EXHIBIT A

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a statement on Schedule 13G (including amendments thereto) with respect to shares of Common Stock, par value $0.001 per share, of Rein Therapeutics, Inc., and further agree that this Joint Filing Agreement be included as an Exhibit to such joint filings.

In evidence thereof, the undersigned, being duly authorized, have executed this Joint Filing Agreement as of August 14, 2026.