President Trump on Thursday announced a drug pricing deal with Regeneron — the last of 17 manufacturers the administration pressured last year to commit to his "most favored nation" policy. Why it matters : The deals with the other companies to lower certain drug prices are being touted as one of the administration's signature health accomplishments, though Democrats question whether the confidential arrangements are really helping consumers. Driving the news : Like other deals, the agreement calls for lower prices for certain drugs offered to Medicaid, as well as to patients paying cash through the TrumpRx website. Trump claimed the deal amounts to "the biggest cut in drug prices in the history of our country, by many percentage points." Department of Health and Human Services chief counselor Chris Klomp said the combined deals now cover 86% of branded pharmaceuticals.…