FDA slaps clinical hold on AstraZeneca cancer drug amid heart safety scare in combo test

FDA Building 2
Amgen suffered a similar FDA fate in 2019 with its rival MCL-1 drug. (FDA)

We found out, via a small and almost unnoticed ClinicalTrials.gov update today, that AstraZeneca suspended trial work on its experimental blood cancer drug AZD5991. Now, we have learned that things are in fact bleaker for the therapy.

AstraZeneca told Fierce Biotech that signs of a heart issue in a patient treated with AZD5991 were found, or, as the Big Pharma put it, “asymptomatic elevation in cardiovascular laboratory parameters,” specifically in one patient with relapsed/refractory acute myeloid leukemia who also had other comorbidities.

Because of this, the company discontinued treatment and placed the trial on a voluntary hold. AstraZeneca has now confirmed that the study has been hit with an FDA clinical hold, too. That asymptomatic elevation occurred among the patient group receiving AZD5991 in combination with AbbVie/Roche’s approved blood cancer medicine Venetoclax, which was one half of the trial. The cardiovascular issue was not seen among patients who received AZD5991 monotherapy.

RELATED: Amid Amgen's similar struggles, AstraZeneca slams the brakes on MCL-1 blood cancer drug

An AstraZeneca spokesperson said: “It is important to note that the asymptomatic elevation has since resolved. We are now in the process of conducting a full analysis of the study data and working closely with the FDA for the benefit of the patients.”

Two years ago, heart safety issues also eventually scuppered work on Amgen’s AMG 397, which is also an MCL-1 inhibitor like AZD5991. That trial was also subject of an FDA trial hold. Earlier this year, the company decided to focus on a backup intravenous MCL-1 known as AMG 176.