CURE COMMUNITY
PARP inhibitors create buzz at ASCO
BY DEBU TRIPATHY | JUNE 8, 2009
What happens when a preliminary study that was not designed for drug approval ends up showing dramatic results? A study in patients with advanced "triple negative" breast cancer (defined as being negative for estrogen, progesterone, and HER2 receptors) compared chemotherapy (Gemzar and carboplatin) with or without BSI-201, a poly ADP-ribose polymerase (PARP) inhibitor. PARP inhibitors have been shown to work exceptionally well in the laboratory against cancers that have defects in DNA repair – this is an abnormality that is prominent in cancers that derive from patients who have inherited mutations in the breast and ovarian cancer predisposing genes BRCA1 and 2. It turns out that BRCA1-associated tumors tend to be triple negative (although not all triple negative tumors have abnormalities of the BRCA pathways). This was a preliminary phase II study, so even though it was randomized, it did not have enough patients to qualify as an FDA-approval trial. But it nevertheless showed unprecedented effects on inducing tumor responses, delaying time to progression, and improving survival – even greater than hormonal therapy and Herceptin have. We all know that smaller studies can sometimes be irreproducible and overestimate real benefits, but given the paucity of therapies and the aggressive nature of refractory triple negative advanced breast cancer, we might see some unusual developments as a result of this study – such as the establishment of a compassionate trial that is made widely available while more definitive trials are being pursued. These results have created quite a buzz among my colleagues in the breast cancer research arena. Many of us wonder whether it would even be possible to randomize patients with this type of cancer to a non-PARP containing arm in a clinical trial. At the same time, these results must be confirmed in a larger and more reliable study. A trial design that allows patients to cross over to the active drug if they progress on the placebo arm is a strategy that might address some of the concerns, but this trial design tends to obscure survival benefits. The trials will also need to be able to explore different biological subsets to pin down exactly what type of patient benefits most. Still, we prefer to have all these dilemmas to address when a potentially new important drug can be added to our armamentarium.
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I am a tripple-negative, BRAC-1, 24-year breast cancer survivor, who has been fighting ovarian cancer for 11 years. I think I might benefit from the PARP-Inhibitor therapy, and thought perhaps you'd have advice on how/where to obtain this treatment.
- Posted by Fran DiGiacomo 6/9/09 7:13 PM
I believe Duke University is one of the places that treats with Parp Inhibitor.
You may want to check http://www.medicinenet.com/script/main/art.asp?art...
- Posted by Hanna Shapira 6/9/09 9:27 PM
Dear Ms. DiGiacomo:
I think you have a few options to find the info you asked about. Using google news, you can find other stories about these developments using the word 'PARP'. From them, you can identify the companies making and testing the drugs. Alternately, if you contact ASCO, you can ask if there is a way you can identify and/or contact the doctors who presented the abstracts that showed these favorable results. In both cases, you might not be given access to those conducting the trials (if this happens, if you can just search the titles of the ASCO abstracts through a publicly accessible link, you might be able to ID the authors and google up contact info using the names and academic affiliations or some key words, or maybe you can find a few names though the news stories), and even if you make contact they might not allow you to enroll in the trials, but if you explain that you are a patient who has had both breast and ovarian it will help your case.
Also, your regular oncologists or gynecologists, or patient support groups, might be able to help you find the specific clinical trials, so ask them as well. Print out the news articles and show them – I expect that all would be enthused by such results and would be glad to help you.
Good luck!
- Posted by Bond Quartermaster 6/10/09 7:50 PM
Hello,
My father has advanced metastatic prostate cancer that has moved to he bones. I am interested in locating clinical trials on PARP inhibitors in which he may participate. Can you help point me to current clinical trials using PARP inhibitors for prostate cancer?
Thanks in advance!
Jo
- Posted by Jo 6/24/09 5:09 PM
Jo,
After doing a quick search on clinicaltrials.gov, there does seem to be a few early-phase trials testing PARP inhibitors in solid tumors, but you may have better luck searching specifically for metastatic prostate cancer trials in phase II or III.
- Posted by Elizabeth 6/25/09 11:20 AM
How do I find out where there may be trials starting up using PARP Inhibitors in treatment of prostate cancer?
- Posted by Veronica M Isaac 6/26/09 6:32 PM
My husband has advanced prostate cancer with bone, brain, and pleural effusion metastasis. He is currently undergoing chemotherapy which he has been on and off since 2005. Would he even be eligible for a PARP inhibitor clinical trial??
- Posted by Honey Miller 6/28/09 10:01 PM
My husband has metastasic prostae cancer to bones. He also has pleural effusion and is currently hospitalized with draining chest tubes. We have been told the effusion is probably from the chemo, and radiation he has undergone for he last 8 years. If only I had seen this PARP sooner, I would have tried to get him ino a trial. Good luck to all that are strugling with this disease-PARP inhibitors may be the prayer many are waiting for. Liz Brady
- Posted by elizabeth brady 7/1/09 10:10 AM
I think I found the inventors of Parp.
They should know who is doing clinical trials.http://www.faqs.org/patents/app/20090131529
- Posted by Brenda 7/1/09 10:19 AM
I have prostate cancer. i underwent prostatectomy in august, 2007. Cancer escaped prostate and I have had hormone treatments since October, 2007. My PSA levels have risen in last six months from .6 to 6.7 Effective 7.17.09 my new drug treatment is Ketoconazole. Currently there is no evidence of bone or other metastases. I am interested in locating clinical trails on PARP inhibitors or any other clinical trials whose aim is to cure rather than delay the cancer. Can you direct me to the appropriate clinical trials?
Sam J.
- Posted by Samuel Jennings 7/17/09 8:39 AM
You can search for clinical trials at www.clinicaltrials.gov and sreach the term PARP inhibitor. Be aware you may need to be willing to travel long distances to participate in these trials.
- Posted by Kathy Galus 8/26/09 2:30 PM