After months of heated accusations and painstaking negotiations, the White House and the pharmaceutical industry neared agreement late last month on a plan to make good on President Trump’s longstanding promise to lower drug prices.

The drug companies would spend $150 billion to address out-of-pocket consumer costs and would even pick up the bulk of the co-payments that older Americans shoulder in Medicare’s prescription drug program.

Then the agreement collapsed. The breaking point, according to four people familiar with the discussions: Mark Meadows, Mr. Trump’s chief of staff, insisted the drug makers pay for $100 cash cards that would be mailed to seniors before November — “Trump Cards,” some in the industry called them.

Some of the drugmakers bridled at being party towhat they feared would be seen as an 11th-hour political boost for Mr. Trump, the people familiar with the matter said.