Treeline Announces Clinical Trial Collaboration and Supply Agreement with Roche to Evaluate TLN-121 in Combination with CD20xCD3 T-Cell-Engaging Bispecific Antibodies

Agreement will evaluate Treeline's BCL6 degrader TLN-121 with Roche’s glofitamab-gxbm (COLUMVI^®) and mosunetuzumab-axgb (LUNSUMIO^®) for the treatment of B-cell lymphomas

Preclinical TLN-121 data show enhanced anti-tumor activity with both CD20xCD3 T-cell-engaging bispecific antibodies and CD19-directed chimeric antigen receptor T-cell (CAR-T cell) therapies

WATERTOWN, Mass.--(BUSINESS WIRE)--Treeline Biosciences, Inc. (“Treeline”) today announced a clinical trial collaboration and supply agreement with Roche (SIX: RO, ROP; OTCQX: RHHBY) to evaluate TLN-121, Treeline's BCL6 degrader, in combination with Roche’s CD20xCD3 T-cell-engaging bispecific antibodies glofitamab and mosunetuzumab in separate combination cohorts for patients with B-cell lymphomas, including diffuse large B-cell lymphoma (DLBCL).

Under the terms of the agreement, Treeline will sponsor and conduct the Phase 1 dose escalation and expansion study, and Roche will supply glofitamab and mosunetuzumab for specific expansion cohorts. Treeline expects to initiate combination dosing for these expansion cohorts in the fourth quarter of 2026.

"CD20xCD3 T-cell-engaging bispecific antibodies such as glofitamab and mosunetuzumab have already transformed the treatment of B-cell lymphomas. We are excited to build on that progress in collaboration with Roche," said Josh Bilenker, M.D., co-founder and Chief Executive Officer of Treeline. “We have generated exciting preclinical data suggesting that TLN-121 enhances the anti-tumor activity of both CD20xCD3 T-cell-engaging bispecific antibodies and CD19 CAR-T cell therapy. These results were predicted by published studies that showed BCL6 impairs the formation of an effective immune synapse between T- and B-cells.”

Preclinical Data Support Combination Strategy

TLN-121 has demonstrated single-agent activity in an ongoing Phase 1 clinical trial, including complete responses, in late-line DLBCL, follicular lymphoma (FL), and T follicular helper peripheral T-cell lymphoma (TFH PTCL).

BCL6 is a transcriptional repressor that helps B-cell lymphomas evade immune attack by silencing genes important for effective T-cell interactions. In DLBCL cell lines, TLN-121 restored expression of T-cell-recruiting cytokines and immune synapse genes. Treeline investigated the combination of TLN-121 and T-cell immunotherapies in DLBCL mouse xenograft models that responded suboptimally to either component as a single agent. In an aggressive DLBCL model supplemented with human T-cells, combining TLN-121 with a CD20xCD3 bispecific antibody produced complete regressions in four of six mice, compared with zero of six for TLN-121 alone and one of five for the antibody alone. In an aggressive DLBCL xenograft model, combining TLN-121 with CD19 CAR-T cells shrank tumors in four of six mice and completely regressed tumors in two of six, compared with no tumor shrinkage or regression in any mice for TLN-121 or the CD19 CAR-T alone.

About Treeline Biosciences, Inc.

Treeline is a clinical-stage biopharma company that aspires to make medicines at the highest level, reliably and repeatedly. We match compelling biological targets with proven drug approaches, including small molecule inhibitors, protein degraders, and targeted therapy antibody-drug conjugates, by integrating in-house R&D with leading-edge computational tools. We choose programs with the potential to redefine the treatment of serious diseases. We are led by a team with deep experience across drug discovery and development, working across the U.S. and Europe. Our pipeline spans oncology, neurology and immunology. Learn more at treeline.bio or connect with us on LinkedIn.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including, among others, Treeline’s product candidates and the potential benefits thereof and potential new indications; Treeline’s expectations with regard to the timing and availability of data from its current and planned clinical trials and preclinical studies; as well as any assumptions underlying any of the foregoing. The words “believe,” “may,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “expect,” and similar expressions are intended to identify forward-looking statements. These forward-looking statements are subject to risks, uncertainties, and assumptions.

Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. These risks include, but are not limited to, risks and uncertainties related to: uncertainties as to the potential for development, commercialization and other benefits of any of Treeline’s product candidates and uncertainties as to Treeline’s anticipated preclinical and clinical drug development activities and related timelines, including the expected timing for commencing clinical trials and announcing data and other clinical results. For information regarding other related risks, see the “Risk Factors” section of Standard BioTools’ Annual Report on Form 10-K for the year ended December 31, 2025, filed with the SEC on March 16, 2026, Standard BioTools’ most recent Quarterly Report on Form 10-Q and in Standard BioTools’ other filings with the SEC, as well as risk factors described in the registration statement on Form S-4 filed by Standard BioTools. Should any of these risks or uncertainties materialize, actual results could differ materially from expectations. These forward-looking statements speak only as of the date hereof. Neither Standard BioTools nor Treeline assumes any obligation to, and does not currently intend to, update any such forward-looking statements except as may be required by law.

Additional Information and Where to Find It

This communication may be deemed to be solicitation material in respect of the proposed transaction involving Standard BioTools and Treeline. In connection with the proposed transaction and required stockholder approval, Standard BioTools has filed with the Securities and Exchange Commission (the “SEC”) a registration statement on Form S-4 that includes a proxy statement and a prospectus of Standard BioTools. This communication is not a substitute for the proxy statement/prospectus or any other document that Standard BioTools has filed or may file with the SEC or will send to its stockholders in connection with the proposed transaction. No offering of securities shall be made, except by means of a prospectus meeting the requirements of Section 10 of the U.S. Securities Act of 1933, as amended. Any definitive proxy statement/prospectus (if and when available) will be mailed to stockholders of Standard BioTools.

INVESTORS AND STOCKHOLDERS OF STANDARD BIOTOOLS ARE URGED TO READ THE PROXY STATEMENT/PROSPECTUS (INCLUDING ALL AMENDMENTS, SUPPLEMENTS AND ANY DOCUMENTS INCORPORATED BY REFERENCE THEREIN) AND OTHER RELEVANT MATERIALS FILED OR TO BE FILED WITH THE SEC WHEN THEY BECOME AVAILABLE BEFORE MAKING ANY VOTING DECISION WITH RESPECT TO THE PROPOSED TRANSACTION BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT STANDARD BIOTOOLS, TREELINE AND THE PROPOSED TRANSACTION. Copies of the materials filed or to be filed by Standard BioTools with the SEC may be obtained free of charge on Standard BioTools’ Investor Relations website at https://investors.standardbio.com or by contacting Standard BioTools’ Investor Relations department at [e-mail]. In addition, all of those materials will be available at no charge on the SEC’s website at www.sec.gov.

Participants in the Solicitation

Standard BioTools, Treeline and certain of their respective directors, executive officers, other members of management and employees may be deemed to be participants in the solicitation of proxies of Standard BioTools stockholders in connection with the proposed transaction under SEC rules. Investors and stockholders may obtain more detailed information regarding the names, affiliations and interests of Standard BioTools’ executive officers and directors in the solicitation by reading Standard BioTools’ proxy statement for its 2026 annual meeting of stockholders (including under the headings “Management and Corporate Governance,” “Executive Officer and Director Compensation,” “Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters,” “Executive Compensation” and “Certain Relationships and Related Transactions, and Director Independence”), its Annual Report on Form 10-K for the fiscal year ended December 31, 2025, subsequent Quarterly Reports on Form 10-Q and Standard BioTools’ other filings with the SEC. Information regarding the persons who may, under SEC rules, be deemed participants in the solicitation of Standard BioTools stockholders in connection with the proposed transaction, including a description of their direct or indirect interests, by security holdings or otherwise, is set forth in the registration statement on Form S-4 and other relevant materials when filed with the SEC in connection with the proposed transaction. Information regarding Treeline’s directors and executive officers who may be deemed participants in the solicitation is contained in the registration statement on Form S-4. These documents are or will be available free of charge at the SEC’s website at www.sec.gov or by going to Standard BioTools’ Investor Relations website at http://investors.standardbio.com or contacting Standard BioTools’ Investor Relations department at [e-mail].

(COLUMVI^® and LUNSUMIO^® are registered trademarks of Genentech, a member of the Roche Group.)