After clashing fiercely for four years over heat-not-burn e-cigarette technology, British American Tobacco and Philip Morris [...] reached a global settlement. This brings one of the biggest global patent battles to an abrupt and surprising end. In the agreement [...] Philip Morris and BAT waive claims from the previous lawsuits. They also waive their right to assert claims against each other over their own patents in the future. The settlement applies globally and, according to a Form K6 filing with the US SEC, the agreement is valid for eight years.