Evaluating the Safety and Tolerability of Orally Administered DF-003 in ROSAH Syndrome Patients

Inclusion Criteria:

1. Sufficient understanding of the purpose and procedures required for the study.

2. Body mass index (BMI) of 18.0 to 35.0 kg/m2, inclusive.

3. Genetic testing for ALPK1 mutations that has been shown to be associated with ROSAHsyndrome (e.g. T237M or Y254C, or T237A mutations).

4. Signs of uveitis (anterior and/or posterior) in the eye (e.g. macula edema, opticnerve edema, retinal vasculitis, or retinal vascular leakage).

5. Patients must be deemed healthy except for diagnosis of ROSAH syndrome and itsclinical manifestation.

6. Patients must be at least 18 years of age but no older than 65 years of age at thetime of Screening.

Exclusion Criteria:

1. Males who plan to father a child or donate sperm while enrolled in this study orwithin 90 days after the last dose of study drug.

2. Females who are pregnant, breastfeeding, planning to become pregnant, or planning todonate eggs while on study medication or within 90 days after the last dose of studydrug.

3. Use of any of the following prohibited medications:

• Agents that are known to have systemic anti-inflammatory responses or high riskfor nephrotoxicity or hepatotoxicity

• Moderate CYP3A4 inhibitors: e.g., amiodarone, amprenavir, conivaptan,delavirdine, diltiazem, erythromycin, fluconazole, fosamprenavir, imatinib,miconazole, verapamil, grapefruit juice, cat's claw (Dolichandra unguis-cati),Echinacea augustifolia, wild cherry, chamomile, licorice

• Strong CYP3A4 inhibitors: e.g., ceritinib, clarithromycin, cobicistat,elvitegravir/ritonavir, idelalisib, indinavir/ritonavir, itraconazole,ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir,paritaprevir/ritonavir, ombitasvir/paritaprevir/ritonavir (and/or dasabuvir),posaconazole, ritonavir, saquinavir/ritonavir, telithromycin,tipranavir/ritonavir, voriconazole.

• Strong CYP3A4 inducers: apalutamide, carbamazepine, enzalutamide, ivosidenib,lumacaftor/ivacaftor, mitotane, phenytoin, rifampin, St. John's wort.

• Digoxin

• Agents known to cause Torsade de Pointes: Disopyramide, procainamide,quinidine, sotalol, azithromycin, clarithromycin, erythromycin, ciprofloxacin,levofloxacin, moxifloxacin, fluconazole, ketoconazole, pentamidine,voriconazole, haloperidol, thioridazine, ziprasidone, citalopram, escitalopram,dolasetron, droperidol, granisetron, and ondansetron

• Investigational agents (small molecules and oligonucleotides), vaccines, orinvasive medical devices within 28 days (4 weeks, or 5 half-lives, whichever islonger) prior to enrollment or having received a biological product within 6months prior to enrollment.

4. History of significant hypersensitivity to products related to DF-003 (includingexcipients of the formulations) as well as severe hypersensitivity reactions (likeangioedema) to any drugs.

5. Recent (within 3 months prior to screening) or acute changes in the followinglaboratory values:

• Platelet count ≤ 120,000/mm3, or

• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > ULN

• Bilirubin (total, direct) > ULN or

• International Normalization Ratio (INR) > ULN, or

• Serum albumin less than the lower limit of normal, or

• Estimated creatinine clearance < 70 mL/min/1.73 m2 at Screening, calculated bythe Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula, or

• Hemoglobin A1c (HbA1c) > 8%.

6. Moderate or severe hepatic impairment (categorized as Child-Pugh class B and C,respectively, on the Child-Pugh Score for Cirrhosis Mortality)