may not be modified, amended or discharged except as expressly stated in this Agreement or by a written agreement signed by the Parties hereto, except that this Agreement shall not supersede or serve to amend (i) any separate confidentiality or non-disclosure agreement that may have been entered into by the Parties, or (ii) the Development Agreement, each of which shall remain in effect in accordance with its terms. 11.3 The provisions of this Agreement shall be deemed separate. Therefore, if any part of this Agreement is rendered void, invalid or unenforceable, such rendering shall not affect the validity and enforceability of the remainder of this Agreement unless the part or parts which are void, invalid or unenforceable shall substantially impair the value of the whole Agreement to either Party. 11.4 Unless otherwise stated in this Agreement, any and all communications required as provided for in this Agreement shall be in writing to the addresses noted above and shall be sent by (i) Certified or Registered Mail, postage prepaid, return receipt requested, (ii) confirmed email or facsimile followed by a letter of confirmation sent by any of the methods stated in (i) and/or (iii) of this clause, or (iii) by an express overnight courier service (for example, Federal Express or Airborne), postage prepaid, return receipt requested and addressed as set forth above. Notices shall be deemed given three (3) days following mailing by Certified or Registered Mail, and one (1) day following overnight courier. Either Party may give written notice of a change of address. After such notice has been received, any notice thereafter shall be given to such Party as above provided at such changed address. 17 Source: KITOV PHARMA LTD., 20-F, 3/26/2019 11.5 The headings used in this Agreement are for the convenience of the Parties only, and shall