A Phase 1b Study of Neoadjuvant Xaluritamig in Subjects With Newly Diagnosed Localized Intermediate or High-Risk Prostate Cancer

Temporary halt TH-131214

Halt date

2026-04-24

Member states concerned

Germany

Publication date

2026-04-28

Reason

Study management related

Explanation

Please refer to the cover letter attached

Follow-up measures

There is one German participant falling within the intermediate-risk category, and this participant has already completed study treatment and is currently in long-term follow-up. Amgen is developing a plan for management of this enrolled participant in Germany with intermediate-risk prostate cancer.

The Corrective Measure CM-DE-0002 linked to this temporary halt including management plan for the intermediate-risk prostate cancer participant will be addressed by future substantial modification, which is due to be submitted before 19 May 2026.
See enclosed cover letter for details.

Benefit-risk balance changed

Yes

Treatment stopped

No

Corrective measure CM-DE-0002

Member state

Germany

Publication date

2026-04-21

Type

3

Reason

5

Immediate action required

Yes

Justification

Corrective measure pursuant to Article 77 (1) (c) of Regulation (EU) No 536/2014

The Member State Concerned has justified grounds to consider that the requirements set out in Regulation (EU) No 536/2014 (CTR) are no longer met for the conduct of Study 2023023 on its territory and therefore requires the Applicant to modify the clinical trial in accordance with Article 77 (1) (c) CTR, section 42 sub-section 4 Medicinal Products Act.

The data provided by the Applicant with Substantial Modification 4 have been reviewed. Based on this review, and considering that alternative therapeutic options are available for these patients, the benefit–risk balance is considered unfavourable for patients with intermediate risk localised prostate cancer in Study 20230237.

According to the Applicant’s report, the incidence of CTCAE grade ≥3 treatment related adverse events is high, with approximately one third of patients affected. Among the 18 subjects treated at the target dose of 1.0 mg, 33% (6/18) experienced grade ≥3 treatment related adverse events. Histopathology results further indicate a lack of efficacy in the intermediate risk subgroup. Of the 22 patients enrolled in Study 20230237, 3 were classified as intermediate risk. None of these 3 patients achieved an R0 (margin negative) resection, which is considered a key marker of treatment success in this setting.

Overall, R0 resection was documented in 9/22 patients (41%), but this benefit was not observed in the intermediate risk group. Although the total number of patients treated, in particular in the intermediate risk subgroup, is limited, the absence of demonstrated benefit in terms of R0 resection together with the notable risk of severe adverse events does not support a favourable benefit–risk balance for patients with localised intermediate risk prostate cancer.

In view of the above, continuation of Study 20230237 in its current form is not acceptable.

The Applicant is requested to modify Study 20230237 as follows:

• Remove patients with intermediate risk localised prostate cancer from the study population.

• Update the inclusion and exclusion criteria accordingly, so that only patients with high risk or very high risk localised prostate cancer are eligible for enrolment.

• Ensure that all future enrolment is restricted to patients with high risk or very high risk disease.

• Submit a revised informed consent form reflecting the updated study population, risk profile, and available alternative treatment options.

• Submit a plan for informing and managing the care of any intermediate risk patients already enrolled in the study, including their safe discontinuation from the trial and transition to appropriate alternative therapies.

The revised protocol and informed consent form, as well as the plan for management of already enrolled intermediate risk patients, must be submitted to the Member State Concerned via CTIS for review and approval prior to resuming enrolment of new subjects.

Failure to implement this corrective measure may lead to further action under Article 77 (1) CTR, including suspension or revocation of the clinical trial authorisation on the territory of Germany.