Subjects with multiple myeloma (MM) who are considered eligible for high-dose therapy and autologous stem cell transplantation by the transplant team at WCI will be enrolled in the study.

Subjects with multiple myeloma (MM) who are considered eligible for high-dose therapy and autologous stem cell transplantation by the transplant team at WCI will be enrolled in the study. Subjects will receive HBO therapy on Days 0, +1 and +2 of the transplant. The treatment consists of exposure to hyperbaric oxygen at 2.5 atmospheric absolutes for a total of 90 minutes after compression to 2.5 atmosphere absolutes in a monoplace hyperbaric chamber (Model 3200/3200R, Sechrist Industries, Inc., USA), breathing 100% oxygen. Subjects will be in the chamber for a total of 120 minutes as approximately 10-15 minutes will be spent during the compression and decompression phases and subjects will have 5-10 minute room air breaks every 30 minutes of hyperbaric oxygen treatment. Subjects will be seen daily until neutrophil recovery is documented . After neutrophil recovery is documented, the subjects will be seen in clinic at least weekly through day +100. A final visit will be scheduled day +100. As part of routine care, subjects will be followed daily or as directed by the treating physician until neutrophil recovery, defined as three consecutive days of achieving a neutrophil count of >500/mm3. Laboratory testing will occur per institutional guidelines. Follow-up will continue until Day +100. Donor chimerism and disease status will be determined by bone marrow biopsy on Day +30 and day +100 post-transplant.

Inclusion Criteria:

• Subjects with Multiple myeloma
• Subjects must be 18 years old
• Karnosfsky Performance of greater than 70 percent
• Adequate hepatic, cardiac and pulmonary function
• Subjects should have New York Heart Association Functional Classification of: Class 1 or Class II.

Exclusion Criteria:

• Pregnant or breastfeeding
• Severe chronic obstructive pulmonary disease requiring oxygen supplementation
• History of spontaneous pneumothorax
• Active ear/sinus infection
• Sinus surgery within the last 5 years
• Claustrophobia
• History of recurrent seizures within 5 years of study enrollment
• Evidence of pneumothorax or significant pulmonary fibrosis on chest imaging within 60 days of transplant
• Prior chest surgery involving thoracotomy or prior direct irradiation to the lungs
• Subjects who have had intrathecal chemotherapy within 2 weeks of starting preparative regimen or cranial irradiation within 4 weeks of starting preparative regimen
• Active and uncontrolled viral, fungal or bacterial infection
• Use of tobacco 72 hours prior to transplant

All individual data collected during the trial will be shared after deidentification, including dictionaries.

Data will be available immediately following publication. No end date.

Anyone who wishes to access the date for any type of analyses.