Oral Galactose in Children With Steroid Resistant Nephrotic Syndrome

RESEARCH PLAN

A: Primary aims:

1. Determine the effect of 4 months of oral galactose administration on the level of FSPF
in children with steroid resistant FSGS

2. Determine the effect of 4 months of oral galactose administration on the first morning
urine protein to creatinine (urine protein: creatinine) ratio and serum albumin level
in children with steroid resistant FSGS.

B: Secondary aims:

1. Determine the effect of 4 months of oral galactose administration on dose of
immunosuppressive medication.

2. Assess first morning urine protein: creatinine ratio, serum albumin level, and change
in immunosuppression dose at 3 months after discontinuation of oral galactose therapy.

B.Background and Significance

Idiopathic nephrotic syndrome (NS) in children is most commonly due to minimal change
nephrotic syndrome and can be successfully treated with steroid therapy. However 10-15% of
children with nephrotic syndrome are diagnosed with FSGS, which is resistant to steroid
therapy and many other immunosuppressive drugs, and is associated with poor outcome.
Approximately 50% of patients with FSGS progress to ESRD within 5-10 years and in about 30%
of children, FSGS can recur after transplantation.(1) African-American children are at
significantly higher risk for FSGS.(2) Recent studies indicate that primary FSGS is a
heterogeneous disorder caused by genetic mutations in nearly a third of cases and as yet
undefined immunological defects in the remaining cases.(3) Immune mediated FSGS has been
associated with a circulating permeability factor, which is thought to increase glomerular
permeability to albumin, leading to proteinuria and contributes to sclerotic lesions in
FSGS. Presence of the FSPF is defined as permeability activity >0.5. (4) Current therapies
for FSGS include plasmapheresis and many immunosuppressive agents that include cyclosporine,
tacrolimus, mycophenolate mofetil, rituximab, and drugs that decrease proteinuria such as
angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) with
inconsistent outcome. Additionally, these drugs have long-term consequences of
immunosuppression and some drugs such as cyclosporine and tacrolimus affect renal function
adversely when used for prolonged periods of time. (5) There is an urgent need for
investigating benign therapies such as galactose. If proven to be useful, it may present a
safe alternative or an adjunct to currently available therapies.

Preliminary Studies:

1. In 2008, Savin et al. showed that galactose, a simple nontoxic sugar, binds with high
affinity to the FSPF in vitro.(6) They also found that trace amounts of galactose (>10-12 M)
inhibited glomerular permeability activity induced by FSPF in vitro. This series of in
vitro experiments also demonstrated that the effect of FSPF activity in serum can be
reversed by its incubation with galactose or alternatively by pre-incubation of glomeruli
with galactose. Additionally, the authors describe significantly decreased permeability
activity in vivo in a single patient with post-transplant FSGS in response to both IV and
oral galactose. The FSPF activity in this patient decreased progressively during the 4 weeks
of galactose ingestion (from 0.8 to 0.1), and persisted 4 weeks after discontinuation of
oral galactose (0.2). The proposed mechanism for this action is that FSPF have
galactose-binding sites which interact with galactose of the glomerular glycocalyx,
activating signal transduction in podocytes. Introduction of free galactose may block the
FSPF binding sites or alter the tertiary structure of the FSPF, thus inhibiting its
activity.

Despite the decrease in FSPF activity in this patient, proteinuria did not improve. The
authors propose the lack of clinical response may be due to the advanced stage of kidney
damage at the time of IV galactose therapy, and this patient was already on dialysis at the
time of oral galactose administration.

It would be important to study the introduction of galactose early in the course of FSGS to
determine if it is effective in decreasing proteinuria and delaying the progression of FSGS.

De Smet et al presented their experience with a case of 48-year old male, with nephrotic
syndrome secondary to FSGS, treated with oral galactose at 10 gm BID for 6 months, at the
annual meeting of American Society of Nephrology 2008 (ASN 08, TH-PO-955). Their patient had
failed to respond to prednisone, cyclophosphamide, mycophenolate mofetil, cyclosporine and
plasma exchanges. Prior to treatment, the FSPF was detected at 0.87 and urinary protein
excretion was 4.3 gm/day. After treatment with galactose, the FSPF decreased to 0.09 and
urinary protein excretion decreased to 0.56 gm/day. The success obtained in this case argues
for trial in additional patients.

Methods:

1. Oral galactose therapy: After obtaining informed consent and assent FSPF will be
obtained at a baseline to determine eligibility. Blood samples for FSPF will be
collected in a "red-top" tube (without anti-coagulant), allowed to clot, then spin and
separate. The serum will be shipped on ice for FSPF analysis to the laboratory of
Virginia Savin, Medical College of Wisconsin, Milwaukee, WI. All other parameters
(including weight, height, blood pressure, urinalysis, urine protein: creatinine ratio,
serum albumin, creatinine, electrolytes, and glucose) will be collected at the same
visit as part of standard of care. Female participants of child bearing age will be
given a urine pregnancy test and excluded from the study if pregnant.

Once patients are found to be eligible, oral galactose will be initiated at a dose of
0.2gm/kg/dose BID to a maximum of 15 gm BID for a period of 4 months. The prescribed
dose of galactose powder will be dispensed to subjects in packets, mixed with 4 ounces
of water, and consumed orally. FSPF will be measured again at week 16. All the other
parameters will be repeated at 4, 10 and 16 weeks after starting oral galactose. Oral
galactose therapy will be stopped after 16 weeks. In order to determine the clinical
significance of the galactose treatment, a set of clinical parameters (weight, height,
blood pressure, urinalysis, first morning urine protein: creatinine ratio, serum
albumin, creatinine, electrolytes, and glucose) will be obtained at 12 weeks after
discontinuation of oral galactose. Measurement of adherence with galactose will be
estimated by counting the number of galactose doses returned at each subsequent monthly
visit. Patients will be considered adherent if they have taken >90% of the prescribed
doses.

2. Adjunct therapy of nephrotic syndrome: Each patient will remain on his or her baseline
therapy immunosuppressive therapy with cyclosporine, tacrolimus or mycophenolate
mofetil. Steroids dose will be tapered to 0.5mg/kg, to a maximum of 40 mg, every other
day at the time of starting galactose. If patient achieves remission, as indicated by
negative first morning urine for protein for 3 consecutive days, alternate day steroid
therapy will be tapered by 0.12mg/kg/dose or by 10 mg/dose, once per week. If patient
has sustained remission for 1 month, and is off prednisone, the dose of
immunosuppressive drugs will be lowered by 25% per month until off. BP will be
controlled to below 95th percentile for height. If patient is on ACE inhibitors or
ARBs, the dose will stay unchanged during the duration of galactose administration
unless patient is experiencing side effects of therapy. If additional therapies for
control of hypertension are needed, they would be chosen from the antihypertensive
drugs other than ACE inhibitors and ARBs. Diuretics will be prescribed as needed for
the symptomatic relief of edema. Adjunct therapy medications described in this section
are standard of care and are not for research purposes.

Result analysis:

Each patient will serve as its own control. Results will be considered clinically
significant if the following criteria are met in response to oral galactose therapy at week
16 and if the reduction in urine protein: creatinine and the increase in serum albumin
persist at 12 weeks after discontinuation of galactose.

1. Reduction in FSPF to <0.5 or decrease in FSPF by > 0.3

2. Decrease in first morning urine protein: creatinine ratio by 50%

3. Increase in serum albumin by >1gm/dl

4. Decrease in dose of prednisone or other immunosuppressive drugs by 25% Statistical
Analysis The primary outcomes are the means of paired pre vs. post galactose treatment
differences in FSPF, urine protein: creatinine ratio, serum albumin and dose of
immunosuppressive drugs. We will use repeated measures ANCOVA models to estimate each
primary outcome as the dependent variable while holding constant pre-treatment levels.
Therefore, the independent variable will be the pre-treatment level of the
corresponding dependent variable, The model will be used to estimate the mean
difference +/- the 95% confidence interval (CI) corresponding to the mean level of the
dependent variable at pre-treatment. We will consider the pre-post difference to be
statistically significant if the 95% CI around the result fails to include 0 and to be
clinically significant if it meets the criteria specified above.

Adequacy of the Sample: We evaluated the effect size difference that could be detected with
80% and 90% power in a pre-post treatment study of galactose involving 10 patients assessed
pre-treatment and post-treatment. The correlation between measurements on the same person
was assumed to be .7 and the two-tailed type 1 error was set at 0.05. The study will have
better than 90% power to detect effect size differences of 0.6 sd and better than 80% power
to detect effect size differences of 0.5 sd. These are considered to be moderate effect
sizes.

Research Facilities: The FS permeability factor will be tested in the laboratory of Virginia
Savin MD (Center for Glomerular Pathophysiology, Medical College of Wisconsin, Milwaukee,
WI) using previously described methods.(7)

Risks and Side Effects:

FSGS is a difficult to treat disease associated with poor outcomes, including progression to
end stage renal disease. Galactose is a naturally occurring simple sugar and oral galactose
supplementation has no known side risks or side effects in humans. Patients eligible for
this study are those who have failed to respond to the current alternative treatments for
FSGS, which include steroids and other immunosuppressive agents, such as cyclosporine,
tacrolimus, mycophenolate mofetil, and rituximab. These alternative immunosuppressive
treatments have many long term complications, some of which include stunted growth,
nephrotoxicity, hyperlipidemia, and diabetes. There is an urgent need for investigating
benign therapies such as galactose, which may present a safe alternative or an adjunct to
current therapies.

There are no known side effects of oral galactose supplementation and no reports of toxicity
with chronic use in humans. The Certificate of Origin for the D-Galactose product from
FerroPfanstiehl is included in the Appendix and certifies that the D-Galactose to be used in
our study is safe for human consumption.

D-Galactose is administered safely in diagnostic testing for both glycogen storage disease
and cirrhotic liver disease (8) and as sonographic contrast agents, such as Levovist ®
(Bayer). Galactose has also been successfully administered as a treatment in Fabry's
disease. (9) In this case report, IV galactose infusions were administered at a dose of 1
g/kg every other day for 2 years during which time liver function tests remained normal.
Possible associations between dairy intake and ovarian cancer has been investigated with
inconclusive results. A 2006 pooled analysis of 12 cohort studies done by Harvard School of
public health found no association of intake of dairy foods with ovarian cancer and a
statistically insignificant increase in risk of ovarian cancer at intakes of lactose > 30
g/d. This study involved analyzing surveys of reported dairy intake, but did not account for
the presence of other factors in milk, such as hormones, that could contribute to ovarian
cancer risk (10). Another 2005 meta-analysis in the European Journal of Cancer Prevention
found no association between milk/dairy products or galactose metabolism and ovarian cancer
risk. (11) In addition to occurring naturally in milk, galactose has been approved by the
FDA as a substance Generally Recognized as Safe (GRAS) as an ingredient in infant formula
and other baby foods and pediatric nutrition supplements in the form of
galacto-oligosaccharides (a compound made of 1 to 7 galactose molecules linked to a glucose
molecule at the reducing end).
(www.fda.gov/food/foodingredientspackaging/generallyrecognizedassafeGRAS/GRASListings/ucm153910.htm)

Benefits:

FSGS is resistant to steroid therapy and many other immunosuppressive drugs, and is
associated with poor outcome. Approximately 50% of patients with FSGS progress to ESRD
within 5-10 years and in about 30% of children, FSGS can recur after transplantation.(1)
Given the devastating course of this disease and the benign nature of the proposed galactose
treatment, the anticipated benefits far outweigh the risks. If effective, galactose
supplementation could stop the progression of FSGS, limiting glomerular damage and
preventing progression of the disease to ESRD. The potential benefit of preserving kidney
function and preventing the need for dialysis or transplantation is significant for both
participants in this study and for other children with FSGS who may benefit from galactose
therapy in the future.

Inclusion Criteria:

1. 2-21 years old

2. Biopsy proven FSGS or minimal change with steroid resistance

3. Presence of FSPF (defined as permeability activity >0.5)

4. Presence of nephrotic range proteinuria (urine protein: creatinine ratio >2) at the
time of enrollment.

5. Persistent nephrotic range proteinuria despite being on stable immunosuppressive
medications (cyclosporine, tacrolimus or mycophenolate mofetil) for at least 12 weeks
and/or persistent nephrotic range proteinuria despite being on stable dose of
angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers
(ARBs) for 12 weeks.

6. Stable serum creatinine (change of less than 0.3 mg/dl) in the prior 3 months.

7. Schwartz estimated (e) glomerular filtration rate (GFR) >60ml/min/1.73m2

Exclusion Criteria:

1. Secondary FSGS

2. Onset of nephrotic syndrome in infancy.

3. Presence of acute renal failure (as defined by acute kidney injury criteria) at the
time of enrollment. These children can be enrolled 1 month after resolution of acute
renal failure (ARF).

4. Decreasing renal function (persistent increase in serum creatinine of greater than
0.3 mg/dl over baseline in the prior 3 months).

5. Use of another investigational drug

6. Pregnant or unable to comply with contraceptive measures in females of child bearing
age

7. eGFR < 60 ml/min per 1.73 m2

8. Children with Galactosemia

9. Children with type 1 or 2 diabetes