VBL Therapeutics has presented more data from a phase 2 trial of VB-111 monotherapy in thyroid cancer patients. The release adds evidence of dose response to support the previously reported difference in progression-free survival between the low- and high-dose cohorts.
Tel Aviv, Israel-based VBL presented top-line data from the trial in 2015 and posted overall survival results last year. Additional details released at the congress of the Federation of the Israel Societies for Experimental Biology this week include a look at the proportion of patients to experience a fall in tumor measurement after one dose of VB-111, a drug designed to kill cells involved in blood vessel formation.
The tumor measurements of seven of the 16 patients in the high-dose cohort fell after one dose of the angiogenic drug, compared to a reduction in one of the 11 participants who received the low, sub-therapeutic dose. VBL sees the data as adding to evidence of dose-dependent responses.
“We are encouraged to see dose-dependent responses and an overall survival benefit with VB-111 monotherapy, in thyroid cancer patients with end-stage disease whose tumors had not responded to multiple lines of therapies, including kinase inhibitors,” VBL CEO Dror Harats said in a statement.
The data on the effect of one dose of VB-111 are in line with earlier results on the proportion of patients who went six months without progressing when given the drug every two months. In the 2015 release of top-line data, VBL reported six of the 17 patients in the high-dose arm—and three of 12 in the low-dose cohort—went six months or more without progressing. Those figures were repeated when VBL presented a look at overall survival results last year.
Today’s publication features slightly different numbers. In the latest release, VBL reported eight of the 17 patients in the high-dose cohort went six months or more without progressing, compared to six of 17 in previous publications. VBL also reported different numbers for the low-dose arm—four out of 12 versus three out of 12—but still said 25% of the subjects met the six-month progression-free survival endpoint.
A spokesperson for VBL said the difference is because the original release featured top-line data, whereas the most recent update uses "clean full data after data lock and analysis done by the independent biostatistician."
VBL’s top priorities are studies of VB-111 in other indications. A phase 3 trial comparing VB-111 plus Avastin to the Roche drug alone is underway in patients with recurrent glioblastoma. And a phase 3 ovarian cancer study is in the works.
Success in the study of glioblastoma, a brain cancer, would add lustre to VBL after a period in which it has suffered setbacks. The Israeli company undid its original Nasdaq IPO in 2014 after a shareholder failed to pay for stock they agreed to buy. Once VBL got onto Nasdaq at the second attempt, it reported phase 2 trials of VB-201 in psoriasis and ulcerative colitis missed their primary endpoints, triggering a collapse in its stock price.