CIEN: Material agreement · New financial obligation · Unregistered securities sale · Other company developments

ITEM 1.01 - ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT Indenture and Notes On June 11, 2026, Ciena Corporation (the “Company”) closed its previously announced private offering (the “Offering”) of $2.875 billion aggregate principal amount of the Company’s 0.00% Convertible Senior Notes due 2031 (the “Notes”), which includes $375.0 million aggregate principal amount of Notes issued in connection with the initial purchasers’ full exercise of their option to acquire additional Notes, pursuant to an indenture, dated June 11, 2026 (the “Indenture”), among the Company, the guarantors named therein and U.S. Bank Trust Company, National Association, as trustee. The Notes are fully and unconditionally guaranteed, on a senior unsecured basis, by each wholly-owned domestic subsidiary of the Company that currently or in the future guarantees its 4.00% senior notes due 2030 or any refinancing of such notes. The Notes will not bear regular interest and the principal amount of the Notes will not accrete. The Notes will mature on September 15, 2031 unless earlier converted, redeemed or repurchased. The initial conversion rate for the Notes is 1.3393 shares of the Company’s common stock per $1,000 principal amount of Notes (equivalent to an initial conversion price of approximately $746.66 per share of the Company’s common stock), subject to adjustment. In connection with the Offering, the Company received gross proceeds of $2.875 billion and net proceeds, after initial purchasers’ discounts and payment of the net cost of the convertible note hedge transactions (as partially offset by the proceeds of the warrant transactions received by the Company) and before offering expenses, of approximately $2.72 billion. The Company used approximately $140.0 million of the net proceeds from the Off