United Therapeutics Corp. has been striking more licensing deals this year, a trend some analysts say illustrates the companyâs strategy to staying ahead of generic competition. The Silver Spring drugmaker announced a global licensing agreement earlier this month with California company Arena Pharmaceuticals Inc. (NASDAQ: ARNA). United Therapeutics (NASDAQ: UTHR) will pay Arena $800 million upfront, plus up to $400 million in milestone payments, for exclusive rights to ralinepag, a phase 3 investigational drug candidate in development for pulmonary arterial hypertension.