I had a brief moment to discuss the significance of the data presented at the 2012 meeting of the American Society of Clinical Oncology (OTC:ASCO) regarding the Safety and long-term maintenance of anti-HER2 immunity following booster inoculations of the NeuVax™ (E75) Galena Biopharma (GALE) breast cancer vaccine with Dr. George Peoples. The discussion was brief but key to the success of the product. The conversation focused on the lessons learned in the phase II clinical trial that will be included in their already underway Phase III trial.
The first point Dr. Peoples wanted to make is the importance of the strategy. "Using the peptide based strategy is simple in contrast to Dendreon's (DNDN) approach with sipuleucel-T (Provenge) and this factor has an impact on the ease of adoption of the drug." (I previously commented on this.)
His second point was that, "we are trying to do this in the adjuvant setting. Most trials are done in metastatic patients and unfortunately that is a very difficult time to gear up the immune system to reject the highly advanced and established tumors."
My comment to him was that this goes for any drug. Here they took patients that are diagnosed, fully treated, disease free and at risk for their tumor coming back (recurrence). By doing this they can control for a patient population that can best benefit from the drug, meaning disease free and possessing an intact immune system. The data he presented was about employing what they have learned over the years about how they can best maintain that immunity. "This is by the use of the peptide based vaccine, doing it in the disease free patient and then maintain the immunity over a long period of time to protect the patient from the recurrence."
Dr. Peoples concluded that, "it (referring to the treatment plan) will require ongoing vaccination which is not a surprise as this is the case for other forms of vaccination against pathogens." What this looks like for the patient is "a periodic challenge with the peptide to continue to boost the immunity." He further stated "if you do this over time, you can keep the patient protected." Dr. Peoples shared with me some of the current data (in round figures) going on in the trial that will end this summer although this was not in detail in the presentation.
In the trial there were 79 control patients with 55 patients receiving the primary vaccine and 53 received the primary vaccine + booster. In the vaccine + booster group only 2 had recurrence out of the 53 at 5 years. The other 55 patients that received the primary vaccine but not boosted, they do better than controls (control ~ 20% recurrence rate) but not as well as the boosted (he could not remember exactly but around 12%). He said "that we would be publishing the data soon since we only have 3 patients left in the trial and this will be the final end study report in a decade long clinical trial." The final point he wanted to make is that everything they have learned thus far has been incorporated into the phase III trial which is underway and is headed by Galena Biopharma meaning that the boosters will be part of the trial. I asked him for main important points (below).
The takeaway message was that:
1. The peptide approach works.
2. Boosting further improves drug efficacy.
a. Vaccinated and boosted < 4% recurrence at 5 years.
b. Vaccinated ~12% recurrence at 5 years.
c. Control ~ 20% recurrence at 5 years.
3. The adjuvant setting is the appropriate setting.
4. That NeuVax™ (E75) was well tolerated by the patients.
Although this is tuning towards Phase III and there are many more factors involved, the data looks encouraging and provide information to even further improve efficacy. Considering that patient survival outcome statistics are directly related to immune response to the drug, this data is very significant.
Look forward to seeing the published results.