Clin Cancer Res. 2011 Nov 8. [Epub ahead of print]
A Pilot Study of MUC-1/CEA/TRICOM Poxviral-Based Vaccine in Patients with Metastatic Breast and Ovarian Cancer.
Mohebtash M,
Tsang KY,
Madan RA,
Huen NY,
Poole DJ,
Jochems C,
Jones J,
Ferrara T,
Heery CR,
Arlen PM,
Steinberg SM,
Pazdur M,
Rauckhorst M,
Jones EC,
Dahut WL,
Schlom J,
Gulley JL.
Source
Authors' Affiliations: Medical Oncology Branch and Laboratory of Tumor Immunology and Biology, Center for Cancer Research; Biostatistics and Data Management Section, National Cancer Institute; and Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, Maryland.
Abstract
PURPOSE:
PANVAC is a recombinant poxviral vaccine that contains transgenes for MUC-1, CEA, and 3 T-cell costimulatory molecules. This study was conducted to obtain preliminary evidence of clinical response in metastatic breast and ovarian cancer patients.Experimental design: Twenty-six patients were enrolled and given monthly vaccinations. Clinical and immune outcomes were evaluated.
RESULTS:
These patients were heavily pretreated, with 21 of 26 patients having 3 or more prior chemotherapy regimens. Side effects were largely limited to mild injection-site reactions. For the 12 breast cancer patients enrolled, median time to progression was 2.5 months (1-37+) and median overall survival was 13.7 months. Four patients had stable disease. One patient had a complete response by RECIST and remained on study for 37 months or more, with a significant drop in serum interleukin (IL)-6 and IL-8 by day 71. Another patient with metastatic disease confined to the mediastinum had a 17% reduction in mediastinal mass and was on study for 10 months. Patients with stable or responding disease had fewer prior therapies and lower tumor marker levels than patients with no evidence of response. For the ovarian cancer patients (n = 14), the median time to progression was 2 months (1-6) and median overall survival was 15.0 months. Updated data are presented here for one patient treated with this vaccine in a previous trial, with a time to progression of 38 months.
CONCLUSIONS:
Some patients who had limited tumor burden with minimal prior chemotherapy seemed to benefit from the vaccine. Further studies to confirm these results are warranted. Clin Cancer Res; 17(22); 1-10. ©2011 AACR.
PMID:22068656 [PubMed - as supplied by publisher]
http://www.cancernetwork.com/breast-.../10165/1988943
Quote:
“I think the reason we haven’t seen many responses is because the patient populations we've used in the past were too advanced, and had too many prior chemotherapy regimens. In addition, I think that the main activity of a therapeutic vaccine may be to eventually slow down the growth rate of cancers. [A response is caused in relatively few patients.] A delay in the slowing of the growth rate may be due to continued refinement and broadening of the immune response following vaccination. This could explain why multiple randomized studies have shown an improved overall survival without initial improved time to progression,” said Gulley.
This trial, and especially the over 3-year sustained response of a patient with advanced breast cancer shows the potential of a therapeutic vaccine for improved outcomes in a selective subset of patients
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Somewhat similar to benefit of Herceptin beyond progression?
Makes me wonder whether other vaccine trials may have been prematurely deemed failures...
Here's some fun looking at variations in headlines:
Researchers claim small victory from experimental cancer vaccine
Vaccines for Breast and Ovarian Cancer Yield Triumphant Results