Holding(s) in Company

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARES

1. Identity of the issuer or the underlying issuer of existing shares to which voting rights are attached:

ARK THERAPEUTICS GROUP PLC

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

An acquisition or disposal of qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

 X

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

An event changing the breakdown of voting rights

Other (please specify):

3. Full name of person(s) subject to the notification obligation:

 Smith and Williamson Holdings Limited

4. Full name of shareholder(s) (if different from 3.):

Detailed as per section 9

5. Date of the transaction and date on which the threshold is crossed or reached:

22/04/2013

6. Date on which issuer notified:

23/04/2013

7. Threshold(s) that is/are crossed or reached:

11%

8. Notified details:

A: Voting rights attached to shares

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

% of voting rights

Direct

Direct

Indirect

Direct

Indirect

Ordinary

GB0034251727

23,477,100

23,477,100

21,477,100

10.26%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate

Exercise/ConversionPeriod

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

 N/A

 N/A

 N/A

 N/A

 N/A

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Exerciseprice

Expirationdate

Exercise/Conversionperiod

Number of votingrights instrumentrefers to

% of voting rights

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

21,477,100

10.26%

9. Chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held, if applicable:

Smith and Williamson Nominees Limited, a subsidiary of Smith and Williamson Investment Management Limited, a subsidiary of Smith and Williamson Holdings Limited - 5,056,157 shares

Royal Bank of Scotland as custodian for Smith & Williamson Fund Administration Ltd, a subsidiary of Smith & Williamson Investment Management Limited, a subsidiary of Smith & Williamson Investment Management Limited, a subsidiary of Smith & Williamson Holdings Limited - 2,000,000 shares

BNP Paribas as custodian for Smith and Williamson Investment Management Limited, a subsidiary of Smith & Williamson Holdings Limited - 675,000 shares

BNP Paribas Securities Services as custodian for Smith & Williamson Investment Management (Ireland) Limited, a subsidiary of Smith & Williamson Holdings Limited - 14,000,000 shares

Proxy Voting:

10. Name of the proxy holder:

 N/A

11. Number of voting rights proxy holder will cease to hold:

 N/A

12. Date on which proxy holder will cease to hold voting rights:

 N/A

13. Additional information:

14. Contact name:

Not advised

15. Contact telephone number:

Not advised