Collateral Damage to Patients From Formulary Restrictions in Multiple Sclerosis (MS): Perspectives from an MS Specialist, a Patient, and a Neurologist in Training

William Kilgo, MD

As a neurologist specializing in multiple sclerosis (MS), I see firsthand how effective treatment with disease modifying treatments (DMT) can dramatically improve patients’ lives. There has been a therapeutic revolution in MS over the last 30 years. Increasing DMT choice has brought us multiple mechanisms of action for treatments. Unfortunately, access to these treatments isn’t always straightforward. MS has emerged as one of the most expensive diseases to treat in the United States with an estimated annual economic burden of $85.4 billion described in a 2022 paper¹ by Bebo, et al.

The drug approval landscape for specialty medications is incredibly difficult to navigate, both for patients and medical professionals. The administrative burden involved in prescribing these medications necessitates having dedicated staff simply to keep up with prior authorizations and appeals. When patients change their insurance provider, one would think a patient who is stable on their DMT would be allowed to continue it. What follows is a recent example of how our increasingly opaque insurance approval process failed a patient of mine.

Dana Campbell, a patient of mine, had been stable on natalizumab for two years. Her MS was well-controlled, with no relapses or signs of progression. She was living independently and managing her condition well. Then, in January, she switched to a new insurance plan. She chose it in part because it offered lower-cost MRI scans, something that seemed like a positive change. She also thought she had the “good insurance” plan with a trusted commercial payer in our state. What she didn’t realize was that natalizumab was not covered under her new plan with a zero-exception step-edit or “fail-these first” formulary restriction that took effect in January.

We immediately appealed the decision, providing clear medical justification for why she needed to stay on natalizumab. The alternative treatments suggested by her insurer weren’t appropriate due to specific medical contraindications, but more importantly, she had already been doing well on natalizumab. There was no clinical rationale to switch her medication.

Despite this, the appeal was denied. What made the situation even more frustrating was that there was no way for me to speak directly with a peer—another neurologist with expertise in MS—about her case. In fact, I could not even speak to anyone. The decision was made by an anonymous reviewer with no opportunity for discussion. It was a bureaucratic process with no room for clinical judgment or individual patient needs. The patient was also ultimately not eligible for the manufacturers’ free drug program.

What followed not long after was a thoracic spinal cord relapse for Ms. Campbell. She experienced weakness and numbness in both legs within 6-8 weeks of coming off her treatment. This required hospitalization and treatment with high dose steroids. She had lingering increased disability for several weeks after this relapse and is just now beginning to ambulate normally again. Late effects of this event will also likely have uncertain effects on her disability status when progression sets in.

Here is what she had to say about the situation:

My name is Petty Officer Dana Campbell, I’m a U.S. Navy Veteran, and I have been living with a Multiple Sclerosis diagnosis for 11 years. During this time, I have developed MS lesions in my brain, brain stem, and cervical spine and have been prescribed several disease modifying drugs that have failed or lost efficacy.

After discussing treatments with my doctor we decided on Tysabri infusions. Since I have a history of breast cancer it was important to choose the right treatment for me. I was receiving Tysabri infusions through my Medicare Advantage insurance plan for almost two years. During this time, my Multiple Sclerosis was stable and I didn’t develop any new lesions.

In 2025, I changed my Medicare Advantage plan from Aetna to Blue Cross Blue Shield of Alabama to be able to afford my MRI copay and so my specialist copays would be more affordable. However, I found out that coverage for Tysabri was suddenly denied. My doctor reached out to them many times with no avail.

This caused me to miss treatments in January and February. At the beginning of March I lost all sensation in my legs and was unable to walk, which caused me to fall several times. I ended up in the emergency room for several days, while being treated with high doses of steroids. This was all frightening and I was dreading that this would be irreversible.

Luckily, I have since regained the use of my legs, through the use of high-dosages of steroids, but an MRI revealed I now have MS lesions on my thoracic spine. I have since discussed and started the "approved" treatment with my doctor, even though it has a breast cancer recurrence warning. I have no idea if this new treatment will work, which is frustrating because I knew that the Tysabri treatment was working.

Today, I’m left worrying whether the paralysis will return and be permanent, or if we will discover evidence of further deterioration.

As a neurology residency program director, I also felt it prudent to include the perspective of a trainee on situations such as this. I spoke with Dr. Daniel Lee, a current PGY3 resident at USA Health:

Q: As a neurology resident, how hopeful are you about the future practice landscape which you are entering?

A: As I enter the last year of my residency, I remain optimistic about the future prospects that neurology has to offer. The field of neurology continues to expand rapidly with cutting edge treatments and technology which ultimately provide great benefits to our patients. However, I believe that as a specialty, we must remain vigilant and ensure that we continue to fund neurology research. Additionally, we have to be able to reasonably provide these treatments for our patients and barriers such as step-therapy and prior authorizations currently limit our ability to do so.

Q: What has been your experience with advocacy as a neurology resident?

A: Advocacy has always been one of my passions since starting medical schools. One of the first mentors who introduced me to advocacy told me "You can only see so many patients in a day, but with advocacy you can change healthcare for millions." That is something I take to heart as I practice clinically and see barriers that physicians and patients face as we try to navigate the healthcare system. With that in mind, I have taken many different roles in advocating at the state level through my state medical association and nationally at the AMA and AAN. I have not only created policy that is now part of the AMA, but I have also met with my congressional representatives and their staff to advocate for common sense reform on a myriad of issues.

As neurology continues to evolve, I have found that care has become more difficult to provide as our field continues to run into issues with coverage for medications. This process is extremely nebulous and difficult to navigate and even the most experienced physicians continued to be plagued by delays due to prior authorization or denials because a certain medication is not preferred by an insurer. As a resident, I've seen patients who have suffered significantly due to the delays in care caused by the aforementioned issues. Additionally, I fear that these continued barriers may impact neurology residents' interest in pursuing subspecialties that often encounter these barriers.

What happened to Ms. Campbell was nothing short of unacceptable, and it is unfortunately not the first time I have seen it. Several patients of mine have faced similar denials of care with medical consequences. There is zero accountability for pharmacy benefit managers or payers when their policies harm our patients.

Adverse outcomes due to denial of care like this should make us all angry. I don’t claim to have the ideal solution to reducing healthcare costs, and techniques such as formulary restriction may have a role. Whichever solutions to this problem are implemented, we must keep the focus first on what is best for our patients.

REFERENCES
Bebo, Bruce et al. “The Economic Burden of Multiple Sclerosis in the United States: Estimate of Direct and Indirect Costs.” Neurology vol. 98,18 (2022): e1810-e1817. doi:10.1212/WNL.0000000000200150