The purpose of this study is to determine the safety and effect of CAL-101 in subjects with allergic rhinitis.

A Phase I, randomized, double-blind crossover study of CAL-101, an oral inhibitor of phosphatidylinositol 3-kinase (PI3K) delta, in patients with allergic rhinitis.

Inclusion Criteria:

1. Age > or = 18 and < or = 55 years
2. Has a history of seasonal allergic rhinitis for at least 2 years
3. Has sensitivity to grass pollen demonstrated by a positive response to skin prick testing
4. Has a positive Radio Allergen Sorbent Test (> or = class 2) for grass pollen during the previous 12 months or at screening
5. Is otherwise healthy, that is, free from clinically significant illness or disease as determined by medical history, physical examination and laboratory tests, including a normal 12-lead electrocardiogram (ECG)
6. Has no conditions which would make the subject unlikely to be able to remain in the allergen challenge chamber for 4 hours
7. Is available to complete all study procedures
8. Is able to provide written informed consent, including compliance with the requirements and restrictions listed in the consent form

Exclusion Criteria:

1. Is a female of childbearing potential (non-childbearing potential means documented surgery resulting in infertility or postmenopausal with no menses for at least 1 year)

2. History of chronic nasal or upper respiratory tract symptoms or disorders other than allergic rhinitis

3. History of nonallergic rhinitis, chronic sinusitis or severe asthma

4. Has a nasal condition likely to affect the outcome of the study, i.e. nasal septal perforations, nasal polyps, sinus disease, chronic nasal obstruction, or other nasal diseases

5. Is currently taking regular medication, whether prescribed or not, including corticosteroids, vitamins, macrolides, anti-fungal agents and herbal remedies, e.g. St. John's Wort. Paracetamol (< or = 2g/day) and as needed use of short-acting B2-agonists are allowed.

6. Has taken a prohibited medication within the specified interval prior to Visit 1:

   • Corticosteroids (depot, 90 days; systemic, 30 days; dermatologic 14 days)
   • Chromones (14 days)
   • Antihistamines (nasal and long-acting oral, 10 days; shorting-acting oral, 2 days; ocular, 3 days)
   • Decongestants (3 days)
   • Leukotriene modifiers (10 days)
   • Anticholinergics (7 days)
   • Opthalmic nonsteroidal
   • anti-inflammatory drugs (3 days)
   • Nasal-ophthalmic wash solutions (12 hr)
   • Immunotherapy (12 hr)

7. Is currently being treated with a medication that induces or inhibits cytochrome P450 (CYP)3A

Qualified external researchers may request IPD for this study after study completion. For more information, please visit our website at http://www.gilead.com/research/disclosure-and-transparency.

18 months after study completion

A secured external environment with username, password, and RSA code.