Holding(s) in Company

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi

1. Identity of the issuer or the underlying issuerof existing shares to which voting rights areattached: ii

SkyePharma 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

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): Increase in total number of voting rights in the issuer as a result of the issuance of ordinary shares pursuant to a mandatory conversion of convertible bonds

X

3. Full name of person(s) subject to thenotification obligation: iii

OrbiMed Advisors LLC and OrbiMed Capital LLC

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

Caduceus Capital Master Fund Limited

Caduceus Capital II, L.P.

UBS Eucalyptus Fund, L.L.C.

Summer Street Life Sciences Hedge Fund Investors LLC

5. Date of the transaction and date onwhich the threshold is crossed orreached: v

24 September 2012

6. Date on which issuer notified:

2 October 2012 (received 4 October 2012)

7. Threshold(s) that is/are crossed orreached: vi, vii

 From 11% to 5%

8. Notified details:

A: Voting rights attached to shares viii, ix

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 x

Direct

Direct xi

Indirect xii

Direct

Indirect

GB00B3BFNB64

2,683,952

2,683,952

2,683,952

5.82%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate xiii

Exercise/Conversion Period xiv

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

% of votingrights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments xv, xvi

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date xvii

Exercise/Conversion period xviii

Number of voting rights instrument refers to

% of voting rights xix, xx

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

2,683,952

5.82%

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

Proxy Voting:

10. Name of the proxy holder:

11. Number of voting rights proxy holder will ceaseto hold:

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

13. Additional information:

SkyePharma PLC's issued share capital was increased on 24 September 2012 following the conversion of convertible bonds. OrbiMed Advisors LLC and OrbiMed Capital LLC (together 'OrbiMed') are affiliated investment advisers registered with the U.S. Securities and Exchange Commission. OrbiMed acts as investment manager or investment adviser for the funds and accounts listed in Item 4, which beneficially own the shares that are the subject of this notification.

14. Contact name:

 John Murphy

15. Contact telephone number:

 020 7881 1174