Phase II Clinical Trials

Hi Dr.Goodman
I have started my second round of chemo with Taxol/carbo for a recurrence. I met with a new Dr at Princess Margaret Hospital in Toronto, who said it was more likely that I have a platinum resistant cancer. (I recurred at about 6.5 months) He told me he would not have started me on the same drugs as last time and gave me two options to try. One is the standard treatment for platinum resistant cancers (can't remember the name of the drugs, but I'm sure you know which ones they are) or he offered me a phase II clinical trial titled "A Phase II Study of PDX101 in Platinum Resistant Epithelial Ovarian Tumors and Micropapillary/Borderline(LMP) ovarian tumors". I have Micropapillary Serous Carcinoma, and he thought this would be good for me. Do you know much about phase II trials? It looks like I will be monitored very closely, but I can't help worrying about the side effects - they seem really similar to Taxol/carbo. How much do they know about a drug at this point? Is it safe to assume that they are obviously seeing good results from this? I would think that if they weren't, they would not be continuing on with it. He said he couldn't discuss any of the results from past expierences with this drug. What are your thoughts on trials? I can't help but think how amazing it would be to help find a treatment for MPSC, seeing as it is such an unpredictable, aggressive cancer.
Your thoughts would be greatly appreciated,
Sincerely,
Becky H

[Annekathryn Goodman, M.D.]

Dear Becky,

I agree with the new Dr. However,now that you have started on carbo and taxol and have received two cycles, before switching to something new, I would reccommend a repeat CT scan. If there is a sign that the tumor is shrinking on scan, that means that at least part of this recurrence is sensitive to carbo/taxol. Then you should keep going. However if after two cycles, you have no change in your scan, I agree that you should change to another type of treatment.

Other drugs that are used in ovarian cancer include (but are not limited to):
Doxil
Topotecan
Cytoxan
Gemcitabine
Tamoxifen
Arimedex

I am not familiar with PDX101. I did a quick search and did not find anything. If you have any more information about it such as the general category of drug let me know and I will look it up for you. You should have received an informed consent document to read about the clinical trial. That should have more information about the nature of this drug.

Phase I clinical trial: A completely unknown drug is being given. The goal of these trials is to determine the right dose of drug and to determine what the toxicities of the drug are. The MTD, maximum tolerated dose, is one of the goals of Phase I studies. MTD is the highest dose one can give before getting unacceptable toxicity.

Phase II trial: the goals include determining whether there is any efficacy to the drug. What is the response rate? How well is the cancer killed? Phase II trials can involve completely unknown drugs that have previously passed phase I dosing studies or known drugs that are being used in a different way or for a different disease.

Here is a nice link that can give you more information:
http://cancerguide.org/trials_glossary.html


let us know how things go.
take care.

[MLWTR]

PDX101 is a histone deacetylase inhibitor (see http://leaddiscovery.blogspot.com/2006/07/further-development-of-hdac-inhibitor.html).

(You may have to copy these links into your browser bar; I don't how to put in hyperlinks.)

They seem to have released virtually no information about it. Here is the only article that I could find: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed  

(In case you have problems with the link, this is the full reference: Plumb JA, Finn PW, Williams RJ, et al.  Pharmacodynamic response and inhibition of growth of human tumor xenografts by the novel histone deacetylase inhibitor PXD101. Mol Cancer Ther. 2003;2:721-728.)

It is mentioned here too, but it doesn't seem to add much: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed

There is an upcoming trial of it in lymphoma (http://www.clinicaltrials.gov/ct/show/NCT00354185;jsessionid=6EC496EC546EAF2C310DBE0BBAD222C4?order=7).

There is also a phase II clinical trial of PBX101 in unresectable malignant pleural mesothelioma (http://www.cancer.gov/search/viewclinicaltrials.aspx?cdrid=489194&version=healthprofessional&protocolsearchid=1984238).

Anyway, it's meager information, but I hope this is some help. Good luck to you, Tybear.