Allakos Inc. terminated all development of its lead drug, anti-Siglec-8 antibody lirentelimab (AK-002), and is cutting its workforce in half, following phase II failures for atopic dermatitis and chronic spontaneous urticaria. The San Carlos, Calif.-based company will now focus on phase I trials for anti-Siglec-6 antibody AK-006 as part of a restructuring that stretches the runway into mid-2026. Shares (NASDAQ:ALLK) sank by 60.2%, down $1.80, to close at $1.19 on Jan. 16.
Mast cells (MCs) are tissue-resident immune cells and are responsible for allergic and inflammatory processes. One potential approach for targeting MCs is to engage inhibitory receptors that can silence MC activation, such as sialic acid-binding immunoglobulin-like lectins (siglecs). Siglec-6 is an inhibitory receptor expressed on human MCs and represents an attractive therapeutic target for this purpose. Siglec-6 engagement with a monoclonal antibody (MAb) was recently shown to inhibit MC activation in vitro.
Discouraging news from two trials with lirentelimab slammed shares of Allakos Inc. (NASDAQ:ALLK), which ended the day at $8.55, down $75.84, or almost 90%. The Redwood City, Calif.-based firm reported data from Enigma 2, a phase III study in patients with biopsy-confirmed eosinophilic gastritis and/or eosinophilic duodenitis, and Kryptos, a phase II/III experiment in biopsy-confirmed eosinophilic esophagitis. Both experiments met their histologic co-primary endpoints but fell short of statistical significance on patient-reported symptomatic co-primary goals.
Data from a prospective study rolled out by Allakos Inc. last month at the Digestive Disease Week meeting made the case for broader prevalence than previously believed of eosinophilic gastritis and/or eosinophilic duodenitis – and the Redwood City, Calif.-based firm may have just the drug for the conditions in lirentelimab (AK-002).
