Gilead asks FDA to expand exclusivity for a key HIV drug

In the latest development in a heated battle between Gilead Sciences and the US Food and Drug Administration, the company petitioned the agency this month to retroactively grant five years of exclusive marketing for an HIV medicine. And the drug maker argues that it otherwise faces lost sales and added expense from fending off a pending generic threat to its Stribild medication.

The move follows a complicated legal battle in which Gilead challenged an FDA policy toward so-called fixed-dose combination drugs, which consist of two or more chemical entities. At stake are untold amounts of revenue as Gilead and other drug makers have battled the agency over its policy, which a federal judge recently ruled is  “arbitrary and capricious.”

Here’s the background: Until October 2014, the FDA would only grant five years of valuable marketing exclusivity if all of the drugs in a combination medicine were new chemical entities. In other words, these would have been drugs that were not previously approved for any use. A fixed-dose combination containing one older drug would have been eligible for just three years of exclusivity instead.

As you might imagine, two years can make a difference because a company has added time to sell a medicine before encountering competition. Consequently, Gilead and another drug maker, Ferring Pharmaceuticals, petitioned the FDA in 2013 to change its rules so that a fixed-dose combination with at least one new chemical entity would be eligible for five years of marketing exclusivity.

As we wrote at the time, the companies argued that “a growing number of safer and effective medicines used to treat serious illnesses are fixed-dose combinations, which include one or more older drugs. By failing to win the added two years of marketing exclusivity, the drug makers contended they were being robbed of incentives to invest in innovative treatments.”

Read more: Gilead defeats AIDS activists who claimed the company manipulated patents

Gilead felt penalized because its Stribild HIV medicine contains four chemical entities, not all of which were new (as for Ferring, the company was arguing to win added exclusivity for a bowel treatment used for preparing for colonoscopies). The FDA acquiesced and altered its policy, but only for newly approved fixed-dose combination drugs as of October 2014, when the agency issued a new guidance.

This angered the drug makers and the battle shifted to federal court, where US District Court Judge Rudolph Contreras last month ruled that the October 2014 cutoff was “arbitrary and capricious.” Although it remains unclear whether the FDA will appeal the decision, this opened the door for Gilead to file its latest petition.

The drug maker notes that since the FDA denied the added exclusivity for Stribild, it has incurred added costs because the company is engaged in what it called “premature” patent litigation with a generic rival and could face competition 18 months sooner than expected, according to the petition. Gilead also argued the uncertainty is detrimental to generic companies pursuing versions of Stribild.

We asked the FDA for comment and will pass along any reply.

Stribild is one of Gilead’s bigger sellers. Last year, the drug generated $1.8 billion in sales, a 52 percent rise from 2014, making it the company’s fifth-largest medicine. Sales growth has tapered more recently, though. During the first six months of this year, Stribild sales were $906 million, up about 13 percent year over year, while during the second quarter, sales fell 4 percent, to $429 million.