(Reuters) - Centrist Democratic Senator Kyrsten Sinema and U.S. House of Representatives Speaker Nancy Pelosi spoke over the weekend on the issue of prescription drug prices, CNN reported on Monday. Progressive Senator Bernie Sanders said on Sunday he was working on getting a provision to lower prescription drug prices into the $1.75 trillion social spending bill pending in the U.S. Congress before a vote by the House. The proposal that would allow the U.S. government’s Medicare health plan for seniors to negotiate cheaper prices for prescription medicines was not included in the social spending bill. Reporting by Kanishka Singh in Bengaluru