SCRIPT1002: Syntax error on IE 11 version

Question

I have a code as shown below which is working perfectly fine on chrome and mozilla. But on IE its throwing an error at Line A.

The error which I am getting is: SCRIPT1002: Syntax error. The version of IE which I am using is 11.775.17763.0

/* greater than 767 px */
document.addEventListener("DOMContentLoaded", function (event) {
    if (window.innerWidth > 767) {
        document.querySelectorAll('.focustop .featured-block .featured-block__item-multi')[0].classList.add('featured-block__item-multi-active');
        const pics = document.querySelectorAll('.focustop .featured-block .featured-block__item-multi');
        const lastPic = pics.length - 1;
        const transitionDuration = 500; // matches CSS
        let transitionDelay =4000;
        const totalDelay = transitionDuration + transitionDelay;
        const intervalDelay = (transitionDuration * 2) + transitionDelay; // time to fade out + time to fade in + time to stay featured-block__item-active

        function toggleClass() {
            const activePic = document.querySelectorAll('.focustop .featured-block .featured-block__item-multi-active')[0];
            const activeIndex = Array.prototype.indexOf.call(pics, activePic);
            const nextIndex = activeIndex === lastPic ? 0 : activeIndex + 1;
            const nextPic = pics[nextIndex];

            setTimeout(() => activePic.classList.remove('featured-block__item-multi-active'), transitionDelay);    // Line A
            setTimeout(() => nextPic.classList.add('featured-block__item-multi-active'), totalDelay);
        }

        setInterval(toggleClass, intervalDelay);
    }
});