Upon receipt of a demand, or a copy thereof, from the International Preliminary Examining Authority, the International Bureau shall promptly transmit to that Authority:
(i) a copy of the written opinion established under Rule 43bis.1, unless the national Office or intergovernmental organization that acted as International Searching Authority is also acting as International Preliminary Examining Authority; and
(ii) a copy of any amendment under Article 19, any statement referred to in that Article, and the letter required under Rule 46.5(b), unless that Authority has indicated that it has already received such a copy.
If, at the time of filing any amendments under Article 19, a demand has already been submitted, the applicant shall preferably, at the same time as he files the amendments with the International Bureau, also file with the International Preliminary Examining Authority a copy of such amendments, any statement referred to in that Article and the letter required under Rule 46.5(b). In any case, the International Bureau shall promptly transmit a copy of such amendments, statement and letter to that Authority.