My company created two PHP-extension for InterSystems.

openexchange.intersystems.com/package/PHP-module-for-IRIS
openexchange.intersystems.com/package/PHP-module-for-Caché

No problem with security. You need run in AWS proxy-server like NGINX with multiple security settings and resctrictions
and run apache on the same host where located InterSystems.

NGINX and Apache will be connected by security and protected channel.

Commercional support and development new functions available.

Article with detail of use PHP-module for InterSystems.

I'm expert in NGINX and PHP for InterSystems.