Genetronics Biomedical Ltd announced interim
dataand results of phase II clinical trials evaluating the
companys electroporation therapy (EPT) system, which combines
an intratumoral injection of a chemotherapeutic agent with a pulsed
electric field, in squamous cell carcinoma of the head and neck. Data
from the trials, which were conducted in the United States and
Canada, were presented at the 35th annual meeting of the American
Society of Clinical Oncology (ASCO). Genetronics also announced
preliminary data and results from a similar study conducted in Europe.
A total of 33 patients with advanced head and neck cancer who had not
responded to conventional therapy with radiation, chemotherapy,
surgery, or a combination of these modalities were enrolled in two
multicenter phase II trials conducted at 17 sites in the United
States and Canada. One of the trials was a crossover, controlled
study; the other was an open-label trial. Twelve additional patients
were treated in a similar, open-label trial conducted in Europe.
In each case, the patients lesions were treated with bleomycin
(Blenoxane) and the EPT system. This treatment increases the
permeability of the cell membranes, resulting in significantly
enhanced intracellular delivery of the drug (bleomycin). In this
interim analysis, clinical response was determined either by complete
disappearance of the tumor or by a reduction in its size (at least 50%).
Results of the Phase II American Studies
Table 1 summarizes the results of
all five studies. The two phase II protocols involved a total of 42
tumors treated with bleomycin and EPT. Tumors treated in the trial
included squamous cell carcinoma of the face, oral cavity, pharynx,
larynx, and sinus. The volume of tumors treated ranged from < 1
mm³ to > 132 mm³.
In the crossover, controlled, phase II study, patients initially
received only bleomycin (the control group). Patients who did not
respond to the drug alone were then treated with the complete system
of drug and electric field. Of the 33 lesions in 23 patients treated
only with drug, none demonstrated a clinical response. Subsequently,
15 of these patients, having 18 lesions, were treated with bleomycin
and EPT, and 61% achieved a clinical response.
In the open-label phase II study, all patients received full
EPT as their initial treatment. Among the 18 patients (24 lesions) so
treated, 67% achieved a clinical response. Overall, therefore, the
two studies showed a clinical response rate of 64%.
Results of the European Study
The European study enrolled 12 patients who had a total of 19 tumors.
A 64% clinical response was measured (12 tumors). In the earlier
phase I/Il trial with eight patients, conducted at
Rush-Presbyterian-St. Lukes Hospital in Chicago, six (75%) of
the eight tumors treated with full EPT demonstrated a clinical
response, with five of the responding tumors disappearing completely.
These interim results suggest that electroporation with
intralesional bleomycin treatment is a promising means for the
treatment of squamous cell carcinoma of the head and neck, said
Paul Goldfarb,MD, medical director at Genetronics. Our EPT
treatment for head and neck cancer potentially offers several
significant advantages compared to conventional therapies.
Because these are interim results, the absolute values, including
percentage of tumors achieving clinical responses, are likely to
change upon more complete analysis of data from the clinical trials.
The clinical trial sites in the United States and Canada are: Abbott
Northwestern Hospital, Minneapolis; University of Arkansas Medical
Center, Little Rock; University of Oklahoma Health Sciences, Oklahoma
City; H. Lee Moffit Cancer Center, Tampa; Louisiana State University
Medical Center, Shreveport; Rush-Presbyterian-St. Lukes Medical
Center, Chicago; University of Tennessee, Memphis; University of
Kansas Medical Center, Kansas City; University of California at San
Diego; Colorado Head and Neck, Denver; Toronto Hospital, Ontario;
Jewish General Hospital, Montreal; Manitoba Cancer Foundation,
Winnipeg; Victoria General Hospital, Halifax; and University of