Abcuro raises $155m for KLRG1 drug trial

Abcuro has raised $155 million in an oversubscribed second financing round that will fund its phase 2/3 trial of lead drug ABC008 for the treatment of inclusion body myositis (IBM).

The Massachusetts-based biotech is pioneering the development of drugs targeting killer cell lectin-like receptor G1 (KLRG1), an inhibitory immune checkpoint receptor, for indications associated with high levels of cytotoxic T-cells.

Lead indication IBM is the most prevalent form of myopathy affecting adults older than 50, with more than 50,000 patients in the US and Europe affected by the muscle-wasting condition. The autoimmune disease is progressive and can result in severe disability and premature death, with the rate of decline highly variable between patients.

There is no approved therapy or even a standard treatment for IBM, and most patients do not respond to mainstay medicines used for autoimmune diseases, such as corticosteroids and immunosuppressant drugs.

Abcuro started the phase 2/3 trial earlier this year, after reporting phase 1 data that showed that ABC008 was able to significantly deplete CD8 T-cells expressing the receptor, which it says are the most cytotoxic form of T-cells. The biotech expects to have initial safety data by the end of this year, which will determine whether the 230-patient study will continue to an efficacy readout.

Along with the study of ABC008 in IBM, the cash injection will also support the completion of a phase 1/2 trial of the antibody in T-cell large granular lymphocytic leukaemia (T-LGLL), a rare and fast-developing form of chronic leukaemia.

"Targeting the depletion of cytotoxic T-cells that express KLRG1 with ABC008 is a novel approach that has generated exciting early data in patients with IBM," said Jeffrey Wilkins, Abcuro's chief medical officer.

"[This data is] also supportive of using ABC008 in other diseases, like T-LGLL, in which cytotoxic T-cells are pathogenic, and mature T- and NK-cell lymphomas, in which KLRG1 expressing cells are malignant."

The $155 million raise – which was co-led by Redmile Group and Bain Capital Life Sciences, with other participants including RA Capital Management, Samsara BioCapital, and Sanofi Ventures – follows a $42 million first round that Abcuro closed in 2021.

Another company looking at KLRG1 as a drug target – Pyxis Oncology – put the development of its PYX-102 antibody on hold last year before it was able to advance the programme into human trials.