Hyperbaric Oxygen Therapy for Hematopoietic Progenitor Cell Collection in Poor Mobilizers

Study subjects will be patients who have failed to achieve an adequate mobilization of
hematopoietic progenitor cells (so-called stem cells) into their blood stream to safely
proceed with hematopoietic stem cell transplantation as a component of treatment for a
hematological malignancy. There are several possible chemo-mobilization procedures that a
primary clinician may prescribe and when blood cell counts at the end of these procedures
document an inadequate number for transplantation, there is no accepted clinical course of
action other than to repeat the procedures and sometimes add another drug, such as
plerixafor. This investigation is based on a single center abstract presented at a
hematological meeting (the 2012 ASCO University Annual Meeting) where 7 of 9 patients
previously identified as poor mobilizers achieved sufficient mobilization with addition of
hyperbaric oxygen therapy to standard care (1). This project is to recapitulate the study in
a somewhat larger patient population (20 subjects).

Once an individual has been identified as a poor mobilizer, meaning they failed with standard
therapy to mobilize sufficient stem cells to proceed with bone marrow transplantation, they
will be approached by one of the investigators, informed of the study and asked to sign
informed consent. After a period of time identified as a 'rest period' (typically 2-4 weeks,
exact duration is a decision to be made by the primary clinician overseeing the patient's
care) they will begin treatment in another attempt to mobilize an adequate number of
hematopoietic progenitor cells (defined as 2 x 10^6 cells/kg body weight). A blood sample
will be obtained to determine the baseline number of stem cells (an aspect of normal clinical
care) and also an extra 4 ml tube of blood will be obtained for additional studies to be done
in the PI's lab (these are added evaluations of hypoxia inducible factors (HIF) within
circulating stem cells that may influence function but are not currently recognized as having
clinical relevance).

A component of normal care at this point is daily injections with a drug called Neupogen. In
order to accommodate the needed time for normal clinical procedures with the anticipated
time-course for hyperbaric oxygen therapy-induced stem cell mobilization, the study protocol
will begin on Thursday with Neupogen injection plus a 90 minute exposure to hyperbaric oxygen
at a pressure of 2.4 atmospheres absolute (the normal protocol followed by the Hyperbaric
Oxygen [HBO2] Therapy Service for daily treatments of elective patients). Neupogen plus HBO2
will be repeated again on Friday, and on Saturday and Sunday Neupogen injections again
administered.

On Monday Neupogen plus HBO2 will be repeated and on Tuesday morning a blood sample will be
obtained. This is for counting stem cells to asses if an adequate number is mobilized (hence
an aspect of normal clinical care) and also an extra 4 ml tube of blood will be obtained for
the additional studies of HIF in stem cells to be done in the PI's lab. If the cell count
exceeds 20/ml blood the subject will undergo apheresis to harvest stem cells on that day. If
the cell count is less than 20/ml, the subject will again receive a Neupogen injection and
HBO2 and an additional drug that is part of normal care called plerixafor. On Wednesday
morning a blood sample will again be obtained to asses if an adequate stem cell number is
mobilized (hence an aspect of normal clinical care) and also an extra 4 ml tube of blood will
be obtained for additional studies to be done in the PI's lab. If the cell count exceeds
20/ml blood the subject will undergo apheresis to harvest stem cells on that day. If the cell
count is still less than 20/ml blood, the subject will again receive a Neupogen injection and
HBO2 and an additional dose of plerixafor. It is anticipated that by Thursday morning, when
another blood cell count will be done, the study subject will be able to proceed with
harvesting their stem cells by the apheresis procedure.

Doses and agents used for chemotherapy will be determined by a patient's primary treating
hematologist according to standard treatment guidelines (Neupogen and plerixafor). The
experimental intervention will be inclusion of daily HBO2 (2.4 ATA for 90 minutes)
administered for 3-5 days. Assessment of blood progenitor cell mobilization will follow
standard clinical evaluations and protocols. No additional interventions will be performed.
The only addition to standard clinical analysis will be obtaining an extra 4 ml tube of blood
at each phlebotomy session for studies to be performed in the PI's lab including analysis of
progenitor cell sub-types, content of hypoxia inducible factors and activity of nitric oxide
synthase-3 in platelets following published methods (3).

Inclusion Criteria:

1. Clinical indication for hematopoietic stem cell transplantation.

2. Those failing to achieve an adequate collection of progenitor cells with standard
chemotherapy treatment to safely perform hematopoietic stem cell transplantation.

Exclusion Criteria:

1. Diabetes mellitus

2. Renal or other organ transplantation and on immunosuppressive agents

3. NYHA Class III or IV heart failure

4. Liver cirrhosis

5. HIV infection and/or AIDS

6. Seizure disorder and not taking anti-seizure medications

7. Asthma/bronchospasm not resolvable with inhaled bronchodilators

8. Eustachian tube dysfunction and inability to equalization of pressure across the
middle ears

9. Confinement anxiety not controlled with oral benzodiazepine therapy.