AstraZeneca trims AZD1390 brain-cancer trial to 159 patients as it nears its end
The Phase 1 study of AZD1390 with radiation therapy closed enrollment below its last stated target, moving to Active, not recruiting as it heads toward a September 2026 completion.
Executive Summary
- AstraZeneca closed enrollment on its Phase 1 trial testing AZD1390 alongside radiation therapy in brain cancer, trimming the patient count from its most recent target and switching the trial's status to Active, not recruiting as it approaches its primary completion date.
- The change locks in the population the trial will report on, the readout the sponsor and any partner will use to judge whether combining an ATM inhibitor with radiotherapy is tolerable enough to advance.
- This is the only industry trial testing an ATM inhibitor with radiation therapy in brain cancer, so its safety data become the mechanism's first human reference point in this setting rather than one entry in a crowded field.
- The trial has pushed its primary completion date more than a dozen times since 2018, but the closing enrollment count and the completion date now move together toward the same near-term point, consistent with a study finishing rather than continuing to slip.
What happened
AstraZeneca's registry record for NCT03423628 now lists 159 patients enrolled under an Actual enrollment type, down from the 180-patient anticipated target set in October 2024. The trial's status moved from Recruiting to Active, not recruiting on the same date, and its primary completion date shifted to September 3, 2026, five days earlier than the prior September 16, 2026 estimate. All three changes landed in the same registry update, a pattern consistent with a trial closing out enrollment at its natural end rather than being cut short mid-course. NCT03423628A Study to Assess the Safety and Tolerability of AZD1390 Given With Radiation Therapy in Patients With Brain CancerNCT03423628
What the trial tests
The study is a first-in-human, open-label, three-arm trial testing AZD1390, an ATM kinase inhibitor, in combination with radiation therapy across three brain-malignancy settings: recurrent glioblastoma, brain metastases, and primary glioblastoma with unmethylated MGMT. Its primary endpoints are the incidence of adverse events and serious adverse events, and dose-limiting toxicities used to define a maximum tolerated dose, both safety measures rather than tumor-response measures. Arm B, the brain-metastases cohort, closed to recruitment earlier in the trial's run, leaving the recurrent- and primary-glioblastoma arms as the source of the enrollment now finalized at 159. NCT03423628A Study to Assess the Safety and Tolerability of AZD1390 Given With Radiation Therapy in Patients With Brain CancerNCT03423628
The readthrough
No other industry-sponsored trial combines an ATM inhibitor with radiation therapy in brain cancer; the nearest related programs are AstraZeneca's own earlier-stage AZD1390 studies and a Phase 1 trial of the same target class, AZD0156, in advanced cancer more broadly. That leaves this trial's safety data as the first human evidence for whether ATM inhibition can be layered onto radiotherapy in brain malignancies without compounding the neurotoxicity or myelosuppression risks that radiosensitizing agents can carry in this setting. Field activity around the ATM target in brain cancer has not produced a second entrant since this trial began enrolling in 2018. NCT03423628A Study to Assess the Safety and Tolerability of AZD1390 Given With Radiation Therapy in Patients With Brain CancerNCT03423628
Operational history
The trial's primary completion date has moved 13 times since 2018, and enrollment has changed five times, a churn rate the registry classifies as high relative to typical Phase 1 studies. Those shifts track a program that has run for eight years across sites in the United States, the United Kingdom, and Japan, adding a Japan dose-confirmation sub-study along the way, rather than a single stalled cohort. The current enrollment reduction and completion-date pull-in both point toward the trial reaching its planned end. NCT03423628A Study to Assess the Safety and Tolerability of AZD1390 Given With Radiation Therapy in Patients With Brain CancerNCT03423628
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.