Abcuro will take an anti-KLRG1 antibody into the clinic with new funding, and has big plans for another.
A little over two years after pulling in its first Series A raise, autoimmune disease and cancer player Abcuro has some more cash to play with.
The Newton, MA-based biotech completed what it’s calling a Series A-1 fundraising round, netting $42 million to advance two antibodies that target KLRG1 in the hopes of modulating cytotoxic T and NK cells. Abcuro’s raise gives it a little over two years of runway, CEO David de Graaf told Endpoints News, and enough funding to run two clinical trials for a lead antibody and prepare its second antibody for IND studies.
That lead candidate is antibody ABC008, seeking to treat sporadic inclusion body myositis, an autoimmune disease where patients’ skeletal muscles are attacked. In this indication, the T cells present KLRG1 and enter the muscle fibers themselves, leading to a chronic progression of the disease.
Whereas other immune diseases may wax and wane, de Graaf said, IBM patients suffer approximately 10% skeletal muscle loss each year and ultimately end up bedridden over 10 to 15 years. The symptoms start small, with individuals first losing fine motor function and noticing they may not be able to button their coats, for example. But with no available treatment, the disease ends up affecting patients’ quality of life while they’re essentially forced to just roll with the punches.
Corticosteroids, a treatment typically used in other autoimmune diseases, have not shown to be effective in IBM, de Graaf said. Other trials have been run to try to build up muscle mass, but Abcuro aims to differentiate itself by instead trying to get rid of the T cells in the muscles themselves.
“The T cells in the complex of the muscle are extremely abundant,” de Graaf said. “No one has just tried to affect those T cells to see if that would help out the disease. That’s the thesis behind the company.”
Abcuro expects to launch a single ascending-dose trial in IBM in the first half of this year that will enroll between 20 and 35 patients. Early signs have shown that one dose of the antibody can affect T cell levels for anywhere between 1 and 3 months, de Graaf said.
ABC008 is also being developed for a second, unnamed indication.
Abcuro’s other antibody is known as ABC015, seeking to restore T and NK cell function in solid tumors. This antibody, as opposed to its counterpart, helps the body realize it’s hosting a tumor and tries to direct the immune system to attack it.
First being studied in multiple myeloma, ABC015 works similarly to other checkpoint inhibitors such as those targeting PD1. But the target, KLRG1, is the same as ABC008, even if the process is different.
“ABC008 only uses KLRG1 really as an address. Essentially it identifies the cells and we kill the whole cell. We don’t affect the function, we just count on its presence. In cancer [with ABC015], we’re trying to disrupt the function as an inhibitory receptor,” de Graaf said. “But our initial focus is really on exploiting everything we know about KLRG1 and its biology.”
Mass General Brigham Ventures and Sanofi Ventures co-led the round, which also included Pontifax Venture Capital, Hongsen Investment Group, RA Capital Management and Samsara BioCapital, among others.