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A phase 1 open-label trial evaluating tuvusertib (M1774) in patients with metastatic or locally advanced unresectable solid tumors (DDRiver™ Solid Tumors 301)1


Location: North America and Europe



Tuvusertib (M1774) is an investigational orally administered inhibitor of ataxia telangiectasia and Rad3-related (ATR) protein kinase, a key component of the DNA damage response (DDR) pathway. Based on preclinical studies, tuvusertib (M1774) is a highly selective and potent inhibitor of ATR activity1,2


Key inclusion criteriaa

  • Metastatic or locally advanced unresectable solid tumors

  • Clinically controlled brain metastases

  • ECOG PS of ≤1

  • In subpart B1a, baseline body weight of <77 kg or platelets <150,000 per mm3

  • In subpart B1b, baseline body weight of ≥77 kg or platelets ≥150,000 per mm3

Key exclusion criteriaa

  • Ongoing toxicities due to prior anticancer therapies that do not improve to grade ≤1 or any other clinical condition or uncontrolled concurrent illness that in the investigator's opinion would not make the participant a good candidate

  • Prior ATR inhibitor and/or CHK1 inhibitor therapy

  • Part B1 only: a diagnosis of hereditary diseases characterized by genetic defects in DNA repair mechanisms

Study design | North America and Europe


How do I enroll patients in DDRiver™ Solid Tumors 301?


Please contact us for more information on this trial, including how to enroll your patients


Tuvusertib (M1774) is being investigated in this clinical trial. This means that it has not been shown to be safe or effective for any purpose or disease. This page describes one of the clinical trials for tuvusertib (M1774), and it includes information about how the safety and efficacy of tuvusertib (M1774) will be measured and evaluated. Therefore, it is important to understand that tuvusertib (M1774) is not a treatment for cancer or any other disease, its use has not been approved by any health authority, such as the European Medicines Agency or the US Food and Drug Administration, and there is no guarantee that tuvusertib (M1774) will be approved in the sought-after indication by any health authority worldwide.

a For a list of all inclusion and exclusion criteria, please visit https://clinicaltrials.gov/ct2/show/NCT04170153.
b Participants will receive tuvusertib (M1774) at the dose and schedule determined as the RDE in part A1.
c Participants with a baseline body weight of <77 kg or a platelet count of <150,000 per mm3.
d Niraparib once daily will be combined with different doses of tuvusertib (M1774).
e Participants with a baseline body weight of ≥77 kg or a platelet count of ≥150,000 per mm3.
f Niraparib once daily will be combined with different doses of tuvusertib (M1774) and schedule determined as RDE in subpart B1a.
g Assessed by investigator per RECIST version 1.1.
h Defined as an OR or stable disease for at least 6 months.

ATR, ataxia telangiectasia mutated and Rad3 related; CHK1, checkpoint kinase 1; DDR, DNA damage response; DLT, dose-limiting toxicity; DNA, deoxyribonucleic acid; DOR, duration of response; ECOG PS, Eastern Cooperative Oncology Group performance status; LOF, loss of function; OR, objective response; OS, overall survival; PFS, progression-free survival; PK, pharmacokinetics; QD, once daily; RDE, recommended dose for expansion; RECIST, Response Evaluation Criteria in Solid Tumors.

1. ClinicalTrials.gov. Accessed June 28, 2023. https://clinicaltrials.gov/ct2/show/NCT04170153; 2. Roidos P, et al. Nat Commun. 2020;11(1):4077.