Despite the highly promising interim blinded survival data from US-based Northwest Biotherapeutics (NW Bio), for the Phase III clinical trial of its personalized autologous dendritic cell vaccine DCVax-L in newly diagnosed glioblastoma multiforme (GBM) patients, a full unblinded dataset is required to truly understand the vaccine’s survival benefit, says leading data and analytics company GlobalData.
GBM is the most aggressive and lethal form of brain cancer and little progress has been made towards its treatment in the last decade.
In the NW Bio’s trial, the aggregate data set include patients from both arms of the trial combined – the arm with two-thirds of the patients, who received standard of care plus DCVax-L, and the arm with one-third of the patients, who received standard of care plus a placebo.
Patients who experienced tumor recurrence were permitted to cross over to receive DCVax-L. Out of all 331 patients that took part in the study, approximately 90% received treatment with DCVax-L, which included crossover use.
Ashwin Oberoi, MChem, Oncology Analyst at GlobalData, says: “The top 100 (30%) of the total 331 patients enrolled showed a median overall survival (OS) of 40.5 months and were considered to be ‘extended survivors.’ Considering that the median OS for GBM patients is around 15 months, this data is quite astonishing.”
“Several key opinion leaders (KOLs) interviewed by GlobalData had mixed views about the dendritic cell vaccine and they are of the opinion that the data was presented in an unusual way for a randomised Phase III trial.”
“The criteria for selection was highly meticulous with an estimated 1599 patients screened and 1268 of these patients excluded from the trial. It is speculated that only the patients expected to live longer were included in the study due to the scrupulous selection criteria, which could have led to bias in the dataset.”
Scepticism notwithstanding, other KOLs did have positive opinions about the data. DCVax-L is unique because it does not target one particular antigen, but uses the patient’s own tumor specimen to create the vaccine.
Oberoi continues: “Even assuming an FDA approval, KOLs mentioned that the personalised vaccine may suffer challenges in terms of preparation of the vaccine. The logistics and requirements for creating such a personalized vaccine would be a barrier for DCVax-L being adopted in routine clinical practice.”
“While the interim data for DCVax-L look encouraging, one must be mindful of the fact that a full unblinded dataset is required to truly understand the vaccine’s survival benefit.”
“Northwest Bio has also been suffering from a low cash flow, which could impact the company’s ability to execute a successful launch. Therefore, a combination of these hurdles is likely to lead to an onerous market launch.”