targeted radiotherapy with an anti-cd66 monoclonal antibody in haematopoietic stem ... · ·...

Targeted Radiotherapy with an anti-CD66

monoclonal antibody in haematopoietic

stem cell transplantation:

Therapy intensification

without toxicity

Kim Orchard

Southampton University Hospital Medical School and Trust

Targeting the bone marrow

Why transplant?

Improves the outcome for many haematological malignancies

• Autologous - myeloma - lymphoma

• Allogeneic - Acute Leukaemias (donor) - chronic leukaemias

- myeloma - lymphoma

How to Transplant

• Conditioning

– Cytotoxic therapy

– Total body irradiation (TBI)

Problem:

- non-specific toxicity to organs

Role of radiation therapy in

transplantation

� Haematological malignancies are radiosensitive

� Radiotherapy provides effective disease eradication

and immunosuppression

� Dose escalation of radiotherapy increases disease

eradication

BUT: dose escalation increases treatment toxicity

Toxicity and Dose

Toxicity

Treatment dose

Lethal toxicity

‘low dose’ ‘High dose’

Tumour cells surviving

The bone marrow as target for therapy

T

B

I

Toxicity of conditioning

Acceptable

• Haematopoietic

Unacceptable

• Gastro-intestinal

- Mucositis- Diarrhoea

• Hepatic

• Renal

• Neurological

• Pulmonary

Manipulation of TBI to reduce toxicity

• dose fractionation

• shielding sensitive organs

e.g. lungs

• lower dose transplant conditioning

- 200 cGy

- no TBI

Targeted radiotherapy

Principles of targeted radiotherapy

• Vector e.g. monoclonal antibody

• Radioisotope gamma for imaging/dosimetry

beta or alpha for therapy

Selection of therapeutic isotope

Isotope half-life radiation energy (MeV) range(mm)

Iodine-131 8.1d gamma+beta 0.6 0.8

Yttrium-90 2.7d beta 2.3 2.7

Rhenium-186 3.8d gamma+beta 1.1 1.1

Rhenium-188 17hr gamma+beta 2.1 2.4

Holmium-166 1.1d gamma+beta 1.9 2.2

Bismuth-212 1hr alpha 6.1 0.04-0.1

Astatine-211 7.2d alpha 5.9 0.04-0.1

Radionuclide selection: Iodine-131 vs Yttrium-90

Advantages of 131I

- published experience in BMT conditioning

- ‘easy’ to conjugate

- preliminary dosimetry possible

- relatively cheap and easily available

Disadvantages of 131I

- Gamma emission high with therapeutic doses

- problems with patient care, bloods, waste

- relatively long physical t1/2 (8 days)

Radionuclide selection: Iodine-131 vs Yttrium-90

Advantages of 90Y

- high beta emission (2.3 MeV vs 0.6 MeV for 131I)

- no gamma emission

- less toxicity to non-haematological tissues

- short physical t 1/2 (2.7 days)

Disadvantages of 90Y

- conjugation chemistry difficult

- high energy beta-particles may damage BM stroma

- preliminary dosimetry difficult

(Indium-111 substitutes)

Targeted Radiotherapy in Haematological Malignancies

Radiation kills at a distance

Bone marrow as target

Vector - Anti-CD66

Isotopes - In-111 imaging

- Y-90 therapy

Phase I - radiation dose escalation

- 5, 10, 25, 37.5 MBq/kg bw

Phase II - set radiation dose at MTD

Clinical study (Southampton)

CD66 antigen

CEA family

Glycoproteins

Variable number of Ig domains

several related

glycoproteins CD66a-f

CD66a,b,c,e expressed by

myeloid series

Vector:

Anti-CD66

murine IgG1 monoclonal Ab

binds to common epitope on CD66a,b,c,e

manufactured to GMP

conjugated to bifunctional chelator

single patient dose vials

Isothiocyanato-2-benzyl-3-methyl-

diethylenetriaminepentaacetic acid

(ITC-2B3M-DTPA)

N

N

C

O

O-

C

O

O-

M

C O

-O

ANTIBODY

N

C

O-O

C

O

-O

NH

CN

S

CH3

(lysine)

Dr Syed Quadri

Targeted radiotherapy flow diagram 1

Antibody prep Patient prep

- purified Candidate pts.

- viral inact’n - initial discussion

- QC - patient info sheet

- second discussion

Conjugated to DTPA

- HPLC - consent

- immunoreactivity

- Scatchard plot

- LAL on bulk

- microbiological screen Pre-study tests

- protein assay

Conjugated antibody stored

in single patient dose vials

Dry-run labelling x2

- ITLC/TLC/HPLC

- LAL

Labelling for patient Administered to pt.

- ITLC/TLC/HPLC

- LAL

Preparation of labelled antibody

1 hr RT

DTPA-conjugated Ab Radiolabelled Ab

+ In-111

or Y-90

Patient selection:

Autologous or allogeneic (sibling or VUD) transplant for

an underlying haematological malignancy

- AML in CR1 but with poor prognostic features

- AML > CR1 or in relapse

- ALL

- transformed myelodysplasia

- CML (AP, BT, poor response to Glivec)

- multiple myeloma.

Patients may be in remission, PR or relapse.

For autologous transplant (HD melphalan)

D –14 D –7 D –2 D 0

Y-90 labelled

Anti-CD66Review, fbc HD Melphalan

Autologous stem cells

D –22 to D –16 In-111 imaging Dosimetry

For allogeneic transplantation

D –14 D –7 D –2 D 0

Y-90 labelled

Anti-CD66

Fludarabine 30mg/m2

CAMPATH 1H 10mg/m2

Melphalan 120mg/m2

Allogeneic stem cells

D –22 to D –16 In-111 imaging Dosimetry

CyA 5mg/kg d –3

3mg/kg d –2

level 100-150 ng/ml

tailing from d +60

MTX d 3, 6, 11 10mg/m2

Dosimetry

• Whole body quantitative gamma imaging

D 1, 2, 4, 5

• SPECT of thorax and pelvis

• Serial blood sampling – blood clearance

• BM biopsy D 2

PatientsPhase I

Ages: 21 – 67 yrs (mean 54)

M/F: 16M 4F

Disease: Myeloma 18

AML 2

Transplant: Autologous 16

Allogeneic 4

Clinical results

Infusion related toxicity

In-111 or Y-90

None

Whole body data

24 hrs post infusion

Anterior Posterior

Reconstructed 3D images

Whole body scan: activity remains in BM

1h1h 5h5h

22h22h 47h47h

120h120h

Effective halfEffective half--

life = 50.5hlife = 50.5h

Cross-sectional image created from

thoracic SPECT scan.

Bone marrow

(vertebral body)

Liver

spleen

Ratio of activity: BM vs Liver 4:1

5.3 ± 1.87.75 ± 2.124.32 ± 4.337.5

12.55 ± 6.33.66 ± 1.215.56 ± 2.025

2.38 ± 1.641.30 ± 0.49.14 ± 1.610

1.14 ± 0.41.40 ± 0.44.14 ± 1.65

GyGyGy

SpleenLiverBone marrow90Y dose

level

MBq/kg

Organ dosimetry

Phase I patients

Bone Marrow absorbed radiation dose and

activity of infused 90Y-labelled anti-CD66

BM absorbed radiation dose for each patient

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

0 500 1000 1500 2000 2500 3000

Y-90 dose in MBq

BM absorbed radiation

dose in Gy

Series1

BM Absorbed radiation dose

in Gy at each yttrium-90 dose level

0

5

10

15

20

25

30

0 5 10 15 20 25 30 35

Yttrium-90 dose level in MBq/kg

BM Absorbed radiation

dose in Gy

dose +/- 1 SD

Clinical results contd

Total leukocytes pre and post Y-90 labelled anti-CD66 Mab

Dose level 1 (5 MBq/kg)

0

1

2

3

4

5

6

1 2 3

week of study

Wbc x 10e9/L

pat i ent 1

pat i ent 2

pat i ent 3

pat i ent 4

pat i ent 5

Leucocytes pre and post Y-90 labelled Ab



Total leukocytes pre and post Y-90 labelled anti-CD66 Mab


0

1

2

3

4

5

6

7

8

1 2 3

week of study

Wbc x 1039/L

pat i ent 6

pat i ent 7

pat i ent 8

pat i ent 9

pat i ent 10



Total leukocyte count pre and post Y-90 therapy


0

2

4

6

8

10

12

1 2 3week of study

wcc x10e9/l

bw011

bw012

bw013

bw014

bw015




Total leukocyte count pre and post Y-90-Labelled anti-CD66

Dose level 4 (37.5 MBq/kg)

0

1

2

3

4

5

6

7

1 2 3

week o f study

Series1

Ser ies2

Ser ies3

Ser ies4

Ser ies5


Dose level 4 (37.5 MBq/kg)


Toxicities

Haematological: 20/20 grade 3 - 4

GI:

mucositis 8/20 grade 1

5/20 grade 2

5/20 grade 3

diarrhoea 12/20 grade 2 – 3

No worse than anticipated for standard

transplant conditioning

No SAEs


Engraftment

19/20 full engraftment

(1 patient delayed platelet engraftment)

Neuts > 0.5 mean 13.8 days (11 – 22)

Plts > 50 mean 12.7 days (10 – 22)

Clinical responses

Radiation level 1

5 MBq/kg bw 001 MM PR PR

002 MM PR PR

003 MM PR CR

004 MM PR PR

005 MM PR PR

Radiation level 2

10 MBq/kg bw 006 MM CR CR

007 MM PR PR

008 AML CR mini allo CR

009 AML CR mini-allo CR

010 MM PR CR

Radiation level 3

25 MBq/kg bw 011 MM CR CR

012 MM PR CR

013 MM PR mini-allo CR

014 MM CR mini-allo CR

015 MM PR CR

Radiation level 4

37.5 MBq/kg bw 016 MM PR CR

017 MM PR CR

018 MM PR CR

019 MM PR CR

020 MM PR PR

Proposed study 1

• Phase II trial (randomised 2 arm)

• RIT with HD melphalan

• Cohort of patients with Myeloma (45)

• 4 centres participating

– Southampton

– Bart’s

– Birmingham

– Mainz

Funded by the Leukaemia Research Fund £250,000

In vivo targeting of

myeloma

Phase II

10 patients transplanted

Ages: 21-62 yrs (mean 57.7)

Donor: Sibling 5; Unrelated donor 5

Indications: CML 2

AML 5

Myeloma 3

Allogeneic reduced toxicity transplants

Mr CG

63 yr male

CML diagnosed 2003

Chronic phase

Poor response to Glivec

Sib allo PBSCT May 2006

Grade 3 mucositis

Normal renal, liver tests

Engraftment: neut D + 15

plts D + 18

Chimaerism 100% donor

BCR-ABL negative

bw021

Mr RO

61 yr male

CML diagnosed 1999

Accelerated phase 2003

Autologous PBSCT 2003 (Poole)

Co-morbid problems:

low transfer factor

poor exercise tolerance

Unrelated donor PBSCT Feb 2006

1 antigen mismatch

Grade 2/3 mucositis

Normal liver, renal function

Engraftment: plt D + 23

neuts D + 24


BCR-ABL PCR Negative

bw022

Mr AG

61 yr male

AML diagnosed 2005

Not in CR after induction

CR after salvage chemo

Unrelated donor PBSCT Apr 2006

1 antigen mismatch

Grade 2/3 mucositis


Engraftment: plts D + 20

neuts D + 13

Cutaneous GvHD (topical Rx)

Chimaerism: 100% D 30

bw023

Mr ML

54 yr male

Myeloma diagnosed 2004

Autologous PBSCT Sept 2005

Recurrent disease

Sibling allo PBSCT June 2006

Grade 2 mucositis


Engraftment: plt D + 14

neut D nr


bw024

Mr JK

22 yr male

Secondary AML diagnosed Nov 2005

HD age 10 yr

upper mantle DXT

relapse

APBSCT age 12 yr

Unrelated donor PBSCT

July 2006

Engraftment plt D +15

neut D + 16


bw025

bw026 Mr KG

55 yr male

Previous MI, x4 CABG

Secondary AML (MDS)

Sibling allo PBSCT

Aug 2006

Engraftment plt D +16

neut D +14


Mr KL

45 yr male

Relapsed MM

1 Ag mismatch VUD allo BM

21st Sept 2006

Engraftment

plt D + 12

neut D + 14

No fever

minimal mucositis

normal LFTs, renal function


bw027

Mr FH

45 yr male

Relapsed MM

Sib allo PBSCT 25.10.2006

Engraftment plt D + 14

neut D + 14

Chimaerism d + 30

- 100% donor

bw028

bw029 Mr KS

57 yr male

Relapsed AML M2

VUD (full match) allo

14.12.06

No mucositis

No fever

Engrafted


11 months4.423.3bw029

12 months4.829.6bw028

13 months9.931.0bw027

14 months4.528.1bw026

15 months3.434.5bw025

16 months10.526.8bw024

19 months10.228.3bw023

21 months5.227.9bw022

18 months4.519.5bw021

postLiverBMPatient

Phase II patients - dosimetry

6.427.7Average

Targeted R/T OSn = 13

0 12 24 36 48 600

10

20

30

40

50

60

70

80

90

100

Months

% Survival

Targeted R/T EFSn = 13

0 12 24 36 48 600

10

20

30

40

50

60

70

80

90

100

Months

% Survival

Targeted radiotherapy with anti-CD66

• Effectively delivers radiation to BM and

spleen

• Up to 35 Gy to BM

• 2-10 fold excess to BM and spleen vs other

organs

• Linear relationship between infused dose of

Y-90 and radiation dose delivered to BM

Summary

Targeted radiotherapy with anti-CD66

• Phase I dose escalation completed

- No increased toxicity

- MTD not reached

• Phase II progressing

• Multi-centre randomised phase II

Summary

Targeted radiotherapy for BMT conditioning

Southampton TheraPharm (Germany)

Nuclear Medicine Dr Maria Tristam Dr Silke Thomsen

and Med Physics Sr Louise Causer Dr Ivan Benes

John Langford

Oncology Prof Peter Johnson

Radiopharmacy James Thom Mainz Dr Ralf Meyer

Clive Jenkins Dr Wolgang Herr

Dr Andreas Helish

St Bart’s

Nuclear Medicine Dr. Maggie Cooper Acknowledgements

Prof. Grant Prentice

Prof John Goldman

USA (Arlington) Dr. Paul Borchardt

Dr. Syed Quadri

Patients participating in study

Staff of Wessex Blood and Marrow Transplantation Unit

SUHT NHS Research and Development

The future for TBI?

targeted radiotherapy with an anti-cd66 monoclonal antibody in haematopoietic stem ... · ·...

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