Company Announcements

TOKYO & BASKING RIDGE, N.J.--(BUSINESS WIRE)--Feb. 4, 2026-- The first patient has been dosed in a first-in-human phase 1/2 trial evaluating DS3790 in patients with relapsed or refractory B-cell non-Hodgkin lymphoma.

DS3790 is a specifically engineered, potential first-in-class CD37 directed DXd antibody drug conjugate (ADC) discovered by Daiichi Sankyo (TSE: 4568).

CD37 is a transmembrane protein that plays a role in regulating cell survival and is overexpressed on malignant B-cells, making it a promising therapeutic target.¹ Currently, there are no CD37 directed therapies approved for any type of cancer.

“The initiation of this trial of DS3790 with its novel CD37 target marks a significant milestone as our first DXd antibody drug conjugate in hematology,” said Ken Takeshita, MD, Global Head, R&D, Daiichi Sankyo. “DS3790 expands our portfolio to seven DXd antibody drug conjugates, all developed using our in-house technology, underscoring our dedication to scientific innovation to create new medicines for patients with cancer.”

About the Phase 1/2 Trial
The multicenter, open-label, multi-cohort, first-in-human phase 1/2 trial will assess the safety and efficacy of DS3790 in patients with relapsed or refractory B-cell non-Hodgkin lymphoma.

The first part of the trial (dose escalation) is evaluating DS3790 as a monotherapy to determine the recommended dose for expansion. The second part of the trial (dose expansion) will consist of multiple expansion cohorts to further evaluate DS3790 as a monotherapy.

Following the assessment of preliminary safety and efficacy in the monotherapy part of the trial, subsequent cohorts will evaluate DS3790 in combination with other targeted therapies in both dose escalation and dose expansion phases.

The trial will evaluate safety endpoints including dose-limiting toxicities and adverse events, as well as efficacy endpoints including overall response, disease control rate, duration of response, time to response, progression-free survival and overall survival. Pharmacokinetics and biomarker endpoints also will be assessed.

The trial is expected to enroll approximately 420 patients across multiple sites globally, including Asia, Europe and North America. For more information, please visit ClinicalTrials.gov.

About CD37
CD37 is a transmembrane protein that plays a role in regulating cell survival and is overexpressed in various B-cell hematological malignancies.¹ B-cells, which are a type of white blood cell (B-lymphocyte) that help the body fight infection, can uncontrollably multiply and fail to function properly.² Because of its high prevalence on B-cells, CD37 is considered a promising therapeutic target for the treatment of B-cell cancers.³ Currently, there are no CD37 directed therapies approved for any type of cancer.

About B-cell Non-Hodgkin Lymphoma
More than 604,000 cases of non-Hodgkin lymphoma were diagnosed in 2021, with approximately 267,000 deaths globally.⁴ B-cell non-Hodgkin lymphoma accounts for more than 85% of all non-Hodgkin lymphoma cases with a five-year survival rate of 74%.⁵

While advances in targeted therapies have improved outcomes in B-cell non-Hodgkin lymphoma, many patients with relapsed or refractory disease continue to face limited treatment durability and poor long-term survival.⁶

About DS3790
DS3790 is an investigational, potential first-in-class CD37 directed ADC. Designed using the proprietary DXd ADC technology of Daiichi Sankyo, DS3790 is comprised of a humanized anti-CD37 IgG1 monoclonal antibody attached to a number of topoisomerase I inhibitor payloads (exatecan derivative, DXd) via tetrapeptide-based cleavable linkers.

About the ADC Portfolio of Daiichi Sankyo
The Daiichi Sankyo ADC portfolio consists of eight ADCs in clinical development crafted from ADC technology discovered in-house by Daiichi Sankyo.

The DXd ADC Technology platform of Daiichi Sankyo consists of seven ADCs in clinical development where each ADC is comprised of a monoclonal antibody attached to a number of topoisomerase I inhibitor payloads (an exatecan derivative, DXd) via tetrapeptide-based cleavable linkers. The DXd ADCs include ENHERTU^® and DATROWAY^®, which are being jointly developed and commercialized globally with AstraZeneca, and ifinatamab deruxtecan (I-DXd), raludotatug deruxtecan (R-DXd) and patritumab deruxtecan (HER3-DXd), which are being jointly developed and commercialized globally with Merck & Co., Inc, Rahway, NJ, USA. DS-3939 and DS3790 are being developed by Daiichi Sankyo.

An additional ADC being developed by Daiichi Sankyo is DS3610, which consists of an antibody attached to a novel payload that acts as an agonist of STING.

Ifinatamab deruxtecan, raludotatug deruxtecan, patritumab deruxtecan, DS-3939, DS3610 and DS3790 are investigational medicines that have not been approved for any indication in any country. Safety and efficacy have not been established.

About Daiichi Sankyo
Daiichi Sankyo is an innovative global healthcare company contributing to the sustainable development of society that discovers, develops and delivers new standards of care to enrich the quality of life around the world. With more than 120 years of experience, Daiichi Sankyo leverages its world-class science and technology to create new modalities and innovative medicines for people with cancer, cardiovascular and other diseases with high unmet medical need. For more information, please visit www.daiichisankyo.com.

References:

1. Moore K, et al. J Pathol. 1987; 152 (1): 13-21.
2. Mayo Clinic. Diffuse large B-cell lymphoma. Accessed November 2025.
3. Payandeh Z, et al. Biotechnol Lett. 2018; 40 (11-12): 1459-66.
4. Li T, et al. Ann Hematol. 2025; doi:10.1007/s00277-025-06559-9.
5. Cleveland Clinic. Non-Hodgkin Lymphoma. Accessed November 2025.
6. Ayyappan A, et al. J Hematol Oncol. 2019; 12 (82): 1.

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Media Contacts:

Global/US:
Jennifer Brennan
Daiichi Sankyo
jennifer.brennan@daiichisankyo.com
+1 908 900 3183 (mobile)

Japan:
Daiichi Sankyo Co., Ltd.
DS-PR_jp@daiichisankyo.com

Investor Relations Contact:
DaiichiSankyoIR_jp@daiichisankyo.com

Source: Daiichi Sankyo