Media Thread, page-209

PERTH, Australia – Sydney-based Imugene Ltd.’s stock shot up 15% on news that an interim analysis of phase II data in its B-cell peptide vaccine, HER-Vaxx, in advanced gastric cancer showed positive survival data, and the data monitoring committee said it could lower the number of patients required for study completion.

Leslie Chong, CEO, Imugene

“We have not only significant survival data, we also have really bolstered and proven our B-cell activating platform with this, because we’re the first kid on the block to get this sort of data out of a B-cell technology,” Imugene CEO Leslie Chong told BioWorld.

“This data represents a clinical proof of concept for HER-Vaxx and supports our B-cell activating immunotherapy platform.

“We’re the forerunners in this space, and now we have data to show that the technology can work in a setting like this,” she added, explaining that the data show a reduced risk of death of 58.2% in the HER-Vaxx plus chemotherapy arm compared to the chemotherapy arm.

The interim analysis showed a survival hazard ratio of 0.418, and Chong said that cancer drugs that have a hazard ratio of better than 0.5 in a registration study will likely lead to approval.

She explained that the hazard ratio is converted into a survival or risk of death percentage, which in this case means that the patients on the study arm “gained almost 60% better at beating the risk of death than the comparator.”

The median overall survival for patients receiving HER-Vaxx plus chemotherapy was 14.2 months compared to 8.8 months in patients treated with chemotherapy alone.

Lead candidate HER-Vaxx was designed to treat tumors that overexpress HER2, such as gastric, breast, ovarian, lung and pancreatic cancers.

The phase II gastric cancer study is designed to measure the efficacy, safety and immune response in 68 patients with metastatic gastric cancer overexpressing the HER2 protein. The CEO said the study has a 1-to-1 randomization comparing the HER-Vaxx plus chemotherapy to chemotherapy alone.

The phase II study is being conducted at multiple sites across Eastern Europe and India where clinicians don’t have access to Herceptin (trastuzumab, Roche Holding AG) and Perjeta (pertuzumab, Roche Holding AG).

Leading the pack in B-cell space

Imugene is developing a pipeline of mimotope-based B-cell peptide vaccines against novel oncology targets that could replace or be used in combination with monoclonal antibodies. Until now, the B-cell approach has largely been ignored in immuno-oncology, but Imugene said the approach has certain advantages and can work with the body’s immune system to produce natural antibodies that are potentially safer.

“Because it’s the B cell producing the antibodies, we were encouraged that we saw no toxicities with our drug, and so it lends itself to other combination therapies,” Chong said. “This data also gives us more options, because we’ve just unearthed that our B-cell technology works, and so we have a lot more choices to consider now.

“As of today, a lot of people will be racing to be where we are.”

Validation from the independent data monitoring committee was significant, she said, since it confirmed a favorable survival outcome with no added toxicity for the control arm, and it has advised Imugene that it can lower the number of patients required for study completion.

“This is a rarity that happens where an independent review committee made up of oncologists, statisticians and immunologists reviewing this data tells us we already achieved the goal of the study to show it is safe and effective, so we don’t really need any more patients to do this,” she said.

“We only have to add five more patients to get to an event that triggers the end of the study,” she said.

The company has another B-cell technology in the pipeline for non-small-cell lung cancer that is getting ready to enter the clinic. That candidate is PD1-Vaxx, which is an anti-PD-1 B-cell antibody against an immune regulatory target.

Imugene also has an oncolytic virus CF33, a chimeric poxvirus, that it acquired from the City of Hope Comprehensive Cancer Center in July 2019.

The oncolytic viruses are designed to selectively kill tumor cells and activate the immune system and have potential applications across many cancers.

The company now has two platforms and four studies either in the clinic or about to enter the clinic, Chong said.

CF33 is being paired with a PD-L1 in triple-negative breast cancer in a phase I study, and then the naked CF33 virus will be put into solid tumor cancers in another phase I study, she said. The company is in the process of working with the FDA on the study design.

With a market cap of AU$459 million (US$336 million), Imugene’s stock on the Australian Securities Exchange (ASX:IMU) was trading at AU11 cents at close of trading Nov. 23.