In Research News

There has been a lot of noise about the INDIGO trial – it is one of the only trials that has met its primary endpoints before the end of the trial, so the trial has been unblinded and those patients who were on the placebo arm are now receiving vorasidenib. This article explains what this means for patients, what the findings were, which patients were included, how it was designed and what happens next.

A patient experience

Craig has been taking part in the trial and has shared his experience:

I found out about this trial via the brainstrust monthly meet ups. I was so lucky to get onto one of the last spaces on the trial and am forever grateful for this. 

From a personal point of view, I have gone through regime. I was on the placebo and had some marginal growth. The trial was unblinded due to the success in data and now I’m on the real drug; my scan looks good so far. It does entail monthly visits with a load of tests every month and sitting in a cancer ward with other people mainly on drips so does make you still feel like a patient but I try to take the positive out of this by seeing the other options over taking a tablet daily and also enjoy speaking to other patients who are various trials for other types of cancer. 

The clinical team at Edinburgh Cancer Centre has made the journey easier and its support from clinical care to advice on life decisions has been brilliant and make the monthly visits has positive as possible. 

Craig is happy to be contacted via his Instagram handle: craigwright83


What does this mean for patients?

For people with grade 2 glioma with IDH mutations, vorasidenib improves progression-free survival and quality of life. The results of this trial offer a chance to change the treatment paradigm for this type of glioma and could bring the first new targeted therapy for low-grade glioma.


What did the study find?

The phase III INDIGO study showed that vorasidenib may help some people with grade 2 glioma live longer without tumour growth. Vorasidenib targets specific genetic changes called IDH mutations that are commonly found in grade 2 gliomas, which mainly affect people who are young and otherwise healthy. It showed that Vorasidenib delays disease progression in grade 2 glioma with an IDH mutation by an average of 27.7 months, compared to 11.1 months for those taking a placebo. Additionally, vorasidenib delayed the need for the next treatment.


Which patients were included?

80% of patients diagnosed with grade 2 glioma have an IDH1 mutation and 4% have an IDH2 mutation. Current treatment options include intensive treatments with surgery, radiation therapy, and chemotherapy that have short-term and long-term side effects that affect quality of life or an active surveillance approach.

The study included 331 people with grade 2 glioma with IDH mutations who had undergone surgery but no other treatment. Participants came from 10 countries, and their ages ranged from 16 to 71.


What was the study design?

Participants were randomly assigned to 1 of 2 groups. The first group (168 people) received a daily oral dose of vorasidenib. The second group (163 people) received a placebo. The treatment cycles lasted for 28 days. The main goal was to see how long it was before the tumour grew, which is called progression-free survival, based on scans with magnetic resonance imaging (MRI). The researchers also looked at the time it took for each patient to need the treatment with traditional therapies.

There were some side effects associated with vorasidenib, including fatigue, headache, diarrhoea, and nausea. Despite these adverse effects, the benefits of treatment with vorasidenib were observed across all patient subgroups.


What happens next?

Vorasidenib was granted fast track designation by the U.S. Food & Drug Administration (FDA) in March 2023. Servier is working to determine timelines for submission of a New Drug Application (NDA) for vorasidenib to the FDA. It is also under evaluation in combination with pembrolizumab an in ongoing phase 1 study in grade 2/3 glioma. It will be a while before this therapy is available in the UK. We would suggest that patients talk with their oncology team.

Find out more about our work with clinical research here.


  1. Mellinghoff IK, Van Den Bent MJ, Blumenthal DT, et al: INDIGO: A global, randomized, double-blinded, phase 3 study of vorasidenib versus placebo in patients with residual or recurrent grade 2 glioma with an IDH1/2 mutation. 2023 ASCO Annual Meeting. Abstract LBA1. Presented June 4, 2023.
  2. Mellinghoff IK, Van Den Bent MJ, Blumenthal DT, et al: Vorasidenib in IDH1- or IDH2-mutant low-grade glioma. N Engl J Med. June 4, 2023 (early release online).


The Brain Tumour Data Dashboard lets you explore up -to-date, population level data about the brain tumours diagnosed in England between 2013 and 2015. Using the drop down menus on the left you can select different groups of patients to view in the charts below. In these charts the number of patients for every 100 diagnoses is displayed as images of people. Patients have been grouped by date of diagnosis, type of tumour, age, gender, and region in England.

For each group of patients you can explore the different routes to diagnosis, the proportion of those who received chemotherapy or radiotherapy, as well as the survival of the patients within each group. For more information about what these metrics mean please see the glossary.

How to use

  1. Select the year of diagnosis using the drop down menu.
  2. Select your patient group of interest from the four drop down menus in the following order:
    1. Tumour group
    2. Age at diagnosis
    3. Region of England
    4. Gender of patient
  3. To view a second chart to compare different groups of patients, click the ‘compare’ button.The second chart will appear below the first chart.

*Note that the tool is best used on a laptop or tablet rather than a mobile phone*

Unavailable data

Some of the data in these charts is not available.There are two main reasons for this:

  1. How the data has been grouped

If you cannot select a patient group from the drop down menus, the data is unavailable because of how the data has been organised.

Public Health England has grouped the data like a branching tree. The bottom of the tree contains all the patients with brain tumours, and then each branch divides the data by a certain characteristics, like age, or location of tumour. But the data is divided in an order, starting with location of the tumour (endocrine or brain), then by age, region, and gender. Age is at the start because it makes a bigger difference to survival rates and treatment rates than gender or region. Sometimes, after the data has been split by type of tumour and age, there is not enough data to be split again. This is because to protect patient confidentiality groups cannot contain less than 100 patients. Because some groups cannot be split further, you cannot create ‘totals’ for everyone by region or gender. For example, you cannot see results for all ages by region, or all brain tumours by gender. If these totals were calculated and released, it might be possible to identify patients, which is why Public Health England cannot release this data.

  1. Statistical reasons and data availability

If you can select a patient group from the chart menus, but the chart does not display, the data is unavailable for one of several reasons:

  1. Data is not yet available for the selected year from Public Health England.
  2. Data is not available because the data quality is too poor to release this statistic.
  3. Data is not available as the statistic is not appropriate for this group.
  4. Data is not available because the standard error of the estimate was greater than 20% and so the estimate has been supressed.

Up to date brain tumour data

Brain tumour data may influence the decisions you make about your care. Data also helps you understand the bigger picture, or landscape, in which you find yourself.

Brain tumour data and statistics influence the focus, and work of organisations like brainstrust. The information helps us to understand the scale and impact of the problems we are setting out to solve.

This tool helps you understand the landscape in which you find yourself having been diagnosed with a brain tumour. This landscape can be particularly tricky to navigate as there are many different types of brain tumour, all of which have a different impact.

The information you see represents the most up-to-date, official, population level brain tumour data available for England. Over time we will be adding to the brain tumour data available and publishing reports, with recommendations, as a result of what we learn from this data.

The data behind this content has come from Public Health England’s National Cancer Registration and Analysis Service (NCRAS) and is a direct result of the ‘Get Data Out’ project.

This project provides anonymised population level brain tumour data for public use in the form of standard output tables, accessible here:


The number or rate (per head of population) of new cases of a disease diagnosed in a given population during a specified time period (usually a calendar year). The crude rate is the total number of cases divided by the mid-year population, usually expressed per 100,000 population.


Malignant tumours which grow by invasion into surrounding tissues and have the ability to metastasise to distant sites


The number or rate (per head of population) of deaths in a given population during a specified time period (usually a calendar year). The crude rate is the total number of deaths divided by the mid-year population, usually expressed per 100,000 population.


Not cancerousNon-malignant tumours may grow larger but do not spread to other parts of the body.


The length of time from the date of diagnosis for a disease, such as cancer, that patients diagnosed with the disease are still alive. In a clinical trial, measuring the survival is one way to see how well a new treatment works. Also called ‘overall survival’ or ‘OS’.

Routes to Diagnosis

Under the ‘Routes to Diagnosis’ tab in the Brain Tumour Data Dashboard, you can explore the ways patients have been diagnosed with brain tumours. There are many ways, or routes, for cancers to be diagnosed in the NHS. A ‘route to diagnosis’ is the series of events between a patient and the healthcare system that leads to a diagnosis of cancer. The routes include:

  1. Two Week Wait

Patients are urgently referred by their GP for suspected cancer via the Two Week Wait system and are seen by a specialist within 2 weeks where they are diagnosed.

  1. GP referral

Diagnosis via a GP referral includes routine and urgent referrals where the patient was not referred under the Two Week Wait system.

  1. Emergency Presentation

Cancers can be diagnosed via emergency situations such as via A&E, emergency GP referral, emergency transfer or emergency admission.

  1. Outpatient

Outpatient cancer diagnoses include diagnoses via an elective route which started with an outpatient appointment that is either a self-referral or consultant to consultant referral. (It does not include those under the Two Week Wait referral system).

  1. Inpatient elective

Diagnosis via an inpatient elective route is where diagnosis occurs after the patient has been admitted into secondary care from a waiting list, or where the admission is booked or planned.

  1. Death Certificate Only

Diagnoses made by Death Certificate Only are made where there is no more information about the cancer diagnosis other than the cancer related death notifications. The date of diagnosis is the same as that of the date of death.

  1. Unknown

For some patients with a cancer diagnosis, there is no relevant data available to understand the route to diagnosis.


More information

If any of the statistical terms in this section of the brainstrust website are hard to understand, we recommend looking them up here:

Cancer Research UK’s Cancer Statistics Explained

If you are looking for help understanding terms relating specifically to brain tumours, and treatment, then the brainstrust glossary is available here: