Participated · Series A · Mar 2021

Asher Biotherapeutics develops therapies that precisely engage specific immune cell types using a proprietary cis-targeting platform, pairing antibodies with modified immunomodulatory proteins. Its lead program, AB248, is a CD8+ T cell–selective IL-2 generated by fusing a reduced‑potency IL‑2 mutein to an anti‑CD8β antibody and is in a Phase 1a/1b study as monotherapy and in combination with pembrolizumab. AB248 is being evaluated in recurrent locally advanced or metastatic solid tumors including melanoma, RCC, NSCLC and SCCHN in patients previously treated with PD‑1/PD‑L1 inhibitors. Initial PK/PD data from the ongoing trial support proof of mechanism and show potent, selective CD8+ T cell activation with early evidence of anti‑tumor activity and a generally well‑tolerated safety profile. The company’s broader portfolio includes AB821 (a CD8‑targeted IL‑21) and early‑stage programs targeting CAR‑T cells, myeloid cells and CD4+ T cells. Asher Bio was founded by Ivana Djuretic and Andy Yeung with support from Third Rock Ventures and is located in South San Francisco. Asher Biotherapeutics develops a modular cis-targeting platform that directs immunomodulatory molecules to specific immune cell types by engaging two receptors on the same cell, aiming to overcome pleiotropy and improve selectivity and safety. Its lead program, AB248, is an engineered interleukin‑2 (IL‑2) designed to specifically target CD8+ effector T cells and has shown preclinical and IND‑enabling data indicating selective CD8+ expansion, enhanced anti-tumor efficacy, and improved tolerability. The company has achieved preclinical proof-of-concept for its first three pipeline programs and is advancing additional candidates including a CD8+ T‑cell cis-targeted STAT3 cytokine and a CAR‑T cis-targeted IL‑2. Proceeds from the recent financing will fund AB248 through clinical proof-of-concept, advance a second program through IND‑enabling studies, and support continued investment in the cis-targeting platform. Asher Bio emphasizes a systematic, modular R&D approach to rapidly create and de-risk additional programs. The company was founded by Ivana Djuretic and Andy Yeung with support from Third Rock Ventures and is located in South San Francisco. Asher Biotherapeutics is developing a cis-targeting platform to create precisely targeted immunotherapies that selectively activate defined immune cell subtypes by requiring engagement of two molecules in cis on the same cell. The platform attenuates immunomodulator affinity and fuses it to a cell-type specific marker to reduce pleiotropic effects and systemic toxicities seen with conventional cytokine and checkpoint therapies. Its lead program, AB248, is an engineered IL-2 designed to be specific to CD8+ effector T cells and has demonstrated superior selectivity and efficacy in multiple preclinical models. Asher plans to bring AB248 into the clinic in 2022 and is building a pipeline including a CAR-T‑stimulating IL-2, a T‑cell cis-targeted STAT3-activating cytokine for cancer, and a Treg cis-targeted cytokine for autoimmune disease. The company launched with a $55 million Series A led by Third Rock Ventures, with participation from Boxer Capital (Tavistock), Invus, Y Combinator and MBC Biolabs. Asher Bio is based in South San Francisco and was founded by academic and industry leaders including Ton Schumacher and Robert Schreiber.