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AI brief of an SEC Form 8-K · Mirum Pharmaceuticals, Inc. (MIRM)

Mirum reports positive Cohort 2 results for ATEBRIOZ in pediatric FOP patients aged 6 to <12

Positive Impact 3 of 5 other Written later

Mirum Pharmaceuticals said its 25-patient Cohort 2 trial of ATEBRIOZ (zilurgisertib) in children aged 6 to under 12 with fibrodysplasia ossificans progressiva showed reduced heterotopic ossification lesion volume and improved joint mobility at Week 24 compared with placebo. The company plans to submit a supplemental New Drug Application in the first half of 2027 to expand the approved indication to this age group.

Key points

  • Mean total HO lesion volume fell 8.09 cm³ with ATEBRIOZ versus a 9.14 cm³ increase with placebo (nominal p=0.003).
  • No ATEBRIOZ-treated patients developed new HO lesions, compared with 1 patient (7.7%) on placebo.
  • Mean CAJIS joint mobility score improved 0.80 points with ATEBRIOZ versus 0.09 points with placebo at Week 24.
  • The company plans a supplemental NDA submission in the first half of 2027; full Cohort 2 results will be presented at an upcoming medical meeting.

The filing

CompanyMirum Pharmaceuticals, Inc. (MIRM)
Form8-K, current report
Filed with the SECOct 26, 2026, 4:47 PM ET
Accession number0001759425-26-000054

Items reported: 8.01 Other Events

Read the filing on SEC.gov ↗

Written by AI on Nov 9, 2026, 11:43 AM ET, from this filing only. Written later: this filing was briefed after the fact, when past filings were added to the site, so the brief may be read with hindsight; the filing itself is the record of what was known on October 26, 2026.

Briefs are written by AI from the filing text and can contain mistakes — open the filing before acting on anything. Impact (1-5) and tone are the AI's reading of the filing for shareholders, not a price forecast. Not investment advice.