Company: SMNR
Filing Date: 2025-08-08
Form Type: S-4/A
Source: 0001193125-25-177097
Chunk: 498

Company: Semnur Pharmaceuticals, Inc.
Filing Date: 2025-08-08
Form: S-4/A
Chunk 498
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 lumbosacral radicular ESI procedures represent 88% of total ESI procedures. ESIs are used when a patient’s pain is inadequately controlled with oral pain medications, topical systems or interventions such as physical therapy. ESIs have demonstrated efficacy in reducing pain, restoring function, reducing the need for other health care and avoiding back surgery. However, in addition to not being FDA-approved for the treatment of sciatica, currently-used ESIs also present various risks and challenges.

When administering an ESI, many physicians use a particulate steroid (including methylprednisolone acetate, triamcinolone acetonide, or betamethasone sodium phosphate or betamethasone sodium acetate) instead of a non-particulate steroid (dexamethasone sodium phosphate) because early studies suggested that the duration of pain relief was longer with the particulates and fewer repeat injections were required, even though dexamethasone is considered an otherwise potent and therapeutically beneficial therapy. Particulate in injectable products is defined as extraneous undissolved particles present in injectable solution products. An example of such particulate is precipitate of insoluble drug product form, or suspended drug product particle. These steroid particles or their aggregates have at least two mechanisms for neurological damage: (1) they can act as emboli if injected into an artery and are of sufficient size to block small terminal arterioles supplying the brain or spinal cord; and (2) several particulate steroids have an immediate and massive effect on microvascular perfusion because of formation of red blood cell aggregates. These emboli can cause rare but catastrophic neurologic injuries including stroke and spinal cord injury that can result in increased pain, severe permanent disability or death. In addition, fungal meningitis has occurred from the injection of steroids manufactured in a compounding pharmacy that did not adhere to sterility standards.

The FDA has been evaluating serious neurologic events with ESIs since 2009, and in 2014, the FDA required a class warning on the currently off-label use of injectable corticosteroids to include information about the risk of serious neurologic events with ESIs. The warning on product labels for all injectable glucocorticoids states that the product is to be used for intramuscular or intravenous purposes only, and specifically includes a warning for serious neurologic adverse reactions with epidural administration. These serious neurologic events have been reported with and without the use of fluoroscopy. The class warning