For decades, drugmakers have argued that patents are critical to bringing new drugs to the market. But in 2004, when a promising H.I.V. treatment emerged, Gilead Sciences decided to slow-walk its release to maximize profit on the company’s existing patents. Rebecca Robbins, who covers the pharmaceutical industry for The Times, discusses one man’s case and how patents can create perverse incentives to delay new and better drugs. Guest: Rebecca Robbins, a business reporter covering the pharmaceutical industry for The New York Times.