HonCode

Go Back   HER2 Support Group Forums > Articles of Interest
Register Gallery FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
Old 09-12-2010, 07:18 PM   #1
Rich66
Senior Member
 
Rich66's Avatar
 
Join Date: Feb 2008
Location: South East Wisconsin
Posts: 3,431
Provenge: implications for measuring effectiveness

http://www.hemonctoday.com/article.aspx?rid=68401

Quote:
...it is not uncommon for physicians to administer drugs without having a full understanding of how they work. He said PROSTVAC-VF, a poxvirus-based vaccine composed of two recombinant vaccinia-based viral vectors containing PSA and three immune costimulatory molecules, and OGX-001, a novel anticlusterin molecule from OncoGenex, are examples of therapies that extend survival without producing any appreciable effect on time-to-progression or tumor shrinkage. “The simple explanation is that the way we measure progression in prostate cancer is problematic,” Kantoff said. “Bone scans are not terribly reliable; the majority of patients don’t have CAT-scan evident diseases. The measurements of stabilization of disease are problematic with respect to PSA.
“The other explanation is that some of these agents, most notably immunotherapies, might take a while before they work. In the Immunotherapy for Prostate Adenocarcinoma Treatment (IMPACT) trial of Provenge, the average time-to-progression is a few months. The average survival in these patients is 2 to 3 years. The effect on the immune system may occur later than an effect on progression is evident,” he said.
In the study that would be the basis for sipuleucel-T’s approval, Kantoff and colleagues recruited 512 men with metastatic castration-resistant prostate cancer and an expected survival of at least 6 months at 75 centers in the United States and Canada from August 2003 through November 2007. Researchers randomly assigned 341 patients to treatment with sipuleucel-T and 172 to placebo. Median survival was 25.8 months in the sipuleucel-T group vs. 21.7 months in the placebo group. Estimated probability of survival 36 months after randomization was 31.7% in the sipuleucel-T group compared with 23% in the placebo group.

However, sipuleucel-T did not improve median time to objective disease progression (14.6 weeks vs. 14.4 weeks) or time to clinical disease progression. Only one patient in the sipuleucel-T group had partial objective response. Eight of 311 patients (2.6%) in the experimental group who were assessed for PSA after baseline had reductions of at least 50% on two visits at least 4 weeks apart compared with two of 153 in the placebo group (1.3%).
“In patients with metastatic castration-resistant prostate cancer, the disease-progression endpoint, as currently defined, has not been a reliable predictor of overall survival,” the researchers wrote. “Several randomized trials that have shown effects of various treatments on overall survival have not shown effects on disease progression and vice versa, including one study in which a therapeutic prostate cancer vaccine was administered in a patient population similar to ours, suggesting a possible class effect or some previously unknown feature of prostate cancer.


__________________

Mom's treatment history (link)
Rich66 is offline   Reply With Quote
Old 09-13-2010, 12:33 PM   #2
Jackie07
Senior Member
 
Jackie07's Avatar
 
Join Date: Jan 2008
Location: "Love never fails."
Posts: 5,808
Re: Provenge: implications for measuring effectiveness

Rich,

Interesting information. Were you trying to demonstrate the lengthy process of getting a new drug approved? I found this long article about Provenge [posted in April, 2010]:

http://www.cancer.org/AboutUs/DrLens...te-Cancer.aspx
__________________
Jackie07
http://www.kevinmd.com/blog/2011/06/doctors-letter-patient-newly-diagnosed-cancer.html
http://www.asco.org/ASCOv2/MultiMedi...=114&trackID=2

NICU 4.4 LB
Erythema Nodosum 85
Life-long Central Neurocytoma 4x5x6.5 cm 23 hrs 62090 semi-coma 10 d PT OT ST 30 d
3 Infertility tmts 99 > 3 u. fibroids > Pills
CN 3 GKRS 52301
IDC 1.2 cm Her2 +++ ER 5% R. Lmptmy SLNB+1 71703 6 FEC 33 R Tamoxifen
Recc IIB 2.5 cm Bi-L Mast 61407 2/9 nds PET
6 TCH Cellulitis - Lymphedema - compression sleeve & glove
H w x 4 MUGA 51 D, J 49 M
Diastasis recti
Tamoxifen B. scan
Irrtbl bowel 1'09
Colonoscopy 313
BRCA1 V1247I
hptc hemangioma
Vertigo
GI - > yogurt
hysterectomy/oophorectomy 011410
Exemestane 25 mg tab 102912 ~ 101016 stopped due to r. hip/l.thigh pain after long walk
DEXA 1/13
1-2016 lesions in liver largest 9mm & 1.3 cm onco. says not cancer.
3-11 Appendectomy - visually O.K., a lot of puss. Final path result - not cancer.
Start Vitamin D3 and Calcium supplement (600mg x2)
10-10 Stopped Exemestane due to r. hip/l.thigh pain OKed by Onco 11-08-2016
7-23-2018 9 mm groundglass nodule within the right lower lobe with indolent behavior. Due to possible adenocarcinoma, Recommend annual surveilence.
7-10-2019 CT to check lung nodule.
1-10-2020 8mm stable nodule on R Lung, two 6mm new ones on L Lung, a possible lymph node involvement in inter fissule.
"I WANT TO BE AN OUTRAGEOUS OLD WOMAN WHO NEVER GETS CALLED AN OLD LADY. I WANT TO GET SHARP EDGED & EARTH COLORED, TILL I FADE AWAY FROM PURE JOY." Irene from Tampa

Advocacy is a passion .. not a pastime - Joe

Last edited by Jackie07; 09-13-2010 at 12:35 PM..
Jackie07 is offline   Reply With Quote
Old 09-13-2010, 12:43 PM   #3
Rich66
Senior Member
 
Rich66's Avatar
 
Join Date: Feb 2008
Location: South East Wisconsin
Posts: 3,431
Re: Provenge: implications for measuring effectiveness

Mostly pointing out how the usual tumor shrinkage/RECIST criteria gauging of effectiveness didn't predict the survival benefit. I'm wondering whether some therapies, maybe immunotherapies in particular, are abandoned prematurely due to shortsighted criteria. It also might tie into the cancer stem cell theory/issue in that they are considered a less visible but maybe important minority of the cells.
__________________

Mom's treatment history (link)
Rich66 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -7. The time now is 04:37 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright HER2 Support Group 2007 - 2021
free webpage hit counter