Sarepta Therapeutics (SRPT - Get Report) is being dragged down unfairly into the price-gouging muck by Marathon Pharmaceuticals.

This shouldn't need to be said but let's clarify what seems like a point of confusion: Sarepta and Marathon are not competing for the treatment of patients with Duchenne muscular dystrophy.

Treating the symptoms of DMD with a cheap, generic steroid has long been a standard of care. Marathon's Emflaza, approved in the U.S. last week, is an old steroid (its scientific name is deflazacort) that has been available outside the country for decades. DMD patients have been prescribed deflazacort or some other steroid for years. Marathon did very little work on its own and spent a relative pittance to secure Emflaza's approval.

Sarepta's Exondys 51 is a novel, first-in-class therapy that targets the underlying cause of DMD. The goal of Exondys 51 is to increase the production of dystrophin, a protein required by muscles to function properly. Yes, the FDA approval of Exondys 51 was controversial. Everyone knows that. But however you feel about Exondys 51, the claim that it competes with Emflaza, or that amenable DMD patients will choose to be treated with Emflaza instead of Exondys 51, is scientifically baseless.

"All boys who participated in our clinical studies for Exondys 51 were on a stable dose of steroids," Sarepta CEO Ed Kaye reminded me (and you.) "Because use of steroids as an adjunct therapy is already widely practiced for well over a decade, we do not believe an approval of a steroid [Marathon's Emflaza] in a DMD indication should have an impact on the reimbursement coverage for Exondys 51."

Emflaza is an egregiously expensive steroid. Marathon wants to charge $89,000 per year even though DMD patients have been able to purchase generic deflazacort -- the same drug -- in Europe for approximately $1,000 per year. Pharmaceutical price gougers aren't popular these days, so Marathon and its CEO Jeff Aronin find themselves in some very hot water.

One sleazy way Aronin has tried to deflect the hate and criticism leveled against him for Emflaza's price tag is remind to people that Sarepta's Exondys 51 carries an even higher price tag -- $300,000 or more per year.

In an open letter to the DMD community about Emflaza posted Monday, Aronin writes,"I also want you to know that we hear and understand your concerns around the price and recognize it is tied to fears you have about reimbursement for other components of Duchenne treatment."

Hmmm.... What other Duchenne treatment component might Aronin be referring to?

There are legitimate concerns about insurance reimbursement for Exondys 51 but they're not exacerbated by Emflaza. Insurers might be greedy but they're not stupid. Denying a DMD patient coverage for Emflaza is not the same as keeping that patient away from Exondys 51. There are other inexpensive steroids that work just as well Emflaza. No such alternative exists for Exondys 51.

Marathon made its own mess. Don't drag Sarepta into it.

Adam Feuerstein writes regularly for TheStreet. In keeping with company editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback; click here to send him an email.