Posts Tagged ‘california’

FDA approves new game changing drug to fight melanoma

The drug, Keytruda (pembrolizumab), was tested on more than 600 patients who had melanoma that had spread throughout their bodies. Because so many of the patients in the early testing showed significant long-lasting responses, the study was continued and the FDA granted the drug “breakthrough therapy” status, allowing it to be fast-tracked for approval.

The largest Phase 1 study in the history of oncology, the research was conducted at UCLA and 11 other sites in the U.S., Europe and Australia.

Keytruda, formerly known as MK-3475, is an antibody that targets a protein called PD-1 that is expressed by immune cells. The protein puts the immune system’s brakes on, keeping its T cells from recognizing and attacking cancer cells, said Dr. Antoni Ribas, the study’s principal investigator and a professor of medicine in the division of hematology-oncology at the David Geffen School of Medicine at UCLA.

For many years, when using immunotherapy to fight cancer, doctors’ strategy has been to bolster the immune system so it could kill the cancer cells. But the approach had limited success because PD-1 prevented the immune system from becoming active enough to attack the cancer.

Keytruda, in effect, cuts the brake lines, freeing up the immune system to attack the cancer.

“This drug is a game changer, a very significant advance in the treatment of melanoma,” said Ribas, who also is a researcher at UCLA’s Jonsson Comprehensive Cancer Center. “For patients who have not responded to prior therapies, this drug now provides a very real chance to shrink their tumors and the hope of a lasting response to treatment.”

Judith Gasson, senior associate dean for research at the David Geffen School of Medicine at UCLA and director of the Jonsson Cancer Center, said researchers have long hoped to develop an effective and lasting immunotherapy to fight cancer.

“We have long believed that harnessing the power of our own immune systems would dramatically alter cancer treatment,” she said. “Based upon work conducted over the past two decades, we are beginning to see the clinical benefits of this research in some of the most challenging cancers.”

Generally, about 1 in 10 patients responded to previous immunotherapy drugs. Some of those who responded, however, exhibited long-lived benefits, which sustained scientists’ interest in the method as an effective mechanism to fight cancer.

The response and duration rates for Keytruda were much greater than for previous drugs, Ribas said. In the new study, 72 percent of patients responded to the drug, meaning that their tumors shrank to some degree. Overall, 34 percent of patients showed an objective response, meaning that their tumors shrank by more than 30 percent, and did not re-grow.

Ribas said Keytruda has the potential to be used to treat other cancers that the immune system can recognize, including cancers of the lung, bladder, head and neck.

Survivors’ stories Kathy Thomas, 59, of Torrance, California, was diagnosed in September 2011 with melanoma that had spread to her liver and was invading her left breast. She underwent several therapies that did not work, and she was weakening fast.

“I lost weight. I threw up nearly every day,” Thomas said. “My hair was thinning. I just had no strength at all. I was so sick I had to use a wheelchair.”

Thomas met with Ribas in 2012 but was skeptical about enrolling in a trial to test an experimental therapy. She soon overcame her hesitation.

“I decided I wanted to survive,” she said. “I wasn’t going to let this disease beat me.”

Since enrolling in the study, Thomas’ tumors have shrunk. She regained her strength and her appetite. She’s out of her wheelchair and walking normally again. She said she has experienced no side effects from the therapy, and she travels monthly to San Francisco to visit her grandson.

“I just enjoy life now, really enjoy it,” she said.

Watch Kathy Thomas discuss her therapeutic experience: http://youtu.be/BOgw7mgQEdc

Tom Stutz, 74, of Sherman Oaks, California, was diagnosed in June 2011 with melanoma that had spread to his lung, liver and other parts of his body. He didn’t see how he could survive, but he decided to enroll in the clinical trial of Keytruda anyway.

“I wasn’t eating. I was on oxygen. I couldn’t walk,” he said. “When I went into the hospital at the end of May [2012], I didn’t think I was coming out.”

Gradually, though, Stutz started feeling better. Today, he’s no longer on oxygen and walks several miles every day.

“It’s the little things that make me happy now,” Stutz said. “I’m very appreciative that I get to get up in the morning, go into my backyard and see my garden. I’m able to be with my children and grandchildren, go on vacations with them. I was close to the end of the road, as far as you can get to the edge of the cliff, and I was pulled back by this treatment.”

Watch Tom Stutz discuss his therapeutic experience: http://youtu.be/-HV2W5XrOZY

Melanoma incidence rates have been increasing for at least 30 years. An estimated 76,100 new cases of melanoma will be diagnosed in the U.S. in 2014, and nearly 10,000 Americans will die from the disease this year. While melanoma accounts for less than 2 percent of all skin cancer cases, it is responsible for the vast majority of skin cancer deaths, according to the American Cancer Society.

source : http://www.sciencedaily.com/releases/2014/09/140904183602.htm

Enzyme controlling metastasis of breast cancer identified

“The take-home message of the study is that we have found a way to target breast cancer metastasis through a pathway regulated by an enzyme,” said lead author Xuefeng Wu, PhD, a postdoctoral researcher at UC San Diego.

The enzyme, called UBC13, was found to be present in breast cancer cells at two to three times the levels of normal healthy cells. Although the enzyme’s role in regulating normal cell growth and healthy immune system function is well-documented, the study is among the first to show a link to the spread of breast cancer.

Specifically, Wu and colleagues with the UC San Diego Moores Cancer Center found that the enzyme regulates cancer cells’ ability to transmit signals that stimulate cell growth and survival by regulating the activity of a protein called p38 which when “knocked down” prevents metastasis. Of clinical note, the researchers said a compound that inhibits the activation of p38 is already being tested for treatment of rheumatoid arthritis.

In their experiments, scientists took human breast cancer cell lines and used a lentivirus to silence the expression of both the UBC13 and p38 proteins. These altered cancer cells were then injected into the mammary tissues of mice. Although the primary tumors grew in these mice, their cancers did not spread.

“Primary tumors are not normally lethal,” Wu said. “The real danger is cancer cells that have successfully left the primary site, escaped through the blood vessels and invaded new organs. It may be only a few cells that escape, but they are aggressive. Our study shows we may be able to block these cells and save lives.”

Researchers have also defined a metastasis gene signature that can be used to evaluate clinical responses to cancer therapies that target the metastasis pathway.

source : http://www.sciencedaily.com/releases/2014/09/140902205145.htm

Finding keys to glioblastoma therapeutic resistance

“There is a growing interest to guide cancer therapy by sequencing the DNA of the cancer cell,” said Clark Chen, MD, PhD, vice-chairman of Research and Academic Development, UC San Diego Division of Neurosurgery and the principal investigator of the study. “Our study demonstrates that the sensitivity of glioblastoma to a drug is influenced not only by the content of its DNA sequences, but also by how the DNA sequences are organized and interpreted by the cell.”

The team of scientists, led by Chen, used a method called comparative gene signature analysis to study the genetic profiles of tumor specimens collected from approximately 900 glioblastoma patients. The method allows investigators to discriminate whether specific cellular processes are “turned on” or “turned off” in glioblastomas. “Our study showed that not all glioblastomas are the same. We were able to classify glioblastomas based on the type of cellular processes that the cancer cells used to drive tumor growth,” said Jie Li, PhD, senior postdoctoral researcher in the Center for Theoretical and Applied Neuro-Oncology at UC San Diego and co-first author of the paper.

One of these cellular processes involves Epidermal Growth Factor Receptor (EGFR). The study revealed that EGFR signaling is suppressed in a subset of glioblastomas. Importantly, this suppression is not the result of altered DNA sequences or mutations. Instead, EGFR is turned off as a result of how the DNA encoding the EGFR gene is organized in the cancer cell. This form of regulation is termed “epigenetic.” Because EGFR is turned off in these glioblastomas, they become insensitive to drugs designed to inhibit EGFR signaling.

“Our research suggests that the selection of appropriate therapies for our brain tumor patients will require a meaningful synthesis of genetic and epigenetic information derived from the cancer cell,” said co-first author Zachary J. Taich.

The paper’s abstract can be found at: http://www.impactjournals.com/oncotarget/index.php?journal=oncotarget&page=article&op=view&path[]=2350

source : http://www.sciencedaily.com/releases/2014/08/140825185321.htm