SCHEDULE: RA Capital Maintains 8.7% Stake in Rhythm Pharma

RA Capital Management and its affiliates reported a continued 8.7% beneficial ownership stake in Rhythm Pharmaceuticals, Inc. as of June 30, 2025.

Summary

• RA Capital Management, L.P., Peter Kolchinsky, Rajeev Shah, and RA Capital Healthcare Fund, L.P. (collectively, the "Reporting Persons") filed an Amendment No. 7 to Schedule 13G.
• The Reporting Persons collectively beneficially own 5,561,359 shares of Rhythm Pharmaceuticals, Inc. Common Stock.
• This represents 8.7% of the Issuer's Common Stock outstanding.
• The percentage is based on 63,621,472 shares outstanding as of April 30, 2025, as reported in the Issuer's Form 10-Q filed on May 7, 2025.
• RA Capital Healthcare Fund, L.P. directly holds the shares.
• RA Capital Management, L.P. serves as the investment adviser for the Fund and holds sole voting and dispositive power over the shares.
• Peter Kolchinsky and Rajeev Shah are controlling persons of RA Capital Management GP, LLC, the general partner of RA Capital Management, L.P.
• The Reporting Persons expressly disclaim status as a "group" for purposes of this Schedule 13G.

Sentiment

Score: 6

Explanation: The filing is a routine disclosure of beneficial ownership by a significant institutional investor. While it doesn't provide direct operational or financial sentiment, the continued substantial stake (8.7%) by a specialized healthcare fund like RA Capital Management can be interpreted as a neutral to slightly positive signal of their ongoing conviction in the company.

Positives

• A significant 8.7% stake held by a specialized healthcare investment firm like RA Capital Management may signal confidence in Rhythm Pharmaceuticals' long-term prospects.

Negatives

• NA

Risks

• The filing itself does not detail specific risks related to Rhythm Pharmaceuticals' operations or financial health, as it is a beneficial ownership report.

Future Outlook

This filing is a disclosure of beneficial ownership and does not contain forward-looking statements or guidance regarding Rhythm Pharmaceuticals' future performance or strategic outlook.

Industry Context

RA Capital Management is a prominent investment firm focused on the healthcare and life sciences sectors, particularly biotechnology. Their significant stake in Rhythm Pharmaceuticals aligns with their investment strategy in companies developing novel therapies. This filing indicates continued institutional interest in the biotechnology space.

Comparison to Industry Standards

• NA This filing is a disclosure of beneficial ownership and does not contain performance metrics for comparison.

Stakeholder Impact

• Shareholders: Provides transparency regarding significant institutional ownership, which can influence market perception and liquidity.
• Investment Professionals: Offers insight into the holdings of a notable healthcare-focused investment firm, potentially informing their own investment decisions.

Key Dates

Keywords

Rhythm Pharmaceuticals, RA Capital Management, Beneficial Ownership, Institutional Investor, Biotechnology, Healthcare Investment, Common Stock, SEC Filing, Schedule 13G