Abstract
Targeted radiopharmaceutical therapy (TRT) using α-particle radiation is a promising approach for treating both large and micrometastatic lesions. We developed prostate-specific membrane antigen (PSMA)–targeted low-molecular-weight agents for 212Pb-based TRT of patients with prostate cancer (PC) by evaluating the matching γ-emitting surrogate, 203Pb. Methods: Five rationally designed low-molecular-weight ligands (L1-L5) were synthesized using the lysine-urea-glutamate scaffold, and PSMA inhibition constants were determined. Tissue biodistribution and SPECT/CT imaging of 203Pb-L1–203Pb-L5 were performed on mice bearing PSMA(+) PC3 PIP and PSMA(−) PC3 flu flank xenografts. The absorbed radiation dose of the corresponding 212Pb-labeled analogs was determined using the biodistribution data. Antitumor efficacy of 212Pb-L2 was evaluated in PSMA(+) PC3 PIP and PSMA(−) PC3 flu tumor models and in the PSMA(+) luciferase-expressing micrometastatic model. 212Pb-L2 was also evaluated for dose-escalated, long-term toxicity. Results: All new ligands were obtained in high yield and purity. PSMA inhibitory activities ranged from 0.10 to 17 nM. 203Pb-L1–203Pb-L5 were synthesized in high radiochemical yield and specific activity. Whole-body clearance of 203Pb-L1–203Pb-L5 was fast. The absorbed dose coefficients (mGy/kBq) of the tumor and kidneys were highest for 203Pb-L5 (31.0, 15.2) and lowest for 203Pb-L2 (8.0, 4.2). The tumor-to-kidney absorbed dose ratio was higher for 203Pb-L3 (3.2) and 203Pb-L4 (3.6) than for the other agents, but with lower tumor-to-blood ratios. PSMA(+) tumor lesions were visualized through SPECT/CT as early as 0.5 h after injection. A proof-of-concept therapy study with a single administration of 212Pb-L2 demonstrated dose-dependent inhibition of tumor growth in the PSMA(+) flank tumor model. 212Pb-L2 also demonstrated an increased survival benefit in the micrometastatic model compared with 177Lu-PSMA-617. Long-term toxicity studies in healthy, immunocompetent CD-1 mice revealed kidney as the dose-limiting organ. Conclusion: 203Pb-L1–203Pb-L5 demonstrated favorable pharmacokinetics for 212Pb-based TRT. The antitumor efficacy of 212Pb-L2 supports the corresponding 203Pb/212Pb theranostic pair for PSMA-based α-particle TRT in advanced PC.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 80-88 |
| Number of pages | 9 |
| Journal | Journal of Nuclear Medicine |
| Volume | 61 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2020 |
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Keywords
- Lead-212
- Murine pharmacokinetics
- Prostate-specific membrane antigen
- Theranostic pair
- α-particle
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
Cite this
Preclinical evaluation of 203/212Pb-labeled low-molecular-weight compounds for targeted radiopharmaceutical therapy of prostate cancer. / Banerjee, Sangeeta Ray; Minn, Il; Kumar, Vivek; Josefsson, Anders; Lisok, Ala; Brummet, Mary; Chen, Jian; Kiess, Ana P.; Baidoo, Kwamena; Brayton, Cory; Mease, Ronnie C.; Brechbiel, Martin; Sgouros, George; Hobbs, Robert F.; Pomper, Martin G.
In: Journal of Nuclear Medicine, Vol. 61, No. 1, 01.2020, p. 80-88.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Preclinical evaluation of 203/212Pb-labeled low-molecular-weight compounds for targeted radiopharmaceutical therapy of prostate cancer
AU - Banerjee, Sangeeta Ray
AU - Minn, Il
AU - Kumar, Vivek
AU - Josefsson, Anders
AU - Lisok, Ala
AU - Brummet, Mary
AU - Chen, Jian
AU - Kiess, Ana P.
AU - Baidoo, Kwamena
AU - Brayton, Cory
AU - Mease, Ronnie C.
AU - Brechbiel, Martin
AU - Sgouros, George
AU - Hobbs, Robert F.
AU - Pomper, Martin G.
PY - 2020/1
Y1 - 2020/1
N2 - Targeted radiopharmaceutical therapy (TRT) using α-particle radiation is a promising approach for treating both large and micrometastatic lesions. We developed prostate-specific membrane antigen (PSMA)–targeted low-molecular-weight agents for 212Pb-based TRT of patients with prostate cancer (PC) by evaluating the matching γ-emitting surrogate, 203Pb. Methods: Five rationally designed low-molecular-weight ligands (L1-L5) were synthesized using the lysine-urea-glutamate scaffold, and PSMA inhibition constants were determined. Tissue biodistribution and SPECT/CT imaging of 203Pb-L1–203Pb-L5 were performed on mice bearing PSMA(+) PC3 PIP and PSMA(−) PC3 flu flank xenografts. The absorbed radiation dose of the corresponding 212Pb-labeled analogs was determined using the biodistribution data. Antitumor efficacy of 212Pb-L2 was evaluated in PSMA(+) PC3 PIP and PSMA(−) PC3 flu tumor models and in the PSMA(+) luciferase-expressing micrometastatic model. 212Pb-L2 was also evaluated for dose-escalated, long-term toxicity. Results: All new ligands were obtained in high yield and purity. PSMA inhibitory activities ranged from 0.10 to 17 nM. 203Pb-L1–203Pb-L5 were synthesized in high radiochemical yield and specific activity. Whole-body clearance of 203Pb-L1–203Pb-L5 was fast. The absorbed dose coefficients (mGy/kBq) of the tumor and kidneys were highest for 203Pb-L5 (31.0, 15.2) and lowest for 203Pb-L2 (8.0, 4.2). The tumor-to-kidney absorbed dose ratio was higher for 203Pb-L3 (3.2) and 203Pb-L4 (3.6) than for the other agents, but with lower tumor-to-blood ratios. PSMA(+) tumor lesions were visualized through SPECT/CT as early as 0.5 h after injection. A proof-of-concept therapy study with a single administration of 212Pb-L2 demonstrated dose-dependent inhibition of tumor growth in the PSMA(+) flank tumor model. 212Pb-L2 also demonstrated an increased survival benefit in the micrometastatic model compared with 177Lu-PSMA-617. Long-term toxicity studies in healthy, immunocompetent CD-1 mice revealed kidney as the dose-limiting organ. Conclusion: 203Pb-L1–203Pb-L5 demonstrated favorable pharmacokinetics for 212Pb-based TRT. The antitumor efficacy of 212Pb-L2 supports the corresponding 203Pb/212Pb theranostic pair for PSMA-based α-particle TRT in advanced PC.
AB - Targeted radiopharmaceutical therapy (TRT) using α-particle radiation is a promising approach for treating both large and micrometastatic lesions. We developed prostate-specific membrane antigen (PSMA)–targeted low-molecular-weight agents for 212Pb-based TRT of patients with prostate cancer (PC) by evaluating the matching γ-emitting surrogate, 203Pb. Methods: Five rationally designed low-molecular-weight ligands (L1-L5) were synthesized using the lysine-urea-glutamate scaffold, and PSMA inhibition constants were determined. Tissue biodistribution and SPECT/CT imaging of 203Pb-L1–203Pb-L5 were performed on mice bearing PSMA(+) PC3 PIP and PSMA(−) PC3 flu flank xenografts. The absorbed radiation dose of the corresponding 212Pb-labeled analogs was determined using the biodistribution data. Antitumor efficacy of 212Pb-L2 was evaluated in PSMA(+) PC3 PIP and PSMA(−) PC3 flu tumor models and in the PSMA(+) luciferase-expressing micrometastatic model. 212Pb-L2 was also evaluated for dose-escalated, long-term toxicity. Results: All new ligands were obtained in high yield and purity. PSMA inhibitory activities ranged from 0.10 to 17 nM. 203Pb-L1–203Pb-L5 were synthesized in high radiochemical yield and specific activity. Whole-body clearance of 203Pb-L1–203Pb-L5 was fast. The absorbed dose coefficients (mGy/kBq) of the tumor and kidneys were highest for 203Pb-L5 (31.0, 15.2) and lowest for 203Pb-L2 (8.0, 4.2). The tumor-to-kidney absorbed dose ratio was higher for 203Pb-L3 (3.2) and 203Pb-L4 (3.6) than for the other agents, but with lower tumor-to-blood ratios. PSMA(+) tumor lesions were visualized through SPECT/CT as early as 0.5 h after injection. A proof-of-concept therapy study with a single administration of 212Pb-L2 demonstrated dose-dependent inhibition of tumor growth in the PSMA(+) flank tumor model. 212Pb-L2 also demonstrated an increased survival benefit in the micrometastatic model compared with 177Lu-PSMA-617. Long-term toxicity studies in healthy, immunocompetent CD-1 mice revealed kidney as the dose-limiting organ. Conclusion: 203Pb-L1–203Pb-L5 demonstrated favorable pharmacokinetics for 212Pb-based TRT. The antitumor efficacy of 212Pb-L2 supports the corresponding 203Pb/212Pb theranostic pair for PSMA-based α-particle TRT in advanced PC.
KW - Lead-212
KW - Murine pharmacokinetics
KW - Prostate-specific membrane antigen
KW - Theranostic pair
KW - α-particle
UR - http://www.scopus.com/inward/record.url?scp=85077401317&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85077401317&partnerID=8YFLogxK
U2 - 10.2967/jnumed.119.229393
DO - 10.2967/jnumed.119.229393
M3 - Article
C2 - 31253744
AN - SCOPUS:85077401317
VL - 61
SP - 80
EP - 88
JO - Journal of Nuclear Medicine
JF - Journal of Nuclear Medicine
SN - 0161-5505
IS - 1
ER -