Dedicated to bringing transformative oral therapies to patients with serious immune-mediated diseases.

Unfortunately, for many patients suffering from debilitating or life-threatening immune-mediated diseases, current treatments inadequately control their disease and/or burden them with off-target side effects. We believe that our proprietary oral therapies have the potential to rival the effectiveness and safety of injectable biologics yet maintain the convenience of a pill. Our drug candidates are involved in multiple ongoing clinical trials that we, or our partner, are conducting.

The following clinical trials are currently enrolling patients:


Status: Phase 3 Ongoing

Phase 3 clinical trial with rilzabrutinib (formerly known as PRN1008) for pemphigus, an autoimmune blistering skin disorder that has few options for treatment. Approximately 120 male or female patients with newly diagnosed or relapsing moderate to severe pemphigus (pemphigus vulgaris or pemphigus foliaceus) will be enrolled in the trial worldwide. The trial will last 68 weeks for each participant. Patients will be randomized at Day one, using a 1:1 ratio to receive rilzabrutinib or placebo twice per day, and by relapsing/newly diagnosed disease history (newly diagnosed defined as within six months of screening). Learn more about the PEGASUS study.

Additional clinical trial information can be found on ClinicalTrials.gov, and information related to the disease can be found on Pemphigus.org.

Phase 2 clinical trial information can also be found on ClinicalTrials.gov.


Status: Phase 1/2 Ongoing

Phase 1/2 clinical trial with oral rilzabrutinib (formerly known as PRN1008) for Immune Thrombocytopenia (ITP), an autoimmune disease-causing low platelet levels in the blood. This is an adaptive, open-label, dose-finding study of rilzabrutinib in up to 40 patients with ITP who are refractory or relapsed with no available and approved therapeutic options, with a platelet count <30,000/μL on two counts no sooner than seven days apart in the 15 days before treatment begins. The active treatment period is 24 weeks and the post-treatment follow-up period is four weeks. Each patient enrolled in the study is allowed to up-titrate their dose after 28 days of rilzabrutinib therapy, if they do not experience a platelet response or a dose-limiting toxicity (DLT) at the last dose level. Patients who respond to rilzabrutinib per protocol may enter a long-term extension.

Clinical trial information can be found on ClinicalTrials.gov, and information related to the disease can be found on PDSA.org.


Status: Phase 1 Ongoing

PRN473 Topical, a reversible covalent BTK inhibitor, is being evaluated in a Phase 1, randomized, double blind, placebo-controlled, single and multiple dose trial to evaluate its safety, tolerability and pharmacokinetics. The trial is being conducted in Australia.

In Part A, doses are evaluated sequentially. Participants in each group are receiving a single dose of either 0.5%, 2%, or 5% PRN473 Topical or placebo.

In Part B, participants are receiving repeat doses of either PRN473 topical (dose determined in Part A) or placebo. Each participant is dosed twice a day for 7 days.

Additional clinical trial information can be found at PRN473 Registry AUSTRALIA.

Advancing Promising Therapies