Understanding Clinical Trials for Anti-cancer Medicines by Dr Kathleen Thompson

All medicines, for a cancer or anything else, must be tested in clinical trials before doctors can prescribe them.

The first clinical trials test increasing doses of the medicine, in small numbers of people, to determine the highest dose before side-effects become unacceptable. As anybody who has had chemotherapy knows, cancer drugs often have serious side-effects. There may be a thin line between an effective anti-cancer dose, and a harmful dose, and knowledge of where this threshold occurs is important.

Anti-cancer medicines are usually only tested in people with cancer. People in the early trials often have serious progressive cancer, for which there are no other effective treatments.  In later studies, when more information is known, people with less advanced cancer can be included.

If possible, clinical trials include a placebo arm, where some participants receive the new medicine, and others receive a placebo (dummy drug). This design gives the most reliable results, however it means leaving some people without any cancer treatment, so, in practise, compromises are often needed. For example, people may be given the test treatment (either new drug or placebo) in addition to a conventional anti-cancer medicine. In this case, any additional effects seen in the group receiving the new medicine can be considered to be due to that. Later trials may compare the effects of the new medicine directly with a conventional treatment.

Clinical trials are performed in a careful, step-wise fashion, to elicit the most accurate and complete information, whilst minimising unnecessary risk to trial participants.

In early studies, tumour size may be measured. Tumour shrinkage is useful to show the medicine has a beneficial effect, but anti-cancer medicines are usually required to show that they can extend people’s lives and this is assessed in the later studies. Overall survival is the best measure, but isn’t always practical, if people are anticipated to survive for many years, or, if they may need additional anti-cancer treatments, which can confuse the study results. Progression-free survival is an alternative measure which is often used. This assesses survival, together with any indications that the cancer is progressing, and often provides the best information to help decide whether a cancer medicine is truly useful.

Further information on how to understand study results and newspaper ‘cancer claims’ is covered in my book (see below).

Taking part in a clinical trial for a new drug can be beneficial. However the drug is still under test and benefit is not guaranteed.  Always read the patient information carefully and discuss with your doctor. If you do take part, you can change your mind at any time, for whatever reason.

Every clinical trial has to be registered but there isn’t one comprehensive data base therefore you need to look at all these registries to check their data bases:-

Should you be interested in clinical trials, the European Medicines Agency (EMA) keeps a database on their website: EU Clinical Trials Register

There is a similar database & registry in the USA at https://clinicaltrials.gov which also covers international clinical trials.

Written by Dr K Thompson, author of From Both Ends of the Stethoscope: Getting through breast cancer – by a doctor who knows. This is an important guide for people with breast cancer, written by a doctor who has had breast cancer herself


Note: This expresses personal views. No warranty is made as to the accuracy or completeness of information given and you should always consult a doctor if you need medical advice.


More Information on clinical trials:

Breast Cancer Trials
Specific trials in the USA but if you find something on there then you could ask your Oncologist if there is anything similar in the UK.  You can sign up to their newsletter.

Cancer Research UK trials database
Look & find out what might be available to you for a specific clinical trial

ECMC (Experimental Cancer Medicine Centre) web site these are for early phase trials

EU Clinical Trials Register

NHIR be part of research data base
UK based – A searchable database of clinical trials from 32 research networks

My Tomorrows  Helping patients discover and access treatment options in development.  Search by requesting a FREE, personalized report listing Clinical Trials and other possible treatment options for your breast cancer.

The Institute of Cancer Research
News and information covering all cancers.

The National Cancer Research Insitute 
Provide information on clinical research.

The Storm Riders
Collated by a patient Christine Hodgdon who has secondary /metastatic breast cancer – her mission to create a one stop tool for SBC/MBC patients to learn about the resources available provided in the most easy to read format and understand. USA based information but massively useful to any patient.  This is an amazing tool.

Comprehensive list of over 600+ drugs >>>https://thestormriders.org/science-research/promising-drugs/

Here’s the link to her web site for clinical trials by disease types >>>https://thestormriders.org/science-research/clinical-trials/

Understanding Clinical Trials: A Jargon Buster Guide comprehensive guide provided by Marie Ennis-O’Connor

NHS clinical trials information
Explanation about clinical trials with links to resources and information for patients.

Her2 climb trial

Beth Roberts who kindly manages the METUPUK twitter account has pulled together all trials in the UK that she is aware of and available.  Please have a look this is great information and ask your Oncologist MBC Research (Last updated 19.1.20)

Diet and Exercise Clinical Trial

B-AHEAD 3 (Breast Activity and Healthy Eating After Diagnosis 3)
Researchers at the Prevent Breast Cancer Centre and Christie Hospital  (Dr Michelle Harvie, Dr Tony Howell and Dr Sacha Howell) are running a ground breaking study to test the effects of diet and exercise on response and toxicity to chemotherapy for women receiving chemotherapy for secondary breast cancer.
Who can take part?
We are recruiting women with secondary breast cancer who are:
• Starting or have recently started a new course of chemotherapy treatment for secondary breast cancer and are willing and physically able to undertake a diet and exercise programme.
• Have a body mass index (BMI) of 24 or higher. To calculate your BMI please follow this link: http://www.nhs.uk/Tools/Pages/Healthyweightcalculator.aspx
We are recruiting women from the following hospitals:
Blackburn, Burnley, Christie, Leighton, Macclesfield, North Manchester, Oldham, Royal Liverpool, Southampton, Stoke, Tameside, Wigan
For more information about the study please follow this link:
Or speak to your Breast Cancer Team or contact the Research Dietitians at University Hospital South Manchester 0161 291 4412 or email lifestyleresearch@nhs.net


Early Access to Medicines Scheme https://www.gov.uk/guidance/apply-for-the-early-access-to-medicines-scheme-eams

The early access to medicines scheme (EAMS) aims to give patients with life threatening or seriously debilitating conditions access to medicines that do not yet have a marketing authorisation when there is a clear unmet medical need.
Under the scheme, the Medicines and Healthcare products Regulatory Agency (MHRA) will give a scientific opinion on the benefit/risk balance of the medicine, based on the data available when the EAMS submission was made.  Read more in the link.