The cover to Newton Comics' Planet of the Apes #5 originally appeared on Marvel Comics' Planet of the Apes #5.
The contents are as follows:
[Terror on the Planet of the Apes] Malaguena Beyond a Zone Forbidden, originally published in Planet of the Apes #6, March 1975.
This chapter follows Evolution's Nightmare! from Planet of the Apes #5 which was published in Planet of the Apes Annual #1.
Planet of the Apes [Chapter Two: World of Captive Humans], originally published in Planet of the Apes #2, October 1974
These five pages complete the reprinting of this chapter.
There is no rehearsal of the summary blurb included in previous instalments, and no reference to the chapter title I Can Write! from Planet of the Apes #4:
The bottom tier is cropped to accommodate the inclusion of the rather rudimentary title panel
Planet of the Apes Chapter Three: Manhunt!, originally published in Planet of the Apes #3, December 1974.
Only the first 9 pages of this chapter are reprinted. There is no proxy title for the continuation of the chapter in the next issue, and all of the pages of this chapter are non-paginated, except for a crudely designated page 35 by hand.
Page 38 is a mess - it has been printed in reverse:
The image is cribbed from the final panel in the story The Keepers of the Crypt which originally appeared in Conan the Barbarian #8, August 1971. This story was reprinted by Newton in Hulk King Size Annual #1 page 81:
This issue includes in-house advertisements for Conan the Barbarian #1, advertised as On Sale 30 August 1975, and Planet of the Apes Annual #1 as Out Now!
The contest expires 22 September 1975. As discussed in my post on Planet of the Apes Annual #1, I believe Planet of the Apes #4, Planet of the Apes Annual #1 and Planet of the Apes #5 were published over a period of three weeks. Accordingly I date this issue as being published on 2 August 1975. I note it's possible all three issues were published one week earlier than my schema, but I favour the dates as I've laid them out.
Update 9/12/2018: A further consideration of the publication dates in discussion of Planet of the Apes #7.