Clinical trials are used to determine the effectiveness and safety of new drugs that are being tested in humans. Mesothelioma, a form of lung cancer caused by exposure to asbestos, is currently the focus of numerous clinical trials for more effective mesothelioma treatment methods. While there is as yet no cure for mesothelioma, clinical trials are ways in which cancer researchers try to find the best possible treatments for a condition.
For anyone considering participating in a clinical trial, it is essential to have a thorough understanding of what the trial involves. Many clinical trials are conducted at larger hospitals and cancer treatment centers, so there may be travel involved for receiving the necessary tests and mesothelioma treatments. In general, care at these facilities is done by medical professionals who are leaders in cancer research and who know about the latest trials and experiments. Clinical trials sometimes allow a patient to have access to brand new drugs before they are widely available. Then again, the outcome of a trial cannot be predicted, so there is the possibility that an experimental treatment my not be as good as the current standard of care.
Every clinical trial has requirements for who may participate, and those requirements differ from trial to trial. Some trials require that the patient has not received other mesothelioma treatments, while other trials seek patients who have had other treatments that have not worked. Some clinical trials are randomized. This means that the experimental treatment is being compared to standard treatment. You could end up being assigned to receive the standard treatment or an experimental treatment. But with cancer drug trials, placebos (“dummy” pills that only contain starch) are rarely used.
Clinical trials are made up of several phases as a treatment is evaluated for widespread use in cancer treatment. Phase I trials usually involve a small number of people, and they test ways in which new treatments are administered. Phase II trials are done to determine whether the new drug or procedure works, and what its safety profile is like. Phase III trials are used to compare new drugs or procedures to current treatments. Phase III trials involve large numbers of people who receive either the standard treatment or the experimental treatment. For mesothelioma, there are numerous trials being conducted to come up with treatments that increase themesothelioma survival rate. Here are several (in no particular order).
New mesothelioma drug studies
A phase III study is testing Suberoylanilide Hydroxamic Acid, or SAHA, against a placebo in advanced mesothelioma cases. SAHA is an orally administered drug that is being investigated for its tolerability and anti-tumor effectiveness. Patients must be over age 18, and must have had prior chemotherapy with pemetrexed with cisplatin or carboplatin that failed, and the patient must have adequate liver, kidney, and bone marrow function. The patient has to spend more than half of waking hours out of bed and must be able to swallow pills.
A phase II study of Eloxatin plus Gemcitabine is being conducted to study the tumor response rate for the two drugs given every 14 days in patients with either pleural or peritoneal mesothelioma. It is for patients who have had no more than one regimen of chemotherapy prior to the trial. Participation in the trial lasts 6 months, and 29 patients are needed for enrollment.
Another phase II study involves chemotherapy followed by intensity modulated radiation therapy to the lungs. It is for patients with locally advanced, unresectable pleural mesothelioma. The drug used is called everolimus and is administered 28 days in a row. If the patient’s condition does not worsen and the toxicity is bearable, a second 28-day course is done, up to four courses. Afterwards, the patients are followed for three years.
A phase II trial of CBP501 plus Pemetrexed, plus Cisplatin in patients with pleural mesothelioma is designed to evaluate full-doses of cisplatin and pemetrexed combined with the drug CBP501. It is for patients with previously untreated, unresectable lung mesothelioma. The patients are randomized in a 2 to 1 ratio to pemetrexed, cisplatin, and CBP501 or pemetrexed and cisplatin only. It is for patients for whom standard mesothelioma treatments either do not exist or are not effective.
Dasatinib is being studied in patients with malignant mesothelioma that has been treated previously. This phase II trial will study the response, toxicity, and mesothelioma survival rate for patients treated with Dasatinib. It is for patients with any type of mesothelioma who have already been treated with a systemic chemotherapy regimen that included pemetrexed disodium alone or in combination with another drug.
Pazopanib hydrochloride is the subject of a phase II study of patients with pleural mesothelioma. The trial will measure the effect of pazopanib hydrochloride on patients with pleural mesothelioma who are free of progression at six months. The patients must have no symptomatic, untreated, or uncontrolled CNS metastases, unless they have had CNS metastases treated with whole brain radiation and have completed the whole brain radiation therapy.
A phase II randomized study of pemetrexed disodium plus either gemcitabine or carboplatin in patients with advanced pleural mesothelioma will study whether a combination of drugs works better than a single drug to either kill tumor cells or stop them from dividing. The results will be compared to historical controls in treatment of patients with advanced pleural mesothelioma.
A drug called AZD2171 is being tested in a phase II clinical trial to see if it stops growth of tumor cells by blocking enzymes the cells need and by blocking the flow of blood to the tumor. It is for patients with pleural mesothelioma that can’t be surgically removed. The study will determine the response rates in patients to mesothelioma treatment with AZD2171, the clinical benefit of the treatment, the one-year mesothelioma survival rate and progression-free rate, and the toxicity of the drug.
The drug bevacizumab will be evaluated when used with cisplatin or pemetrexed for untreated mesothelioma. The study will evaluate the time to progression in cancer in patients receiving cisplatin, pemetrexed and bevacizumab as well as overall response rate and overall mesothelioma survival rate.
Induction combination chemotherapy with methotrexate, vinorelbine ditartrate, and cisplatin with or without surgery and chemotherapy in patients with pleural mesothelioma. Because the different drugs work in different ways to stop tumors from growing, this type of chemotherapy can work before surgery to make the tumor smaller and reduce the amount of tissue that must be removed. Radiation and chemotherapy after surgery may kill tumor cells that are left over. This phase II study will study how well the combination chemo (with or without surgery and radiation) works in treating pleural mesothelioma.
A phase II experiment involving PDX101 as a second line mesothelioma treatment for patients with pleural mesothelioma that is not treatable with surgery is designed to determine the response rate of patients to the drug, determine survival time and time to progression, evaluate the drug’s toxicity, and to perform molecular level studies of the tumor tissue and peripheral blood. It’s for patients who have had no more than one systemic chemotherapy regimen and patients who do not have brain metastases.
The orally administered drug milataxel (TL139) is being studied in a phase II clinical trial. Milataxel is a new drug that may have certain advantages over currently available drugs in its class (taxanes). The study is to determine the response rate in patients with progressive or recurring disease after having received chemotherapy. It is a non-randomized study, and patients who qualify receive milataxel on the first day of a 21 day cycle. If the first cycle does not produce toxicity greater than Grade 1 in severity, patients will then receive a higher dose on the next and subsequent cycles, up to six cycles. More cycles can be done at the discretion of the principle investigator if the patient is stable or makes progress on the drug.
These are only a small number out of the total number of clinical trials that are being done on treatments for mesothelioma. Anyone who is interested in clinical trials can go to the URL http://www.cancer.gov/clinicaltrials/search and perform a search for clinical trials based on the type of cancer that they have, the stage of their cancer, and even based on geographical location. Clinical trials don’t only include chemotherapy drugs. There are also drugs in clinical trials being evaluated for pain management and other aspects of cancer care.
Mesothelioma is difficult to treat
Most people who come down with mesothelioma have had jobs that exposed them to inhaled asbestos particles, or else they were exposed to dust or fibers of asbestos in other settings. Asbestos breaks down into tiny particles in the body, and the tiny particles can eventually lead to malignant mesothelioma.
Though mesothelioma is considered one of the more difficult types of cancer to treat, a recent study to be published in the American Journal of Respiratory and Critical Care Medicine shows that researchers have actually come up with an investigational vaccine for the disease. The vaccine was tested on 10 patients in the Netherlands, and researchers discovered that it causes the patient’s own T-cells to attack the tumors.
According to the American Cancer Society, up to 3,000 new cases of mesothelioma are diagnosed every year, and the scientists studying the vaccine hope they will be able to save many thousands of lives. Demographically, experts believe that cases of mesothelioma will continue to increase until the year 2020, when they should drop off due to a decrease in the numbers of people exposed to asbestos in work environments.
Mesothelioma has been in the news in 2010 with the deaths of actor Merlin Olsen and music producer Malcolm McLaren. In the case of McLaren, there have been no indications as to how he was exposed to asbestos. According to the Independent, a UK daily newspaper, McLaren’s partner has said she believes he was exposed to asbestos when he broke up the ceiling of a London shop he shared with British designer Vivienne Westwood in the early 1970s. McLaren had shattered the ceiling to give the effect of a bomb having exploded in the punk-themed shop. He was diagnosed with the disease in October 2009.
In Olsen’s case, he believed that he may have been exposed to asbestos as a child, and during a time when he worked in construction, though he left open the possibility that he was exposed to asbestos working in television studios with NBC, 20th Century Fox, and NBC Universal. His widow is pursuing the lawsuits that he initiated before his death in March 2010. He was diagnosed with the disease in July 2009.
Mesothelioma usually does not exhibit any symptoms until the disease is advanced. It takes up to several decades to develop, and when it is found early, it is usually because it is found accidentally in the course of diagnosing other illnesses. When found early, the mesothelioma survival rates are far higher. The number of clinical trials underway related to mesothelioma survival indicate that the scientific and medical communities are hopeful they will develop a breakthrough in mesothelioma treatment.