– Phase 1 data demonstrate AK002 rapidly depletes blood eosinophils after a single dose –

– AK002 may provide an important new option in treating chronic allergic and inflammatory diseases such as eosinophilic gastrointestinal diseases –

SAN CARLOS, Calif., March 5, 2018 – Allakos Inc., a private, clinical-stage biopharmaceutical company focused on the development of antibodies for the treatment of allergic, inflammatory and proliferative diseases, today announced positive results from a Phase 1 clinical trial presented at the Joint Congress of the American Academy of Allergy Asthma and Immunology (AAAAI) and the World Allergy Organization (WAO) in Orlando, Florida.

The Company’s presentation outlined the results from a randomized, double-blind, placebo-controlled, single ascending dose portion of a Phase 1 study of AK002. AK002 is a humanized Siglec-8 monoclonal antibody being developed by Allakos to potentially address a number of diseases where eosinophils and/or mast cells have been shown to be involved in disease pathology. Eosinophils and mast cells play a significant role in both the innate and adaptive immune response, and act as key effector cells in inflammatory diseases such as eosinophilic gastrointestinal diseases, urticaria, atopic keratoconjunctivitis, atopic dermatitis, and asthma.

The key findings are summarized as follows:

• AK002 was found to rapidly deplete blood eosinophils after a single dose:
  • All AK002 dose groups recorded complete depletion of blood eosinophils by the first post-dosing timepoint (1 hour); eosinophil levels were not significantly changed in the placebo group
  • Duration of eosinophil depletion increased with dose level and was sustained for at least 28 days and up to 84 days in the 0.3 and 1.0 mg/kg dose groups, respectively
• AK002 was generally safe and well tolerated:
  • Transient mild to moderate infusion reactions occurred and resolved quickly, including headache and nausea, all of which are consistent with monoclonal antibodies exhibiting potent antibody-dependent cell-mediated cytotoxicity (ADCC) activity
  • No changes in vital signs, electrocardiograms (ECGs), clinical laboratory parameters, and physical examination (PE) were observed

About the Phase 1 Clinical Trial

The clinical trial, A Phase 1, Double-Blind, Placebo-Controlled, Single Ascending and Multiple Dose Study to Evaluate the Safety Tolerability, Pharmacokinetics and Pharmacodynamics of AK002 in Healthy Participants, included  normal healthy subjects randomized (4:2 ratio) to receive AK002 or placebo, intravenously, across seven AK002 dose cohorts (0.001, 0.003, 0.01, 0.03, 0.1, 0.3, and 1.0 mg/kg). The primary objective was to evaluate the safety and tolerability of single ascending doses and multiple doses of AK002 in healthy subjects. Secondary objectives included evaluations of AK002 pharmacokinetics (PK) in healthy subjects and pharmacodynamics (PD) as measured by changes in absolute peripheral blood counts of eosinophils.                                                                                 

About Allakos

Allakos is a privately held clinical-stage company developing antibodies that target immunomodulatory receptors present on the surface of immune effector cells involved in allergic, inflammatory, and proliferative diseases. The Company’s lead antibody, AK002, targets Siglec-8, an inhibitory receptor expressed on the surface of human mast cells and eosinophils. AK002 has completed two Phase 1 studies, one in healthy volunteers and a single ascending dose study in patients with ISM. In addition, patients with ISM are currently being treated with AK002 for up to six months in a repeat dose study. In these studies, AK002 was well tolerated and demonstrated pharmacological activity on objective measures as well as patient reported symptoms. For more information, please visit the Company's website at www.Allakos.com.
 

INVESTOR CONTACT

Adam Tomasi, COO, CFO
investors@allakos.com

MEDIA CONTACT

Denise Powell
denise@redhousecomms.com