A Multiple Ascending Dose Study of PUL-042 in Stem Cell Transplant Recipients

This is an open-label multiple ascending dose study with a 3+3 study design to examine the
safety and tolerability of PUL-042 Inhalation Solution in subjects with hematologic
malignancies or recipients of a first allogenic or autologus hematopoietic stem cell
transplant. Subjects will receive 4 doses over 2 weeks.

Cohort size will be 3 subjects, once 3 subjects have completed treatment and follow-up at a
dose level, subject data will be evaluated by an independent data safety monitoring committee
prior to dosing additional subjects. The Committee may recommend increasing the dose,
maintaining the same dose, or decreasing the dose.

Once the maximum dose is determined, there may be up to 6 additional subjects dosed at that
level.

Inclusion Criteria:

1. Subjects with hematologic malignancies or recipients of a first allogeneic or
autologous hematopoietic stem cell transplantation and presently clinically stable

2. Pulse oximetry of hemoglobin saturation ≥92% on room air

3. Adult (≥18 years)

4. Spirometry (FEV1 and forced vital capacity [FVC]) ≥80% of predicted value

5. If female, must be either post-menopausal (one year or greater without menses),
surgically sterile, or, for female subjects of child-bearing potential who are capable
of conception must be: practicing two effective methods of birth control

6. If female, must not be pregnant, plan to become pregnant, or nurse a child during the
study and through 30 days after completion of the study

7. If male, must be surgically sterile or willing to practice two effective methods of
birth control

8. Ability to understand and give informed consent

Exclusion Criteria:

1. Subjects with any evidence of respiratory infection including any signs or symptoms of
either a lower respiratory infection (LRI) or upper respiratory infection (URI)

2. Known history of chronic pulmonary disease

3. Subjects who are being treated for fungal, viral, or bacterial pneumonia

4. Exposure to any investigational agent (defined as any agent not approved by the Food
and Drug Administration [FDA]) within 30 days prior to the Screening Visit

5. Patients with a relapsed and/or refractory underlying hematologic malignancy

6. HSCT recipients who underwent ex vivo T-cell depletion of the graft, or a mismatched,
or cord or haplo identical blood transplantation

7. HSCT recipients with active and/or chronic graft versus host disease

8. Patients on systemic corticosteroids (oral or intravenous)

9. Absolute neutrophil count (ANC) < 1,000 cells/mL

10. Clinically significant bacteremia or fungemia

11. Current smokers or subjects with any history of smoking