SMA Treatment Delay FAQ
Last Updated: 03/31/26
We know our community has many pressing questions related to the FDA approval delay of Scholar Rock’s apitegromab. This FAQ was developed to address the most common concerns and provide the latest updates as we continue to work closely with Scholar Rock and the FDA.
Biogen's High Dose SPINRAZA (nusinersen), originally featured on this FAQ page, has been removed due to its FDA approval. Learn more about this approval here.
What is Cure SMA doing?
Cure SMA continues to regularly engage with and seek answers from the FDA and the companies regarding the treatment's next steps and timelines. We are also mapping out possible actions where we can have influence and impact, including elevating the urgent needs and goals of the SMA community. Please watch for future updates through Cure SMA. For more information on Cure SMA’s drug pipeline, please visit here.
Usually, after a CRL re-submission has been received (and accepted) by the FDA there is either a 2 month or a 6 month timeline for the FDA to decide on whether to approve. This is an area that Cure SMA will be working on now, to look for opportunities to get the FDA to work for a faster decision than the normal regulated periods.
We have recently conducted some direct advocacy initiatives with the new head of CDER at the FDA, along with several outreach efforts to legislative champions in the House and Senate. We expect to increase and broaden these efforts over the next weeks and months based on the decisions and timelines received back from the FDA on resubmission.
Cure SMA was present and active at the Type A FDA meeting on Apitegromab to represent our community to ensure that the patient voice and the patient need were heard and factored into decisions. In particular, stressing the urgency needed to address unmet needs across the entire age spectrum in SMA.
FDA History
References
August 2025
Cure SMA shares patient voice and needs with FDA
https://www.curesma.org/cure-sma-shares-patient-voice-and-needs-with-fda/
March 2025
SMA Community Risk Tolerance Update – Comparison of 2022 and 2017 SMA risk-Benefit Survey Data
https://www.curesma.org/sma-community-risk-tolerance-update-comparison-of-2022-and-2017-sma-risk-be…
https://www.curesma.org/wp-content/uploads/2025/02/SMA-Community-Risk-Tolerance-Update_02.25.pdf
July 2024
State of SMA Report (sent to FDA)
https://www.curesma.org/wp-content/uploads/2024/06/9042024_State-of-SMA_vWeb.pdf
August 2022
Cure SMA holds patient-led listening session with FDA
https://www.curesma.org/cure-sma-holds-patient-led-listening-session-with-fda/
If there are issues with the manufacturing - should those people who are on current dosage or through trials or EAP be concerned about the safety?
No, there are no current concerns with current approved product or product made for trials or EAP programs.
I would like to better understand what is meant by the reference to "unexpected manufacturing-related issues" in the context of FDA approval. My understanding is that capacity or supply chain limitations would not typically affect the FDA's decision to approve a pharmaceutical product. Should this instead be interpreted as concerns related to the quality, consistency, or sourcing of raw materials used in the manufacturing process?
This is correct that the FDA approvals are not linked to capacity items around making enough of new treatments. But they are involved in reviewing the quality and consistency of the manufacturing processes to make the new treatments. This is sometimes done in-person at the actual manufacturing sites and also with the documentation that tracks and details the specific manufacturing processes.
When will this drug and others that are not available, finally be available to Type 1 young adults?
While the issues raised here from the FDA are not about any concerns with efficacy or safety (which is a good thing, as those would significantly slow or stop this program), we do not have any new information yet on what the labels would be if and when they do get approved. However, we have been doing a lot of advocacy work over the last two years to reinforce the needs for approvals and labels to cover all with SMA, and especially those who are older in our community.
When is it realistic to expect approvals after this delay?
We do not know for certain, but based on past FDA actions, an approval decision on a re-submitted application could occur as soon as 3 to 5 months (under a shorter re-review process) or within 9 to 12 months (under a longer re-review process)
Apitegromab from Scholar Rock
On September 23, 2025, Scholar Rock announced that the U.S. Food and Drug Administration (FDA) has delayed the approval with a Complete Response Letter (CRL) for the apitegromab Biologics License Application (BLA) for the treatment of people living with spinal muscular atrophy (SMA). To read Scholar Rock's initial community statement, please click here. To read Scholar Rock's updated community statement as of 10/29/25, please click here.
On November 12, 2025, Scholar Rock, alongside Cure SMA, held an in-person Type A meeting with the FDA to discuss next steps for BLA resubmission. To read Scholar Rock’s community statement on these latest BLA updates, please click here.
On March 31, 2026, Scholar Rock announced that it had resubmitted its Biologics License Application (BLA) to the Food and Drug Administration (FDA) for apitegromab.
Below are answers from Scholar Rock addressing initial questions from the SMA community.
What is a Biologics License Application?
A Biologics License Application (or BLA) is an application submitted to the U.S. Food and Drug Administration (FDA) seeking approval to make a treatment available in the United States.
What is a BLA resubmission?
A BLA resubmission is an updated application that includes additional information requested by the FDA after a previous review. It is important to note that a resubmission does not guarantee BLA acceptance.
What does it mean if the BLA is accepted?
BLA acceptance means that the FDA has determined the application is complete enough to begin full review. BLA acceptance is an important step in the regulatory process but does not guarantee approval by the FDA.
Does BLA resubmission mean that the application has been accepted?
No, the FDA must first review the resubmitted BLA to determine whether it is complete before starting a full review. We will share more information as the process proceeds.
When will the FDA decide to accept the BLA?
We expect the FDA to determine acceptance of the apitegromab resubmission within 30 days. Scholar Rock will update the community as information becomes available.
When will the FDA issue an approval decision?
If the BLA is accepted, the FDA will begin a full review of the application. We anticipate up to a six-month review period from the date of resubmission, with a regulatory decision date expected in late September 2026.
If approved, who will be eligible for apitegromab?
Eligibility for apitegromab will depend on the FDA-approved label.
What about patients outside the U.S.?
In Europe, the European Medicines Agency (EMA) review of our application for apitegromab is ongoing, with a decision anticipated in mid-2026.
Why did Scholar Rock need to resubmit its BLA?
As previously shared in September 2025, Scholar Rock received a Complete Response Letter (CRL) solely related to observations identified during an inspection of a third-party fill-finish manufacturing facility. This facility is operated by Catalent Indiana, LLC (part of Novo Nordisk).
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- The observations were not specific to apitegromab.
- The FDA did not raise concerns regarding efficacy or safety data.
- The observations were not related to the drug substance manufacturer.
What changed between your first BLA submission and this resubmission?
- Our BLA resubmission follows constructive and collaborative interactions, including an in-person Type A meeting in November 2025 and a meeting between Catalent Indiana and the FDA early in the first quarter of 2026. No additional corrective actions were requested by FDA during that meeting.
- Our resubmission also now includes a second U.S.-based fill-finish manufacturing facility for apitegromab, which is intended to strengthen our supply chain and support demand in the future. The inclusion of the second facility follows a constructive Type C meeting between Scholar Rock and the FDA, which occurred on March 3, 2026.
- The apitegromab BLA resubmission is aligned with FDA guidance from the March 3, 2026 Type C meeting.
- Updates to the apitegromab BLA for the resubmission were limited in scope and primarily composed of a standard safety update.
What is a Type C meeting?
- A Type C meeting is a meeting between the FDA and a new drug applicant and is requested by the applicant to discuss the development and review of a new product.
- A Type C meeting offers the opportunity to discuss important aspects of drug development programs, outside of the more structured Type A and B meeting formats.
How was it decided to resubmit the BLA now?
- As a reminder, the sole approvability issue for apitegromab noted in the CRL was related to observations identified at the Catalent Indiana fill-finish manufacturing facility, owned and operated by Novo Nordisk. After our in-person Type A Meeting with the FDA, where we were joined by Cure SMA and Novo Nordisk, we have been gratified by the shared sense of urgency to bring apitegromab through the final step in the U.S. regulatory process.
- Since that Type A meeting, we have made steady and rapid progress. This has enabled us to resubmit our BLA in alignment with the FDA to include Catalent Indiana and Scholar Rock’s additional fill-finish manufacturing facility, reflecting the meaningful progress at both fill-finish facilities.
- The decision to resubmit our BLA was made in alignment with the FDA and following an FDA site visit to Catalent Indiana where no additional corrective actions were requested by the FDA to the site remediation plan. FDA also stated that it intends to conduct a site reinspection following routine manufacturing activities – which resumed in late February.
- Based on this progress, we were pleased to align with the FDA to resubmit our BLA prior to reinspection.
Why was the second fill finish added to the resubmission?
- Scholar Rock had always planned to onboard a second fill-finish facility. The addition of this facility reflects our efforts to strengthen supply continuity and support future demand.
- The second facility currently manufactures FDA-approved products and has a strong regulatory inspection track record.
Definitions:
Class 2 Resubmission review: The FDA’s standard six-month review timeline for a resubmission.
Class 1 Resubmission review: The FDA’s standard three-month review timeline for a resubmission
Complete Response Letter - CRL: The FDA’s way of saying “revise and resubmit” – aspects of the application need to be updated before FDA can complete its review and make a decision. The details of a CRL vary across drug applications. Receiving a CRL means that the review of the BLA or NDA has stopped and the FDA review will only continue when changes have been made and resubmitted. Once a BLA or NDA is resubmitted, a new review cycle starts.
CMC (Chemistry, Manufacturing, and Controls): What does CMC mean? In drug development, chemistry relates to the drug substance itself – its molecular structure, purity and stability. Manufacturing covers all the processes involved in producing the drug, from synthesizing the active ingredients to formulating the final product. Controls are the procedures put in place to guarantee that the drug consistently meets predefined quality standards throughout its entire lifecycle including determining its shelf life and storage conditions.