Chief Scientific Officer and Co-founder — Dr. Harlan Robins: Dr. Robins transitioned into a strategic consultant role.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

The Notes were issued to the initial purchasers in reliance upon Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”), in transactions not involving any public offering. The Notes were resold by the initial purchasers to persons reasonably believed to be “qualified institutional buyers,” as defined in, and in accordance with, Rule 144A under the Securities Act. Any shares of common stock that may be issued upon conversion of the Notes will be issued in reliance upo…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement. The disclosure set forth in

Termination of Material Definitive Agreement On June 22, 2026, the Company used $156.9 million of proceeds from the Notes offering to repurchase all Revenue Interests (as defined below) and repay in full all of its obligations under the revenue interest purchase agreement (the “OrbiMed Purchase Agreement”), dated September 12, 2022, with OrbiMed Royalty & Credit Opportunities IV, LP (“OrbiMed”), an affiliate of OrbiMed Advisors LLC, as collateral agent and administrative agent for the purchas…

Entry into a Material Definitive Agreement. 0% Convertible Senior Notes due 2031 On June 22, 2026, Adaptive Biotechnologies Corporation (the “Company”) issued $345 million in aggregate principal amount of 0% Convertible Senior Notes due 2031 (the “Notes”). The Notes issued include the full exercise by the initial purchasers on June 17, 2026 of their option to purchase an additional $45 million in aggregate principal amount of Notes. Use of Proceeds The Company’s net proceeds from this offerin…

Other Events. On June 15, 2026, Adaptive Biotechnologies Corporation (the “ Company ”) issued a press release announcing that it intends to offer, subject to market conditions and other factors, $250 million in aggregate principal amount of convertible senior notes due 2031 (the “ Notes ”) to persons reasonably believed to be qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “ Offering ”). The Company expects to grant a 13-day option to the…

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Termination of Material Definitive Agreement. On August 13, 2025, the Strategic Collaboration and License Agreement between Adaptive Biotechnologies Corporation (“Adaptive”) and Genentech, Inc. (“Genentech”), dated as of December 19, 2018 (the “Agreement”), was terminated, with termination effective February 9, 2026. Adaptive and Genentech entered into the Agreement in 2018 to collaborate on research and development of certain cancer cell therapy products. The parties will wind down activitie…

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Chief Financial Officer — Kyle Piskel: Kyle Piskel was promoted to Chief Financial Officer with a new compensation package and equity grants.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Chief Financial Officer — Tycho Peterson: The CFO resigned voluntarily with a successor already in place.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Director — Kevin Conroy: Mr. Conroy voluntarily resigned from the Board.

and the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.