JOINT FILING AGREEMENT

                                                                       Exhibit 1

                             JOINT FILING AGREEMENT

We, the signatories of the statement on Schedule 13G to which this Agreement is
attached, hereby agree that such statements is, any amendments thereto filed by
any of us will be, filed on behalf of each of us.

           , 2003                         ARTAL GROUP S.A.

                                          By:      /s/ XXXX XXXXXX
                                          Name:    Xxxx Xxxxxx
                                          Title:   Managing Director


                                          ARTAL INTERNATIONAL S.A.

                                          By:      /s/ XXXX XXXXXX
                                          Name:    Xxxx Xxxxxx
                                          Title:   Managing Director


                                          ARTAL LUXEMBOURG S.A.

                                          By:      /s/ XXXX XXXXXX
                                          Name:    Xxxx Xxxxxx
                                          Title:   Managing Director