Wave Life Sciences Ltd

Singapore Goods and Services Tax (“GST”) Rate

The issue or transfer of ownership of our ordinary shares would be exempt from GST, although the sale of our ordinary shares by a GST-registered investor may be considered to be a taxable supply subject to GST at 0% if certain conditions are met. Services consisting of arranging, brokering, underwriting or advising on the issue, allotment or transfer of ownership of our ordinary shares rendered by a GST-registered person to an investor belonging in Singapore for GST purposes in connection with the investor’s purchase, sale or holding of our ordinary shares will be subject to GST at the prevailing standard rate of 9%. Similar services rendered by a GST-registered person contractually to an investor belonging outside Singapore and for the direct benefit of an investor belonging outside Singapore or a GST-registered person in Singapore should generally, subject to the satisfaction of certain conditions, be subject to GST at 0%.

Rule 10b5-1 Trading Plans

During the three months ended December 31, 2024, certain of our officers (as defined in Rule 16a-1(f) of the Exchange Act) entered into contracts, instructions or written plans (each, a “Rule 10b5-1 Trading Plan” and collectively, the “Rule 10b5-1 Trading Plans”) for the purchase or sale of our securities that are intended to satisfy the conditions specified in Rule 10b5-1(c) under the Exchange Act for an affirmative defense against liability for trading in securities on the basis of material nonpublic information. We describe the material terms of these Rule 10b5-1 Trading Plans below.

On November 24, 2024, Christian Henry, MBA, Chairman of our Board, adopted a Rule 10b5-1 Trading Plan providing for the sale of up to an aggregate of 105,670 ofour ordinary shares pursuant to the terms of such Rule 10b5-1 Trading Plan. Mr. Henry’s Rule

10b5-1 Trading Plan is active until August 29, 2025, or earlier, if and when all transactions under the Rule 10b5-1 Trading Plan are completed.

On November 25, 2024, Kyle Moran, CFA, our Chief Financial Officer, adopted a Rule 10b5-1 Trading Plan providing for the sale of up to an aggregate of 196,000 of our ordinary shares pursuant to the terms of such Rule 10b5-1 Trading Plan. Mr. Moran’s Rule 10b5-1 Trading Plan is active until June 30, 2025, or earlier, if and when all transactions under the Rule 10b5-1 Trading Plan are completed.

On November 25, 2024, Christopher Francis, Ph.D., our Senior Vice President, Corporate Development, Head of Emerging Areas, adopted a Rule 10b5-1 Trading Plan providing for the sale of up to an aggregate of 435,564 of our ordinary shares pursuant to the terms of such Rule 10b5-1 Trading Plan. Dr. Francis' Rule 10b5-1 Trading Plan is active until November 3, 2025, or earlier, if and when all transactions under the Rule 10b5-1 Trading Plan are completed.

On November 25, 2024, Chandra Vargeese, Ph.D., our Chief Technology Officer, Head of Platform Discovery Sciences, adopted a Rule 10b5-1 Trading Plan providing for the sale of up to an aggregate of 86,972 of our ordinary shares pursuant to the terms of such Rule 10b5-1 Trading Plan. Dr. Vargeese's Rule 10b5-1 Trading Plan is active until August 31, 2025, or earlier, if and when all transactions under the Rule 10b5-1 Trading Plan are completed.