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SCHEDULE 13D Filed 2026-06-18 Event 2026-06-11 SEC 0001346824-26-000178 →

RA CAPITAL MANAGEMENT, L.P. Parabilis Medicines, Inc. PBLS

Stake: 23.80% Shares: 28,933,371 CUSIP: 698955101 Class: Common Stock, par value $0.0001 per share

Item 4 — Purpose of Transaction

The Reporting Persons acquired the voting common stock reported herein for investment purposes and not with an intent, purpose or effect of changing control of the Issuer. The Reporting Persons may, from time to time, acquire additional equity securities or debt securities of the Issuer, which debt securities may be convertible or non-convertible, secured or unsecured, and could involve the monetization of potential revenue streams deriving from development-stage or commercial programs of the Issuer, or dispose of Issuer securities they beneficially own, on the open market or in private transactions or otherwise (including by means of 10b5-1 programs), consistent with their investment purposes and in amounts, on such terms and at such times as to be determined by the Reporting Persons based upon a number of factors, including, without limitation, their ongoing assessment of the Issuer's business prospects, the availability of Issuer securities at prices that would make the purchase or sale of such securities desirable, prevailing market conditions, the availability of other investment opportunities, and/or other considerations. In addition, consistent with their investment purpose, the Reporting Persons may engage in communications with persons associated with the Issuer, including stockholders of the Issuer, officers of the Issuer, members of the board of directors of the Issuer, and/or or other third parties, to discuss matters regarding the Issuer, including but not limited to its operations, strategic direction, governance or capitalization, and potential business combinations or dispositions involving the Issuer or certain of its businesses. Dr. Jake Simson, a Partner of RA Capital, currently serves as a director of the Issuer and therefore will engage in regular discussions with the Issuer's board of directors and management as part of his duties as a director. Neither Dr. Simson (other than in his capacity as a director) nor the Reporting Persons have any present plans or proposals that relate to, or could result in, any of the matters referred to in paragraphs (a) through (j), inclusive, of the instructions to Item 4 of Schedule 13D. Depending on various factors including, without limitation, the Issuer's financial position, results and strategic direction, actions taken by the Issuer's management and Board, other investment opportunities available to RA Capital, the price levels of the Issuer securities, conditions in the securities markets and general economic and industry conditions, the Reporting Persons may change their purpose and formulate and implement plans or proposals with respect to the Issuer at any time and from time to time. Any such action may be made by the Reporting Persons alone or in conjunction with other stockholders, potential acquirers, financing sources and/or other third parties and could include one or more purposes, plans or proposals that relate to or would result in actions required to be reported herein in accordance with Item 4 of Schedule 13D.

Cross-References

Insider Activity (last 365d)
0 transactions
0 buys · 0 sales · 0 awards/exercises
Issuer Cluster
1 13D/G filings on this issuer
0 other filings besides this one
Filer Track Record
78 filings by this filer
77 other filings in the data moat
Short Interest · settle 2026-07-15
DTC 8.30
3,954,390 shares short · +42.8% vs prior

Post-Filing Returns · since 2026-06-11 on PBLS

+1 day
0.0%
+5 days
0.0%
+30 days
-2.4%
+60 days
+90 days
+180 days

Anchor price 30.35 on closest trading day on/after 2026-06-11. Source: Yahoo Finance daily adj_close (split + dividend adjusted).

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Showing 20 of 77

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