Traditional AV response times to new threats are too slow. Traditional AV only stops 30-50 percent of new zero-hour malware when its first seen. A recent study by the Enterprise Strategy Group showed that almost half of the enterprises polled had suffered a successful malware attack even though they were running anti-virus. An anti-exploit program is a zero-day focused, lightweight product that works with your traditional AV product to block threats that AV misses. The layered approach to security, along with good good good maintenance practices, can help you stay safe.”]
Source: https://blog.malwarebytes.com/101/2015/11/three-reasons-why-anti-virus-alone-is-no-longer-enough/