By Brian Kennedy

When the U.S. Food and Drug Administration approved a revolutionary medication for Duchenne muscular dystrophy in September, it marked a historic milestone for thousands of families with no treatment options for their loved ones. Developing new treatments for rare diseases can be a challenging process - oftentimes, it results in failure.

The celebration has been short lived for some patients, families, and health-care providers. A number of health insurers are creatively denying treatment coverage for the 1,200 to 1,500 boys in the United States whose genetic mutation makes them eligible for the medication.

In some cases, insurers are calling this breakthrough treatment "investigational." In reality, FDA's approval process holds drugs to rigorous safety and efficacy standards. In other instances, insurers are first demanding extraordinary measures such as biopsies, which take away critical muscle mass and require already vulnerable patients to undergo anesthesia in an inpatient hospital setting.

Unfortunately, these coverage decisions mark a troubling sign of things to come.

As precision medicine becomes the new normal, insurers will undoubtedly encounter many more high-cost, high-value treatments. Some will face an acceptable level of uncertainty at the time of approval. Most all will offer direct benefit, albeit for a small patient population.

To better prepare for these rare disease treatments, we should address three primary issues:

First, we must acknowledge insurers' lack of expertise in assessing whether or not a rare disease treatment is effective. Unlike treatments for widespread conditions such as cancer, HIV/AIDS, and diabetes, medicines for rare diseases like Duchenne muscular dystrophy (DMD)are being evaluated for coverage for the first time. Just as these diseases are rare, so too is an understanding of how they develop, progress, and impact patients.

In the case of the DMD treatment, for example, fewer than a dozen credible experts in the world understand how dystrophin - a protein required for muscle function throughout the body - can slow the progression of the disease. Beyond DMD, some insurers are pushing back against the first-ever treatment for spinal muscular atrophy, which was granted full FDA approval in December. This constitutes a troubling trend.

Conclusions about a treatment's effectiveness are better left in the hands of final decision makers at the FDA - and, after approval, physicians.

Second, insurers' approach needs to align with how the FDA approves new medications. Up until 2012, the agency's accelerated review process typically applied only to cancer and HIV/AIDS drugs. That year, Congress expanded the process with the specific goal of expediting approval for rare disease treatments. To see that vision materialize and to provide options for patients who currently have none, FDA and insurers' approaches must complement each other.

Third, we need to address the bioethical issues involved, lest insurers' approach to Duchenne muscular dystrophy treatments set a dangerous precedent. The fact that some insurers are denying coverage outright or requiring unethical prerequisites to treatment raises significant concerns. Here we have an opportunity to focus on ensuring coverage decisions that reduce strain on our health-care system and focus on treating patients, not harming them.

Providing access to innovative medicines is a wise decision. It's the right and timely thing to do by patients. By addressing the three issues identified, we can send a signal that approval and access should go hand in hand.

Brian Kennedy is executive director of the Alliance for Patient Access.