Month: May 2011

The biotechnology company OncoPep is developing a vaccine against a deadly form of cancer before it becomes evident in patients at risk to contract the disease.  The vaccine is designed to prevent the onset of multiple myeloma, a type of cancer that attacks the bone marrow and forms tumors inside the bone.  The disease also strikes the immune system, increasing the production of antibodies and leading to pain and excess bleeding.

The vaccine represents a new step in the growing field of immunotherapy. Scientists who research immunotherapy treatments for various cancers develop methods for the body’s own immune system to combat cancer.  Immunotherapy research had led to the creation of vaccines that can prevent cancer, such as the human papillomavirus (HPV) vaccine that prevents cervical cancer in women. The field has also produced vaccines by programming antibodies to fight cancer as they would fight infections or other diseases.

The myeloma vaccine fits in an intermediate stage in cancer treatment. The primary treatment group would consist of patients who have a preliminary, pre-cancer stage of the disease, known as smoldering multiple myeloma (SMM).  Patients with SMM have abnormal growth rates in the plasma cells that create antibodies, but do not have the tumors and other symptoms that come with the full onset of the disease.

A team of researchers at the Dana Farber Cancer Institute in Boston developed a method to administer a vaccine made up of a mix of protein molecules called peptides.  The peptides contain protein molecules that myeloma tumors require for sustained life and growth.  As the antibodies attack the peptides, they also attack the myeloma cells. The immune system then robs the cancer cells of the proteins they need to survive.

Just as with blood types, doctors have classified patients into different types of immune systems, called “human leukocyte antigen (HLA) types”.  Doctors commonly use HLA typing to match donors and recipients in bone marrow transplants.  Researchers on the myeloma vaccine will target the treatment at patients with the most common HLA type, known as HLA type A2. Doris Peterkin, CEO of OncoPep, said that the peptides were more likely to trigger the needed antibodies in patience with the most common HLA type, and would be more effective in preventing SMM from becoming full myeloma.

As promising as the preliminary results have been, the road to a vaccine for multiple myeloma is still a long one.  Although patients with SMM develop full myeloma in almost 80 percent of all cases, only 10 percent of those cases progress to that stage each year.  OncoPep and the research team will still need to collect data for several years on the effectiveness of the vaccine before it will be ready for the wider marketplace.

Dr. Kenneth Anderson, one of the research team leaders who developed the vaccine, said that he hopes it could be used as a preventative measure for patients with SMM, who currently do not have treatment options available until the disease becomes full-blown myeloma.  “The idea (behind the vaccine) would be to prevent the development of an active cancer, ” Dr. Anderson said.

Sources:
http://www.technologyreview.com/printer_friendly_article.aspx?id=37520
http://www.fiercevaccines.com/story/oncopep-vax-aims-stop-multiple-meyloma-it-starts/2011-05-05
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001609/

A new study from researchers at the University of Geneva shows that the breast cancer drug Tamoxifen may also be useful in combating lung cancer. The study found that women who were undergoing treatment for breast cancer, with Tamoxifen as part of their chemotherapy routines, also showed a reduced death rate from lung cancer. The research team examined data from women who received Tamoxifen from 1980 to 2003 and found that the death rate from lung cancer in those patients was eighty-seven percent lower than those who did not take the drug.

Tamoxifen has been used for decades to suppress the production of estrogen, a female sex hormone. Previous research efforts have tied the production of estrogen to breast cancer. Recent studies have also linked hormone replacement therapy, often prescribed to post-menopausal women, to an increased incidence of lung cancer. One of the premises of the Geneva study was to learn if suppressing hormones could be used as a therapy to treat lung cancer.

The study data did not show a decrease rate in the appearance of lung cancer in women who took Tamoxifen, but the results did show a remarkable reduction in the mortality rate from the disease. Dr. Elisabetta Rapiti, the study’s team leader, said that the data shows clear signs, “that there is a hormonal influence on lung cancer”. She also cited earlier findings that showed that lung cancer cells have receptors for estrogen and progesterone, another female sex hormone, which suggests that the mutated cells could feed off the hormones.

Oliver Childs, the senior science information officer at the British research facility Cancer Research UK, told reporters that it was “possible” that Tamoxifen and other anti-estrogen drugs could also have a positive effect on lung cancer patients. However, he also said that the results from the Geneva study were inconclusive since “the number of women who developed lung cancer (in the study) was small”.

In Dr. Rapiti’s study, out of more than six thousand patient records examined, only forty of the women showed signs of lung cancer. Less than half of the Geneva study patients underwent treatment with Tamoxifen or other hormone suppressants, and only one-third of the patients had ever smoked. The study data shows that nearly as many smokers used Tamoxifen as underwent other kinds of chemotherapy for their breast cancer.

The study authors also mentioned that the data was incomplete in places, including how the breast cancer diagnosis affected the women’s smoking behaviors. They also mentioned that they often lacked specific information on the types and dosages of anti-estrogen therapies the women received during their chemotherapy treatments.

Mr. Childs said that “large-scale clinical trials” would be necessary to determine how Tamoxifen could be used as a potential weapon against lung cancer. Dr. Rapiti also mentioned “prospective studies” to examine the findings further. She also said that, if any new studies confirm the earlier findings, it “could have substantial implications for clinical practice” in the treatment of lung cancer.

Sources: http://www.bbc.co.uk/news/health-12243206 http://www.medpagetoday.com/HematologyOncology/LungCancer/24487 http://www.financialexpress.com/news/Breast-cancer-drug-may-also-cut-lung-cancer-deaths–Study/741687/

The development of new chemotherapy drugs that target cancerous tumor cells – while leaving healthy cells alone – has been a breakthrough in the cancer treatment field. However, these treatments have been shown to work only on a select few patients. Even when they do work, the tumor can create a resistance to the drugs, leaving the patient with fewer options. Several scientific research teams are working on new drugs that will work with a wider range of patients and target tumors before they can develop a resistance to the treatments.

The main component in the research behind these new cancer drugs comes from a deeper knowledge of how cancer cells come into being, grow, multiply and spread throughout the body.  One study at the Massachusetts Institute of Technology examines lung cancer cells and how scientists can synthesize drugs that can target the tumors.  The treatments can also be modified to help the patient as they proceed through the chemotherapy routines.

The MIT study takes a close look at a class of drugs known as “epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors”. Tyrosine kinase is a protein that functions as an “on/off” switch for many cell functions. When the proteins that regulate cell growth are permanently set in the “on” position, the cells can grow quickly and in uncontrolled ways, a common occurrence in cancer cells. Tyrosine kinase inhibitors act to slow down or stop the wild cell growth and stabilize or reduce the size of lung cancer tumors.

EGFR inhibitors are effective in less than 40 percent of all lung cancer patients. The drug’s effectiveness varies widely based on the patient’s medical history, smoking habits, race, gender and ethnicity. Dr. Philip Sharp, Professor at the Koch Institute for Integrative Cancer Research at MIT, said that laboratories around the world have “hundreds of drugs” that are in various stages of testing and development. “To personalize cancer care, we must interpret changes in (tumors) to predict the correct drug combination to use.”

Another factor in customizing cancer treatments is that some patients carry a mutation in the gene for EGFR, which makes the drugs more effective. The MIT study examined the differences between those patients and patients that did not respond to the drug. MIT researcher Doug Lauffenburger, along with a team of researchers, developed mathematical models to simulate the behavior of different types of cancer cells. The models revealed that the cancer cells that responded to the drug had a slower uptake of EGFR than the less responsive tumors.

While these methods require further verification, scientists are hopeful that the findings can lead to a possible screening test for lung cancer patients to determine the effectiveness of EGFR inhibitors in individual cases. Lauffenburger and his team also learned that the EGFR inhibitors could be more effective in certain cases when combined with another class of chemotherapy drug known as MEK inhibitors, which are often used to treat melanoma. In terms of tailoring drug combinations to individual patients, Dr. Sharp remarked that these findings “indicate that this is beginning to become possible.”

Sources: Technology Review, Medscape.com