Pontifax Management 2 G.P. (2007) Ltd.

Row 1 · Balance 187,156

F1: This amendment is being filed to include Pontifax Management II, L.P. ("PM"), Pontifax Management 2 G.P. (2007) Ltd. ("PMGP") and Ran Nussbaum ("Nussbaum") as additional reporting persons to the Form 3 filed by Tomer Kariv ("Kariv") on 1/29/13 and to reflect Kariv as a 10% owner. The reporting persons have re-reported the securities held in Table I solely to gain access to the EDGAR filing system and the Amount of Securities Beneficially Owned has been adjusted to reflect a 1-for-8 combination of the Issuer's common stock completed on 10/29/13.

F2: PM is the general partner of each of Pontifax (Cayman) II L.P. ("PC"), Pontifax (Israel) II L.P. ("PI") and Pontifax (Israel) II - Individual Investors L.P. ("PIII" and together with PC and PI, the "Pontifax Funds"). PMGP is the general partner of PM. Each of Kariv and Nussbaum are directors of PMGP. PM and PMGP, through the Pontifax Funds, share a contractual right to designate one member of the Issuer's board of directors and may be deemed to be directors by deputization for purposes of Section 16 of the Exchange Act. The purpose of this amendment is to add PM, PMGP and Nussbaum as reporting persons to the Form 3 originally filed by Kariv on 1/29/13 in order to reflect that the securities shown on such form as held by the Pontifax Funds are beneficially owned by PM, PMGP, Nussbaum and Kariv.

F3: This form is also intended to amend the Form 4 statements filed by Kariv on each of 4/10/13, 5/7/13, 6/5/13, 10/31/13, 1/14/16 and 8/17/16, and a Form 5 filed on 2/17/15 (the "Prior Statements") to reflect that the securities shown therein as indirectly held by Kariv through the Pontifax Funds are also beneficially owned by PMII, PMGP and Nussbaum. Each of the reporting persons disclaims beneficial ownership of the securities held by the Pontifax Funds except to the extent of their respective pecuniary interests therein, and this report shall not be deemed an admission by any reporting person that such person is the beneficial owner of such securities for purposes of Section 16 of the Securities Exchange Act or for any other purpose.

F4: Each of PM, PMGP and Nussbaum disclaims beneficial ownership of the securities directly held by Kariv as reflected in the Prior Statements, except to the extent of his or its pecuniary interest therein, and this Form 3/A shall not be deemed an admission by PM, PMGP or Nussbaum that any is a beneficial owner of any securities held by Kariv for purposes of Section 16 or any other purpose.

Row 2 · Balance 140,977

F1: This amendment is being filed to include Pontifax Management II, L.P. ("PM"), Pontifax Management 2 G.P. (2007) Ltd. ("PMGP") and Ran Nussbaum ("Nussbaum") as additional reporting persons to the Form 3 filed by Tomer Kariv ("Kariv") on 1/29/13 and to reflect Kariv as a 10% owner. The reporting persons have re-reported the securities held in Table I solely to gain access to the EDGAR filing system and the Amount of Securities Beneficially Owned has been adjusted to reflect a 1-for-8 combination of the Issuer's common stock completed on 10/29/13.

F2: PM is the general partner of each of Pontifax (Cayman) II L.P. ("PC"), Pontifax (Israel) II L.P. ("PI") and Pontifax (Israel) II - Individual Investors L.P. ("PIII" and together with PC and PI, the "Pontifax Funds"). PMGP is the general partner of PM. Each of Kariv and Nussbaum are directors of PMGP. PM and PMGP, through the Pontifax Funds, share a contractual right to designate one member of the Issuer's board of directors and may be deemed to be directors by deputization for purposes of Section 16 of the Exchange Act. The purpose of this amendment is to add PM, PMGP and Nussbaum as reporting persons to the Form 3 originally filed by Kariv on 1/29/13 in order to reflect that the securities shown on such form as held by the Pontifax Funds are beneficially owned by PM, PMGP, Nussbaum and Kariv.

F3: This form is also intended to amend the Form 4 statements filed by Kariv on each of 4/10/13, 5/7/13, 6/5/13, 10/31/13, 1/14/16 and 8/17/16, and a Form 5 filed on 2/17/15 (the "Prior Statements") to reflect that the securities shown therein as indirectly held by Kariv through the Pontifax Funds are also beneficially owned by PMII, PMGP and Nussbaum. Each of the reporting persons disclaims beneficial ownership of the securities held by the Pontifax Funds except to the extent of their respective pecuniary interests therein, and this report shall not be deemed an admission by any reporting person that such person is the beneficial owner of such securities for purposes of Section 16 of the Securities Exchange Act or for any other purpose.

F4: Each of PM, PMGP and Nussbaum disclaims beneficial ownership of the securities directly held by Kariv as reflected in the Prior Statements, except to the extent of his or its pecuniary interest therein, and this Form 3/A shall not be deemed an admission by PM, PMGP or Nussbaum that any is a beneficial owner of any securities held by Kariv for purposes of Section 16 or any other purpose.

Row 3 · Balance 54,725

F1: This amendment is being filed to include Pontifax Management II, L.P. ("PM"), Pontifax Management 2 G.P. (2007) Ltd. ("PMGP") and Ran Nussbaum ("Nussbaum") as additional reporting persons to the Form 3 filed by Tomer Kariv ("Kariv") on 1/29/13 and to reflect Kariv as a 10% owner. The reporting persons have re-reported the securities held in Table I solely to gain access to the EDGAR filing system and the Amount of Securities Beneficially Owned has been adjusted to reflect a 1-for-8 combination of the Issuer's common stock completed on 10/29/13.

F2: PM is the general partner of each of Pontifax (Cayman) II L.P. ("PC"), Pontifax (Israel) II L.P. ("PI") and Pontifax (Israel) II - Individual Investors L.P. ("PIII" and together with PC and PI, the "Pontifax Funds"). PMGP is the general partner of PM. Each of Kariv and Nussbaum are directors of PMGP. PM and PMGP, through the Pontifax Funds, share a contractual right to designate one member of the Issuer's board of directors and may be deemed to be directors by deputization for purposes of Section 16 of the Exchange Act. The purpose of this amendment is to add PM, PMGP and Nussbaum as reporting persons to the Form 3 originally filed by Kariv on 1/29/13 in order to reflect that the securities shown on such form as held by the Pontifax Funds are beneficially owned by PM, PMGP, Nussbaum and Kariv.

F3: This form is also intended to amend the Form 4 statements filed by Kariv on each of 4/10/13, 5/7/13, 6/5/13, 10/31/13, 1/14/16 and 8/17/16, and a Form 5 filed on 2/17/15 (the "Prior Statements") to reflect that the securities shown therein as indirectly held by Kariv through the Pontifax Funds are also beneficially owned by PMII, PMGP and Nussbaum. Each of the reporting persons disclaims beneficial ownership of the securities held by the Pontifax Funds except to the extent of their respective pecuniary interests therein, and this report shall not be deemed an admission by any reporting person that such person is the beneficial owner of such securities for purposes of Section 16 of the Securities Exchange Act or for any other purpose.

F4: Each of PM, PMGP and Nussbaum disclaims beneficial ownership of the securities directly held by Kariv as reflected in the Prior Statements, except to the extent of his or its pecuniary interest therein, and this Form 3/A shall not be deemed an admission by PM, PMGP or Nussbaum that any is a beneficial owner of any securities held by Kariv for purposes of Section 16 or any other purpose.