CD40

Initial interim data show favorable drug exposure and confirm ALG.APV-527 biological activity Early promising signs of clinical activity in heavily pretreated patients Dose-escalation trial data on track for readout 2H 2024 LUND, SWEDEN and SEATTLE WA / ACCESSWIRE / March 7, 2024 / Alligator Bioscience AB ("Alligator") (ATORX) and Aptevo Therapeutics ("Aptevo") (Nasdaq:APVO) today announced positive interim data from the dose escalation phase of their Phase 1 trial evaluating ALG.APV-527 for the treatment of solid tumors likely to express the tumor antigen 5T4. The multi-center, dose escalation trial is now more than 50% enrolled, and preliminary results include: Treatment was overall well-tolerated, and a maximum tolerated dose has not yet been determined, dose-escalation in higher-dose cohorts is ongoing ALG.APV-527 could be measured in all patients with plasma concentration of ALG.APV-527 consistent with the administered dose Biomarker analyses indicate the expression of the targets (4-1BB and 5T4) in tumor biopsies and confirm biological activity of ALG.APV-527 Of particular interest, signs of clinical activity were observed for both enrolled patients with heavily pre-treated breast cancer. These patients demonstrated measurable level of drug in circulation (pharmacokinetic) and reproducible elevation of serum pharmacodynamic markers with dosing, suggesting the drug is biologically active. One patient remained on study for seven months and a second remains on study beyond nine months. Both patients achieved best overall response of stable disease. "I am pleased to share that we are now dosing cohort four, heading into higher dose ranges where we believe there is potential for increased signs of clinical activity based on preclinical models. We have treated patients with multiple tumor types including breast, pancreatic, non-small cell lung cancer and colorectal cancer. It is our belief that continued analysis of this cross section of tumor types will offer important insights about ALG.APV-527 that can be used to increase our success in later stage development," said Dirk Huebner, MD, Chief Medical Officer at Aptevo. "Additionally, as the trial has progressed, we have seen growing enthusiasm among our clinical sites, evidenced by a long and growing waiting list of patients who would like to participate in the study. We look forward to announcing additional data later in the year." "We're thrilled to share positive interim Phase 1 data from our trial with ALG.APV-527, a testament to our dedicated collaboration with Aptevo. The presence of both targets in tumor biopsies is a particularly encouraging finding, which underlines the potential of our novel bispecific antibody to treat multiple indications," said Sumeet Ambarkhane, MD, CMO at Alligator Bioscience. "We very much look forward to continuing this journey together, to make a meaningful impact in the fight against cancer." About the Trial The ALG.APV-527 Phase 1 trial is a multi-center, multi-cohort, open-label trial that will include six cohorts (dose levels) in a 3+3 design*. The trial will be conducted at up to 10 sites in the U.S. among adult patients with multiple solid tumor types/histologies likely to express the 5T4 antigen. ALG.APV-527 will be given intravenously once every two weeks. The trial will assess the safety and tolerability, pharmacokinetics, pharmacodynamics and preliminary anti-tumor activity of ALG.APV-527. *The 3+3 design proceeds in cohorts of three patients treated at increasing dose levels. Dose escalation stops when at least two out of three or six patients experience dose limiting toxicities or DLTs at that dose level. About ALG.APV-527 ALG.APV-527 is a bispecific conditional 4-1BB agonist, only active upon simultaneous binding to 4-1BB and 5T4. This has the potential to be clinically important because 4-1BB can stimulate the immune cells (antitumor-specific T cells and NK cells) involved in tumor control, making 4-1BB a particularly compelling target for cancer immunotherapy. 5T4 is an oncofetal tumor associated antigen overexpressed on numerous solid tumors including non-small-cell lung carcinoma (NSCLC), breast, head and neck, cervical, renal, gastric, and colorectal cancer. Preclinical studies, highlighting the differentiated design of the molecule that minimizes systemic immune activation, allowing for highly efficacious tumor-specific responses as demonstrated by potent activity in preclinical models, were recently published in the peer-reviewed publication, Molecular Cancer Therapeutics, a journal of the American Association for Cancer Research (AACR). About Alligator Bioscience Alligator Bioscience AB is a clinical-stage biotechnology company developing tumor-directed immuno-oncology antibody drugs. Alligator's portfolio includes several promising drug candidates, with the CD40 agonist mitazalimab as its key asset. Furthermore, Alligator is co-developing ALG.APV-527 with Aptevo Therapeutics Inc., several undisclosed molecules based on its proprietary technology platform, Neo-X-Prime™, and novel drug candidates based on the RUBY™ bispecific platform with Orion Corporation. Out-licensed programs include AC101/HLX22, in Phase 2 development, by Shanghai Henlius Biotech Inc. and an undisclosed target to Biotheus Inc. Alligator Bioscience's shares are listed on Nasdaq Stockholm (ATORX) and is headquartered in Lund, Sweden. For more information, please visit alligatorbioscience.com. About Aptevo Therapeutics Aptevo Therapeutics Inc. is a clinical-stage biotechnology company focused on developing novel bispecific immunotherapies for the treatment of cancer. Aptevo is seeking to improve treatment outcomes and transform the lives of cancer patients. For more information, please visit . Safe Harbor Statement This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, including, without limitation, Aptevo's expectations about the activity, efficacy, safety and tolerability of its therapeutic candidates and potential use of any such candidates as therapeutics for treatment of disease, whether preclinical studies will be indicative of later stage studies or clinical trials, whether biomarker analyses will continue to confirm biological activity of ALG.APV-527, whether higher dose ranges will result in increased signs of clinical activity, whether further study of ALG.APV-527 across a cross section of multiple tumor types will continue to show clinical benefit, whether Aptevo's final trial results will vary from its preliminary or interim assessments, the possibility and timing of preliminary or interim data readouts for ALG.APV-527, statements related to the progress of and enthusiasm for Aptevo's clinical programs, its expectations regarding the effectiveness of its ADAPTIR and ADAPTIR-FLEX platforms, and any other statements containing the words "may," "continue to," "believes," "expects," "optimism," "potential," "designed," "promising," "plans," "will" and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based on Aptevo's current intentions, beliefs, and expectations regarding future events. Aptevo cannot guarantee that any forward-looking statement will be accurate. Investors should realize that if underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results could differ materially from Aptevo's expectations. Investors are, therefore, cautioned not to place undue reliance on any forward-looking statement. There are several important factors that could cause Aptevo's actual results to differ materially from those indicated by such forward-looking statements, including a deterioration in Aptevo's business or prospects; further assessment of preliminary data or different results from later clinical trials; adverse events and unanticipated problems, adverse developments in clinical development, including unexpected safety issues observed during a clinical trial; and changes in regulatory, social, macroeconomic and political conditions. For instance, actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the uncertainties inherent in the results of preliminary data and preclinical studies being predictive of the results of later-stage clinical trials, initiation, enrollment and maintenance of patients, and the completion of clinical trials, the availability and timing of data from ongoing clinical trials, expectations for the timing and steps required in the regulatory review process, expectations for regulatory approvals, the impact of competitive products, our ability to enter into agreements with strategic partners or raise funds on acceptable terms or at all and other matters that could affect the availability or commercial potential of Aptevo's product candidates, business or economic disruptions due to catastrophes or other events, including natural disasters or public health crises such as the coronavirus (referred to as COVID-19), geopolitical risks, including the current war between Russia and Ukraine and the rising conflict in the Middle East, and macroeconomic conditions such as economic uncertainty, rising inflation and interest rates, increased market volatility and decreased consumer confidence. These risks are not exhaustive, Aptevo faces known and unknown risks. Additional risks and factors that may affect results are set forth in Aptevo's filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K for the fiscal year ended December 31, 2023, and its subsequent reports on Form 10-Q and current reports on Form 8-K. The foregoing sets forth many, but not all, of the factors that could cause actual results to differ from Aptevo's expectations in any forward-looking statement. Any forward-looking statement speaks only as of the date of this press release, and, except as required by law, Aptevo does not assume any obligation to update any forward-looking statement to reflect new information, events, or circumstances. Alligator Bioscience Søren Bregenholt, CEO E-mail: soren.bregenholt@alligatorbioscience.com Phone: +46 46-540 82 00 LifeSci Advisors Investor Relations Guillaume van Renterghem E-mail: gvanrenterghem@lifesciadvisors.com Phone: +41 (0)76 735 01 31 Aptevo Therapeutics Miriam Weber Miller Email: IR@apvo.com or millerm@apvo.com Phone: 206-859-6629 SOURCE: Aptevo Therapeutics View the original press release on accesswire.com

Crescendo Biologics to present at the 2024 AACR Annual Meeting Cambridge, UK, 6 March 2024 – Crescendo Biologics Ltd (Crescendo), a clinical stage, immuno-oncology company developing novel, targeted T cell enhancing therapeutics, will be presenting two poster presentations at the 2024 American Association for Cancer Research (AACR) Annual Meeting, taking place in San Diego, California from 5-10 April 2024. Details of the abstracts:Archer, S et al, CB307: A dual targeting costimulatory Humabody® VH therapeutic for treating PSMA-positive tumors, Poster Section 3, Abstract #5313 Pierce, AJ et al, CB699: A novel mesothelin-binding Humabody® CD40 and CD137 dual-agonist for enhancing immune cell responses against MSLN+ tumors, Poster Section 3, Abstract #5302 Both posters will be presented in the Immune Modulation Employing Agonist or Co-Stimulatory Approaches Session, on Tuesday 9 April 2024, 1:30 pm - 5:00 pm PST, and will be made available on the Publications section of the company’s website following their presentation at the meeting. -Ends- For more information, please contact: Crescendo BiologicsICR Consilium Theodora Harold, CEO + 44 (0) 12 2349 7140 investors@crescendobiologics.com media@crescendobiologics.comMary-Jane Elliott, David Daley, Sukaina Virji crescendo@consilium-comms.com About CB307 CB307 is Crescendo’s lead clinical candidate, a first-in-class, half-life extended, CD137 x PSMA bispecific Humabody®, designed to deliver a safer and more durable anti-cancer T cell response. CB307 conditionally activates only tumour-specific T cells, exclusively within the tumour microenvironment using the CD137 co-stimulatory mechanism. Its unique format enables potent, tumour-specific killing, while avoiding systemic toxicity and can be applied to a broad range of PSMA+ cancer indications to address a large unmet medical need. Clinical development of CB307 is on track with the Phase 1b POTENTIA trial ongoing in adult patients with PSMA+ metastatic castration-resistant prostate cancer (mCRPC). POTENTIA (NCT04839991) is an open-label, dose escalation and cohort expansion study to assess the safety, tolerability and preliminary efficacy of CB307 as a monotherapy and in combination with pembrolizumab (KEYTRUDA®). About Crescendo Biologics Crescendo Biologics is a private, clinical-stage immuno-oncology company developing novel, targeted T cell-enhancing therapeutics derived from its proprietary Humabody® VH platform. Beyond Crescendo’s proprietary pipeline, the Company has global, multi-target discovery and development collaborations with Takeda and BioNTech, and an exclusive worldwide licensing agreement with Zai Lab. Located in Cambridge, UK, Crescendo is backed by blue-chip investors including Sofinnova Partners, Andera Partners, IP Group, BioNTech, Takeda, Quan Capital and Kreos Capital. Visit www.crescendobiologics.com and follow on LinkedIn and X (Twitter).

AUSTIN, TX and DURHAM, NC, March 04, 2024 (GLOBE NEWSWIRE) -- Shattuck Labs, Inc. (Shattuck) (Nasdaq: STTK), a clinical-stage biotechnology company pioneering the development of bifunctional fusion proteins as a new class of biologic medicine for the treatment of patients with cancer and autoimmune disease, today announced the appointment of Clay Siegall, Ph.D., and Kate Sasser, Ph.D., to its Board of Directors, effective March 1, 2024. Both Dr. Siegall and Dr. Sasser are highly successful executives and scientific pioneers who bring valuable industry experience to Shattuck. “It is a pleasure to welcome Clay and Kate, esteemed industry leaders, to our Board of Directors,” said Taylor Schreiber, M.D., Ph.D., Chief Executive Officer of Shattuck. “Clay's impressive record of building and leading companies from drug discovery through commercialization, together with Kate’s drug development expertise and insight in leading translational research, are invaluable as we transition to late-stage clinical development of SL-172154. Following the next clinical updates expected mid-year, we anticipate continued expansion of and future pivotal studies for SL-172154 in multiple indications. This was an appropriate time for us to expand our already strong Board of Directors, and we are eager to begin working with Clay and Kate as we progress towards these important inflection points.” Dr. Siegall added, "I have gotten to know Taylor and the team at Shattuck over the past several years and am delighted with the company’s progress. I have developed CD40 targeted therapies in the past, followed the CD47 landscape, and the emerging clinical data suggests that the design of SL-172154 may address the historical challenges for both targets. I look forward to offering my guidance to company management as they execute on their strategic objectives and position the company for continued growth.” Dr. Clay Siegall is the President, Chief Executive Officer and Chairman of the Board of Immunome, Inc. (Nasdaq: IMNM). With a distinguished career in leadership and drug development, he has significantly contributed to the pharmaceutical industry, including spearheading the establishment of antibody-drug conjugates as a backbone of cancer therapy in many indications. Previously, Dr. Siegall held the positions of Chief Executive Officer, President, and Chairman of the Board at Seagen Inc. (formerly Seattle Genetics, Inc.). He was the founder of Seattle Genetics, established in 1998, where he guided the company to prominence as a pharmaceutical leader, particularly in the development of antibody-drug conjugates for cancer therapy. Prior to founding Seattle Genetics, Dr. Siegall held numerous leadership positions at Bristol Myers Squibb’s Pharmaceutical Research Institute and the National Cancer Institute. Dr. Siegall holds a Ph.D. in Genetics from George Washington University as well as a B.S. in Zoology from the University of Maryland. Dr. Sasser added, "Joining Shattuck’s Board of Directors is an exciting opportunity. Shattuck’s new class of dual function fusion proteins has the potential to create novel therapeutics for patients with cancer and autoimmune diseases. The emerging clinical data with SL-172154 suggests that the CD40 agonism is differentiated from multiple agonists developed in the past. I look forward to working with the outstanding management team and Board of Directors to advance the company’s pipeline, unlock further value from the proprietary Agonist Redirected Checkpoint platform technology, and lay the foundation for sustained growth.” Dr. Kate Sasser is the Chief Scientific Officer of Tempus. Dr. Sasser brings over 25 years of experience in translational research and precision medicine in biological sciences across academia and the pharmaceutical and biotech industry. Prior to Tempus, she led the translational research, precision medicine, and R&D operations organizations within Genmab A/S, a biotech company focused on developing transformative antibody therapeutics as medicine. She also led translational research for oncology at Johnson and Johnson Innovative Medicine (formerly Janssen Pharmaceuticals Companies). Dr. Sasser holds a Ph.D. in Integrated Biomedical Sciences from the Ohio State University as well as a B.S. from Oregon State University. About Shattuck Labs, Inc.Shattuck Labs, Inc. (Nasdaq: STTK) is a clinical-stage biotechnology company pioneering the development of bi-functional fusion proteins as a new class of biologic medicine for the treatment of patients with cancer and autoimmune disease. Compounds derived from Shattuck’s proprietary Agonist Redirected Checkpoint (ARC®) platform are designed to simultaneously inhibit checkpoint molecules and activate costimulatory molecules with a single therapeutic. The company’s lead SL-172154 (SIRPα-Fc-CD40L) program, which is designed to block the CD47 immune checkpoint and simultaneously agonize the CD40 pathway, is being evaluated in multiple Phase 1 trials. Shattuck has offices in both Austin, Texas and Durham, North Carolina. For more information, please visit: www.ShattuckLabs.com. Forward-Looking StatementsCertain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, statements regarding: clinical development plans and strategies for SL-172154, timing of anticipated clinical data, future plans for Shattuck’s pipeline and Shattuck’s strategies. Words such as “anticipate,” “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While the company believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to the company on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in Shattuck’s filings with the U.S. Securities and Exchange Commission (SEC)), many of which are beyond the company’s control and subject to change. Actual results could be materially different. Risks and uncertainties which could cause such outcomes to change include: global macroeconomic conditions and related volatility; expectations regarding the initiation, progress, and expected results of Shattuck’s preclinical studies, clinical trials and research and development programs; expectations regarding the timing, completion and outcome of the company’s clinical trials; the unpredictable relationship between preclinical study results and clinical study results; the timing or likelihood of regulatory filings and approvals; liquidity and capital resources and other risks and uncertainties identified in Shattuck’s Annual Report on Form 10-K for the year ended December 31, 2023 and subsequent disclosure documents filed with the SEC. Shattuck claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. Shattuck expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. The Company intends to use the investor relations portion of its website as a means of disclosing material non-public information and for complying with disclosure obligations under Regulation FD. Investor & Media Contact: Conor RichardsonVice President of Investor RelationsShattuck Labs, Inc.InvestorRelations@shattucklabs.com