The present invention provides, inter alia, methods of treating or ameliorating the effects of a cancer in a subject. The methods include administering to the subject an effective amount of (i) a first anti-cancer agent, which is BVD-523 or a pharmaceutically acceptable salt thereof and (ii) a second anti-cancer agent, which is a type 1 RAF inhibitor (such as dabrafenib) or another RAF inhibitor (such as regorafenib) or a pharmaceutically acceptable salt thereof, to treat or ameliorate the effects of the cancer. Also provided are pharmaceutical compositions and kits for treating or ameliorating the effects of a cancer in a subject.