25,203 ) Multiplied by standard rate of corporation tax of 19% (2018: 19% and 2017: 19.25%) (7,449 ) (4,585 ) (4,852 ) Effects of: Non-deductible expenses 515 540 675 Fair value adjustment on derivative financial instruments (303 ) 232 (1,280 ) Research and development incentive (3,119 ) (1,846 ) (2,116 ) Temporary differences not recognized (6 ) (3 ) (2 ) Difference in overseas tax rates 16 8 136 Tax losses carried forward not recognized 3,152 1,394 2,739 Adjustment in respect of prior periods (71 ) 28 (6 ) Total tax credit (7,265 ) (4,232 ) (4,706 )
Disclosure of temporary difference, unused tax losses and unused tax credits	The following tables represent deferred tax balances recognized in the Consolidated Statement of Financial Position. There were no movements in either the deferred tax asset or the deferred tax liability. As at December 31, 2019 As at December 31, 2018 £'000s £'000s Deferred tax assets 332 250 Deferred tax liabilities (332 ) (250 ) Net balances — —

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of detailed information about intangible assets [abstract]
Disclosure of reconciliation of changes in goodwill	As of December 31, 2019 As of December 31, 2018 £'000s £'000s Goodwill at January 1 and December 31 441 441

Intangible assets (Tables)

Intangible assets (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of detailed information about intangible assets [abstract]
Disclosure of reconciliation of changes in intangible assets and goodwill	IP R&D Computer software Patents Total £'000s £'000s £'000s £'000s Cost At January 1, 2018 (Restated) 1,953 11 727 2,691 Additions — 4 251 255 Disposals — — (6 ) (6 ) At December 31, 2018 (Restated) 1,953 15 972 2,940 Accumulated amortization At January 1, 2018 — 6 232 238 Charge for year — 5 85 90 Disposals — — (6 ) (6 ) At December 31, 2018 — 11 311 322 Net book value At December 31, 2018 (Restated) 1,953 4 661 2,618 IP R&D Computer software Patents Total £'000s £'000s £'000s £'000s Cost At January 1, 2019 1,953 15 972 2,940 Additions — 3 242 245 At December 31, 2019 1,953 18 1,214 3,185 Accumulated amortization At January 1, 2019 — 11 311 322 Charge for year — 4 102 106 At December 31, 2019 — 15 413 428 Net book value At December 31, 2019 1,953 3 801 2,757

Property, plant and equipment (

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of detailed information about property, plant and equipment [abstract]
Disclosure of detailed information about property, plant and equipment	Computer hardware Total £'000s £'000s Cost At January 1, 2018 26 26 Additions 13 13 At December 31, 2018 39 39 Accumulated depreciation At January 1, 2018 10 10 Charge for the year 8 8 At December 31, 2018 18 18 Net book value At December 31, 2018 21 21 Computer hardware Total £'000s £'000s Cost At January 1, 2019 39 39 Additions 38 38 At December 31, 2019 77 77 Accumulated depreciation At January 1, 2019 18 18 Charge for the year 16 16 At December 31, 2019 34 34 Net book value At December 31, 2019 43 43

Right-of-use assets - propert_2

Right-of-use assets - property leases Right-of-use assets - property leases (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of leases [Abstract]
Disclosure of quantitative information about right-of-use assets	The Consolidated Statement of Financial Position shows the following amounts relating to leases: Year ended December 31, 2019 As of January 1, 2019* £'000s £'000s Right-of-use assets Right-of-use assets 971 326 971 326 Lease liabilities Current (460 ) (316 ) Non Current (491 ) — (951 ) (316 )
Disclosure of additional information about leasing activities for lessee	£'000s Lease commitments (including prepayments) disclosed as at December 31, 2018 600 Less: adjustments relating to prepaid lease payments (28 ) Lease commitments as at December 31, 2018 572 Discounted using the group’s incremental borrowing rate 526 Less: short-term leases recognized on a straight-line basis as expense (210 ) Lease liability recognized as at January 1, 2019 316 The Consolidated Statement of Comprehensive Income includes the following amounts relating to leases: Year ended December 31, 2019 Year ended December 31, 2018 £'000s £'000s Depreciation charge of right-of-use assets Right-of-use assets (382 ) — (382 ) — Interest expense (including finance cost) 50 — Expense relating to short-term leases (included in general and administrative expenses) 78 —

Prepayments and other receiva_2

Prepayments and other receivables (Tables)	12 Months Ended
	Dec. 31, 2019
Subclassifications of assets, liabilities and equities [abstract]
Description of prepayments and other receivables	As of December 31, 2019 As of December 31, 2018 £'000s £'000s Prepayments 1,309 1,362 Other receivables 1,461 1,101 Total prepayments and other receivables 2,770 2,463

Share Capital (Tables)

Share Capital (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of share capital, reserves and other equity interest [Abstract]
Movements in the Company's share capital	The movements in the Company's share capital are summarized below: Date Description Number of shares Share Capital amounts in £'000s January 1, 2018 105,017,401 5,251 August 9, 2018 Vesting of RSUs 58,112 3 September 20, 2018 Vesting of RSUs 251,125 12 As at December 31, 2018 105,326,638 5,266 As at December 31, 2019 105,326,638 5,266

Share-based payments charge (Ta

Share-based payments charge (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of share-based payment arrangements [Abstract]
Disclosure of indirect measurement of fair value of goods or services received, share options granted during period	The following assumptions were used for the Black-Scholes valuation of share options and RSUs granted in 2018 and 2019 . For the options granted under the Unapproved Scheme the table indicates the ranges used in determining the fair-market values, aligning with the various dates of the underlying grants. The volatility is calculated using historical weekly averages of the Company's share price over a period that is in line with the expected life of the options and RSUs. Issued in 2018 Unapproved Restricted Stock Units Options granted 2,090,847 273,390 Risk-free interest rate 1.08% - 1.22% 1.08% - 1.22% Expected life of options 5.5 - 7 years 5.5 - 7 years Annualized volatility 69.88% -71.35% 69.88% -71.35% Dividend rate 0.00 % 0.00 % Vesting period 1 to 4 years 1 to 4 years Issued in 2019 Unapproved Restricted Stock Units Options granted 5,569,050 740,496 Risk-free interest rate 0.39% - 0.82% 0.76% - 0.82% Expected life of options 5.5 - 7 years 5.5 - 7 years Annualized volatility 67.98% - 69.71% 63.82% - 69.71% Dividend rate 0.00 % 0.00 % Vesting period 1 to 4 years 1 to 4 years
Disclosure of number and weighted average exercise prices of share options	Outstanding and exercisable share options by scheme as of December 31, 2019 : Plan Outstanding Exercisable Weighted average exercise price in £ for Outstanding Weighted average exercise price in £ for Exercisable Unapproved 13,965,212 5,552,293 1.12 1.55 EMI 213,984 213,984 3.06 3.06 Total 14,179,196 5,766,277 1.15 1.61 As of December 31, 2019 there were no restricted share options exercisable ( 2018 : nil ) and there is no exercise price for restricted share options. The options outstanding at December 31, 2019 had a weighted average remaining contractual life of 7.7 years ( 2018 : 8.0 years ). For 2018 and 2019 , the number of options granted and expired and the weighted average exercise price of options were as follows: Number of options Weighted average exercise price (£) At January 1, 2018 7,527,458 1.53 Options granted in 2018: Employees 1,222,089 1.46 Directors 868,758 1.46 Options forfeited in the year (799,524 ) 1.43 Options expired in the year (66,667 ) 1.75 At December 31, 2018 8,752,114 1.53 Exercisable at December 31, 2018 3,542,884 1.66 Number of options Weighted average exercise price (£) At January 1, 2019 8,752,114 1.53 Options granted in 2019: Employees 4,042,106 0.55 Directors 1,526,944 0.53 Options forfeited in the year (121,970 ) 0.82 Options expired in the year (19,998 ) 2.00 At December 31, 2019 14,179,196 1.15 Exercisable at December 31, 2019 5,766,277 1.60 The Company had the following share options movements in the year ended December 31, 2019 : Year of issue Exercise At January 1, 2019 Options granted Options forfeited Options expired At December 31, 2019 Expiry date 2012 2.50 - 7.50 99,993 — — — 99,993 June 1, 2022 2013 2 99,990 — — (19,998 ) 79,992 April 15, 2023 2013 2.00 159,999 — — — 159,999 July 29, 2023 2014 1.75 109,998 — — — 109,998 May 15, 2024 2014 1.75 49,998 — — — 49,998 May 15, 2024 * 2015 1.25 41,997 — — — 41,997 January 29, 2025 * 2015 1.25 549,999 — — — 549,999 January 29, 2025 2016 2 240,000 — — — 240,000 February 2, 2026 2016 2.00 21,996 — — — 21,996 February 2, 2026 * 2016 1.80 676,664 — — — 676,664 August 3, 2026 2016 1.89 299,997 — — — 299,997 September 13, 2026 2016 2.04 300,000 — — — 300,000 September 16, 2026 2017 1.32 - 1.525 4,093,164 — — — 4,093,164 April 26, 2027 2018 1.46 2,008,319 — (34,614 ) — 1,973,705 March 8, 2028 2019 570.00 — 3,903,050 (87,356 ) — 3,815,694 March 29, 2029 2019 595.00 — 346,000 — — 346,000 June 11, 2029 2019 457.00 — 100,000 — — 100,000 August 22, 2029 2019 0.436 — 720,000 — — 720,000 November 6, 2029 2019 445.00 — 500,000 — — 500,000 November 26, 2029 Total 8,752,114 5,569,050 (121,970 ) (19,998 ) 14,179,196 * Options granted under the EMI Scheme.
Disclosure of number and weighted average exercise prices of other equity instruments	The Company had the following RSU movements in the year ended December 31, 2019 : Year of issue Exercise At January 1, 2019 Units Units Units At December 31, 2019 Expiry date 2017 729,987 — — — 729,987 April 26, 2027 2018 132,486 — — — 132,486 March 8, 2028 2019 740,496 — — 740,496 March 29, 2027 Total 862,473 740,496 — — 1,602,969 The following table shows the number of RSUs issued, exercised and forfeited in 2018. The fair value of each unvested RSU at grant date was £1.46 . Number of At January 1, 2018 1,052,236 Granted: Employees 136,404 Directors 136,986 RSUs vested in the year (309,237 ) RSUs forfeited in the year (153,916 ) At December 31, 2018 862,473 The following table shows the number of RSUs issued in 2019. There were no RSUs forfeited, canceled or vested in 2019. The fair value of each unvested RSU granted in 2019 was £0.57 . Number of At January 1, 2019 862,473 Granted: Employees 474,072 Directors 266,424 RSUs vested in the year — RSUs forfeited in the year — At December 31, 2019 1,602,969

Warrants (Tables)

Warrants (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of share capital, reserves and other equity interest [Abstract]
Disclosure of indirect measurement of fair value of goods or services received, other equity instruments granted during period	The table below presents the assumptions in applying the Black-Scholes model to determine the fair value of the warrants. As of December 31, 2019 As of December 31, 2018 Shares available to be issued under warrants 12,401,262 12,401,262 Exercise price £ 1.7238 £ 1.7238 Risk-free interest rate 0.540 % 0.760 % Expected term to exercise 2.34 years 3.34 years Annualized volatility 65.56 % 60.72 % Dividend rate 0.00 % 0.00 % Derivative financial instrument Derivative financial instrument 2019 2018 £'000s £'000s At January 1 2,492 1,273 Fair value adjustments recognized in profit or loss (1,597 ) 1,219 At December 31 895 2,492 For the amount recognized at December 31, 2019 , the effect when the following parameter deviates up or down is presented in the below table. Volatility (up / down 10% pts) £'000s Variable up 1,306 Base case, reported fair value 895 Variable down 535

Trade and other payables (Table

Trade and other payables (Tables)	12 Months Ended
	Dec. 31, 2019
Subclassifications of assets, liabilities and equities [abstract]
Disclosure of trade and other payables	As of December 31, 2019 As of December 31, 2018 £'000s £'000s Trade payables 1,455 2,839 Other payables — 12 Accruals 6,806 4,882 Total trade and other payables 8,261 7,733

Assumed contingent obligation_2

Assumed contingent obligation related to the business combination (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of other provisions, contingent liabilities and contingent assets [Abstract]
Disclosure of contingent liabilities in business combination	Re-measurements relating to changes in estimated cash flows and pr

General information (Details)

General information (Details)	12 Months Ended
	Dec. 31, 2019subsidiary
Disclosure of notes and other explanatory information [Abstract]
Number of subsidiaries	2

Accounting policies - Going con

Accounting policies - Going concern (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2017
Disclosure of changes in accounting policies, accounting estimates and errors [Abstract]
Loss for the year	£ (31,941)	£ (19,901)	£ (20,497)
Accumulated loss	£ (100,627)	£ (68,633)		£ (28,244)

Accounting policies - Descripti

Accounting policies - Description of property, plant and equipment useful life (Details)	12 Months Ended
	Dec. 31, 2019
Computer hardware
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment life	3 years

Accounting policies - Intangibl

Accounting policies - Intangible assets and goodwill (Details)	12 Months Ended
	Dec. 31, 2019
Patents
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives	10 years
Computer software
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives	2 years

Accounting policies - Assumed c

Accounting policies - Assumed contingent obligation related to the business combinations (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2006
Disclosure of detailed information about business combination [line items]
Payments of lease liabilities, classified as financing activities	£ 426
Rhinopharma Limited
Disclosure of detailed information about business combination [line items]
Effective interest rate		12.00%

Accounting policies - Change in

Accounting policies - Change in accounting policy narrative (Details) - GBP (£) £ in Thousands	Jan. 01, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2017
Disclosure of contingent liabilities in business combination [line items]
Accumulated loss		£ 100,627	£ 68,633			£ 28,244
Right-of-use assets	£ 326	971
Lease liabilities	316	£ 951
Adjustments relating to prepaid lease payments			28
Weighted average lessee's incremental borrowing rate applied to lease liabilities recognised at date of initial application of IFRS 16		8.00%
Payments of lease liabilities, classified as financing activities		£ 426
General and administrative expense		(7,607)	(6,297)	£ (6,039)
Finance expense		474	£ 1,325	£ 2,465
Additions to right-of-use assets		£ 1,047
Increase (decrease) due to changes in accounting policy [member]
Disclosure of contingent liabilities in business combination [line items]
Accumulated loss	20					£ (484)
Lease liabilities	316
General and administrative expense	123
Finance expense	£ 50
Rhinopharma Limited
Disclosure of contingent liabilities in business combination [line items]
Measurement period adjustments recognised for particular assets, liabilities, non-controlling interests or items of consideration					£ 484

Accounting policies - Accountin

Accounting policies - Accounting restatement (Details) - GBP (£) £ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2017
Disclosure of changes in accounting estimates [line items]
Accumulated loss	£ 100,627		£ 68,633	£ 28,244
Intangible assets other than goodwill	2,757		2,618
IP R&D
Disclosure of changes in accounting estimates [line items]
Intangible assets other than goodwill	£ 1,953		£ 1,953	1,953
Previously stated [member]
Disclosure of changes in accounting estimates [line items]
Accumulated loss				28,728
Previously stated [member] | IP R&D
Disclosure of changes in accounting estimates [line items]
Intangible assets other than goodwill				1,469
Increase (decrease) due to changes in accounting policy [member]
Disclosure of changes in accounting estimates [line items]
Accumulated loss		£ 20		(484)
Increase (decrease) due to changes in accounting policy [member] | IP R&D
Disclosure of changes in accounting estimates [line items]
Intangible assets other than goodwill				£ 484

Accounting policies - Adjustmen

Accounting policies - Adjustment for lease pronouncement (Details) - GBP (£) £ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Disclosure of changes in accounting policies, accounting estimates and errors [Abstract]
Lease commitments (including prepayments) disclosed as at December 31, 2018			£ 600
Less: adjustments relating to prepaid lease payments			(28)
Discounted using the group’s incremental borrowing rate			£ 572
Discounted using the group’s incremental borrowing rate		£ 526
Less: short-term leases recognized on a straight-line basis as expense		(210)
Lease liability recognized as at January 1, 2019	£ 951	£ 316

Accounting policies - New stand

Accounting policies - New standards, amendments and interpretations issued but not effective (Details) - GBP (£) £ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Disclosure of changes in accounting policies, accounting estimates and errors [Abstract]
Lease liabilities	£ 951	£ 316
Right-of-use assets	£ 971	£ 326

Financial Instruments - Summary

Financial Instruments - Summary quantitative data about entity's exposure to risk (Details) - Currency risk - GBP (£) £ in Thousands	Dec. 31, 2019	Dec. 31, 2018
GBP | Cash and cash equivalents
Disclosure of credit risk exposure [line items]
Cash deposits	£ 18,517	£ 11,293
GBP | Short Term Investments
Disclosure of credit risk exposure [line items]
Cash deposits	6,316	19,850
GBP | Trade and other payables
Disclosure of credit risk exposure [line items]
Cash deposits	3,226	2,872
USD | Cash and cash equivalents
Disclosure of credit risk exposure [line items]
Cash deposits	4,399	8,470
USD | Short Term Investments
Disclosure of credit risk exposure [line items]
Cash deposits	1,507	25,069
USD | Trade and other payables
Disclosure of credit risk exposure [line items]
Cash deposits	4,306	4,329
EUR | Cash and cash equivalents
Disclosure of credit risk exposure [line items]
Cash deposits	18	21
EUR | Short Term Investments
Disclosure of credit risk exposure [line items]
Cash deposits	0	0
EUR | Trade and other payables
Disclosure of credit risk exposure [line items]
Cash deposits	£ 728	£ 532

Financial Instruments - Disclos

Financial Instruments - Disclosure of effect of changes in foreign exchange rates [text block] (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
EUR | Strengthening
Disclosure of credit risk exposure [line items]
Profit or loss and equity	£ (36)	£ (26)
EUR | Weakening
Disclosure of credit risk exposure [line items]
Profit or loss and equity	36	26
USD | Strengthening
Disclosure of credit risk exposure [line items]
Profit or loss and equity	80	1,461
USD | Weakening
Disclosure of credit risk exposure [line items]
Profit or loss and equity	£ (80)	£ (1,461)

Financial Instruments - Narrati

Financial Instruments - Narrative (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of fair value measurement of assets [line items]
Cash deposits	£ 22,934	£ 19,784	£ 31,443	£ 39,785
Short-term deposits, not classified as cash equivalents	£ 7,823	44,919
Increase in interest rates	0.25%
Bottom of range
Disclosure of fair value measurement of assets [line items]
Trade payable term	30 days
Rates of interest	0.00%
Top of range
Disclosure of fair value measurement of assets [line items]
Trade payable term	45 days
Rates of interest	2.87%
Derivative financial instrument
Disclosure of fair value measurement of assets [line items]
Gains (losses) recognised in profit or loss including exchange differences, fair value measurement, liabilities	£ 1,597
Derivative financial instrument | Level 3
Disclosure of fair value measurement of assets [line items]
Gains (losses) recognised in profit or loss including exchange differences, fair value measurement, liabilities	£ (1,597)	£ 1,219

Financial Instruments - Discl_2

Financial Instruments - Disclosure Of Detailed Information About Cash And Cash Equivalents Placement Explanatory (Details) - GBP (£) £ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of financial assets [line items]
Cash and cash equivalents	£ 22,934	£ 19,784	£ 31,443	£ 39,785
Short term investments	7,823	44,919
Royal Bank of Scotland
Disclosure of financial assets [line items]
Cash and cash equivalents	1	150
Short term investments	5,616	9,186
Lloyds Bank
Disclosure of financial assets [line items]
Cash and cash equivalents	8,355	15,862
Short term investments	0	1,567
Standard Chartered
Disclosure of financial assets [line items]
Short term investments	0	15,450
Citibank
Disclosure of financial assets [line items]
Cash and cash equivalents	6,529	3,135
Short term investments	0	7,053
Barclays
Disclosure of financial assets [line items]
Cash and cash equivalents	1,968	449
Short term investments	2,207	11,663
Wells Fargo
Disclosure of financial assets [line items]
Cash and cash equivalents	111	188
Close Brothers
Disclosure of financial assets [line items]
Cash and cash equivalents	£ 5,970	£ 0

Financial Instruments - Discl_3

Financial Instruments - Disclosure of financial instruments by type of interest rate (Details) - GBP (£) £ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Disclosure of financial instruments by type of interest rate [line items]
Short-term deposits, not classified as cash equivalents	£ 7,823	£ 44,919
Interest rate risk | Floating interest rate
Disclosure of financial instruments by type of interest rate [line items]
Cash deposits	10,006	15,082
Interest rate risk | Fixed Interest rate
Disclosure of financial instruments by type of interest rate [line items]
Cash deposits	20,751	49,621
Cash deposits | Interest rate risk | Floating interest rate
Disclosure of financial instruments by type of interest rate [line items]
Cash deposits	10,006	15,082
Cash deposits | Interest rate risk | Fixed Interest rate
Disclosure of financial instruments by type of interest rate [line items]
Cash deposits	12,928	4,702
Short Term Investments | Interest rate risk | Floating interest rate
Disclosure of financial instruments by type of interest rate [line items]
Cash deposits	0	0
Short Term Investments | Interest rate risk | Fixed Interest rate
Disclosure of financial instruments by type of interest rate [line items]
Cash deposits	£ 7,823	£ 44,919

Financial Instruments - Discl_4

Financial Instruments - Disclosure of maturity analysis of undiscounted cash outflows to repurchase derecognised financial assets or amounts payable to transferee in respect of transferred assets (Details) - Liquidity risk - GBP (£) £ in Thousands	Dec. 31, 2019	Dec. 31, 2018
LESS THAN 1 YEAR
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	£ 8,737	£ 7,733
BETWEEN 1 AND 2 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	557	0
BETWEEN 2 AND 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0	0
OVER 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	1,807	1,807
Trade payables | LESS THAN 1 YEAR
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	1,455	2,839
Trade payables | BETWEEN 1 AND 2 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0	0
Trade payables | BETWEEN 2 AND 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0	0
Trade payables | OVER 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0	0
Other payables | LESS THAN 1 YEAR
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows		12
Other payables | BETWEEN 1 AND 2 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows		0
Other payables | BETWEEN 2 AND 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows		0
Other payables | OVER 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows		0
Accruals | LESS THAN 1 YEAR
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	6,806	4,882
Accruals | BETWEEN 1 AND 2 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0	0
Accruals | BETWEEN 2 AND 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0	0
Accruals | OVER 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0	0
Lease liability | LESS THAN 1 YEAR
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	476
Lease liability | BETWEEN 1 AND 2 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	557
Lease liability | BETWEEN 2 AND 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0
Lease liability | OVER 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0
Assumed contingent liability(1) | LESS THAN 1 YEAR
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0	0
Assumed contingent liability(1) | BETWEEN 1 AND 2 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0	0
Assumed contingent liability(1) | BETWEEN 2 AND 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	0	0
Assumed contingent liability(1) | OVER 5 YEARS
Disclosure of financial liabilities [line items]
Trade and other payables, undiscounted cash flows	£ 1,807	£ 1,807

Financial Instruments - Discl_5

Financial Instruments - Disclosure of fair value measurement of assets and liabilities (Details) - Derivative financial instrument - GBP (£) £ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of fair value measurement of assets [line items]
Financial assets	£ 895	£ 2,492
Level 3
Disclosure of fair value measurement of assets [line items]
Financial assets	£ 895	£ 2,492	£ 1,273

Financial Instruments - Discl_6

Financial Instruments - Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities (Details) - Derivative financial instrument - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of changes in fair value measurement, liabilities [abstract]
Beginning balance	£ 2,492
Fair value adjustments recognized in profit and loss	1,597
Ending balance	895	£ 2,492
Level 3
Reconciliation of changes in fair value measurement, liabilities [abstract]
Beginning balance	2,492	1,273
Fair value adjustments recognized in profit and loss	(1,597)	1,219
Ending balance	£ 895	£ 2,492

Financial Instruments - Change

Financial Instruments - Change in liabilities arising from financing activities (Details) £ in Thousands	12 Months Ended
	Dec. 31, 2019GBP (£)
Changes in fair value measurement, liabilities [abstract]
Payment of lease liability - cash	£ (426)
Derivative financial instrument
Changes in fair value measurement, liabilities [abstract]
Beginning balance	2,492
Fair value adjustments - non cash	(1,597)
Ending balance	895
Lease liability
Changes in fair value measurement, liabilities [abstract]
Beginning balance	316
Capitalization of rental leases - non cash	1,061
Payment of lease liability - cash	(426)
Ending balance	£ 951

Critical accounting estimates_2

Critical accounting estimates and judgments (Details) £ / shares in Units, £ in Thousands	6 Months Ended
	Jun. 30, 2020GBP (£)	Dec. 31, 2019GBP (£)shares	Dec. 31, 2018GBP (£)shares	Dec. 31, 2017GBP (£)	Jul. 31, 2016shareswarrant	Jul. 29, 2016shareswarrant£ / shares
Disclosure of detailed information about business combination [line items]
Assumed contingent liability | £		£ 1,103	£ 996	£ 875
Number of units issued (in shares) | shares					31,115,926	31,115,926
Placing price (in pounds per unit) | £ / shares						£ 1.4365
Number of ordinary shares (in shares) | shares					1	1
Number warrants (in warrants) | warrant					1	1
Warrants
Disclosure of detailed information about business combination [line items]
Number of shares subscribed from warrant maximum (in shares) | shares		12,401,262	12,401,262
Bottom of range | Forecast
Disclosure of detailed information about business combination [line items]
Increase (decrease) in contingent liabilities recognised in business combination | £	£ 15,000
Top of range | Forecast
Disclosure of detailed information about business combination [line items]
Increase (decrease) in contingent liabilities recognised in business combination | £	£ 30,000

Earnings per share (Details)

Earnings per share (Details) - £ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of earnings per share [Abstract]
Loss per ordinary share — basic and diluted (pence per share)	£ (30.3)	£ (18.9)	£ (23.4)
Basic earnings (loss) per share (per share)	£ (0.303)	£ (0.189)	£ (0.234)
Weighted average number of ordinary shares (in shares)	105,326,638	105,110,504	87,748,031

Segmental reporting (Details)

Segmental reporting (Details)	12 Months Ended
	Dec. 31, 2019segment
Disclosure of entity's operating segments [Abstract]
Number of operating and reportable segments	1

Operating loss - Description Of

Operating loss - Description Of Operating Loss (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Research and development costs:
Total research and development costs	£ 33,476	£ 19,294	£ 23,717
General and administrative costs:
Depreciation of right-of-use assets (note 14)	382	0
Loss / (gain) on variations in foreign exchange rate	(8)	0	0
Total general and administrative costs	7,607	6,297	6,039
Operating loss	41,083	25,591	29,756
Research and development costs
Research and development costs:
Employee benefits (note 8)	4,688	3,360	3,435
Legal, professional consulting and listing fees	537	161	331
Other research and development expenses	28,149	15,688	19,840
Total research and development costs	33,476	19,294	23,717
General and administrative costs:
Employee benefits (note 8)	4,688	3,360	3,435
Legal, professional consulting and listing fees	537	161	331
Research and development costs | Patents
Research and development costs:
Amortization	102	85	111
General and administrative costs:
Amortization	102	85	111
General and administrative costs
Research and development costs:
Employee benefits (note 8)	3,093	3,240	2,857
Legal, professional consulting and listing fees	2,155	1,296	2,045
General and administrative costs:
Employee benefits (note 8)	3,093	3,240	2,857
Legal, professional consulting and listing fees	2,155	1,296	2,045
Depreciation of property, plant and equipment (note 13)	16	8	7
Depreciation of right-of-use assets (note 14)	382
Operating lease charge — land and buildings		384	294
Loss / (gain) on variations in foreign exchange rate	345	(9)	36
Other general and administrative expenses	1,612	1,373	795
Total general and administrative costs	7,607	6,297	6,039
Operating loss	41,083	25,591	29,756
General and administrative costs | Computer software
Research and development costs:
Amortization	4	5	5
General and administrative costs:
Amortization	£ 4	£ 5	£ 5

Directors' emoluments and sta_3

Directors' emoluments and staff costs (Details)	12 Months Ended
	Dec. 31, 2019GBP (£)employee	Dec. 31, 2018GBP (£)employee	Dec. 31, 2017GBP (£)employee
Disclosure of transactions between related parties [line items]
The average number of employees (excluding directors) of the Company during the year: | employee	22	14	12
Aggregate emoluments of directors:
Share-based payment charge	£ 2,440,000	£ 2,900,000
Aggregate other staff costs:
Share-based payment charge	2,440,000	2,900,000
Post-employment benefit expense, defined contribution plans	77,000	63,000	£ 55,000
Prepaid or accrued contributions	0	0	0
Directors
Aggregate emoluments of directors:
Salaries and other short-term employee benefits	850,000	830,000	897,000
Social security costs	112,000	94,000	103,000
Incremental payment for additional services	26,000	26,000	0
Other pension costs	10,000	10,000	17,000
Total directors' emoluments	998,000	960,000	1,017,000
Share-based payment charge	925,000	1,337,000	1,037,000
Directors' emoluments including share-based payment charge	1,923,000	2,297,000	2,054,000
Aggregate other staff costs:
Social security costs	112,000	94,000	103,000
Share-based payment charge	925,000	1,337,000	1,037,000
Other pension costs	10,000	10,000	17,000
Executive Officers
Aggregate emoluments of directors:
Social security costs	98,000	83,000	81,000
Other pension costs	21,000	19,000	17,000
Share-based payment charge	751,000	769,000	1,332,000
Aggregate other staff costs:
Wages and salaries	1,150,000	857,000	864,000
Social security costs	98,000	83,000	81,000
Share-based payment charge	751,000	769,000	1,332,000
Other pension costs	21,000	19,000	17,000
Total other staff costs	2,020,000	1,728,000	2,294,000
Other Staff
Aggregate emoluments of directors:
Social security costs	265,000	150,000	101,000
Other pension costs	46,000	34,000	21,000
Share-based payment charge	765,000	795,000	550,000
Aggregate other staff costs:
Wages and salaries	2,788,000	1,622,000	1,272,000
Social security costs	265,000	150,000	101,000
Share-based payment charge	765,000	795,000	550,000
Other pension costs	46,000	34,000	21,000
Total other staff costs	£ 3,864,000	£ 2,601,000	£ 1,944,000
Research and development
Disclosure of transactions between related parties [line items]
The average number of employees (excluding directors) of the Company during the year: | employee	13	7	7
General and administrative
Disclosure of transactions between related parties [line items]
The average number of employees (excluding directors) of the Company during the year: | employee	9	7	5

Finance income and expense (Det

Finance income and expense (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finance income:
Interest received on cash balances	£ 754	£ 861	£ 345
Foreign exchange gain on translating foreign currency denominated balances	0	1,922	0
Fair value adjustment on derivative financial instruments (note 18)	1,597	0	6,650
Other Income	0	0	23
Total finance income	2,351	2,783	7,018
Finance expense:
Fair value adjustment on derivative financial instruments (note 18)	0	1,219	0
Interest on discounted lease liability	50	0	0
Foreign exchange loss on translating foreign currency denominated balances	305	0	2,392
Unwinding of discount factor related to the assumed contingent arrangement (note 20)	119	106	73
Total finance expense	£ 474	£ 1,325	£ 2,465

Taxation - Disclosure of major

Taxation - Disclosure of major components of tax expense (income) (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current tax:
Adjustment in respect of prior periods	£ (71)	£ 28	£ (6)
Total tax credit	(7,265)	(4,232)	(4,706)
Factors affecting the tax credit for the year
Loss on ordinary activities before taxation	(39,206)	(24,133)	(25,203)
Multiplied by standard rate of corporation tax of 19% (2018: 19% and 2017: 19.25%)	£ (7,449)	£ (4,585)	£ (4,852)
Standard rate of corporation tax	19.00%	19.00%	19.25%
Effects of:
Non-deductible expenses	£ 515	£ 540	£ 675
Fair value adjustment on derivative financial instruments	(303)	232	(1,280)
Research and development incentive	(3,119)	(1,846)	(2,116)
Temporary differences not recognized	(6)	(3)	(2)
Difference in overseas tax rates	16	8	136
Tax losses carried forward not recognized	3,152	1,394	2,739
Adjustment in respect of prior periods	(71)	28	(6)
Total tax credit	(7,265)	(4,232)	(4,706)
UK
Current tax:
U.K. tax credit	(7,250)	(4,290)	(5,006)
US
Current tax:
U.K. tax credit	£ 56	£ 30	£ 306
Factors affecting the tax credit for the year
Standard rate of corporation tax	27.60%	27.60%	35.00%

Taxation - Narrative (Details)

Taxation - Narrative (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Standard rate of corporation tax	19.00%	19.00%	19.25%
Unrecognized deferred tax asset percent	17.00%	17.00%
Unrecognized deferred tax asset	£ 9,270	£ 6,650
U.S. federal tax
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Standard rate of corporation tax	27.60%	27.60%	35.00%

Taxation - Disclosure of tempor

Taxation - Disclosure of temporary difference, unused tax losses and unused tax credits (Details) - GBP (£) £ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Disclosure of income tax [Abstract]
Deferred tax assets	£ 332	£ 250
Deferred tax liabilities	(332)	(250)
Net balances	£ 0	£ 0

Goodwill (Details)

Goodwill (Details) - GBP (£)	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2017
Disclosure of detailed information about intangible assets [abstract]
Goodwill at January 1 and December 31	£ 441,000		£ 441,000
Market capitalization	65,300,000		92,200,000
Equity attributable to owners of parent	33,865,000	£ 63,398,000	£ 63,418,000	£ 80,365,000	£ 34,953,000
Impairment loss recognised in profit or loss, intangible assets other than goodwill	£ 0

Intangible assets - Disclosure

Intangible assets - Disclosure of reconciliation of changes in intangible assets and goodwill (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about intangible assets [line items]
Beginning balance	£ 2,618
Ending balance	2,757	£ 2,618
Cost
Disclosure of detailed information about intangible assets [line items]
Beginning balance	2,940	2,691
Additions	245	255
Disposals		(6)
Ending balance	3,185	2,940
Accumulated depreciation
Disclosure of detailed information about intangible assets [line items]
Beginning balance	322	238
Disposals		(6)
Charge for year	106	90
Ending balance	428	322
IP R&D
Disclosure of detailed information about intangible assets [line items]
Beginning balance	1,953
Ending balance	1,953	1,953
IP R&D | Cost
Disclosure of detailed information about intangible assets [line items]
Beginning balance	1,953	1,953
Additions	0	0
Disposals		0
Ending balance	1,953	1,953
Computer software
Disclosure of detailed information about intangible assets [line items]
Beginning balance	4
Ending balance	3	4
Computer software | Cost
Disclosure of detailed information about intangible assets [line items]
Beginning balance	15	11
Additions	3	4
Disposals		0
Ending balance	18	15
Computer software | Accumulated depreciation
Disclosure of detailed information about intangible assets [line items]
Beginning balance	11	6
Disposals		0
Charge for year	4	5
Ending balance	15	11
Patents
Disclosure of detailed information about intangible assets [line items]
Beginning balance	661
Ending balance	801	661
Patents | Cost
Disclosure of detailed information about intangible assets [line items]
Beginning balance	972	727
Additions	242	251
Disposals		(6)
Ending balance	1,214	972
Patents | Accumulated depreciation
Disclosure of detailed information about intangible assets [line items]
Beginning balance	311	232
Disposals		(6)
Charge for year	102	85
Ending balance	£ 413	£ 311

Intangible assets - Narrative (

Intangible assets - Narrative (Details) - GBP (£)	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2017
Disclosure of detailed information about intangible assets [line items]
Market capitalization	£ 65,300,000		£ 92,200,000
Net assets	33,865,000	£ 63,398,000	£ 63,418,000	£ 80,365,000	£ 34,953,000
Impairment	£ 0
Patents
Disclosure of detailed information about intangible assets [line items]
Amortization period	10 years

Property, plant and equipment_2

Property, plant and equipment (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cost
Property, plant and equipment beginning balance	£ 21
Property, plant and equipment ending balance	43	£ 21
Accumulated depreciation
Property, plant and equipment beginning balance	21
Property, plant and equipment ending balance	43	21
Net book value
Property plant and equipment	43	21
Cost
Cost
Property, plant and equipment beginning balance	39	26
Additions	38	13
Property, plant and equipment ending balance	77	39
Accumulated depreciation
Property, plant and equipment beginning balance	39	26
Property, plant and equipment ending balance	77	39
Net book value
Property plant and equipment	77	39
Accumulated depreciation
Cost
Property, plant and equipment beginning balance	18	10
Property, plant and equipment ending balance	34	18
Accumulated depreciation
Property, plant and equipment beginning balance	18	10
Charge for the year	16	8
Property, plant and equipment ending balance	34	18
Net book value
Property plant and equipment	34	18
Computer hardware
Cost
Property, plant and equipment beginning balance	21
Property, plant and equipment ending balance	43	21
Accumulated depreciation
Property, plant and equipment beginning balance	21
Property, plant and equipment ending balance	43	21
Net book value
Property plant and equipment	43	21
Computer hardware | Cost
Cost
Property, plant and equipment beginning balance	39	26
Additions	38	13
Property, plant and equipment ending balance	77	39
Accumulated depreciation
Property, plant and equipment beginning balance	39	26
Property, plant and equipment ending balance	77	39
Net book value
Property plant and equipment	77	39
Computer hardware | Accumulated depreciation
Cost
Property, plant and equipment beginning balance	18	10
Property, plant and equipment ending balance	34	18
Accumulated depreciation
Property, plant and equipment beginning balance	18	10
Charge for the year	16	8
Property, plant and equipment ending balance	34	18
Net book value
Property plant and equipment	£ 34	£ 18

Right-of-use assets - propert_3

Right-of-use assets - property leases - Additional Information (Details) £ in Thousands	12 Months Ended
	Dec. 31, 2019GBP (£)
Disclosure of leases [Abstract]
Additions to right-of-use assets	£ 1,047
Weighted average lessee's incremental borrowing rate applied to lease liabilities recognised at date of initial application of IFRS 16	8.00%
Cash outflow for leases	£ 492

Right-of-use assets - propert_4

Right-of-use assets - property leases - Statement of financial position, Right-of-use Asset (Details) - GBP (£) £ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Disclosure of leases [Abstract]
Right-of-use assets	£ 971	£ 326
Current	(460)	(316)
Non Current	(491)	0
Lease liabilities	£ 951	£ 316

Right-of-use assets - propert_5

Right-of-use assets - property leases - Statement of comprehensive income, Right-of-use Asset (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of leases [Abstract]
Depreciation charge of right-of-use assets	£ (382)	£ 0
Interest expense (including finance cost)	50	0	£ 0
Expense relating to short-term leases (included in general and administrative expenses)	£ 78	£ 0

Prepayments and other receiva_3

Prepayments and other receivables (Details) - GBP (£) £ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Subclassifications of assets, liabilities and equities [abstract]
Prepayments	£ 1,309	£ 1,362
Other receivables	1,461	1,101
Total prepayments and other receivables	£ 2,770	£ 2,463

Share Capital - Movements in th

Share Capital - Movements in the Company's share capital (Details) £ in Thousands	Sep. 20, 2018GBP (£)shares	Aug. 09, 2018GBP (£)shares	Dec. 31, 2019GBP (£)shares	Dec. 31, 2018GBP (£)shares	Dec. 31, 2017GBP (£)shares
Number of shares
Beginning balance (in shares)			105,326,638	105,017,401
Issuance of shares (in shares)	251,125	58,112	5,569,050
Ending balance (in shares)			105,326,638	105,326,638	105,017,401
Share Capital amounts in £'000s
Issued capital | £			£ 5,266	£ 5,266	£ 5,251
Issuance of shares | £	£ 12	£ 3		£ 15	£ 70,325

Share Capital - Narrative (Deta

Share Capital - Narrative (Details)	12 Months Ended
	Dec. 31, 2018shares	Dec. 31, 2019GBP (£)£ / sharesshares	Dec. 31, 2017shares
Disclosure of classes of share capital [line items]
Price per share (in pounds per share) | £ / shares		£ 0.05
Number of shares authorized		200,000,000
Share capital | £		£ 10,000,000
Number of shares allotted, unrestricted, called up and fully paid (in shares)	105,326,638	105,326,638	105,017,401
Restricted Stock Units
Disclosure of classes of share capital [line items]
Number of shares subscribed from warrant maximum (in shares)	309,237

Share-based payments charge - N

Share-based payments charge - Narrative (Details) £ / shares in Units, £ in Thousands	Sep. 20, 2018shares	Aug. 09, 2018shares	Dec. 31, 2019GBP (£)shares£ / shares	Dec. 31, 2018GBP (£)shares£ / shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share-based payment charge | £			£ 2,440	£ 2,900
Number of share options granted (in shares)	251,125	58,112	5,569,050
Weighted average remaining contractual life of outstanding share options			7 years 8 months 12 days	8 years
Incentive Award Plan 2017
Disclosure of terms and conditions of share-based payment arrangement [line items]
Fair value of equity instruments | £			£ 2,250	£ 2,320
Restricted Stock Units
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period			5 years
Vesting trigger, share price to be maintained for 30 days | £ / shares			£ 2
Number of other equity instruments exercisable in share-based payment arrangement (in shares)			0	0
Weighted average exercise price of other equity instruments granted in share-based payment arrangement | £ / shares			£ 0.57	£ 1.46
Restricted Stock Units | Bottom of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period			1 year	1 year
Restricted Stock Units | Top of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period			4 years	4 years
Restricted Stock Units | Incentive Award Plan 2017
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of share options granted (in shares)			740,496
Unapproved Scheme | Bottom of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period			1 year	1 year
Unapproved Scheme | Top of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period			4 years	4 years
Unapproved Scheme | Incentive Award Plan 2017
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of share options granted (in shares)			5,569,050	273,390
EMI | Incentive Award Plan 2017
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of share options granted (in shares)				2,090,847

Share-based payments charge - D

Share-based payments charge - Disclosure of indirect measurement of fair value of goods or services received, share options granted during period (Details)	Sep. 20, 2018shares	Aug. 09, 2018shares	Dec. 31, 2019sharesyear	Dec. 31, 2018year
Disclosure of terms and conditions of share-based payment arrangement [line items]
Options granted (in shares) | shares	251,125	58,112	5,569,050
Restricted Stock Units
Disclosure of terms and conditions of share-based payment arrangement [line items]
Dividend rate			0.00%	0.00%
Vesting period			5 years
Unapproved Scheme
Disclosure of terms and conditions of share-based payment arrangement [line items]
Dividend rate			0.00%	0.00%
Bottom of range | Restricted Stock Units
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate			39.00%	1.08%
Expected life of options			5.5	5.5
Annualized volatility			67.98%	69.88%
Vesting period			1 year	1 year
Bottom of range | Unapproved Scheme
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate			76.00%	1.08%
Expected life of options			5.5	5.5
Annualized volatility			63.82%	69.88%
Vesting period			1 year	1 year
Top of range | Restricted Stock Units
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate			82.00%	1.22%
Expected life of options			7	7
Annualized volatility			69.71%	71.35%
Vesting period			4 years	4 years
Top of range | Unapproved Scheme
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate			82.00%	1.22%
Expected life of options			7	7
Annualized volatility			69.71%	71.35%
Vesting period			4 years	4 years

Share-based payments charge - S

Share-based payments charge - Share options movements (Details)	Sep. 20, 2018shares	Aug. 09, 2018shares	Dec. 31, 2019shares£ / shares	Dec. 31, 2018shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Beginning balance (in shares)			8,752,114	7,527,458
Options granted (in shares)	251,125	58,112	5,569,050
Options forfeited (in shares)			(121,970)	(799,524)
Options expired (in shares)			(19,998)	(66,667)
Ending balance (in shares)			14,179,196	8,752,114
Year Of Issue, 2012, Expiry Date June 1, 2022
Disclosure of terms and conditions of share-based payment arrangement [line items]
Beginning balance (in shares)			99,993
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			99,993	99,993
Year Of Issue, 2012, Expiry Date June 1, 2022 | Bottom of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 2.50
Year Of Issue, 2012, Expiry Date June 1, 2022 | Top of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			7.50
Year Of Issue, 2013, Expiry Date April 15, 2023
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 2
Beginning balance (in shares)			99,990
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			(19,998)
Ending balance (in shares)			79,992	99,990
Year Of Issue, 2013, Expiry Date July 29, 2023
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 2
Beginning balance (in shares)			159,999
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			159,999	159,999
Year Of Issue, 2014, Expiry Date May 15, 2024
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 1.75
Beginning balance (in shares)			109,998
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			109,998	109,998
Year Of Issue, 2015, Expiry Date January 29, 2025
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 1.25
Beginning balance (in shares)			549,999
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			549,999	549,999
Year Of Issue, 2016, Expiry Date February 2, 2026
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 2
Beginning balance (in shares)			240,000
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			240,000	240,000
Year Of Issue, 2016, Expiry Date August 3, 2026
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 1.80
Beginning balance (in shares)			676,664
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			676,664	676,664
Year Of Issue, 2016, Expiry Date September 13, 2026
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 1.89
Beginning balance (in shares)			299,997
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			299,997	299,997
Year Of Issue, 2016, Expiry Date September 16, 2026
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 2.04
Beginning balance (in shares)			300,000
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			300,000	300,000
Year Of Issue, 2017, Expiry Date April 26, 2027
Disclosure of terms and conditions of share-based payment arrangement [line items]
Beginning balance (in shares)			4,093,164
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			4,093,164	4,093,164
Year Of Issue, 2017, Expiry Date April 26, 2027 | Bottom of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 1.32
Year Of Issue, 2017, Expiry Date April 26, 2027 | Top of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			1.525
Year Of Issue, 2018, Expiry Date March 8, 2028
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 1.46
Beginning balance (in shares)			2,008,319
Options granted (in shares)			0
Options forfeited (in shares)			(34,614)
Options expired (in shares)			0
Ending balance (in shares)			1,973,705	2,008,319
Year Of Issue, 2019, Expiry Date March 29, 2029 [Member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 570
Beginning balance (in shares)			0
Options granted (in shares)			3,903,050
Options forfeited (in shares)			(87,356)
Options expired (in shares)			0
Ending balance (in shares)			3,815,694	0
Year Of Issue, 2019, Expiry Date June 11, 2029 [Member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 595
Beginning balance (in shares)			0
Options granted (in shares)			346,000
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			346,000	0
Year Of Issue, 2019, Expiry Date August 22, 2029 [Member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 457
Beginning balance (in shares)			0
Options granted (in shares)			100,000
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			100,000	0
Year Of Issue, 2019, Expiry Date November 6, 2029 [Member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 436
Beginning balance (in shares)			0
Options granted (in shares)			720,000
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			720,000	0
Year Of Issue, 2019, Expiry Date November 26, 2029 [Member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 445
Beginning balance (in shares)			0
Options granted (in shares)			500,000
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			500,000	0
EMI
Disclosure of terms and conditions of share-based payment arrangement [line items]
Ending balance (in shares)			213,984
EMI | Year Of Issue, 2014, Expiry Date May 15, 2024
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 1.75
Beginning balance (in shares)			49,998
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			49,998	49,998
EMI | Year Of Issue, 2015, Expiry Date January 29, 2025
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 1.25
Beginning balance (in shares)			41,997
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			41,997	41,997
EMI | Year Of Issue, 2016, Expiry Date February 2, 2026
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | £ / shares			£ 2
Beginning balance (in shares)			21,996
Options granted (in shares)			0
Options forfeited (in shares)			0
Options expired (in shares)			0
Ending balance (in shares)			21,996	21,996

Share-based payments charge -_2

Share-based payments charge - Disclosure of number and weighted average exercise prices of other equity instruments (Details) - Restricted Stock Units - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of terms and conditions of share-based payment arrangement [line items]
Beginning balance (in shares)	862,473	1,052,236
Options granted (in shares)	740,496
Options exercised (in shares)	0	(309,237)
Options forfeited (in shares)	0	(153,916)
Ending balance (in shares)	1,602,969	862,473
Year Of Issue, 2017, Expiry Date April 26, 2027
Disclosure of terms and conditions of share-based payment arrangement [line items]
Beginning balance (in shares)	729,987
Options granted (in shares)	0
Options exercised (in shares)	0
Options forfeited (in shares)	0
Ending balance (in shares)	729,987	729,987
Year Of Issue, 2018, Expiry Date March 8, 2028
Disclosure of terms and conditions of share-based payment arrangement [line items]
Beginning balance (in shares)	132,486
Options granted (in shares)	0
Options exercised (in shares)	0
Options forfeited (in shares)	0
Ending balance (in shares)	132,486	132,486
Year Of Issue, 2019, Expiry Date March 29, 2027
Disclosure of terms and conditions of share-based payment arrangement [line items]
Options granted (in shares)	740,496
Options exercised (in shares)	0
Options forfeited (in shares)	0
Ending balance (in shares)	740,496

Share-based payments charge - O

Share-based payments charge - Outstanding and exercisable share options by scheme (Details)	Dec. 31, 2019shares£ / shares	Dec. 31, 2018shares£ / shares	Dec. 31, 2017shares£ / shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Outstanding (in shares) | shares	14,179,196	8,752,114	7,527,458
Exercisable (in shares) | shares	5,766,277	3,542,884
Exercise price, outstanding (per share) | £ / shares	£ 1.15	£ 1.53	£ 1.53
Exercise price, exercisable (per share) | £ / shares	£ 1.60	£ 1.66
Unapproved Scheme
Disclosure of terms and conditions of share-based payment arrangement [line items]
Outstanding (in shares) | shares	13,965,212
Exercisable (in shares) | shares	5,552,293
Exercise price, outstanding (per share) | £ / shares	£ 1.12
Exercise price, exercisable (per share) | £ / shares	£ 1.55
EMI
Disclosure of terms and conditions of share-based payment arrangement [line items]
Outstanding (in shares) | shares	213,984
Exercisable (in shares) | shares	213,984
Exercise price, outstanding (per share) | £ / shares	£ 3.06
Exercise price, exercisable (per share) | £ / shares	£ 3.06
Unapproved And EMI Share Option Schemes
Disclosure of terms and conditions of share-based payment arrangement [line items]
Outstanding (in shares) | shares	14,179,196
Exercisable (in shares) | shares	5,766,277
Exercise price, outstanding (per share) | £ / shares	£ 1.15
Exercise price, exercisable (per share) | £ / shares	£ 1.61

Share-based payments charge -_3

Share-based payments charge - Number of options granted, expired and the weighted average exercise price of options (Details)	Sep. 20, 2018shares	Aug. 09, 2018shares	Dec. 31, 2019shares£ / shares	Dec. 31, 2018shares£ / shares	Dec. 31, 2017£ / shares
Disclosure of number and weighted average remaining contractual life of outstanding share options [line items]
Beginning balance (in shares)			8,752,114	7,527,458
Options granted (in shares)	251,125	58,112	5,569,050
Options forfeited (in shares)			(121,970)	(799,524)
Options expired (in shares)			(19,998)	(66,667)
Ending balance (in shares)			14,179,196	8,752,114
Exercisable (in shares)			5,766,277	3,542,884
Exercise price, outstanding (per share) | £ / shares			£ 1.15	£ 1.53	£ 1.53
Exercise price, forfeited (per share) | £ / shares			0.82	1.43
Exercise price, expired (per share) | £ / shares			2	1.75
Exercise price, exercisable (per share) | £ / shares			£ 1.60	£ 1.66
Employees
Disclosure of number and weighted average remaining contractual life of outstanding share options [line items]
Options granted (in shares)			4,042,106	1,222,089
Exercise price, granted (per share) | £ / shares			£ 0.55	£ 1.46
Directors
Disclosure of number and weighted average remaining contractual life of outstanding share options [line items]
Options granted (in shares)			1,526,944	868,758
Exercise price, granted (per share) | £ / shares			£ 0.53	£ 1.46

Share-based payments charge - E

Share-based payments charge - Equity instruments other than options granted (Details) - Restricted Stock Units - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of terms and conditions of share-based payment arrangement [line items]
Beginning balance (in shares)	862,473	1,052,236
Options granted (in shares)	740,496
Number of other equity instruments exercised or vested in share-based payment arrangement	0	(309,237)
Restricted stock units forfeited (in shares)	0	(153,916)
Ending balance (in shares)	1,602,969	862,473
Employees
Disclosure of terms and conditions of share-based payment arrangement [line items]
Options granted (in shares)	474,072	136,404
Directors
Disclosure of terms and conditions of share-based payment arrangement [line items]
Options granted (in shares)	266,424	136,986

Warrants - Narrative (Details)

Warrants - Narrative (Details) £ / shares in Units, £ in Thousands	Feb. 10, 2017	Dec. 31, 2019GBP (£)shareswarrant£ / shares	Dec. 31, 2018GBP (£)shareswarrant	Dec. 31, 2017GBP (£)	Jul. 31, 2016shareswarrant	Jul. 29, 2016shareswarrant£ / shares
Disclosure of classes of share capital [line items]
Number of units issued (in shares)					31,115,926	31,115,926
Placing price (in pounds per unit) | £ / shares						£ 1.4365
Number of ordinary shares (in shares)					1	1
Number warrants (in warrants) | warrant					1	1
Number of shares subscribed (in shares)		0.4
Transaction costs allocated to the issue of warrants (note 19) | £				£ 7,453
Warrants forfeited (in shares)		121,970	799,524
Consolidation of shares	0.02
Fair value warrant | £		£ 895	£ 2,492	1,273
Fair value adjustments recognized in loss | £		0	1,219	0
Fair value adjustment on derivative financial instruments (note 18) | £		£ 1,597	£ 0	£ 6,650
Warrants
Disclosure of classes of share capital [line items]
Exercise price (pounds per share) | £ / shares		£ 1.7238
Number of shares subscribed from warrant maximum (in shares)		12,401,262	12,401,262
Warrants forfeited (in shares) | warrant		0	0

Warrants - Assumptions in apply

Warrants - Assumptions in applying the Black-Scholes model, fair value warrants (Details) - Warrants - £ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of classes of share capital [line items]
Warrants (in shares)	12,401,262	12,401,262
Exercise price (pounds per share)	£ 1.7238
Risk-free interest rate	0.54%	0.76%
Expected term to exercise	2 years 4 months 2 days	3 years 4 months 2 days
Annualized volatility	65.56%	60.72%
Dividend rate	0.00%	0.00%

Warrants - Fair value adjustmen

Warrants - Fair value adjustments (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation Of Changes in Warrants Outstanding [Roll Forward]
Beginning balance	£ 2,492	£ 1,273
Fair value adjustments recognized in loss	0	1,219	£ 0
Fair value adjustments recognized in profit	(1,597)	0	(6,650)
Ending balance	£ 895	£ 2,492	£ 1,273

Warrants - Effect when underlyi

Warrants - Effect when underlying parameters deviate (Details) - GBP (£) £ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of share capital, reserves and other equity interest [Abstract]
Variable up, Volatility (up / down 10% pts)	£ 1,306
Base case, Volatility (up / down 10% pts)	895	£ 2,492	£ 1,273
Variable down, Volatility (up / down 10% pts)	£ 535

Trade and other payables (Detai

Trade and other payables (Details) - GBP (£) £ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Subclassifications of assets, liabilities and equities [abstract]
Trade payables	£ 1,455	£ 2,839
Other payables	0	12
Accruals	6,806	4,882
Total trade and other payables	£ 8,261	£ 7,733

Assumed contingent obligation_3

Assumed contingent obligation related to the business combination - Narrative (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2006	Dec. 31, 2017
Disclosure of detailed information about business combination [line items]
Assumed contingent liability	£ 1,103	£ 996		£ 875
Rhinopharma Limited
Disclosure of detailed information about business combination [line items]
Increase in value of the assumed contingent obligation	£ 107	£ 121
Discount percent			12.00%

Assumed contingent obligation_4

Assumed contingent obligation related to the business combination - Reconciliation of changes in contingent liabilities (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of changes in contingent liabilities recognised in business combination [abstract]
Beginning balance	£ 996	£ 875
Impact of changes in foreign exchange rates	(12)	15
Unwinding of discount factor	119	106
Ending balance	£ 1,103	£ 996

Assumed contingent obligation_5

Assumed contingent obligation related to the business combination - Reported change to the value of the liability (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about business combination [line items]
Assumed contingent liability	£ 1,103	£ 996	£ 875
Rhinopharma Limited
Disclosure of detailed information about business combination [line items]
Revenue assumption, % lower	10.00%
Revenue assumption, % higher	10.00%
Risk assumption, % lower	1.00%
Risk assumption, % higher	1.00%
Discount Rate, 1% Variable | Rhinopharma Limited
Disclosure of detailed information about business combination [line items]
Contingent liabilities recognised in business combination, variable up	£ 1,067
Assumed contingent liability	1,103
Contingent liabilities recognised in business combination, variable down	1,141
Revenue Concentration Risk, 10% Variable | Rhinopharma Limited
Disclosure of detailed information about business combination [line items]
Contingent liabilities recognised in business combination, variable up	1,135
Assumed contingent liability	1,103
Contingent liabilities recognised in business combination, variable down	£ 1,071

Related parties transactions _2

Related parties transactions and other shareholder matters (Details) - GBP (£) £ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Chief financial officer
Disclosure of transactions between related parties [line items]
Number of ordinary shares purchased in related party transaction (in shares)	88,415
Amount of ordinary shares purchased in related party transaction	£ 53	£ 0
Chief executive officer
Disclosure of transactions between related parties [line items]
Number of ordinary shares purchased in related party transaction (in shares)	3,250
Amount of ordinary shares purchased in related party transaction	£ 5
Board of Directors Chairman
Disclosure of transactions between related parties [line items]
Number of ordinary shares purchased in related party transaction (in shares)	247,600
Amount of ordinary shares purchased in related party transaction	£ 124	14
Key management personnel of entity or parent
Disclosure of transactions between related parties [line items]
Amounts receivable, related party transactions	£ 126
Amounts Receivable, Related Party Transactions, Interest Rate	3.90%
Other employee expense	£ 26	£ 26	£ 0
Vivo Capital, OrbiMed And Abingworth | Entities with joint control or significant influence over entity
Disclosure of transactions between related parties [line items]
Percent of issued ordinary shares	6.50%

Uncategorized Items - vrna-2019

Label	Element	Value
Increase (decrease) due to changes in accounting policy [member]
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	£ 484,000
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	(20,000)
Share capital [member]
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	2,568,000
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	5,266,000
Retained earnings [member]
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	(28,244,000)
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	(68,653,000)
Retained earnings [member] | Increase (decrease) due to changes in accounting policy [member]
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	484,000
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	(20,000)
Reserve of share-based payments [member]
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	2,103,000
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	7,923,000
Share premium [member]
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	58,526,000
Equity attributable to owners of parent	ifrs-full_EquityAttributableToOwnersOfParent	£ 118,862,000