A trial looking at radiotherapy with and without temozolomide for anaplastic glioma (CATNON; EORTC 26053-22054)

The results so far show that temozolomide after radiotherapy could be a useful treatment for some people with anaplastic glioma. 

Results
A total of 751 people with anaplastic glioma joined this trial. They were put into 1 of 4 treatment groups at random:

• 189 people had radiotherapy alone
• 188 people had radiotherapy and temozolomide at the same time
• 186 people had radiotherapy and then temozolomide
• 188 people had radiotherapy and temozolomide at the same time, and then more temozolomide

The trial team looked at how many people were living by 2019. The people taking part had been on the trial for between just over 4 years and just over 7 years by then.

They found it was:

• more than 4 out of 10 people (43%) who had radiotherapy alone
• nearly 5 out of 10 people (48%) who had radiotherapy and temozolomide at the same time
• nearly 6 out of 10 people (58%) who had radiotherapy and then temozolomide
• just over 6 out of 10 people (61%) who had radiotherapy and temozolomide at the same time, and then more temozolomide

Genetic changes
This trial was for people who didn’t have changes in chromosomes 1p or 19q. But some people did have a change in genes called IDH1 or IHD2. The trial team looked at how well treatment worked for these people.

When they looked at how many people were living, they found it was:

• more than 6 out of 10 people (66%) who did have a gene change
• less than 2 out of 10 people (15%) who didn’t have a gene change

When they looked in more detail, they found that:

• radiotherapy followed by temozolomide worked well for people with a gene change
• radiotherapy and temozolomide at the same time didn’t work as well for people with a gene change
• neither temozolomide with or after radiotherapy worked very well for people who didn’t have a gene change

The team are also looking at various other genes and genetic changes in brain tumour cells. They want to find out which treatments work best for different types of tumours and why. They think that the type of gene change in brain tumour cells can affect how well treatment works. They want to find out more about this.

Side effects
Most people who took part had at least one side effect from treatment. Many of these were mild or didn’t last long.  

Between 8 and 21 out of each 100 people had a side effect that was more severe. The most common of these was a drop in blood clotting cells (platelets). This happened in:

• just under 1 in 10 people (9%) who had radiotherapy and temozolomide at the same time
• more than 1 in 10 people (15%) who had radiotherapy followed by temozolomide
• no one who had radiotherapy alone 

A total of 49 people stopped treatment because of side effects they were having. Most of these were in the group who had radiotherapy and temozolomide at the same time followed by more temozolomide.

We have more information about the side effects of radiotherapy to the brain and of temozolomide.

Conclusion
The team concluded that radiotherapy followed by temozolomide was better than radiotherapy alone. But that radiotherapy and temozolomide at the same time was not better than radiotherapy alone. 

This is for people with anaplastic glioma who:

• don’t have changes in chromosomes 1p or 19q
• do have changes in their IDH1 or IDH2 gene

More detailed information
There is more information about this research in the references below. 

Please note, the information we link to here is not in plain English. It has been written for healthcare professionals and researchers.

Interim results from the CATNON trial (EORTC study 26053-22054) of treatment with concurrent and adjuvant temozolomide for 1p/19q non-co-deleted anaplastic glioma: a phase 3, randomised, open-label intergroup study
Martin J van den Bent and others
The Lancet, 2017. Volume 390, Issue 10103, pages 1645-1653.

Adjuvant and concurrent temozolomide for 1p/19q non-codeleted anaplastic glioma (CATNON; EORTC study 26053-22054): second interim analysis of a randomised, open-label, phase 3 study
Martin J van den Bent and others
The Lancet Oncology, 2021. Volume 22, issue 6, pages 813-823.

Non-IDH1-R132H IDH1/2 mutations are associated with increased DNA methylation and improved survival in astrocytomas, compared to IDH1-R132H mutations
C. Mircea S. Tesileanu and others
Acta Neuropathologica, 2021. Volume 141, pages 945–957.

Temozolomide and Radiotherapy versus Radiotherapy Alone in Patients with Glioblastoma, IDH-wildtype: Post Hoc Analysis of the EORTC Randomized Phase III CATNON Trial
C. Mircea S. Tesileanu and others
Clinical Cancer Research, 2022. Volume 28, issue 12, pages 2527–2535.

Where this information comes from    
We have based this summary on the information in the articles above. These have been reviewed by independent specialists (peer reviewed ) and published in medical journals. We have not analysed the data ourselves.