Studies in 211 At Conjugation Chemistry

Transcription

1 Studies in 211 At Conjugation Chemistry Martin W. Brechbiel Radioimmune & Inorganic Chemistry Section Radiation ncology Branch, National Cancer Institute

2 The fall in dose at small radii outweighs the reduction in cell number, making it improbable that micrometastases can be eliminated solely by β -emitters targeted to the tumour cells. Nahum, A. Phys Med Bio 1996, 41, 1957

3

4 α vs β-particle Radioimmunotherapy α-particle μm range 5-8 MeV β-particle 1-10 mm range MeV Milenic, Brady, and Brechbiel Nature Rev. Drug Disc. 2004, 3, 488.

5 Periodic Table of the Elements Milenic, Brady, and Brechbiel Nature Rev. Drug Disc. 2004, 3, 488.

6 211 At Decay Chain 211 At 7.21 hr α 41.7 % EC 58.3% α 211 Po s 207 Bi 33.4 y β 207 Pb Stable

7 211 At Conjugation ptions Metal or Halogen? Chelated by: Thiols Phosphines DTPA Calixarene (R) 3 Sn X (CH 2 ) X C 2 Active

8 ur Favorite Instrumentation!

9 Synthesized Aryl Active Ester 211 At Linkers CR CR CR CR 211 At CH 3 CH 3 CH At CH At 211 At R denotes a hydroxysuccinimidyl ester Yordanov, A. T., et al, Nucl. Med. Biol. 2001, 28, 845.

10 Synthesized Aryl Active Ester 211 At Linkers A Representative Synthesis CH CCH 3 CCH 3 CH 3 H, H + Sn 2 Bu 6 1) H - CH 3 CH 3 PdPh 4 CH 3 2) H + Br Br SnBu 3 CH CR CR NHS, EDC 211 At, NCS CH 3 CH 3 CH 3 SnBu 3 SnBu At R denotes a hydroxysuccinimidyl ester Yordanov, A. T., et al, Nucl. Med. Biol. 2001, 28, 845.

11 Synthesized Non-Aryl Active Ester 211 At Linker Synthesis of SAPS NH 2 NH 2 N CH H Sn 2 Bu 6 NHS, EDC PdPh 4 Br SnBu 3 SnBu 3 N H CR N H CR 211 At, NCS SnBu At R denotes a hydroxysuccinimidyl ester 5 Yordanov, A. T., et al, Nucl. Med. Biol. 2001, 28, 845.

12 Comparative Blood Clearance of: (ο) Hu-anti-Tac- 125 I (direct labeling); (Δ) Hu-anti-Tac-1; ( ) Hu-anti-Tac-2; ( ) Hu-anti-Tac- 3; ( ) Hu-anti-Tac-5 (SAPS) in non-tumor bearing nude mice Time (hr) Yordanov, A. T., et al, Nucl. Med. Biol. 2001, 28, 845.

13 Comparative Blood Clearance of SAPS, SIPS, and Direct Iodination of Hu-anti-Tac in non-tumor bearing nude mice. ( ) SAPS; (Δ) SIPS; ( ) Direct iodination ( 125 I) Time (hr) Yordanov, A. T., et al, Nucl. Med. Biol. 2001, 28, 845.

14 (A) Comparative blood clearance of 211 At-labeled HAT vs 125 I-labeled HAT (SAPS vs SIPS). (B) The metabolism of simultaneously administered 125 I-labeled HAT and 211 At-labeled HAT in cynomolgus monkeys (SAPS vs SIPS). Wesley, J. N., et al, Nucl. Med. Biol. 2004, 31, 357.

15 Survival of cardiac allografts in cynomolgus monkeys None (controls), HAT, 212 Bi-labeled HAT 0.45mCi/kg on days 3 & 6 posttransplant (total dose of 0.90 mci/kg) or 211 At-labeled HAT at a dose of 0.06 mci/kg on days 2, 4, 7, & 9 (total dose 0.24 mci/kg) Wesley, J. N., et al, Nucl. Med. Biol. 2004, 31, 357.

16 The effect of 211 At-labeled HAT on leukocyte count/μlof blood following 211 At-labeled HAT administration Wesley, J. N., et al, Nucl. Med. Biol. 2004, 31, 357.

17 Biodistribution of 211 At 201B in BALB/c mice radiolabeled using SAPS hr. 2 hr. 4 hr. 8 hr. 24 hr %ID/g skin muscle bone uterus/ovaries stomach small intestine large intestine liver kidney spleen sternum thymus heart lung 0 blood Kennel, S. J., et al, Rad. Res. 2002, 157, 633.

18 BALB/c mice bearing EMT-6 lung colonies treated with vascular-targeted 211 At % survival A cold MAb 201B 5μ Ci 211 At-MAb 14 5μ Ci 211 At-MAb 201B Survival of mice (n = 10) injected i.v. with 10 4 EMT-6 cells treated on day 5 with 211 At MAb 201B, 37 kbq/μg; 211 At MAb 14, 23 kbq/μg; 211 At glycine mixed with cold MAb 201B at 37 kbq/μg; or 10 μg cold MAb 201B. B days 10μ Ci 211 At-MAb 201B Panel A shows the results from treatment with 185 kbq per animal. 80 % survival cold MAb 201B 10μ Ci 211 At-glycine 10μ Ci 211 At-control MAb 14 Panel B shows the results from treatment with 370 kbq per animal days Kennel, S. J., et al, Rad. Res. 2002, 157, 633.

19 Survival of karpas299 leukemia bearing SCID/ND mice treated with 211 At-7G7/B6. At day 20, sil-2r was undetectable in the 211 At-7G7/B6 treated group while in the control and 211 At- 11F11 groups sil-2r was 37,016 and 5,796 pg/ml, respectively. % of mice surviving Control At-7G7 At-11F Days after therapy Zhang, M., et al, Cancer Res. 2006, 66, 8227.

20 Therapeutic study of 211 At-HeFi-1 or unmodified HeFi-1 or their combination in the karpas299 leukemia model. (A)Kaplan Meier survival plot of the karpas299 leukemia-bearing SCID/ND mice. (B) Serum sil-2r levels of the karpas299 leukemia-bearing SCID/ND mice at day 26 after therapy. Zhang, M., et al, PNAS 2007, 104, 8444.

21 Therapeutic study of 90 Y-HeFi-1 in the SUDHL-1 model. (A)Tumor volume. (B) Kaplan Meier survival plot of the SUDHL-1-bearing nude mice. Zhang, M., et al, PNAS 2007, 104, 8444.

22 %ID/mL A Pharmacokinetics of 211 At- and 125 I- labeled Herceptin using athymic mice bearing LS-174T xenografts coinjected (i.v.) with the appropriate pair of 211 At- (~3.5 or 6 μci) and 125 I- labeled (~1μCi) Herceptin. %ID/mL B Herceptin was labeled with 211 At using Methyl-SAPS ( ) or SAPS ( ) and with 125 I using Methyl-SIPS ( ) or SIPS (Δ). Panel A presents the first 2 hr of the study while Panel B illustrates the entire 48 h Time (hr) Talanov, V. S., et al, Nucl. Med. Biol. 2006, 33, 469.

23 211 At-SAPS-C6.5 Diabody Therapy of s.c. MDA-MB361 Breast Carcinoma Xenografts Percent of Initial Tumor Volume x Controls uci 30 uci 45 uci Tumor Age in Days

24 Synthesized Non-Aryl Active Ester 211 At Linker Synthesis of SAPS Side-product! N H C 2 H NHS, EDCI N H C 2 N N SnBu 3 SnBu 3 SnBu 3 Talanov, V. S., et al, Nucl. Med. Biol. 2006, 33, 469.

25 Synthesis of Succinimidyl N-2-(4-tributylstannylphenethyl)- N-methyl succinamate for Radio-iodination and Astatination H 1. (CCl) 2 NHMe BH 3 THF NHMe Br 2. MeNH 2 Br Br (SnBu 3 ) 2 [Pd] Bu 3 Sn NHMe NHS, EDCI Bu 3 Sn N Me C 2 N Talanov, V. S., et al, Nucl. Med. Biol. 2006, 33, 469.

26 Effect of long-term storage at -15 o C on radiolabeling yield ( 211 At) to Form SAPS ( ) and N-Methyl-SAPS ( ) %Yield SAPS N -Methyl SAPS Days in Storage Talanov, V. S., et al, Nucl. Med. Biol. 2006, 33, 469.

27 Synthesis of Aryl Active Ester 211 At Linkers with Donor Heteroatoms C 2 H C 2 Me C 2 Me C 2 Me C 2 N a b c d Me I I CH 2 Br I CH 2 XMe SnBu 3 CH 2 XMe SnBu 3 CH 2 XMe 1 2: X = 3: X=S 4: X = 5: X = S 6: X = 7: X = S Talanov, V. S., et al, Nucl. Med. Biol. 2004, 31, 1061.

28 Therapy of Disseminated Intraperitoneal Disease with mab Targeted α-emitter Radiation Therapy ( 212 Pb, 213 Bi, 211 At) Animal Model: i.p. tumors created by inoculation with LS-174T cells. Therapy at either 3 post-inoculation. Controls die at ~ days. Trastuzumab, cetuximab, and panitumumab bind to this cell line.

29 Treatment of Disseminated Intraperitoneal Disease with Herceptin Targeted α-emitter Radiation Therapy ( 212 Pb, 213 Bi, 211 At) Targeting Vectors: Cetuximab, targets the epidermal growth factor receptor (EGFR), a transmembrane glycoprotein receptor, has been approved to treat metastatic colorectal and H&N cancer. Trastuzumab, a humanized antibody to ErbB2 (HER2), has been approved to treat breast cancer. Panitumumab, a humanized antibody to epidermal growth factor receptor (EGFR), has been approved treat metastatic colorectal cancer.

30 Survival of Athymic Mice Bearing i.p. LS-174T Xenografts Treated with 213 Bi-CHX-A"-trastuzumab i.p. 1.2 Surviving Fraction Control 250 μci trastuzumab 500 μci trastuzumab 750 μci trastuzumab 500 μci HuIgG Days Post-Tumor Implantation Milenic, et. al., Clin. Cancer Res. 2004, 10,7712.

31 Percent Surviving Survival of Mice Bearing 5 Day Human Colon Carcinoma Xenografts (LS-174T; i.p.) Following i.p. Treatment with 212 Pb-TCMC-Labeled trastuzumab Control (n=8) trastuzzumab 7 μci (n=4) trastuzumab 13 μci (n=4) trastuzumab 20 μci (n=4) trastuzumab 40 μci (n=4) trastuzumab 60 μci (n=3) HuIgG 20 μci (n=3) HuIgG 60 μci (n=3) HuIgG 100 μci (n=3) Days Post mab Treatment RIT-3 Milenic, et. al., Cancer Biother. Radiopharm. 2005, 20, 557.

32 Survival of Athymic Mice Bearing Human Colon Carcinoma Xenografts (LS-174T; i.p.) Following a Single Administration of 212 Pb-Labeled cetuximab Percent Surviving Control 10 μci cetuximab 20 μci cetuximab 30 μci cetuximab 40 μci cetuximab 10 μci HuIgG 20 μci HuIgG 30 μci HuIgG 40 μci HuIgG Days Post Tumor Implantation

33 Survival of Athymic Mice Bearing Human Colon Carcinoma Xenografts (LS-174T; i.p.) Following a Single 10 μci Administration of 212 Pb-Labeled mabs Percent Surviving Days Post Tumor Implantation Control trastuzumab cetuximab panitumumab HuIgG

34 Survival of Athymic Mice Bearing Human Colon Carcinoma Xenografts (LS-174T; i.p.) Following a Single Administration of GEM 24 hr before 10 μci of 212 Pb-Labeled cetuximab Percent Surviving Days Post Tumor Implantation Control GEM cetuximab cetuximab & GEM HuIgG HuIgG & GEM

35 STATUS & CNCLUSINS Re-synthesizing and validating N-Methyl SAPS precursor!! Pre-clinical studies planned: 211 At MTD determination with trastuzumab 211 At MTD determination with cetuximab 211 At MTD determination with panitumumab Combination and Multi-dosing Studies

36 Radioimmune & Inorganic Chemistry Section RB, CCR, NCI Martin W. Brechbiel, Ph.D. Kayhan Garmestani, Ph.D. Kwamena Baidoo, Ph.D. Tapan Nayak, Ph.D. Kido Nwe, Ph.D. Aaron Villaraza, Ph.D Diane Milenic, M.S. Ambika Bumb xford/marshall/nci

37

38 Give me the power to destroy Give me a radioactive toy!

39

40 Slides Prepared by JKB Enterprises A Carrot at the End of the Tunnel Production