Non Transplant Options for Aplastic Anemia Jong Wook Lee, MD, PhD. Department of Hematology, Seoul...
Transcript of Non Transplant Options for Aplastic Anemia Jong Wook Lee, MD, PhD. Department of Hematology, Seoul...
Non Transplant Options
for Aplastic Anemia
Jong Wook Lee, MD, PhD.
Department of Hematology, Seoul St. Mary’s Hospital
The Catholic University of Korea, Seoul, Korea
CytotoxicT cell
CytotoxicT cell
CytotoxicT cell
CytotoxicT cell
Haemopoieticcell
Interleukin-2
TNF-β
INF-γ
Fas ligand
INF-γ
TNF-β
INF-γreceptor
TNF-βreceptor
Fasreceptor
Expansion of T-cell clones
IRF-1
↑ ICE apoptosis
Jak 1
Stat 1
Stat 3
i NOS
NOToxicity for other cells
dsRNA-PKR
RNaseL
elF-2↓protein synthesis
↓Cell cycling
Immune-mediated aplastic anemia
Anemia
Leukopenia (neutropenia)
Thrombocytopenia
CD34+ cell↓
CFU-GM, BFU-E ↓
LTC-IC ↓
Young N, Maciejewski J. N Engl J Med. 1997;336:1365-72. Young N, et al. Blood 2006;108:2509-19.
Genetic aplastic anemia
Telomere shortening1–3
● Abnormal telomere shorting in AA: relapse after IST, clonal evolution, survival in SAA
1. Ball SE, et al. Blood. 1998;91:3582-92. 2. Brummendorf TH, et al. Blood 2001;97:895-900. 3. Scheinberg P, et al. J Am Med Assoc. 2010;304:1358-64.
4. Yamaguchi H, et al. N Engl J Med. 2005;352:1413-24.5. Fogarty PF, et al. Lancet. 2003;362:1628-30. 6. Yamaguchi H, et al. Blood. 2003;102:916-8.
Mutation in both TERT and TERC genes4–6
● Mutation of TERC: 3/210 of AA, PNH, and DKC ● Mutation of TERC in 2 families ● Mutation of TERT: 7/200 AA vs 0/528 control
– heterozygous mutations in the TERT gene impair telomerase activity and may be risk factors for bone marrow failure
Embryonicstem cells
Adultstem cells
Telomeres
Chromosome
Telomere is a repeating
DNAsequence
Telomeraseinactive
or absent
Telomereshort
Telomerelong
Telomeraseactive
DKC = dominant dyskeratosis congenita; IST = immunosuppressive therapy; PNH = paroxysmal nocturnal haemoglobinuria; SAA = severe AA.
Auto-antibodies (Ab) against distinct proteinsKinectin - a 1300 amino acid protein expressed on human hematopoietic cell, liver, ovary, testis & brain - IgG Anti-kinectin Ab found in 7/18 (39%) of US AA vs. in 3/30 (10%) of Japanese AA
(Hirano, Blood, 2003)
Anti-PMS1 (postmeiotic segregation increased 1) Ab - Japanese AA, 3/10 (30%) vs. US AA, 0% (0/18) (Hirano, BJH, 2004)
Diazepam-binding related protein-1
- anti-DRS-1 in 38% (27/71) of PNH+AA, 6.3% (2/32) of PNH-AA,
38.5% (5/13) of PNH+MDS.
- response to IST in AA patients with DRS-1 Ab (100% vs. 55%) (Feng, Blood, 2004)
Moesin:
- a membrane cytoskeleton linker protein
- antimoesin Abs in 25/67 (37%) of AA - marker for response to IST (Takamatsu, Blood, 2007)
Treatment options of aplastic anemia
1. Allogeneic BMT– age < 50 years– HLA-matched donor (+)– severe or very severe AA
2. Immunosuppressive therapy (IST)– hematological recovery in 60~70% of patients1,2
3. Supportive care– blood transfusions, management of infections, iron
chelation therapy
1. Rosenfeld SJ, et al. Blood. 1995;85:3058-65.2. Bacigalupo A, et al. Blood. 1995;85:1348-53.BMT = bone marrow transplantation.
Supportive care
1. Transfusion
Red cell (PRC) : Hb 7.0 g/dl ↓
PLT : 10,000/mm3 ↓
* Irradiation (2,500 rad)
* Leukocyte-depleted filter
* Iron chelation therapy
2. Infection control
Algorithm for treatment
Maciejewski JP, Risitano AM. Hematology Am Soc Hematol Educ Program. 2005:110-7.
BMT
uBMT;androgens, 2nd IST
Adequate blood count
Observation
Blood counts
Acquired AA
Severe Non-severe
Older adults
No family donor
ATG+CsA
R
Follow for relapse,late clonal ds
Allo-BMT;androgens, 2nd IST
Clinical status
ATG+CsA
R
CsA; androgen, 2nd IST
ATG+CsA
Clinical statusTx-
dependentChildren,
young adults
Age
Siblingmatch
HLA typing
Blood count improvement
at 3–6 mo
Non-R
Non-R Non-R
ATG = antithrombocyte globulin; CsA = ciclosporin; ds = disease; R = response; uBMT = unrelated bone marrow transplantations.
ATG
CyclophosphamideCyclosporin
Inhibition of T cell function
Proposed mechanisms through which ATG can interfere with the immune response
1) T-cell depletion in blood and lymphoid tissues through complement-dependent lysis and T-cell apoptosis
2) induction of B-cell apoptosis
3) modulation of cell-surface molecules (adhesion and chemokine receptors) that mediate leukocyte/endothelium interactions
4) Interference with DC functional properties (maturation and migration)
5) Induction of Treg and NK-T cells.
Morthy M. Leukemia 21:1387–1394, 2007
Comparative study of IST in AA
Treatment
(mg/kg/day)
No. of patients (SAA)
RR (CR+PR) Survival
(F/U duration)
German study
ATG+CsA (12)
ATG43 (31)
41 (29)
70%
46% p<0.05
64% (41 mon)
58% p=0.16
NIH ATG+CsA (12)
ATG51 (51)
70 (70)
67%
29% p=0.001
62% (3 yrs)
_
EBMT ATG+CsA (5)
CsA
54 (0)
61 (0)
74%
46% p=0.02
90% (6 mon)*
67% p=0.001
Korean
study
ATG+CsA (5)
ATG
53 (39)
40 (27)
41%
18% p=0.01
98% (6 mon)
90% p=0.16
Factors for predicting response of IST
● Young age● Presence of PNH clone● Higher reticulocyte count (>25x109/L)● Higher lymphocyte counts (>1x109/L)● Early treatment within 21 days after diagnosis● CsA therapeutic level/late tapering● HLA-DR15
Predictors for response to IST (n=324)
Kim SY et al, GENES, CHROMOSOMES & CANCER 49:844–850, 2010
Factors to predict relapse after IST
● Shorter telomeres● Rapid tapering of CsA : General recommendation is to taper CsA by 10% every month,
starting at least 1 year from IST (Sarraco et al, Br J Haematol 2008,
Marsh et al, Br J Haematol 2009)
● Suboptimal therapeutic range of CsA
Improving on ATG+CSA
● Addition of G-CSF
- improved neutrophil counts but similar response or survival
● Addition of other immunosuppressive drugs
+ High dose of methylprednisolone: toxicities ↑
+ MMF: no benefit (Scheinberg, 2006)
+ Rapamycin/sirolimus: not superior (Scheinberg, 2009)
Alternative immunosuppressive regimens
● Cyclophosphamide (CY)1) John’s Hopkins (Brodsky et al, 1996 & 2010)
- CY 50 mg/kg/d for 4d in 33 untreated SAA
- CR at 50 months; 65%, OS 86%
2) NIH trial (Tisdale et al, 2000 & 2002)
- CY (50 mg/kg/d for 4d) + CsA vs. ATG + CSA
- Response rate: 6/13 (46%) vs. 9/12 (75%)
- Higher fungal infection & death in CY arm
● Alemtuzumab 1) EBMT study : OR 58% (Risitano et al, Br J Haematol 2010)
2) NIH study : 10mg/d, IV for 10 days (Scheinberg et al, Blood 2012)
Refractory SAA (n=27) : OR 37%
Relapsed disease (n=25) : OR 56%
Treatment-naïve (n=16) : OR 19%
Moderate AA
● IST– Better survival with ATG + CyA than CyA alone
(Marsh, 1999)
● Daclizumab (humanized monoclonal Ab of IL-2 receptor)
- 16 AA : response 6/16 (38%) with little toxicity (Maciejewski, 2003)
● Androgen
- stimulate TERT expression via estrogen receptor
increase telomerase activity in lymphocytes and CD34+ cells
(Calado, 2005)
Various ATG preparations
● Horse ATG
- ATGAM® (40 mg/kg per day for 4 d)
- Lymphoglobuline® (15 mg/kg per day for 5 d)
● Rabbit ATG
- Thymoglobuline® (2.5~3.75mg/kg per day for 5 D)
- ATG-Fresenius® (5mg/kg/d for 5 D)
: inferior response to hATG (53% vs 78%, p=0.03),
5 yr-OS (66% vs 80%, p=0.002)
(Zheng et al, Exp Hematol 34:826, 2006)
Phase II prospective study from Cleveland
SAA treated with rabbit ATG (n=21) versus matched historical control treated with horse ATG (n=67).
Rabbit ATG : 3.5 mg/kg/day for 5 days Horse ATG: 40mg/kg/day for 4 days
Cyclosporine – maintain until response or developing renal complications.
Afable et al, Haematologica 96:1269, 2011
Type of ATG
n Early mortality
Response (%) Relapse (%)
3 months 6 months 12 months
Rabbit ATG 20 2 40 (CR: 0) 45 (CR: 0) 50 (CR: 0) 5
Horse ATG 67 6 55 (CR: 5) 58 (CR: 6) 58 (CR: 8) 16
p value 1.0 0.43 0.44 0.61 0.28
Atta et al, Annals of hematology. 89:851, 2010
Horse ATG Rabbit ATG p value
N 42 29
Partial response at 6 months 20 (47.6%) 8 (27.6%) 0.14
Complete response at 6 months 5 (11.9%) 2 (6.9%) 0.69
Overall response at 6 months 25 (59.5%) 10 (34.5%) 0.05
Interval between ATG and response (days) 99 (39-166) 88.5 (39-161)
0.98
Overall survival at 2 years 78.4% 55.4% 0.03
Relapse 9 (36%) 3 (30%) 1
A retrospective comparative study from Brazil
Rabbit ATG : 2.5 mg/kg (range, 1.5-3 mg/kg),
Horse ATG : 15 mg/kg (range, 10-21.4 mg/kg)
Randomized prospective study in NIH (n=120)
Rabbit ATG (3.5mg/kg for 5 days) vs Horse ATG (40mg/kg for 4 days)
Cyclosporine – continued for at least for 6 months
Scheinberg et al, NEJM 365:430, 2011
Response Horse ATG
Rabbit ATG
p
3 months 37 (62) 20 (33%) 0.002
6 months 41 (68%) 22 (37%) <0.001
Comparison of response between horse ATG (n=53) and rabbit ATG group (n=46) in SAA
Horse ATG (OR)Rabbit ATG (OR)Horse ATG (CR)Rabbit ATG (CR)
p value OR 0.319 0.834 0.925 0.757
CR 0.123 0.048 0.387 0.905
Shin, et al 2011 ASH #3430
Similar OS between rATG and hATG
P=0.46
Shin, et al 2011 ASH #3430
Lymphocytes depletion after ATG treatment
Scheinberg et al, NEJM 365:430, 2011
Lymphocytes depletion after ATG treatment
Scheinberg et al, NEJM 365:430, 2011
Comparison between horse and rabbit ATG
2.5mg/kg/d Х 5 days
3.5mg/kg/d Х 5 days
3.5mg/kg/d Х 5 days
3.5mg/kg/d Х 5 days
2.5mg/kg/d Х 5 days
n=22 n=67n=29 n=42 n=60 n=60 n=33 n=29 n=53 n=46
(1) Atta E, et al. Ann Hematol. 2010 89(9):851-9. (2) Sheinberg, et al. N Engl J Med. 2011 365(5):430-8.
(3) Chang M, et al. Eur J Haematol. 2010 84(2):154-9. (4) Afable M, et al. Haematologica. 2011 96(9):1269-75
(5) Shin, et al 2011 ASH #3430.
International Clinical Trial
● A prospective randomized multicenter study comparing different dosages of rabbit antithymocyte globulin (Thymoglobuline) in patients with severe aplastic anemia
● A total of 256 SAA patients will be enrolled, with 128 patients randomized to arm A (2.5mg/kg/d) and 128 patients to arm B (3.5mg/kg/d).
● Korea, Japan, China
Conclusions
1. For the last 20 years, the standard immunosuppressive regimen for AA patients has been ATG plus CsA, which results in response rates ranging between 50% and 60%, and even higher overall survival.
2. Response rates of rabbit ATG seem to be similar to horse ATG.
3. Thymoglobuline might need more time to reach the best response after IST in comparison to horse ATG.
4. CsA should be continued for at least 12 months after achieving
maximal hematological response, followed by a very slow tapering,
to reduce the risk of relapse.
5. Optimal dose of rabbit ATG to be determined.