Alisha A. Alaimo
President, Head of North America at Biogen
Thank you, Chris. Good morning to everyone that's able to join the call today. I'm Alisha Alaimo, and as Chuck shared, I lead our business in North America. This is a really unique period in Biogen's history with multiple first-in-class drug launches in the U.S., which gives us an opportunity to drive our return to growth. And for our team, it's also meaningful to support more people living with Alzheimer's, Friedreich's ataxia, and postpartum depression. We thought it might be helpful to provide a perspective on the market dynamics of the launches and share how we're seeking a tailored approach to help provide patients with access to our therapies.
Let me begin with the Alzheimer's market. As Chris mentioned, we are seeing many major health systems across the country take a deliberate staged and phased approach, meaning they are setting up their pathways to get patients started with diagnosis, treatment, and monitoring. We believe we are now seeing a dynamic where some IDNs are turning the page and they are focusing on expanding and extending their model. In Q1, we saw several IDNs across regions scale their patient volume. Among our priority 100 IDNs, units more than tripled in quarter one compared to quarter four, which contributed to the overall estimated patients on therapy increasing approximately 2.5 times in quarter one versus quarter four. We believe this acceleration in new patients really began to emerge at the end of the quarter.
For example, more than 20% of new patients since launch were added in March. Today, among our 100 priority IDNs, more than 80% have approved LEQEMBI through their P&T process and nearly 85% of those IDNs with approval have placed an order. Chris also mentioned that we're seeing more physicians gain experience with LEQEMBI. We saw the number of unique prescribers in quarter one double compared to quarter four. We believe that we're still in the early phases of unlocking the potential to treat a high volume of patients at the priority IDNs. And I thought it might be helpful to share some examples of these dynamics at the site level.
There is one large health system in the Midwest that added LEQEMBI to its formulary in July of last year. Six months later, entering Q1, this system had ordered only 300 units. However, by the end of March, they had ordered 2,700 units. Similar to the example I just shared, there is also a health system in the Southeast that added LEQEMBI to its formulary in August of '23. Five months later, entering Q1, the system ordered about 560 units. By the end of Q1, this system ordered more than 1,750 units to treat their patients. For context, a local neurologist network in that same region ordered 3,000 units through the same time period, perhaps because they've been able to scale their processes to treat more patients. However, we believe this well-known Southeast IDN is planning to move beyond their flagship side of care to treat at multiple locations, which is another example of the expand and extend trend at the IDNs.
We believe many systems just now appear to be completing the staging phase. And we think the recent trends observed support our continued belief that LEQEMBI represents a significant commercial opportunity over the mid to longer term. With access and infrastructure progressing and patient volume accelerating, we believe this is also the right time to expand the field force. Biogen leaders are working to hire a customer-facing field team, which will join Eisai.
Simultaneously to activate the patient community, Biogen and Eisai have launched new direct-to-patient and caregiver omnichannel marketing campaigns. These digital programs and point-of-care resources are focused on the already-diagnosed patients, who we believe are under the care of a neurologist. With these promising signals emerging, we look forward to providing more updates in the future.
Now moving to SKYCLARYS. We believe we're driving strong performance with the launch as we continue to exceed market penetration rates of most rare disease launch analogs. As of April 19, we now have over 1,100 patients on therapy. With an estimated 4,500 addressable Friedreich's ataxia patients in the U.S., we have achieved 24% market penetration, which exceeds our own strong SPINRAZA launch. As is typical with rare disease launches, we believe we are now moving beyond the catch-up population to reach additional patients who previously received a diagnosis of or are suspected to have Friedreich's ataxia. Though patient numbers may be uneven, we anticipate adding patients each month.
Last quarter, we shared how we've integrated some of our sophisticated rare disease capabilities to drive improvements in access, logistics and patient support. Notably, our market access team continued to make progress with securing favorable policies in quarter one. Today, nearly 80% of all U.S. pharmacy lives now have SKYCLARYS reimbursement. These patient support and access efforts are critical to help patients start therapy as soon as possible and remain on treatment for the long term.
With a meaningful foundation of patients on therapy, we are focusing on two key areas in this next phase of our launch. First, educating community neurologists and PCPs about Friedreich's ataxia and SKYCLARYS; and second, engaging additional appropriate patients. I'll begin with our focus on HCPs. Remember with Friedreich's ataxia, in addition to patients being concentrated the top centers of excellence, we believe they are also being treated in the community. To support these physicians, we've expanded our field footprint and we are using AI to analyze data to help reach the HCPs who may have untreated patients. With insights into the relevant sites of care and when patients last engage with their physician, we believe we can help more patients even sooner. And with genetic testing, we anticipate patients can confirm a potential diagnosis and determine if SKYCLARYS is a treatment option.
As far as our patient activation focus, we are encouraged by real-world experiences that patients are sharing on social media, as in our experience, these stories can help other diagnosed patients. Many of these stories about the impact of SKYCLARYS include reports of slowing of disease progression, and in some cases, even an improvement in their symptoms long term. In addition to these organic stories, we anticipate launching our SKYCLARYS social media campaign soon. So we believe we're off to a strong start, but we know there are more people living with Friedreich's ataxia that we can help. And we look forward to supporting them, which now brings me to ZURZUVAE.
As Chris mentioned, we are encouraged by the performance of the launch to date and we think we are seeing several positive trends with providers, patient experience, and reimbursement. First, let me begin with providers. Across multiple physician types, we believe many providers are demonstrating an urgency to treat. Notably, OB-GYNs led overall prescribing in quarter one, which we believe is encouraging as they are often the first to see PPD patients. Furthermore, breadth of adoption has continued to grow. In March, nearly double the number of HCPs prescribed ZURZUVAE compared to just January. We've seen that some early prescribers require only a few calls before they treat. Keep in mind that ZURZUVAE is a scheduled product available through a specialty pharmacy. While we believe psychiatrists are generally familiar with working with specialty pharmacy, this could be a new process for many OB-GYNs. We're working to educate these providers on the steps required so that they can support their appropriate patients.
Second, some HCPs have early experience with ZURZUVAE have shared that some of their patients reported significant improvement in depressive symptoms within days of starting treatment. Several patients are sharing their personal 14-day treatment experiences on platforms like TikTok, and we believe their courage to tell their story will help educate other women living with postpartum depression.
Third, we believe we're making good progress with government and commercial access. Many payers already have policies in place, the majority of which have been favorable, while some others continue to cover ZURZUVAE even without formal policies in place. Two of the three national pharmacy benefit managers are providing coverage for ZURZUVAE without overly burdensome restrictions. We are in active discussions with the third national PBM as we await their decision. And while Medicaid tends to take longer, almost half of the states, including several of the largest, accelerated reviews into quarter one, which we believe is unusual for a process that can typically take up to a year after FDA approval. We are encouraged that approximately two-thirds of Medicaid lives with published policies appear to have minimal access restrictions. We anticipate the remaining states will review coverage throughout 2024, and we will continue to support their reviews as much as possible.
Before handing it over to Mike, I want to underscore that we have an important responsibility to help people living with Alzheimer's, Friedreich's ataxia, and postpartum depression. And we are working with urgency to help these patient communities. We believe we're making significant progress in that mission, and we look forward to continuing to share updates with you.
With that, I'd like now to pass it over to Mike.