Study of Efficacy of CDZ173 in Patients With APDS/PASLI

This study is designed to explore CDZ173, a selective PI3Kδ inhibitor, in patients with
genetically activated PI3Kδ, i.e., patients with APDS/PASLI (Activated phosphoinositide
3-kinase delta syndrome/ p110δ-activating mutation causing senescent T cells, lymphadenopathy
and immunodeficiency)I.

The study consists of two parts. Part I is the open label part designed to establish the
safety and pharmacokinetics of CDZ173 in the target population, as well as to select the
optimal dose to be tested in part II.

Part II is designed to assess efficacy and safety of CDZ173 in this population.

Key Inclusion Criteria:

- patients who have a documented APDS/PASLI-associated genetic PI3K delta mutation

- In Part I and Part II, patients must have nodal and/or extranodal lymphoproliferation,
and clinical findings and manifestations compatible with APDS/PASLI such as a history
of repeated oto-sino-pulmonary infections and/or organ dysfunction (e.g., lung,
liver). Additionally, in part II, patients must have at least one measurable nodal
lesion on a CT or MRI scan.

Key Exclusion Criteria:

- Any medically significant disease or condition that is unrelated to APDS/PASLI

Other protocol-defined inclusion/exclusion criteria may apply.