Crescendo Biologics announces first U.S. patients dosed in expanded Phase 1b clinical trial of CB307 for patients with mCRPC

• Crescendo expands trial of lead programme first-in-class, bispecific Humabody®, CB307 beyond Europe with first US trial site, the Fred Hutchinson Cancer Centre in Seattle, Washington

Cambridge, UK, 6 December 2023 – Crescendo Biologics Ltd (Crescendo), a clinical stage immunooncology company developing novel, targeted T cell enhancing therapeutics, today announces that the first patients in the U.S. have been dosed as part of the ongoing Phase 1b study of CB307, Crescendo’s lead programme in PSMA+ metastatic castration-resistant prostate cancer (mCRPC).

CB307 is a first-in-class, half-life extended, CD137 x PSMA bispecific Humabody®, designed to achieve a longer lasting anti-cancer effect whilst avoiding systemic toxicity. The ongoing dose expansion part of the Phase 1b POTENTIA trial (NCT04839991) comprises two cohorts, assessing the safety and efficacy of CB307 as a monotherapy and in combination with pembrolizumab (KEYTRUDA®).

The US part of the trial has seen patients successfully dosed in both the monotherapy and combination cohorts at the Fred Hutchinson Cancer Centre. Patients continue to be recruited across European trial sites in the UK, Spain and Netherlands.

Theodora Harold, CEO at Crescendo Biologics commented: “Dosing our first patients in the U.S. marks another important milestone, following the addition of the combination cohort earlier this year. As we continue to press ahead with enrolment into the expansion cohorts, our goal is to help improve outcomes for patients with end-stage prostate cancer, where there are currently very few effective immunotherapies approved yet.”

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For more information, please contact:

Crescendo Biologics

Theodora Harold, CEO + 44 (0) 12 2349 7140 investors@crescendobiologics.com media@crescendobiologics.com

ICR Consilium

Mary-Jane Elliott, Suki Virji, David Daley

+ 44 (0) 20 3709 5700

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 T cell response to cancer.

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 openlabel, dose escalation and cohort expansion study to assessthe 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).