WVE · Wave Life Sciences Ltd.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2026.

The price reflected is the weighted-average sale price for stock sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $5.16 to $5.42 per share. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2026.

On August 11, 2026, the reporting person sold 432 shares of common stock solely to cover taxes associated with the vesting of restricted stock units on August 11, 2026. These sales were made pursuant to a previously adopted 10b5-1 Trading Plan.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2026.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2026.

These stock options are fully vested.

On August 11, 2026, the reporting person sold 3,864 shares of common stock solely to cover taxes associated with the vesting of restricted stock units on August 11, 2026. These sales were made pursuant to a previously adopted 10b5-1 Trading Plan.

The price reflected is the weighted-average sale price for stock sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $6.01 to $6.03 per share. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $6.305 to $6.665 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, Dr. Kolchinsky and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein.

Held directly by the Fund.

The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $6.09 to $6.74 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, Dr. Kolchinsky and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein.

Held directly by the Fund.

The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $6.365 to $6.40 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, Dr. Kolchinsky and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein.

Held directly by the Fund.

The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $5.365 to $6.36 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, Dr. Kolchinsky and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein.

Held directly by the Fund.

The sole holder of Wave's Series A preferred shares, SNBL USA, Ltd. ("SNBL USA") and Shin Nippon Biomedical Laboratories, Ltd. ("SNBL"), elected to convert its Series A preferred shares into ordinary shares on a one-for-one basis on March 23, 2026. Due to processing issues among the Issuer's vendors, complicated by the time difference with Singapore, the date of the conversion was not confirmed to be effective until well after March 23, 2026.

Includes (i) 2,100,000 shares held by SNBL USA and (ii) 1,801,348 shares held by SNBL.

Includes an aggregate of (i) 6,107,593 shares held by SNBL USA and (ii) 3,498,815 shares held by SNBL.

Ken Takanashi, a director of the Issuer, is a director of SNBL USA and SNBL and Mr. Takanashi may be deemed to beneficially own the reported securities held by SNBL USA and SNBL. Pursuant to Rule 16a-1 under the Securities Exchange Act of 1934, as amended (the "Act"), Mr. Takanashi disclaims beneficial ownership of the reported securities held by SNBL USA and SNBL, except to the extent of his pecuniary interest therein. The filing of this Form 4 shall not be construed as an admission that Mr. Takanashi is or was for the purposes of Section 16(a) of the Act, or otherwise, the beneficial owner of any of the reported securities held by SNBL USA or SNBL.

The sole holder of Wave's Series A preferred shares, SNBL USA, Ltd. ("SNBL USA") and Shin Nippon Biomedical Laboratories, Ltd. ("SNBL"), elected to convert its Series A preferred shares into ordinary shares on a one-for-one basis on March 23, 2026. Due to processing issues among the Issuer's vendors, complicated by the time difference with Singapore, the date of the conversion was not confirmed to be effective until well after March 23, 2026.

Includes (i) 2,100,000 shares held by SNBL USA and (ii) 1,801,348 shares held by SNBL.

Ken Takanashi, a director of the Issuer, is a director of SNBL USA and SNBL and Mr. Takanashi may be deemed to beneficially own the reported securities held by SNBL USA and SNBL. Pursuant to Rule 16a-1 under the Securities Exchange Act of 1934, as amended (the "Act"), Mr. Takanashi disclaims beneficial ownership of the reported securities held by SNBL USA and SNBL, except to the extent of his pecuniary interest therein. The filing of this Form 4 shall not be construed as an admission that Mr. Takanashi is or was for the purposes of Section 16(a) of the Act, or otherwise, the beneficial owner of any of the reported securities held by SNBL USA or SNBL.

The option vests as to 25% of the shares on February 5, 2025, and vests as to an additional 6.25% of the shares quarterly thereafter until February 5, 2028.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The option vests as to 25% of the shares on February 17, 2024 and vests as to an additional 6.25% of the shares quarterly thereafter until February 17, 2027.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $15.00 to $15.10 per share. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

On February 9, 2026, the reporting person sold 1,883 ordinary shares solely to cover taxes associated with the vesting of restricted share units ("RSUs") on February 8, 2026. These sales were made pursuant to a provision in the reporting person's RSU agreement that requires automatic sales of shares to cover tax withholding obligations.

On February 9, 2026, the reporting person sold 3,588 ordinary shares solely to cover taxes associated with the vesting of restricted share units ("RSUs") on February 8, 2026. These sales were made pursuant to a provision in the reporting person's RSU agreement that requires automatic sales of shares to cover tax withholding obligations.

On February 9, 2026, the reporting person sold 3,228 ordinary shares solely to cover taxes associated with the vesting of restricted share units ("RSUs") on February 8, 2026. These sales were made pursuant to a provision in the reporting person's RSU agreement that requires automatic sales of shares to cover tax withholding obligations.

On February 9, 2026, the reporting person sold 10,480 ordinary shares solely to cover taxes associated with the vesting of restricted share units ("RSUs") on February 8, 2026. These sales were made pursuant to a provision in the reporting person's RSU agreement that requires automatic sales of shares to cover tax withholding obligations.

The option vests as to 25% of the shares on February 8, 2027, and vests as to an additional 6.25% of the shares quarterly thereafter until February 8, 2030.

The option vests as to 25% of the shares on February 8, 2027, and vests as to an additional 6.25% of the shares quarterly thereafter until February 8, 2030.

Consists of restricted share units (RSUs). The RSUs vest in four equal annual installments of 25% on February 8, 2027 through February 8, 2030.

Consists of restricted share units (RSUs). The RSUs vest in four equal annual installments of 25% on February 8, 2027 through February 8, 2030.

Includes 1,983 ordinary shares acquired on January 14, 2026, under the issuer's 2019 Employee Share Purchase Plan.

Consists of restricted share units (RSUs). The RSUs vest in four equal annual installments of 25% on February 8, 2027 through February 8, 2030.

Consists of restricted share units (RSUs). The RSUs vest in four equal annual installments of 25% on February 8, 2027 through February 8, 2030.

Includes 3,162 ordinary shares acquired on July 15, 2025, and January 14, 2026, under the issuer's 2019 Employee Share Purchase Plan.

The option vests as to 25% of the shares on February 8, 2027, and vests as to an additional 6.25% of the shares quarterly thereafter until February 8, 2030.

The option vests as to 25% of the shares on February 8, 2027, and vests as to an additional 6.25% of the shares quarterly thereafter until February 8, 2030.

These share options are fully vested.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $15.56 to $16.54 per share. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $16.61 to $16.79 per share. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The shares reported herein are held of record by Glaxo Group Limited, a wholly-owned subsidiary of GSK plc (the "Reporting Person").

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 13, 2025.

The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $20.00 to $20.22 per share. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 13, 2025.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 13, 2025.

These share options are fully vested.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 13, 2025.

The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $20.00 to $20.22 per share. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

Includes 1,147 ordinary shares acquired on July 14, 2025, under the issuer's 2019 Employee Share Purchase Plan.

These share options are fully vested.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 6, 2025.

These share options are fully vested.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 6, 2025.

The share option represented a right to purchase a total of 272,200 ordinary shares that vest as to 25% of the shares on February 17, 2024 and vests as to an additional 6.25% of the shares quarterly thereafter until February 17, 2027.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 13, 2025.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 5, 2025.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 13, 2025.