Targeting the bone marrow

Transcription

1 Targeting the bone marrow 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

2 Why transplant? Improves the outcome for many haematological malignancies Autologous Allogeneic (donor) - myeloma - lymphoma - Acute Leukaemias - chronic leukaemias - myeloma - lymphoma

3 How to Transplant Conditioning Cytotoxic therapy Total body irradiation (TBI) Problem: - non-specific toxicity to organs

4 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

5 Toxicity and Dose Tumour cells surviving Lethal toxicity Toxicity low dose High dose Treatment dose

6 Toxicity and Dose Tumour cells surviving Lethal toxicity Toxicity low dose High dose Treatment dose

7 The bone marrow as target for therapy T B I

8 Toxicity of conditioning Acceptable Haematopoietic Unacceptable Gastro-intestinal - Mucositis - Diarrhoea Hepatic Renal Neurological Pulmonary

9 Manipulation of TBI to reduce toxicity dose fractionation shielding sensitive organs e.g. lungs lower dose transplant conditioning cgy - no TBI Targeted radiotherapy

10 Principles of targeted radiotherapy Vector e.g. monoclonal antibody Radioisotope gamma for imaging/dosimetry beta or alpha for therapy

11 Selection of therapeutic isotope Isotope half-life radiation energy (MeV) range(mm) Iodine d gamma+beta Yttrium d beta Rhenium d gamma+beta Rhenium hr gamma+beta Holmium d gamma+beta Bismuth-212 1hr alpha Astatine d alpha

12 Radionuclide selection: Iodine-131 vs Yttrium-90 Advantages of 131 I - published experience in BMT conditioning - easy to conjugate - preliminary dosimetry possible - relatively cheap and easily available Disadvantages of 131 I - Gamma emission high with therapeutic doses - problems with patient care, bloods, waste - relatively long physical t 1 / 2 (8 days)

13 Radionuclide selection: Iodine-131 vs Yttrium-90 Advantages of 90 Y - high beta emission (2.3 MeV vs 0.6 MeV for 131 I) - no gamma emission - less toxicity to non-haematological tissues - short physical t 1 / 2 (2.7 days) Disadvantages of 90 Y - conjugation chemistry difficult - high energy beta-particles may damage BM stroma - preliminary dosimetry difficult (Indium-111 substitutes)

14 Targeted Radiotherapy in Haematological Malignancies Radiation kills at a distance

15 Bone marrow as target

16 Bone marrow as target

17 Clinical study (Southampton) 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

18 CD66 antigen CEA family Glycoproteins Variable number of Ig domains several related glycoproteins CD66a-f CD66a,b,c,e expressed by myeloid series

19 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

20 Isothiocyanato-2-benzyl-3-methyldiethylenetriaminepentaacetic acid (ITC-2B3M-DTPA) ANTIBODY (lysine) N C N H CH 3 S N O C C O - N O - M - O - O - O C O C O C N Dr Syed Quadri O O

21 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 - ITLC/TLC/HPLC - LAL Administered to pt.

22 Preparation of labelled antibody DTPA-conjugated Ab Radiolabelled Ab + In-111 or Y-90 1 hr RT

23 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.

24 For autologous transplant (HD melphalan) D 22 to D 16 In-111 imaging Dosimetry Y-90 labelled Anti-CD66 Review, fbc HD Melphalan D 14 D 7 D 2 D 0 Autologous stem cells

25 For allogeneic transplantation D 22 to D 16 In-111 imaging Dosimetry Y-90 labelled Anti-CD66 Melphalan 120mg/m 2 Fludarabine 30mg/m 2 CAMPATH 1H 10mg/m 2 D 14 D 7 D 2 D 0 CyA 5mg/kg d 3 3mg/kg d 2 level ng/ml tailing from d +60 Allogeneic stem cells MTX d 3, 6, 11 10mg/m 2

26 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

27 Patients Phase I Ages: yrs (mean 54) M/F: 16M 4F Disease: Myeloma 18 AML 2 Transplant: Autologous 16 Allogeneic 4

28 Clinical results Infusion related toxicity In-111 or Y-90 None

29 Whole body data 24 hrs post infusion Anterior Posterior

30

31 Reconstructed 3D images

32 Whole body scan: activity remains in BM 1h 5h 22h 47h 120h Effective half- life = 50.5h

33 Cross-sectional image created from thoracic SPECT scan. Liver Bone marrow (vertebral body) spleen Ratio of activity: BM vs Liver 4:1

34 Organ dosimetry Phase I patients 90 Y dose level Bone marrow Liver Spleen MBq/kg Gy Gy Gy ± ± ± ± ± ± ± ± ± ± ± ± 1.8

35 Bone Marrow absorbed radiation dose and activity of infused 90 Y-labelled anti-cd66 BM absorbed radiation dose for each patient BM absorbed radiation dose in Gy Series Y-90 dose in MBq

36 BM Absorbed radiation dose in Gy at each yttrium-90 dose level BM Absorbed radiation dose in G y dose +/- 1 SD Yttrium-90 dose level in MBq/kg

37 Clinical results contd Leucocytes pre and post Y-90 labelled Ab Total leukocytes pre and post Y-90 labelled anti-cd66 Mab Dose level Dose level 1 1 (5 MBq/kg) 6 pati ent 4 pati ent 5 5 Wbc x 10e9/L pati ent 2 pati ent 1 pati ent week of study

38 Clinical results contd Leucocytes pre and post Y-90 labelled Ab Total leukocytes pre and post Y-90 labelled anti-cd66 Mab Dose level Dose level 2 (10 2 MBq/kg) 8 7 pati ent 8 6 Wbc x 1039/L pati ent 10 pati ent 7 pati ent 6 pati ent week of study

39 Clinical results contd Leucocytes pre and post Y-90 labelled Ab Total leukocyte count pre and post Y-90 therapy Dose Dose level level 33 (25 MBq/kg) bw011 bw012 bw013 bw014 bw015 8 wcc x10e9/l week of study

40 Clinical results contd Leucocytes pre and post Y-90 labelled Ab Total leukocyte count pre and post Y-90-Labelled anti-cd66 Dose Dose level level 44 (37.5 MBq/kg) Series1 Series2 Series3 Series4 Series week o f study

41 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

42 Engraftment Clinical results contd 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)

43 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 MBq/kg bw 016 MM PR CR 017 MM PR CR 018 MM PR CR 019 MM PR CR 020 MM PR PR

44 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

45 In vivo targeting of myeloma

46 Phase II Allogeneic reduced toxicity transplants 10 patients transplanted Ages: yrs (mean 57.7) Donor: Sibling 5; Unrelated donor 5 Indications: CML 2 AML 5 Myeloma 3

47 bw021 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

48 bw022 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 antigen mismatch Grade 2/3 mucositis Normal liver, renal function Engraftment: plt D + 23 neuts D + 24 Chimaerism 100% donor BCR-ABL PCR Negative

49 bw023 Mr AG 61 yr male AML diagnosed 2005 Not in CR after induction CR after salvage chemo Unrelated donor PBSCT Apr antigen mismatch Grade 2/3 mucositis Normal liver, renal function Engraftment: plts D + 20 neuts D + 13 Cutaneous GvHD (topical Rx) Chimaerism: 100% D 30

50 bw024 Mr ML 54 yr male Myeloma diagnosed 2004 Autologous PBSCT Sept 2005 Recurrent disease Sibling allo PBSCT June 2006 Grade 2 mucositis Normal liver, renal function Engraftment: plt D + 14 neut D nr Chimaerism 100% donor

51 bw025 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 Chimaerism 99% donor

52 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 Chimaerism 98% donor

53 bw027 Mr KL 45 yr male Relapsed MM 1 Ag mismatch VUD allo BM 21 st Sept 2006 Engraftment plt D + 12 neut D + 14 No fever minimal mucositis normal LFTs, renal function Chimaerism 100% donor

54 bw028 Mr FH 45 yr male Relapsed MM Sib allo PBSCT Engraftment plt D + 14 neut D + 14 Chimaerism d % donor

55 bw029 Mr KS 57 yr male Relapsed AML M2 VUD (full match) allo No mucositis No fever Engrafted Chimaerism 98% donor

56 Phase II patients - dosimetry Patient BM Liver post bw months bw months bw months bw months bw months bw months bw months bw months bw months Average

57 % Survival Targeted R/T OS n = Months

58 % Survival T argeted R/T EFS n = Months

59 Targeted radiotherapy with anti-cd66 Effectively delivers radiation to BM and spleen Up to 35 Gy to BM Summary 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

60 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

61 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

62 SUHT NHS Research and Development

63 The future for TBI?