SCHEDULE 13G/A

Cabaletta Bio Inc

Common Stock, par value $0.00001 per share · CUSIP: 12674W109

Event date: 2025-09-30

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Alyeska Investment Group, L.P.

  Shares: 5,800,000.00 · Class: 6.03%

• Alyeska Fund GP, LLC

  Shares: 5,800,000.00 · Class: 6.03%

• Anand Parekh

  Shares: 5,800,000.00 · Class: 6.03%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.