Case-sensitive URL Redirection

I assume you're getting a 404 because the request is for /home and that doesn't exist on the web servers in the apache pool.

Instead of ==, try using matches_regex. Also, you should specify the protocol in the redirect.

if (http_host == "www.primarysite.com" and http_uri matches_regex "/[hH][oO][mM][eE]") {   
   redirect to "https://www.secondarysite.com/secure/"
} else {      
   use pool APACHE_WEB_SERVERS   
}

Aaron