VBL Therapeutics’ lead oncology product candidate, VB-111 (ofranergene obadenovec), is a targeted anti-cancer gene-based biologic agent that is positioned to potentially treat a wide range of solid tumors. It is conveniently administered as an IV infusion once every two months.
Completed Clinical Trials
VBL conducted a Phase 1 “all comers” clinical trial of VB-111 in the United States as an open-label, dose-escalating trial to assess the safety and pharmacokinetics and pharmacodynamics of VB-111 in 56 patients with advanced metastatic cancer. In that trial, VB-111 was well-tolerated and showed a dose dependent extension in median overall survival across a range of tumor types.
Based on the Phase 1 results, VBL decided to proceed with the development of VB-111 for the lead indication of rGBM, as well as to investigate VB-111 as a monotherapy for the treatment of thyroid cancer and, in combination with chemotherapy, for ovarian cancer.
- Phase 2 single-arm open-label multicenter trial of VB-111 in patients with rGBM –
In September 2015 at the European Cancer Conference (ECC 2015), VBL Therapeutics reported full Phase 2 data from a multi-center clinical trial of VB-111 in rGBM, which met the primary endpoint of statistically significant increase in overall survival.
Study data also suggest that VB-111 may induce an immuno-therapeutic effect. Of the 46 patients who received VB-111, 25 patients experienced a fever post-dosing of VB-111 at least once, while 21 patients did not. Feverish patients demonstrated increased overall survival of 16 months, compared to non-feverish patients, who had a median overall survival of 8.5 months (p=0.03). This correlation between clinical activity and fever suggests that VB-111 may induce an immune response in patients and supports a role of the immune system as part of VB-111’s mechanism of action. These findings support VB-111 preclinical data, which showed an elevated immune response in tumors of VB-111-treated animals.
In June 2016, at the 2016 American Society of Clinical Oncology (ASCO) annual meeting, VBL reported new data comparing Phase 2 clinical outcomes with VB-111 with pooled data from 8 studies that investigated Avastin in recurrent glioblastoma (rGBM). In the Phase 2 VB-111 trial, the median overall survival of patients who received continuous exposure of VB-111 in combination with Avastin was 59 weeks. This is compared to 32 weeks in the pooled data from the 8 studies in the meta-analysis (p= 0.0295 Hazard Ratio 0.62, 95% CI: 0.40-0.96). Median survival ranged from 26.0 weeks to 45.7 weeks in the meta-analysis. Overall survival at 12 months for patients on continuous exposure of VB-111 was 57%, compared to 24% overall survival (range 16% – 38%) for the pooled data (p= 0.03). See also the VB-111 rGBM Poster at ASCO 2016 .
At ASCO 2017, VBL presented additional analyses from the Phase 2 study, which demonstrate that tumor growth kinetics were significantly attenuated upon longer treatment with VB-111. See also VB-111 data at ASCO 2017 and the ASCO 2017 Poster
The FDA granted fast track designation for the investigation of VB-111 for prolongation of survival in patients with glioblastoma that has recurred following treatment with temozolomide. VB-111 was also granted orphan designation for treatment of malignant glioma by the FDA, and for treatment of glioma in Europe.
- Phase 3 pivotal, randomized, controlled trial of VB-111 in Patients with rGBM
VBL Therapeutics’ pivotal Phase 3 GLOBE trial of VB-111 in rGBM under a special protocol assessment granted by the FDA has been completed. The trial, which was conducted in the US, Canada and Israel, enrolled 256 patients in total.In March 2018, we announced top-line results from the GLOBE study, which showed that the study did not meet its pre-specified primary endpoint of overall survival (OS) or the secondary endpoint of progression-free survival (PFS). We are still performing analyses on the data from GLOBE study, which we intend to report later this year. However, Investigating the Phase 3 data in comparison to the Phase 1 and Phase 2, so far did not reveal any difference in the prognostic factors which may explain their different outcomes.To the best of our knowledge, the only difference was in the Phase 3 trial regimen, as dictated by the Special Protocol Assessment (`SPA`) for the GLOBE study. In the Phase 2 study of VB-111 in rGBM, which demonstrated meaningful OS benefit, VB-111 was given alone until progression (`priming`). On the other hand, in the Phase 3 trial there was no priming with VB-111, which was administered in combination with Avastin from the beginning. We believe that there is a good possibility that this regimen may have impaired the efficacy of VB-111 and thus resulted in an unsuccessful readout.
As a result of the failure of the GLOBE trial to meet its pre-determined endpoints, we have decided to put further development of VB-111 in rGBM on hold at this point. However, we still believe in the biological activity of VB-111 as seen in our Phase 1 and Phase 2 trials, and do not think that results of the particular GLOBE study that investigated VB-111 in combination with bevacizumab in rGBM, will necessarily have implications on the prospects for VB-111 in other tumor types, in different patients populations, or in different regimens.
Phase 1/2 clinical trial of VB-111 in ovarian cancer –
This is a Phase 1/2 investigator-initiated clinical trial under VBL’s IND, which was conducted as an open- label, dose-escalating trial to assess the safety and efficacy of bi-monthly doses of VB-111 in combination with weekly paclitaxel in patients with recurrent epithelial ovarian cancer. In June 2016, at the 2016 ASCO meeting, VBL reported results from a Phase 1/2 trial of VB-111 in patients with recurrent platinum resistant ovarian cancer. The data demonstrate a median overall survival of 810 days in the VB-111 therapeutic dose arm, versus 172 days in the low dose arm, a result that was statistically significant. There was also a durable doubling in the response rate, as measured by a reduction in the CA-125 biomarker, compared to historical rates of Avastin® (bevacizumab) plus chemotherapy in ovarian cancer. Durable RECIST responses and disease stabilizations were also observed. An immunotherapeutic effect was also observed in biopsies taken from patients. The trial was conducted at Massachusetts General Hospital and Dana Farber Cancer Institute, Boston, MA.See also the VB-111 Ovarian Cancer Poster at ASCO 2016 .
- Phase 2 clinical trial of VB-111 in thyroid cancer –
We conducted an exploratory Phase 2 clinical trial in the United States to assess the safety and efficacy of single or multiple doses of VB-111. Our open-label dose-escalating study enrolled patients with advanced, recently-progressive, differentiated thyroid cancer that was unresponsive to radioactive iodine, in two cohorts. Most patients had tumors that had not responded to multiple therapies prior to enrollment, including radiation and kinase inhibitors. In the first cohort, thirteen patients received a single intravenous infusion of VB-111 at a sub-therapeutic dose of 3X1012 viral particles (VPs). The second cohort included seventeen patients, who received VB-111 at a therapeutic dose of 1013 VPs every two months until disease progression. One patient proceeded from a single low dose to receive later multiple high doses at progression and was included in both groups (for PFS only). VB-111 was well-tolerated in this study, with no signs of clinically significant safety issues.The primary endpoint of the trial, defined as 6-month progression-free-survival (PFS-6) of 25%, was met with a dose response. Forty-seven percent (47%; 8/17) of patients in the therapeutic-dose cohort reached PFS-6, versus 25% (4/12) in the sub-therapeutic cohort, both groups meeting the primary endpoint. Reduction in tumor measurement after the first dose was seen in 44% (7/16) of patients in the therapeutic-dose cohort, compared to 9% (1/11) in the sub-therapeutic-dose cohort. An overall survival benefit was seen with a tail of more than 40% at 3.7 years for the therapeutic-dose cohort (mOS 684 days). This is similar to historical data for pazopanib* (Votrient®), a tyrosine kinase inhibitor; however, most patients in the VB-111 study had tumors that previously had progressed on pazopanib or other kinase inhibitors. The trial was conducted at Mayo Clinic and Massachusetts General Hospital, Boston, MA.
Ongoing Clinical Trials
- OVAL – Phase 3 randomized, controlled study of VB-111 in recurrent platinum-resistant ovarian cancer – The Phase 3 OVAL study in recurrent platinum-resistant ovarian cancer has been designed to enroll up to 350 adult patients at approximately 70 clinical sites in the United States and Israel. Patients will be randomized 1:1 to VB-111 in combination with chemotherapy, or chemotherapy alone. The OVAL study is conducted in collaboration with the GOG Foundation, Inc., a leading organization for research excellence in the field of gynecologic malignancies.
Detailed information on the clinical trials can be found at www.clinicaltrials.gov