Register a sanitization callback for the custom setting

sample.php

<?php
/**
 * Register a sanitization callback for the custom setting.
 */
 
 add_action( 'genesis_settings_sanitizer_init', 'cpt_as_genesis_sanitize_settings' );
/**
 * Callback for Genesis 'genesis_settings_sanitizer_init' action.
 *
 * Add the settings to the filter.
 * 
 * @global $_genesis_admin_cpt_archives_testimony Genesis_Admin_CPT_Archive_Settings object for the 'testimony' post type.
 *
 * @uses genesis_add_option_filter
 *
 * @since 0.0.1
 * 
 * @return void
 */
function cpt_as_genesis_sanitize_settings() {

    global $_genesis_admin_cpt_archives_testimony;

    genesis_add_option_filter(
        'absint',
        $_genesis_admin_cpt_archives_testimony->settings_field,
        array(
            'posts_per_page',
        )
    );

}