On November 11, 2022 OncoSec Medical Incorporated (NASDAQ: ONCS) (the "Company" or "OncoSec"), a clinical-stage biotechnology company developing intratumoral immunotherapies that stimulate the patient’s immune system to target cancer cells and eradicate disease, reported data from the Phase 2 KEYNOTE-695 clinical trial (Press release, OncoSec Medical, NOV 11, 2022, View Source;keytruda-in-patients-with-advanced-melanoma-refractory-to-anti-pd-1-treatment-301675588.html [SID1234623854]). This global, open-label single-arm trial is evaluating TAVO, OncoSec’s proprietary IL-12 encoding plasmid delivered by intratumoral electroporation (TAVO-EP), in combination with pembrolizumab in patients with unresectable or metastatic (Stage III/IV) melanoma who had progressed on immediate prior anti-PD-1 antibody therapy (pembrolizumab or nivolumab). The last patient started treatment in December 2020, and clinical database lock occurred in October 2022.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

The key secondary endpoint of KEYNOTE-695 was met. Investigator assessment of overall response rate (ORR) per RECIST v1.1, from 101 efficacy evaluable patients, with at least one post-baseline tumor assessment, showed a confirmed ORR of 18.8% (95% confidence interval: 11.7, 22.8), which exceeds the pre-specified clinically meaningful ORR of ≥17% (95% CI: 10.2, 25.8).

Three patients achieved a complete response (CR) and 16 patients had a partial response (PR). Of note, 2 patients with CR had discontinued treatment with immediate prior nivolumab/ipilimumab. The disease control rate (CR + PR + stable disease) was 40.6%. The investigator-assessed durable response rate of ≥24 weeks was 15.8%, the median duration of response had not been reached. The median overall survival was 22.7 months (95% CI: 14.4, 35.5) after a median follow-up period of 33.4 months. The trial enrolled and collected safety data on 105 patients who had received at least 12 weeks of anti-PD-1 treatment and had confirmed disease progression. The combination therapy was generally well tolerated with no Grade 4/5 treatment-related adverse events (TRAEs). Grade 3 TRAEs were observed in 4.8% of patients.

Top-line results of the primary endpoint of the KEYNOTE-695 trial, ORR by blinded, independent central review (BICR) based on RECIST v1.1, are expected to be announced in the first quarter of 2023.

"Patients with PD-1 refractory melanoma have limited treatment options. Therefore, we are encouraged by the observed response to treatment with TAVO-EP and pembrolizumab in this difficult to treat patient segment," said Robert Arch, Ph.D., Chief Executive Officer of OncoSec. "In addition to the ORR of 18.8% in the full trial population of KEYNOTE-695, we are intrigued by the observed 19.5% investigator-assessed ORR, including 2 CRs and 6 PRs, in a subset of 41 patients who had prior exposure to ipilimumab (anti-CTLA-4 antibody) in addition to anti-PD-1 therapy. The data of TAVO-EP combination treatment in patients who had failed multiple checkpoint inhibitors is encouraging and speaks to the differentiation of our TAVO-EP approach from checkpoint inhibitors and other immunotherapies. I want to thank all patients who participated in the trial and our team at OncoSec that remains focused on developing TAVO-EP as a novel intratumoral treatment approach for cancer patients with unmet medical needs."

Adil Daud, MD, Professor; UCSF Helen Diller Family Comprehensive Cancer Center commented on the data: "Patients with unresectable advanced melanoma who have progressed on prior anti-PD-1 therapy are not expected to gain benefit from retreatment with anti-PD-1 therapy. Therefore, the KEYNOTE-695 data highlight the value of intratumoral IL-12 as treatment for patients with checkpoint inhibitor refractory melanoma. Importantly, TAVO-EP in combination with pembrolizumab in this highly refractory patient population with no standard-of-care treatment options showed durable responses and good tolerability. These data suggest that TAVO-EP combined anti-PD-1 antibodies could make a major difference for a group of patients with a high unmet medical need."