Discover what this could mean for your patients          ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏
ISEMBYLD brand logo
Now Approved: The First and Only Muscle-Targeted Treatment for SMA1

[Hello/Dear/Hi/Good morning/Good afternoon/Good evening/Greetings] [Dr/Doctor/Miss/Mr/Mrs/Ms] [Type in recipient’s name],

[It’s nice to meet you over email. I want to share some information on ISEMBYLD, a new treatment option for adult and pediatric patients with SMA who are 2 years of age and older and are currently receiving an SMN2‑targeted treatment./I am looking forward to our upcoming meeting. In preparation, I want to share some information on ISEMBYLD, a new treatment option for adult and pediatric patients with SMA who are 2 years of age and older and are currently receiving an SMN2‑targeted treatment. We can review it together in more detail when we meet./It was great to connect with you recently. Based on our conversation, I thought you would be interested in this information on ISEMBYLD, a new treatment option for adult and pediatric patients with SMA who are 2 years of age and older and are currently receiving an SMN2‑targeted treatment./I hope you have been well. I wanted to follow up with the information that we discussed about ISEMBYLD, a new treatment option for adult and pediatric patients with SMA who are 2 years of age and older and are currently receiving an SMN2‑targeted treatment./I’m reaching out to share some information about a new treatment option for adult and pediatric patients with SMA who are 2 years of age and older and are currently receiving an SMN2‑targeted treatment.]

Progressive muscle wasting is a clinical hallmark of SMA,2 and long-term clinical data demonstrate that after initial motor function improvement, many patients with SMA who are on survival motor neuron 2 (SMN2)-targeted treatment experience a period of stabilization, then eventual decline to or below baseline.3,4
ISEMBYLD is indicated for the treatment of SMA in adults and pediatric patients 2 years of age and older who are currently receiving an SMN2‑targeted treatment.1
ISEMBYLD demonstrated clinically meaningful gains in motor function1
SAPPHIRE was a pivotal, phase 3, randomized, double-blind, placebo-controlled, multicenter study in patients with SMA aged 2-21 years (N=188).1
The main efficacy population consisted of 156 patients aged 2-12 years; 53 were randomized to receive ISEMBYLD 10 mg/kg (the recommended dose) via intravenous infusion once every 4 weeks for approximately 52 weeks, and 50 were randomized to receive placebo. All patients were receiving an approved SMN2-targeted treatment (nusinersen or risdiplam).1
Primary endpoint was mean change from baseline at 52 weeks in the Hammersmith Functional Motor Scale—Expanded (HFMSE), the most widely studied motor function scale in SMA.1,5
  • ISEMBYLD (10 mg/kg) with an SMN2-targeted treatment (n=53) showed a clinically meaningful 2.2-point improvement in HFMSE score over SMN2-targeted treatment alone (n=50) at 1 year (nominal P value=0.0121) in patients aged 2-12 years. Treatment effect was consistent across predefined subgroups including adults and adolescents.*
*The adults and adolescent subgroup was defined as individuals in the study aged 13-21 years.
INDICATION
ISEMBYLD (apitegromab-mstn) is indicated for the treatment of spinal muscular atrophy (SMA) in adults and pediatric patients 2 years of age and older who are currently receiving a survival motor neuron 2 (SMN2)‑targeted treatment.
IMPORTANT SAFETY INFORMATION
WARNINGS AND PRECAUTIONS
Fractures
ISEMBYLD may increase the risk of fractures, including serious fractures. Use with caution in patients with a history of low bone density or multiple fractures. In patients who experience fractures, weigh the risks and benefits of continuing ISEMBYLD.
ADVERSE REACTIONS
The most common adverse reactions (incidence ≥20% of patients treated with ISEMBYLD and more frequent than placebo) were upper respiratory tract infections, vomiting, cough, other viral infections, headache, gastroenteritis, pharyngitis, and hypersensitivity.
USE IN SPECIFIC POPULATIONS
Pregnancy and Lactation
Based on animal data, ISEMBYLD may cause fetal harm. There are no adequate data on the developmental risk associated with the use of ISEMBYLD in pregnant women.
There are no data on the presence of ISEMBYLD in human milk, the effects on the breastfed infant, or the effects of the drug on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for ISEMBYLD, and any potential adverse effects on the breastfed infant.
Females and Males of Reproductive Potential
Based on animal data, ISEMBYLD may affect male and/or female reproductive function.
Please see full Prescribing Information.

[I’d like to discuss further the recent FDA approval of ISEMBYLD, the first muscle-targeted treatment in SMA. Please let me know the date, time, and location that is best for you, and I will follow up with a meeting invitation./I look forward to meeting with you soon–and please reach out with any questions in the meantime./Let’s talk further about how ISEMBYLD could benefit children and adults with SMA. Please let me know the best date, time, and location for you, and I will follow up with a meeting invitation.]

[Sincerely] [Best] [Regards],
[Scholar Rock field team member first name and last name]
[Scholar Rock field team member title]
[Scholar Rock field team member phone number]
[Scholar Rock field team member email address]
In accordance with applicable state law, pricing information for ISEMBYLD (apitegromab-mstn) is available here.
References:
1. ISEMBYLD. Prescribing information. Scholar Rock, Inc; 2026. 2. Wirth B, Mendoza-Ferreira N, Torres-Benito L. Spinal muscular atrophy disease modifiers. In: Sumner CJ, Paushkin S, Ko CP, eds. Spinal Muscular Atrophy: Disease Mechanisms and Therapy. Elsevier; 2017:191-210. 3. Finkel RS, Mercuri E, Meyer OH, et al. Diagnosis and management of spinal muscular atrophy: Part 2: pulmonary and acute care; medications, supplements and immunizations; other organ systems; and ethics. Neuromuscul Disord. 2018;28(3):197-207. 4. Servais L, Day JW, Deconinck N, et al. SUNFISH parts 1 and 2: 5-year efficacy and safety data of risdiplam in types 2 and 3 spinal muscular atrophy (SMA). Poster presented at: Muscular Dystrophy Association (MDA) Clinical and Scientific Conference; March 16-19, 2025. Dallas, TX. 5. Wu J, Pepler L, Maturi B, et al. Systematic review of motor function scales and patient-reported outcomes in spinal muscular atrophy. Am J Phys Med Rehabil. 2022;101:590-608.
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US-APIT-0297 09/26
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