INTRODUCTION: There is mounting evidence describing the immunosuppressive role of bulky metastatic disease, thus countering the therapeutic effects of tumor vaccine. Therefore, adjuvant immunotherapy may have a better impact on clinical outcome. In this phase II clinical trial, we aimed to test the feasibility of using a specific mutant ras peptide vaccine as an adjuvant immunotherapy in pancreatic and colorectal cancer patients. MATERIALS AND METHODS: Twelve patients with no evidence of disease (NED), five pancreatic and seven colorectal cancer patients were vaccinated subcutaneously with 13-mer mutant ras peptide, corresponding to their tumor's ras mutation. Vaccinations were given every 4 weeks, up to a total of six vaccines. RESULTS: No serious acute or delayed systemic side effects were seen. We detected specific immune responses to the relevant mutant ras peptide by measuring IFN-gamma mRNA expression by quantitative real-time PCR. Five out of eleven patients showed a positive immune response. Furthermore, the five pancreatic cancer patients have shown a mean disease-free survival (DFS) of 35.2+ months and a mean overall survival (OS) of 44.4+ months. The seven colorectal cancer patients have shown a mean disease-free survival (DFS) of 27.2+ months and a mean overall survival (OS) of 41.5+ months. CONCLUSION: In this study, we found that it is feasible to use mutant ras vaccine in the adjuvant setting. This vaccine is safe, can induce specific immune responses, and it appears to have a positive outcome in overall survival. Therefore, we believe that such an approach warrants further investigation in combination with other therapies.
INTRODUCTION: There is mounting evidence describing the immunosuppressive role of bulky metastatic disease, thus countering the therapeutic effects of tumor vaccine. Therefore, adjuvant immunotherapy may have a better impact on clinical outcome. In this phase II clinical trial, we aimed to test the feasibility of using a specific mutant ras peptide vaccine as an adjuvant immunotherapy in pancreatic and colorectal cancerpatients. MATERIALS AND METHODS: Twelve patients with no evidence of disease (NED), five pancreatic and seven colorectal cancerpatients were vaccinated subcutaneously with 13-mer mutant ras peptide, corresponding to their tumor's ras mutation. Vaccinations were given every 4 weeks, up to a total of six vaccines. RESULTS: No serious acute or delayed systemic side effects were seen. We detected specific immune responses to the relevant mutant ras peptide by measuring IFN-gamma mRNA expression by quantitative real-time PCR. Five out of eleven patients showed a positive immune response. Furthermore, the five pancreatic cancerpatients have shown a mean disease-free survival (DFS) of 35.2+ months and a mean overall survival (OS) of 44.4+ months. The seven colorectal cancerpatients have shown a mean disease-free survival (DFS) of 27.2+ months and a mean overall survival (OS) of 41.5+ months. CONCLUSION: In this study, we found that it is feasible to use mutant ras vaccine in the adjuvant setting. This vaccine is safe, can induce specific immune responses, and it appears to have a positive outcome in overall survival. Therefore, we believe that such an approach warrants further investigation in combination with other therapies.
Authors: Osama E Rahma; Ed Ashtar; Malgorzata Czystowska; Marta E Szajnik; Eva Wieckowski; Sarah Bernstein; Vincent E Herrin; Mortada A Shams; Seth M Steinberg; Maria Merino; William Gooding; Carmen Visus; Albert B Deleo; Judith K Wolf; Jeffrey G Bell; Jay A Berzofsky; Theresa L Whiteside; Samir N Khleif Journal: Cancer Immunol Immunother Date: 2011-09-17 Impact factor: 6.968
Authors: Osama E Rahma; Ed Ashtar; Ramy Ibrahim; Antoun Toubaji; Barry Gause; Vincent E Herrin; W Marston Linehan; Seth M Steinberg; Frank Grollman; George Grimes; Sarah A Bernstein; Jay A Berzofsky; Samir N Khleif Journal: J Transl Med Date: 2010-01-28 Impact factor: 5.531