Item 1.

(a)     Ciena Corp

(b)     7035 Ridge Road
        Hanover, Maryland 21076
	United States

Item 2.

(a) Platinum Investment Management Limited

(b) Level 8, 7 Macquarie Place
    Sydney NSW 2000
    Australia
(c) Australia
(d) Common Stock
(e) 171779309

Item 3.
(e) An IA in accordance with Section 240.13d-1(b)(1)(ii)(e)

Item 4.

(a) 7,229,200
(b) 7.0%
(c) (i) 6,582,220
(ii) 0
(iii) 7,229,200
(iv) 0

Item 5
No

Item 6
The clients of Platinum Investment Management Ltd including pooled
investment vehicles and other managed accounts have the right to
receive or power to direct the receipt of dividends from, and the
proceeds from the sale of, Ciena Corp.

Item 7
N/A

Item 8
N/A

Item 9
N/A


Item 10
(a) By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were acquired and are held
in the ordinary course of business and were not acquired and are not
held for the purpose of or with the effect of changing or influencing
the control of the issuer of the securities and were not acquired and
are not held in connection with or as a participant in any transaction
having that purpose or effect.
(b) N/A


After reasonable inquiry and to the best of my
knowledge and belief, I certify that the information
set forth in this statement is true, complete and correct.