Malignant Mesothelioma Treatment Therapies
If you have been diagnosed with malignant mesothelioma it is imperative that a ‘specialist’ respiratory physician; and if applicable, an oncologist and thoracic surgeon conversant in asbestos related diseases be consulted.
Malignant mesothelioma is mainly initially diagnosed in one of two areas of the body, in the chest cavity (pleural and/or pericardium), or in the stomach area (peritoneal) – it can be initially diagnosed in both areas, but this is rare. Many people wrongly believe, when talking about malignant pleural mesothelioma (MPM), that it is lung cancer. MPM is a cancer of the lining that surrounds the lung, it is not classed as lung cancer – they are totally different cancers. This is particularly important to understand and remember if you are on social media or are reading media reports – malignant mesothelioma, of any form, is not lung cancer.
This page covers the following:
Immunotherapy [including Keytruda]
Chemotherapy is the most common treatment for mesothelioma, and is the only form of drug therapy listed for treating malignant mesothelioma, by the relevant authorities, worldwide. Chemotherapy drugs can be given by mouth or injection. Because the medicines travel through the blood stream to the entire body, chemotherapy is considered a body-wide (systemic) treatment.
Chemotherapy may be used to:
Assist in attempting to keep the cancer from spreading
Ease symptoms of the cancer
Chemotherapy medicines usually target cells that quickly divide. However, normal cells – including those found in the blood, and the lining of the gastrointestinal tract also divide very quickly. That means chemotherapy can also damage or kill these healthy cells. When this occurs, side effects such as nausea and anaemia can occur. Other side effects that are commonly experienced are fatigue, nerve pain, infection, changing bowel habits and rashes.
The most common chemotherapy drugs used in Australia (and around the world) to treat malignant mesothelioma are:
*Cisplatin (a platinum based chemotherapy)
*Carboplatin (a platinum based chemotherapy)
Gemcitabine (superseded by Alimta in 2008 as an adjunct to either of the platinum based chemotherapies – but can still be used as an alternative to Alimta – but is not covered by the PBS, and does cost in the low $100s per dose)
*These are the only chemotherapies (or indeed any drug therapies) registered by Australia’s Therapeutic Goods Administration for treating malignant mesothelioma; they are also the only drugs listed on Australia’s PBS (Pharmaceutical Benefits Scheme – commonly called the free list) for treating malignant mesothelioma. This is the case in all countries that have similar authorities and run similar schemes.
They are normally given in combinations of either:
Cisplatin – Alimta
Carboplatin – Alimta
Cisplatin – Gemcitabine
Carboplatin – Gemcitabine
Alimta (can be, and is used as a stand alone last resort therapy)
Note: Cisplatin or Carboplatin given in conjunction with Alimta at 3 week intervals for a course of 4 up to 6 treatments, is the standard 1st line mesothelioma treatment throughout the world. Normally a sufferer will have a Hi Resolution CT scan before either the fourth (4th) or fifth (5th) treatment to see whether or not the chemo is working – before the fourth (4th) treatment is the most common, but this will be a decision the treating oncologist will make depending on a number of factors. Every suffer responds differently to chemotherapy, so it is important you be guided by the specialist treating oncologist.
Please don’t hesitate to contact the Bernie Banton Foundations Support Co-ordinator to discuss the pros and cons of these treatments, and the side effects a sufferer being treated with these chemotherapies can realistically expect to experience.
Immunotherathy is a relative new class of drug that is designed to switch on, or re-activate the sufferers own immune system. As with chemotherapy, the medicines travel through the blood stream to the entire body, and therefore are considered a body-wide (systemic) treatment. An important factor with this class of drug is that compared to chemotherapy treatments, in the main sufferers do not report experiencing as many harsh side effects – however, some have had severe adverse side effects. The down side is, being a new class of drug, immunotherapies are largely untrialed for use in treating mesothelioma, and none are registered for use as a mesothelioma treatment in any country in the world.
Please remember, if you are on social media or are reading media reports – malignant mesothelioma, of any form, is not lung cancer.
Mesothelioma oncologist Dr Tom John says, ‘Physicians should be cautiously optimistic.’
Assoc Prof Tom John is one of the leading mesothelioma clinical oncologists and researchers in Australia. He is based at the Oliver Newton John Cancer Centre in Melbourne, Victoria, Australia. His observations on the new wave of immune checkpoint inhibitors (immunotherapy drugs such as Keytruda) were published in the ASCO Connection magazine 13 October 2016 under the heading: Outlook on Immunotherapy Treatment for Mesothelioma
Extract quoted in part:
“We finally have some drugs that are showing great promise in mesothelioma, but they do not work in everyone,” he said. “We need to temper our enthusiasm so that we can figure out exactly who benefits from these drugs and determine whether there is a way to manipulate the immune response to also help those that don’t benefit.”
More trials are necessary to determine exactly what mechanisms work in different forms of mesothelioma and in other malignancies. “It is important that we generate data and don’t just use immunotherapies on everyone without asking questions. If we can do that, I have no doubt that we will continue to see improvements and hopefully turn mesothelioma into a chronic disease,” he said.
“Clinical trials are the only way of determining the best therapeutic options for patients,” Dr. John said.
There are a number of different immunotherapy drugs seemingly doing similar things, but the one common factor they all have at this stage, is none are approved for treating mesothelioma, and they all have not concluded any meaningful mesothelioma specific trials. The one most in the news is MSD’s Pembrolizumab [commonly known as “Keytruda”].
Keytruda is classed as a new type of drug developed to switch the immune system back on in patients who have the tumours expressing PD-L1 factors, it is manufactured by Merck (MSD in Australia). It has been approved for use in Australia (and elsewhere) for treating advanced melanoma (commonly called skin cancer), and for advanced non-small cell lung cancer (only where sufferers express the protein factor PD-L1), where it is having a reasonable success rate. But it is early days, and too early to say it is a cure or life saving drug for sufferers of advanced melanoma or advanced non-small cell lung cancer, but overall it is certainly seems better than its nearest chemotherapy treatment rival in treating these diseases – but remember, malignant mesothelioma of any form is not lung cancer.
Due to the fact it has been approved for use in humans it can be used to treat patients with other forms of cancers, but only up to the dosage approved for use treating advanced melanoma. As it stands in Australia, an oncologist may use it to treat mesothelioma, but only up to the melanoma dosage rate. It is not on the PBS, so will generally cost about $5,000 a dose (depending on the sufferers weight and the generosity of MSD at the time). If a sufferer is registered with the NSW Government’s icare Dust Diseases Care agency, and has met certain treatment criteria, treatment using Keytruda may be covered by them.
Mesothelioma specialists may use Keytruda as a 1st line treatment, however it normally seems to be used as a second line, or last resort treatment after standard chemotherapy has proven to not be working.
Whilst Keytruda is universally acknowledged, in most cases, as being relative free of harsh side effects (compared to chemotherapy), it is not however devoid of side effects. These can range from being barely noticeable to (very rare) severe life ending side effects – this is the same for most drugs. The important thing to consider is that Keytruda (and all other immunotherapy drugs) is largely untrialed, therefore there is the element off unknown factors associated with being treated with it.
There is much discussion, mainly animating from social media about the fact Keytruda has not been put on the Australian Government’s Pharmaceutical Benefits Scheme (PBS) for treating mesothelioma. There are a number of very good reasons why it has not been put on the PBS:
First and foremost the Australian Government’s Therapeutic Goods Administration has not listed it as a treatment for mesothelioma – it is doubtful that MSD has applied for them to do so. Neither Keytruda or any other immunotherapy drug is listed as a treatment for mesothelioma anywhere in the world.
Secondly, MSD has not applied for it to be on the PBS – if the manufacturer does not apply, the government can’t even consider it!
Thirdly, there is no documented trial evidence at this stage, to suggest it should be listed as a treatment, or included on the PBS – naturally, and hopefully this could change.
Take 15 minutes out to listen to this radio interview, Rod Smith, the Bernie Banton Foundation’s Support Co-ordinator, participated in concerning Keytruda on the 26th May 2016.