High Dose Ascorbic Acid for Plasma Cell Disorders

In this study, patients will be treated with low dose melphalan and 4 doses of HDAA for one
cycle only. In total, 9 patients will be enrolled in this study. Bone marrow examination and
imaging with PET and/or MRI will be performed 4 weeks from last dose of HDAA. Patients will
be regularly followed up.

Inclusion Criteria:

1. Subject has provided informed consent.

2. Patients who have been previously treated with 3 lines of therapy, i.e. proteasome
inhibitors, immuno-modulatory agents such as lenalidomide and monoclonal antibodies
such as daratumumab, and have progressed within past 6 months. Participants with
previous failed autologous transplant and progressed within 6 months after autologous
transplant. Note: induction with or without hematopoietic stem cell transplant and
with or without maintenance therapy is considered a single regimen.

3. Patients have failed treatment with, are intolerant to or are not candidates for
available therapies that are known to confer clinical benefit to patients with
relapsed and refractory MM.

4. Subjects must have measurable disease (as determined by the central lab), including at
least one of the criteria below:

- M-protein quantities ≥ 0.5 g/dl by SPEP or

- ≥ 200 mg/24 hour urine collection by UPEP or

- serum free light chain levels > 100 mg/L (milligrams/liter involved light chain)
and an abnormal kappa/lambda (κ/λ) ratio in patients without detectable serum or
urine m-protein or

- For patients with immunoglobulin class A (IgA) myeloma whose disease can only be
reliably measured by quantitative immunoglobulin measurement, a serum IgA level ≥
500 mg/dL.

Non-secretory participants are eligible provided the participant has > 20% bone marrow
plasmacytosis OR multiple (≥3) plasmacytomas or lesions on MRI at the time of
diagnosis or study enrollment, OR the presence of lesions (≥ 3) on PET/CT scan.

5. Adequate organ function:

- Absolute neutrophil count (ANC) ≥ 1.0 x 109/L without growth factor support for 7
days (14 days if pegfilgastrim)

- Platelets (plt) ≥ 50 x 109/L without transfusion for 7 days

- Potassium within normal limits or correctable with supplements

- Aspartate aminotransferase (AST/SGOT) and alanine aminotransferase (ALT/SGPT) ≤
2.5 x upper limit of normal (ULN)

- Serum bilirubin ≤ 1.5 x ULN

- Estimated serum creatinine clearance of ≥ 45 mL/min using the Cockcroft-Gault
equation or directly calculated from the 24-hour urine collection method

- International normalized ratio (INR) < 1.5 x ULN and partial thromboplastin time
(PTT) < 1.5 x ULN

- Ejection fraction by ECHO or MUGA of ≥ 40% performed.

- Participants must have adequate pulmonary function studies (PFTs), > 50% of
predicted on mechanical aspects (FEV1, FVC) and diffusion capacity ( DLCO) > 50%
of predicted (adjusted for hemoglobin). If the participant is unable to complete
PFTs due to disease-related pain or other circumstances that make it difficult to
reliably perform PFTs, documentation of pulmonary function adequate for
transplant will occur via a CT scan without evidence of major pulmonary disease,
and arterial blood gas results.

6. Participants must have a performance status of 0-2 based on ECOG criteria.
Participants with poor performance status (3-4) based solely on bone pain will be
eligible, provided there is documentation to verify this.

7. Negative serum or urine pregnancy test (sensitivity of at least 25 mIU/mL) at
screening.

Exclusion Criteria:

1. Prior allogeneic transplant.

2. Known hypersensitivity or allergy to ascorbic acid or melphalan.

3. Participants must not have a concurrent malignancy unless it can be adequately treated
by non-chemotherapeutic intervention. Participants may have a history of prior
malignancy, provided that he/she has not had any chemotherapy within 365 days of study
entry AND that life expectancy exceeds 5 years at the time of study entry.

4. Participants must not have life-threatening comorbidities.

5. History or evidence of myeloma associated with immunodeficiency states (e.g.:
Hereditary immune deficiency, HIV, organ transplant or leukemia).

6. Known human immunodeficiency virus (HIV) disease (requires negative test for
clinically suspected HIV infection).

7. Evidence of CNS myeloma.

8. Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, recent (within 6 months) myocardial infarction, uncontrolled or symptomatic
congestive heart failure, unstable angina pectoris, cardiac arrhythmia, uncontrolled
hypertension on appropriate therapy or psychiatric illness/social situations that
would limit compliance with study requirements.

9. Concurrent use of Coumadin (warfarin)

10. Patients with G6PD deficiency

11. Patients with a history of oxalate renal stones or a known history of multiple renal
stones

12. Diabetic patients who rely on a glucometer to dose insulin as ascorbate can interfere
with glucometer readings