Bayer reveals phase 3 data for improved MRI contrast agent

Bayer is on the brink of filing a new MRI contrast agent for approval that can reduce levels of gadolinium, a rare earth metal that can have health and environmental consequences.

The company has reported the first phase 3 results in hand for gadoquatrane, which reduces the dose of gadolinium delivered during an MRI scan by around 60% compared to current macrocyclic gadolinium-based contrast agents (GBCAs) used to enhance medical image contrast and improve diagnostic accuracy.

While gadolinium is considered safe for MRIs, it can lead to side effects in people with kidney dysfunction, including a potentially fatal disease known as nephrogenic systemic fibrosis (NSF). There are also concerns that in some people – even those with healthy kidneys – it can linger in the body for a long time, causing toxic effects.

Studies have also found evidence of gadolinium contaminating sewage water, surface water, and drinking water in many regions of the world, leading to calls for efforts to reduce its use.

Gadoquatrane offers an opportunity to help achieve that objective and – in the first phase 3 trial from Bayer's QUANTI programme – has shown it is at least as effective as current GBCAs gadobutrol (sold by Bayer as Gadovist), gadoterate meglumine/gadoteric acid, and gadoteridolin in visualising tissues during an MRI, with equivalent sensitivity and specificity for the detection of lesions.

The QUANTI CNS trial – presented as late-breaking data during a scientific session at the 2025 European Congress of Radiology (ECR), which started in Vienna this morning – looked at MRIs of 305 people with known or suspected pathologies of the central nervous system.

In January, all the studies in the QUANTI programme – which also includes QUANTI OBR in other body regions and QUANTI Paediatric in children from birth to 17 years – had met their primary and main secondary endpoints, allowing it to press ahead with regulatory filings.

"Contrast-enhanced magnetic resonance imaging is one of the most powerful diagnostic tools in contemporary clinical medicine, offering unparalleled insight into the human body," said QUANTI CNS principal investigator Dr Benjamin Liu, of Northwestern University Feinberg School of Medicine in Chicago.

"A reduced gadolinium dose could be particularly valuable for patients suffering from [CNS] pathologies, as many of them undergo multiple MRI examinations along their diagnostic and treatment pathway," he added. "It is always advisable to administer the lowest efficacious dose of any drug."

Bayer's radiology products generated about €2 billion ($2.1 billion) in sales in 2023. The company is due to report its 2024 results on 6th March.