Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Phase I clinical trial shows drug shrinks melanoma brain metastases

18.05.2012
3-pronged study reveals high response rate in other advanced melanoma patients and activity in multiple cancers

An experimental drug targeting a common mutation in melanoma successfully shrank tumors that spread to the brain in nine out of 10 patients in part of an international phase I clinical trial report in the May 18 issue of The Lancet.

The drug dabrafenib, which targets the Val600 BRAF mutation that is active in half of melanoma cases, also cut the size of tumors in 25 of 36 patients with late-stage melanoma that had not spread to the brain. The drug also showed activity in other cancer types with the BRAF mutation.

"Nine out of 10 responses among patients with brain metastases is really exciting. No other systemic therapy has ever demonstrated this much activity against melanoma brain metastases," said study co-lead author Gerald Falchook, M.D., assistant professor in the Department of Investigational Cancer Therapeutics at The University of Texas MD Anderson Cancer Center.

Melanoma patients whose disease has spread to their brains have a median overall survival of four or five months, the researchers noted. Drugs used to treat brain metastases have response rates of 10 percent or lower. Surgery and stereotactic or whole-brain radiation also are used.

Tumor shrinkage in the nine responders ranged from 20 percent to 100 percent. In four cases, the brain metastases disappeared.

Drug's reach into brain a surprise

These results will need to be validated in additional clinical trials with larger groups of patients, Falchook said. "This changes how we think of this drug and exclusion criteria for future trials."

"Most clinical trials exclude patients with brain metastases because the drugs are assumed not to cross the blood-brain barrier," Falchook said. "These are the patients most in need of a clinical trial because their treatment options are so limited."

Dabrafenib, made by GlaxoSmithKline, was not designed to cross the blood-brain barrier, which protects the brain from toxic substances in the blood.

The drug's activity against brain metastases was initially a serendipitous finding at one study site. In one patient, a research PET scan performed just before starting dabrafenib revealed a brain metastasis, but this result was not available until after treatment began. The institution's ethics board approved the patient to continue treatment because a follow-up PET scan two weeks later showed decreased metabolic activity in the brain metastasis and subsequent MRIs showed a reduction in its size.

The team then designed a sub-study for 10 patients with untreated brain metastases, Falchook said. The mechanism by which dabrafenib reaches tumors in the brain is under investigation.

"In all of these patients with melanoma brain metastases, the tumors eventually progressed," Falchook said. Prevention of drug resistance remains a challenge in advanced cancers.

High response rate for those without brain metastases

184 patients enrolled at eight sites in the United States and Australia. Of these, 156 patients had melanoma that had spread to other organs. MD Anderson enrolled 64 patients.

The main purpose of a phase I clinical trial is to gradually escalate an experimental drug's dosage to evaluate side effects and establish the highest possible dose that can be safely given.

The researchers never reached a maximum-tolerated dose limit. No patients had to discontinue the drug due to side effects, and few patients experienced severe toxicity. "This is a very non-toxic drug, which is common with these newer, targeted therapies," Falchook said.

Based on response rates and the drug's pharmacokinetics – how the body metabolizes it – the team recommended an oral dose of 150 mg twice daily for future phase II and phase III trials. In the second stage of the phase I trial, they tested that dose in:

36 patients with melanoma with the Val600 BRAF mutation without brain metastases,

10 patients with untreated melanoma brain metastases, and

28 patients with other BRAF-mutant cancers.
Among the 36 melanoma patients without untreated brain metastases:
25 (69 percent) had a partial or complete response, which is shrinkage of at least 30 percent as determined by measuring tumor shrinkage with radiographic imaging,

18 (50 percent) had a confirmed response, meaning the reduction in size was observed in a second imaging scan at least one month later,

17 (47 percent) stayed on the trial for more than six months, and

Responses were seen in the less common Val600Lys BRAF mutation.
The confirmed response rate was similar to that in a phase III study of vemurafenib, the first drug approved for treatment of BRAF-mutant melanoma.

Among those with other types of cancers, patients with papillary thyroid, non-small cell lung and colorectal cancers had partial responses.

"This is further evidence that a tumor's molecular profile is as important, and possibly more important, than the organ where the cancer begins," Falchook said.

"We need to screen for BRAF and other molecular abnormalities in our patients' tumors," he said. "In many other tumor types BRAF mutations occur in small percentages of patients. If we're not testing for it routinely, these patients might never be treated with a promising targeted agent for their cancer."

Falchook has six melanoma patients still receiving dabrafenib, including five who are in complete remission. In addition, Falchook is still treating six papillary thyroid patients and one colorectal cancer patient whose tumors have not progressed on the treatment.

GlaxoSmithKline sponsored and funded the clinical trial. Phase II and phase III trials of dabrafenib for melanoma are under way.

Co-authors with Falchook are Razelle Kurzrock, M.D., of MD Anderson's Department of Investigational Cancer Therapeutics, and Kevin Kim, M.D. of MD Anderson's Department of Melanoma Medical Oncology; co-lead author Georgina Long, M.D., Ph.D., and senior author Richard Kefford, M.D., Ph.D., of Melanoma Institute Australia, Westmead Institute for Cancer Research and Westmead Hospital, University of Sydney, in Sydney, Australia; Tobias Arkenau, M.D., Ph.D., Prince of Wales Hospital, Randwick, Australia; Michael Brown, M.D., Ph.D., Royal Adelaide Hospital and University of Adelaide, Adelaide, Australia; Omid Hamid, M.D., and Steven O'Day, M.D., of The Angeles Clinic and Research Institute. Los Angeles, Calif.; Jeffrey Infante, M.D., Sarah Cannon Research Institute, Nashville, Tenn.; Michael Millward, M.D., Cancer Council of Western Australia, Sir Charles Gairdner Hospital and University of Western Australia, Perth, Australia; Anna Pavlick, M.D., New York University School of Medicine; and Samuel Blackman, M.D., Ph.D., C. Martin Curtis, Peter Lebowitz, M.D., Ph.D., Bo Ma, Ph.D., and Daniele Ouellet, Ph.D., of GlaxoSmithKline Research and Development, Philadelphia.

Scott Merville | EurekAlert!
Further information:
http://www.mdanderson.org

More articles from Studies and Analyses:

nachricht Rising CO2 has unforeseen strong impact on Arctic plant productivity
21.02.2019 | Max-Planck-Institut für Meteorologie

nachricht Scientists Create New Map of Brain’s Immune System
18.02.2019 | Universitätsklinikum Freiburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: (Re)solving the jet/cocoon riddle of a gravitational wave event

An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.

In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....

Im Focus: Light from a roll – hybrid OLED creates innovative and functional luminous surfaces

Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.

The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

JILA researchers make coldest quantum gas of molecules

22.02.2019 | Physics and Astronomy

Understanding high efficiency of deep ultraviolet LEDs

22.02.2019 | Materials Sciences

Russian scientists show changes in the erythrocyte nanostructure under stress

22.02.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>