Advaxis has licensed its antigen delivery technology for use in Sellas’ cancer immunotherapy. The project will combine Advaxis’ approach to bioengineering bacteria to Sellas’ phase 3-ready WT1 antigens to foster more precise immune responses.
Sellas has enlisted Advaxis to handle pre-IND work on the program, beyond which it will take over and move the candidate through the clinic. In return for Advaxis’ contributions, Sellas will pay up to $358 million in milestones, plus royalties if the candidate makes it to market.
Angelos Stergiou, M.D., CEO of Sellas, sees the outlay boosting the effectiveness of the company’s therapeutic approach.
“The combined Advaxis-Sellas Lm-WT1 active immunotherapy candidate has the potential to deliver Sellas’ WT1 proprietary peptide antigens in a novel way, taking advantage of our antigen’s ability to target a wide variety of tumors of diverse immune system HLA genotypes. The delivery afforded by the Advaxis technology expands upon our current programs and should substantially enhance the clinical utility seen with galinpepimut-S,” Stergiou said in a statement.
Galinpepimut-S, Sellas’ WT1-targeted heteroclitic peptide antigen mixture, has advanced to the cusp of phase 3 on the strength of midstage data suggesting it may improve overall survival in patients with acute myeloid leukemia and malignant pleural mesothelioma. Sellas licensed the candidate from Memorial Sloan Kettering Cancer Center (MSKCC).
The prevalence of WT1 in cancers—and its rarity in healthy adult cells—make it a closely watched target. But hitting the target has proven to be a challenge. Sellas' approach is to induce T cells to target and kill WT1-expressing cancer cells. Others have different approaches. Novartis entered the fray in 2014 when it licensed a WT1 monoclonal antibody from Eureka Therapeutics and MSKCC.
Sellas has data to suggest that its use of four peptide chains to induce an innate immune response can control cancers. But the company suspects it can make more of an impact when combined with the bacterial bioengineering approach Advaxis uses to stimulate the innate immune system and trigger T-cell responses. The Advaxis approach is designed to make the immune system see cancer cells as being potentially infected with bacteria and target them for destruction.
The technology underpins Advaxis’ lead candidate axalimogene filolisbac. That candidate uses the approach to target HPV-associated cancers. In advancing to phase 3, axalimogene filolisbac has delivered data to validate the approach but also caused some low points for the company. In 2015, the FDA placed a clinical hold on a trial of the drug after listeria—the bacteria bioengineered for use in the therapeutic—was found in the blood of a patient who died.
Advaxis has since regained its footing and is now moving through phase 3, albeit with a share price that is well down on the highs of 2015. The deal with Sellas follows a pact with Amgen covering Advaxis’ second technology, MINE.