SOUTH SAN FRANCISCO, Calif.—Asher Biotherapeutics announced its launch today, following a $55 million Series A financing led by Third Rock Ventures with participation from Boxer Capital of Tavistock Group, Invus, Y Combinator, and MBC Biolabs.
“Following an exhaustive assessment of the cytokine immunotherapy landscape, Third Rock is excited to partner with Asher Bio and their unique approach, which we believe has breakthrough potential to generate multiple differentiated product candidates,” said Dr. Jeffrey Tong, partner at Third Rock Ventures.
“Asher Bio has assembled a strong team, including two world-class academic founders in Ton Schumacher and Robert Schreiber, to execute on a big vision — to develop an entirely new biotherapeutic class to harness the therapeutic power of cytokine immunotherapies,” added Dr. Reid Huber, also a partner at Third Rock Ventures. “The company is well positioned to bring its lead oncology program, AB248, into the clinic in 2022 while building out a pipeline of additional products across multiple disease areas.”
The company plans to bring a new approach to immunotherapy, called cis-targeting, that seeks to selectively activate only the immune cells that drive a desired immune response. This is said to address the limitations of immunotherapies due to their heterogenous effects on multiple cell types.
Asher Bio’s cis-targeted immunotherapies require the engagement of two molecules in cis on the same cell for activation — an immunomodulatory receptor and a cell-type specific marker. Without both targets present on the same cell the therapies are inactive, which should reduce undesirable effects.
“Our founders had the insight to focus on designing immunotherapies that would only have their effect on defined immune cell subtypes rather than trying to localize the effect of inherently non-specific molecules. Our solution seeks to provide product candidates with superior selectivity and with broad applications across multiple tumor types, as well as treatment of infections and autoimmune diseases,” pointed out Dr. Craig Gibbs, CEO of Asher Bio.
“We have implemented a systematic process to discover novel cis-targeted therapies that can be applied universally to multiple immunomodulatory molecules and target cell types,” noted Dr. Andy Yeung, co-founder and chief technology officer of Asher Bio. “We first identify the immune cell subtype we want to target, next we attenuate the affinity of the immunomodulator towards receptors across all cell-types, then we create a fusion protein to direct the therapy only to the desired immune cell type, and finally we optimize the pharmacological properties.”
The most advanced development candidate in Asher Bio’s pipeline is AB248, an engineered form of IL-2 designed to be specific to CD8+ effector T cells. Native IL-2 is a clinically approved immunotherapy, although its use has been limited due to side effects.
“Recent insights have underscored that the anti-tumor efficacy of IL-2 is predominantly mediated via CD8+ effector T cells, whereas counter-productive and adverse activities are imparted via other IL-2 receptor-expressing cells such as regulatory T cells, NK cells, and endothelial cells. AB248, which was designed to target only CD8+ effector T cells, has demonstrated superior selectivity and efficacy in multiple preclinical models and is expected to enter trials for the treatment of solid tumors in 2022,” explained Dr. Ivana Djuretic, co-founder and chief scientific officer of Asher Bio.
Aside from AB248, Asher Bio’s pipeline also includes a cis-targeted IL-2 designed to specifically stimulate CAR-T cells, a T cell cis-targeted STAT3 activating cytokine for cancer treatment, and a Treg cis-targeted cytokine for treating autoimmune disease.