[Janus Letterhead]

October 24, 2019

EDGAR Operations Branch

Securities and Exchange Commission

Division of Investment Management

100 F Street, N.E.

Washington, D.C. 20549-0505

Dear Sir or Madam:

On behalf of the Registrant, and pursuant to Rule 497(e) under the Securities Act of 1933, as amended (the “1933 Act”), transmitted herewith for filing is an interactive data file in the manner provided by Rule 405(b)(2) of Regulation S-T and General Instruction C.3.(g) of Form N-1A, containing the risk/return summary information provided in the Supplement dated October 15, 2019 to the currently effective Prospectus for Janus Henderson Short Duration Income ETF filed pursuant to Rule 497(e) under the 1933 Act.

Please call me at (303) 336-5065 with any questions or comments.

Respectfully,

/s/ James D. Kerr

James D. Kerr

Assistant Secretary

Enclosures (via EDGAR only)

cc:

Byron Hittle, Esq.

Eric Purple, Esq.