Mylan ($MYL) was already cruising without competition to key product EpiPen. But now, wannabe rival Teva Pharmaceutical ($TEVA) has run into a hurdle that could keep the treatment flying high through next year.

On Monday, the Israeli generics giant disclosed that it had received an FDA rejection for its generic version--and in that rejection, regulators flagged "certain major deficiencies." With serious problems to fix, the company expects its copycat to be "significantly delayed"--meaning it's not anticipating a launch before 2017.

It's a break for Mylan, which now likely won't have to deal with the $200 million in generics erosion that analysts were expecting, Evercore ISI's Umer Raffat wrote in a Monday note to clients. "Based on timing of FDA review of resubmission, 2017 may have limited to no headwinds at all," he said.

And it's not the first break the company has caught lately. Back in November, Sanofi's ($SNY) Auvi-Q--the first real competition to EpiPen in years--ran into trouble, with an injector fault and hefty recall prompting the French drugmaker to pull it from the marketplace. Then, last week, PDL BioPharma CEO John McLaughlin told investors that his company had received word that Sanofi was bailing on its marketing deal for the product altogether, putting the drug's future in limbo.

RELATED: Price increases have led to congressional scrutiny and calls for an 'urgent briefing' on the Hill. In response, Mylan rolls out new EpiPen access plan.

With its nemeses sidelined, Bernstein analyst Ronny Gal has predicted EpiPen could capture about 95% of the blockbuster epinephrine injection market--a position that would allow Mylan to up its price on the med, which climbed by 222% between 2007 and 2014. But while Mylan may be sitting pretty in the EpiPen department, it isn't letting up elsewhere; last month, it struck a $7.2 billion deal for Sweden's Meda to further its OTC ambitions.

Meanwhile, the knockoff's delay won't help Teva revive its generics sales, which dove 9% in Q4 to $2.26 billion. The company is pushing hard to close a $40.5 billion deal for Allergan's ($AGN) generics unit as fast as it can, though, which will strengthen its position at the top of the generics ranks.

- read Teva's filing

Special Report: Top 20 generics companies by 2014 revenue - Teva - Mylan