---
schema_version: "secwatch.filing_event.v1"
accession: "0001628280-26-043170"
form_type: "8-K"
ticker: "RYTM"
cik: "0001649904"
company_name: "RHYTHM PHARMACEUTICALS, INC."
filed_at: "2026-06-15T20:07:28+00:00"
generated_at: "2026-06-15T20:08:40.740514+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Rhythm posts positive PWS Phase 2 data; MC4R agonist results at ENDO 2026

## Summary
- Interim Phase 2 PWS: 17 patients; mean BMI -3.06% at 6 months; 8/10 with moderate-severe hyperphagia improved ≥7 on HQ-CT.
- Setmelanotide in acquired HO: -18.9% mean BMI reduction after up to 2.5 years (n=11).
- Oral bivamelagon in HO: -16.6% BMI at 1 year for 600 mg dose (n=7).
- Real-world BBS: 62% of adults achieved ≥10% body weight loss at 12 months (n=286); reduced outpatient visits (p<0.05).
- Company plans Phase 3 development in PWS based on data.

## SEC filing metadata
- accession: 0001628280-26-043170
- form_type: 8-K
- ticker: RYTM
- cik: 0001649904
- company_name: RHYTHM PHARMACEUTICALS, INC.
- filed_at: 2026-06-15T20:07:28+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1649904/000162828026043170/0001628280-26-043170-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1649904/000162828026043170/rytm-20260613.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001628280-26-043170
- JSON: https://secwatch.observer/filing/0001628280-26-043170.json
- Plain text: https://secwatch.observer/filing/0001628280-26-043170.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.