OncoSec, Merck Partner to Test Immunotherapy Combo in Phase 2 Trial for Triple-negative Breast Cancer

OncoSec, Merck Partner to Test Immunotherapy Combo in Phase 2 Trial for Triple-negative Breast Cancer

OncoSec Medical and Merck have joined efforts to conduct a Phase 2 trial evaluating the safety and effectiveness of ImmunoPulse IL-12 in combination with Keytruda (pembrolizumab) for the treatment of triple-negative breast cancer.

The study plans to include patients with advanced triple-negative breast cancer who are not eligible for surgical treatment or have not responded to at least one prior treatment with chemotherapy or immunotherapy.

The trial’s main goal is to determine the proportion of patients who respond to the therapy, a measure called objective response rate. OncoSec expects to begin the trial sometime this year.

Under the terms of the agreement, OncoSec will be responsible for sponsoring the study, as well as providing the financial support required to complete the study. Merck, known as MSD outside the United States and Canada, will supply the checkpoint inhibitor Keytruda. Further information on the terms of the partnership was not disclosed.

“We are pleased to initiate a second clinical trial collaboration with Merck — one of the world’s leading immuno-oncology companies — in late stage TNBC, a disease which has few treatment options,” Daniel J. O’Connor, CEO of OncoSec, said in a press release. “This collaboration is another example of OncoSec’s strategy to work with innovative immuno-oncology leaders, combining our ImmunoPulse IL-12 program with checkpoint inhibitor therapies to advance the care of patients.”

ImmunoPulse IL-12 delivers the DNA sequence of interleukin-12 (IL-12) — an immune-stimulating protein — directly into tumors. Then, an electrical stimulus, which increases the permeability of the cell membrane, helps the DNA molecules enter the cells. This strategy promotes IL-12 production in the tumor microenvironment, which then stimulates the recruitment and expansion of tumor-infiltrating T-cells.

In most cases, checkpoint inhibitors like Keytruda are ineffective against triple-negative breast cancers because they lack infiltrating T-cells. Combining these therapies with ImmunoPulse IL-12 provides a new therapeutic opportunity for these patients.

In a prior Phase 1 trial (NCT02531425) for triple-negative breast cancer patients, ImmunoPulse IL-12 was generally safe and well-tolerated, with patients reporting only mild transient pain and fatigue.

Investigators also saw a significant increase in infiltrating T-cells in lesions receiving the treatment. Two patients with refractory tumors experienced tumors reductions, including in lesions that had not been treated with ImmunoPulse IL-12.