Rhu-pGSN to Mitigate Proinflammatory Responses to Decompression in Healthy SCUBA Divers

Healthy trained SCUBA divers will be randomized into three groups and exposed to a high-pressure profile in a hyperbaric chamber. The high-pressure profile simulates the pressure at a depth of 30 meters of sea water (MSW) for 35 minutes. In the control group, the subjects will receive intravenous normal saline immediately before and after the high-pressure exposure. The second group will receive intravenous recombinant human gelsolin (rhu-pGSN) 24 mg/kg immediately prior to the exposure, and saline post-exposure. The third group will receive saline pre-exposure and rhu-pGSN post-exposure. Blood samples will be collected at multiple time points pre- and post-exposure to assess levels of inflammatory markers, including interleukin (IL)-1β. Other assessments include screening for gas bubbles, a validated questionnaire to assess the incidence of clinical decompression sickness (DCS), measurement of plasma gelsolin (pGSN) levels, and measurement of anti-pGSN antibodies.

Inclusion Criteria: 1. Experienced healthy trained female or male SCUBA divers without known underlying comorbidities 2. Age ≥18 3. Informed consent obtained from subject 4. During the course of the study starting at screening and for at least 3 months after their final study treatment: * Female subjects of childbearing potential must agree to use 2 medically accepted and approved birth control methods * Male subjects with a partner who might become pregnant must agree to use reliable forms of contraception (i.e., vasectomy, abstinence), or an acceptable method of birth control must be used by the partner * All subjects must agree not to donate sperm or eggs Exclusion Criteria: 1. Any co-morbidity contraindicating SCUBA diving 2. Pregnant or lactating women 3. History of unrepaired cardiac shunt or echocardiographic evidence of patent foramen ovale or atrial septal defect 4. Any active underlying conditions including but not limited to cancer or other illness treated with systemic chemotherapy, immunomodulatory biologics, or radiation therapy during the last 360 days or expected to be treated in the upcoming 120 days 5. Refusal or inability to use adequate contraception 6. Participation in an investigational clinical trial (e.g., device, drug, or biologic) in the previous 30 days 7. Any acute illness or vaccination in the previous 30 days 8. History of alcohol or recreation drug use disorder 9. Known allergy to study drug or excipients 10. Weight \>125 kg 11. Unsuitable for study participation, in the opinion of the Investigator