Featured Research

from universities, journals, and other organizations

Combination of targeted treatment drugs delays resistance in melanoma patients

Date:
September 29, 2012
Source:
Massachusetts General Hospital
Summary:
Combined treatment with two drugs targeting different points in the same growth-factor pathway delayed the development of treatment resistance in patients with BRAF-positive metastatic malignant melanoma.

Combined treatment with two drugs targeting different points in the same growth-factor pathway delayed the development of treatment resistance in patients with BRAF-positive metastatic malignant melanoma. The results of a phase I/II study of treatment with the kinase inhibitors dabrafenib and trametinib will be published in the New England Journal of Medicine and are being released online to coincide with a presentation at the European Society for Medical Oncology meeting in Vienna.

"We investigated this combination because of research we and others have conducted into the molecular underpinnings of resistance to BRAF inhibitor therapy," says Keith Flaherty, MD, of the Massachustts General Hospital (MGH) Cancer Center, lead author of the NEJM report and principal investigator of the study. "We found that adding the MEK inhibitor trametinib to BRAF inhibitor dabrafenib clearly delays the emergence of resistance. In fact, the combination was at least twice as effective as BRAF inhibition alone."

In around half of patients with metastatic melanoma, tumor growth is driven by mutations that keep the BRAF protein -- part of the MAPK cell growth pathway -- constantly activated. In recent years, drugs that inhibit BRAF activity have rapidly halted and reversed tumor growth in about 90 percent of treated patients, but most patients' response is temporary, with tumor growth resuming in six or seven months. Investigations into how this resistance emerges have suggested that the MAPK pathway gets turned back on through activation of MEK, another protein further down the pathway. Based on promising results of animal studies, the current investigation was designed to test whether inhibiting both the BRAF and MEK proteins could delay treatment resistance.

Sponsored by GlaxoSmithKline, the study by researchers at 14 sites in the U.S. and Australia tested two of the company's drugs -- BRAF inhibitor dabrafenib and MEK inhibitor trametinib, both oral medications currently being evaluated by the FDA as single-agent therapeutics -- in adult patients with BRAF-expressing malignant melanoma. Phase I testing confirmed that there were no drug-to-drug interactions between the two agents and evaluated the safety of different dose combinations. In the open-label phase II portion of the study, 162 patients were randomized into three groups that received different dose combinations: two daily 150 mg doses of dabrafenib plus one 2 mg trametinib dose, the same dabrafenib dose with a 1 mg dose of trametinib, or treatment with dabrafenib alone. Participants receiving dabrafenib alone were able to cross over to the full-dose combination treatment if their cancer resumed progression.

Treatment with both combination regimens led to a significant delay -- about four months longer than with dabrafenib alone -- in the emergence of resistance. After one year of treatment, 41 percent of those receiving full-dose combination treatment had no progression of their cancer, compared with only 9 percent of those receiving one drug. The occurrence of side effects such as skin rash and the development of squamous cell carcinoma, a less malignant skin cancer, was similar to that typically seen when only one of the two drugs is used, and some side effects were less frequent with the combination therapy.

Noting that the tested combination, now being tested in a larger Phase III study, delayed but did not prevent resistance in most participants, Flaherty says, "We need to continue focusing on resistance mechnisms occuring with this combination approach so we can better understand how to treat patients once resistance emerges or to develop other combination regimens to further prevent relapse. We also need to see if this approach could serve as an effective adjuvant therapy used following surgery to prevent recurrence. That might have the biggest impact on patients." Flaherty is an associate professor of Medicine at Harvard Medical School.


Story Source:

The above story is based on materials provided by Massachusetts General Hospital. Note: Materials may be edited for content and length.


Journal Reference:

  1. K.T. Flaherty et al. BRAF and MEK Inhibition in Melanoma. New England Journal of Medicine, September 29, 2012 DOI: 10.1056/NEJMoa1210093

Cite This Page:

Massachusetts General Hospital. "Combination of targeted treatment drugs delays resistance in melanoma patients." ScienceDaily. ScienceDaily, 29 September 2012. <www.sciencedaily.com/releases/2012/09/120929140232.htm>.
Massachusetts General Hospital. (2012, September 29). Combination of targeted treatment drugs delays resistance in melanoma patients. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2012/09/120929140232.htm
Massachusetts General Hospital. "Combination of targeted treatment drugs delays resistance in melanoma patients." ScienceDaily. www.sciencedaily.com/releases/2012/09/120929140232.htm (accessed July 25, 2014).

Share This




More Health & Medicine News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins