| 1. |
- Abouzayed, Ayman, et al.
(författare)
-
Preclinical Evaluation of 99mTc-Labeled GRPR Antagonists maSSS/SES-PEG2-RM26 for Imaging of Prostate Cancer
- 2021
-
Ingår i: Pharmaceutics. - : MDPI. - 1999-4923. ; 13:2
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Gastrin-releasing peptide receptor (GRPR) is an important target for imaging of prostate cancer. The wide availability of single-photon emission computed tomography/computed tomography (SPECT/CT) and the generator-produced 99mTc can be utilized to facilitate the use of GRPR-targeting radiotracers for diagnostics of prostate cancers.Methods: Synthetically produced mercaptoacetyl-Ser-Ser-Ser (maSSS)-PEG2-RM26 and mercaptoacetyl-Ser-Glu-Ser (maSES)-PEG2-RM26 (RM26 = d-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2) were radiolabeled with 99mTc and characterized in vitro using PC-3 cells and in vivo, using NMRI or PC-3 tumor bearing mice. SPECT/CT imaging and dosimetry calculations were performed for [99mTc]Tc-maSSS-PEG2-RM26.Results: Peptides were radiolabeled with high yields (>98%), demonstrating GRPR specific binding and slow internalization in PC-3 cells. [99mTc]Tc-maSSS-PEG2-RM26 outperformed [99mTc]Tc-maSES-PEG2-RM26 in terms of GRPR affinity, with a lower dissociation constant (61 pM vs 849 pM) and demonstrating higher tumor uptake. [99mTc]Tc-maSSS-PEG2-RM26 had tumor-to-blood, tumor-to-muscle, and tumor-to-bone ratios of 97 ± 56, 188 ± 32, and 177 ± 79, respectively. SPECT/CT images of [99mTc]Tc-maSSS-PEG2-RM26 clearly visualized the GRPR-overexpressing tumors. The dosimetry estimated for [99mTc]Tc-maSSS-PEG2-RM26 showed the highest absorbed dose in the small intestine (1.65 × 10−3 mGy/MBq), and the effective dose is 3.49 × 10−3 mSv/MBq.Conclusion: The GRPR antagonist maSSS-PEG2-RM26 is a promising GRPR-targeting agent that can be radiolabeled through a single-step with the generator-produced 99mTc and used for imaging of GRPR-expressing prostate cancer.
|
|
| 2. |
- Abouzayed, Ayman, et al.
(författare)
-
The GRPR Antagonist [Tc-99m]Tc-maSSS-PEG(2)-RM26 towards Phase I Clinical Trial : Kit Preparation, Characterization and Toxicity
- 2023
-
Ingår i: Diagnostics. - : MDPI AG. - 2075-4418. ; 13:9, s. 1611-
-
Tidskriftsartikel (refereegranskat)abstract
- Gastrin-releasing peptide receptors (GRPRs) are overexpressed in the majority of primary prostate tumors and in prostatic lymph node and bone metastases. Several GRPR antagonists were developed for SPECT and PET imaging of prostate cancer. We previously reported a preclinical evaluation of the GRPR antagonist [Tc-99m]Tc-maSSS-PEG2-RM26 (based on [D-Phe(6), Sta(13), Leu(14)-NH2]BBN(6-14)) which bound to GRPR with high affinity and had a favorable biodistribution profile in tumor-bearing animal models. In this study, we aimed to prepare and test kits for prospective use in an early-phase clinical study. The kits were prepared to allow for a one-pot single-step radiolabeling with technetium-99m pertechnetate. The kit vials were tested for sterility and labeling efficacy. The radiolabeled by using the kit GRPR antagonist was evaluated in vitro for binding specificity to GRPR on PC-3 cells (GRPR-positive). In vivo, the toxicity of the kit constituents was evaluated in rats. The labeling efficacy of the kits stored at 4 degrees C was monitored for 18 months. The biological properties of [Tc-99m]Tc-maSSS-PEG2-RM26, which were obtained after this period, were examined both in vitro and in vivo. The one-pot (gluconic acid, ethylenediaminetetraacetic acid, stannous chloride, and maSSS-PEG(2)-RM26) single-step radiolabeling with technetium-99m was successful with high radiochemical yields (>97%) and high molar activities (16-24 MBq/nmol). The radiolabeled peptide maintained its binding properties to GRPR. The kit constituents were sterile and non-toxic when tested in living subjects. In conclusion, the prepared kit is considered safe in animal models and can be further evaluated for use in clinics.
|
|
| 3. |
- Bragina, Olga, et al.
(författare)
-
Phase I clinical evaluation of 99mTc-labeled Affibody molecule for imaging HER2 expression in breast cancer
- 2023
-
Ingår i: Theranostics. - : Ivyspring International Publisher. - 1838-7640. ; 13:14, s. 4858-4871
-
Tidskriftsartikel (refereegranskat)abstract
- The determination of tumor human epidermal growth factor receptor type 2 (HER2) status is of increasing importance with the recent approval of more efficacious HER2-targeted treatments. There is a lack of suitable methods for clinical in vivo HER2 expression assessment. Affibody molecules are small affinity proteins ideal for imaging detection of receptors, which are engineered using a small (molecular weight 6.5 kDa) nonimmunoglobulin scaffold. Labeling of Affibody molecules with positron emitters enabled the development of sensitive and specific agents for molecular imaging. The development of probes for SPECT would permit the use of Affibody-based imaging in regions where PET is not available. In this first-in-human study, we evaluated the safety, biodistribution, and dosimetry of the Tc-99m-ZHER2:41071 Affibody molecule developed for SPECT/CT imaging of HER2 expression.Methods: Thirty-one patients with primary breast cancer were enrolled and divided into three cohorts (injected with 500, 1000, or 1500 mu g ZHER2:41071) comprising at least five patients with high (positive) HER2 tumor expression (IHC score 3+ or 2+ and ISH positive) and five patients with low (IHC score 2+ or 1+ and ISH negative) or absent HER2 tumor expression. Patients were injected with 451 +/- 71 MBq Tc-99m-ZHER2:4107. Planar scintigraphy was performed after 2, 4, 6 and 24 h, and SPECT/CT imaging followed planar imaging 2, 4 and 6 h after injection.Results: Injections of Tc-99m-ZHER2:41071 were well tolerated and not associated with adverse events. Normal organs with the highest accumulation were the kidney and liver. The effective dose was 0.019 +/- 0.004 mSv/MBq. Injection of 1000 mu g provided the best standard discrimination between HER2-positive and HER2-low or HER2-negative tumors 2 h after injection (SUVmax 16.9 +/- 7.6 vs. 3.6 +/- 1.4, p < 0.005). The Tc-99m-ZHER2:41071 uptake in HER2-positive lymph node metastases (SUVmax 6.9 +/- 2.4, n = 5) was significantly (p < 0.05) higher than that in HER2-low/negative lymph nodes (SUVmax 3.5 +/- 1.2, n = 4). Tc-99m-ZHER2:41071 visualized hepatic metastases in a patient with liver involvement.Conclusions: Injections of Tc-99m-ZHER2:41071 appear safe and exhibit favorable dosimetry. The protein dose of 1000 mu g provides the best discrimination between HER2-positive and HER2-low/negative expression of HER2 according to the definition used for current HER2-targeting drugs.
|
|
| 4. |
- Bragina, Olga, et al.
(författare)
-
Phase I study of 99mTc-ADAPT6, a scaffold protein-based probe for visualization of HER2 expression in breast cancer
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Radionuclide molecular imaging of human epidermal growth factor (HER2) expression may be helpful to stratify breast and gastroesophageal cancer patients for HER2-targeting therapies. ADAPTs (albumin-binding domain derived affinity proteins) are a new type of small (46-59 amino acids) proteins useful as probes for molecular imaging. The aim of this first in-human study was to evaluate biodistribution, dosimetry, and safety of HER2-specific 99mTc-ADAPT6.METHODS. Twenty-two patients with HER2-positive (n=11) or HER2-negative (n=11) primary breast cancer were intravenously injected with 385125 MBq. The injected amount of protein was either 500 μg (n=11) or 1000 μg (n=11). Planar scintigraphy followed by SPECT imaging was performed after 2, 4, 6 and 24 h. An additional cohort received a dose of 250 μg, and the planar scintigraphy followed by SPECT imaging was performed after 2 h only.RESULTS. Injection of 99mTc-ADAPT6 was well tolerated for all doses evaluated in the study, and was not associated with any adverse effects. 99mTc-ADAPT6 cleared rapidly from the blood and the majority of tissues. The normal organs with the highest accumulation were kidney, liver and lung. The effective doses were determined to 0.0090.002 and 0.0100.003 mSv/MBq when injecting protein amounts of 500 and 1000 μg, respectively. Injection of 500 μg resulted in excellent discrimination between HER2-positive and HER2-negative tumors already 2 h after injection (tumor-to-contralateral breast ratio was 3719 vs 52, p < 0.01). The tumor-to-contralateral breast ratios for HER2-positive tumors were significantly (p < 0.5) higher for the injected mass of 500 μg than for both 250 and 1000 μg. In one patient, the imaging using 99mTc-ADAPT6 revealed three bone metastases, which were not found at the time of diagnosis by CT or 99mTcpyrophosphate bone scan. MRI imaging confirmed this finding.CONCLUSION. Injections of 99mTc-ADAPT6 are safe and associated with low absorbed and effective doses. A protein dose of 500 μg is preferable for discrimination between tumors with high and low expression of HER2. 99mTc-ADAPT6 is a promising imaging probe for the stratification of patients for HER2-targeting therapy.
|
|
| 5. |
- Bragina, Olga, et al.
(författare)
-
Phase I study of 99mTc-ADAPT6, a scaffold protein-based probe for visualization of HER2 expression in breast cancer
- 2021
-
Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 62:4, s. 493-499
-
Tidskriftsartikel (refereegranskat)abstract
- Radionuclide molecular imaging of human epidermal growth factor (HER2) expression may be helpful to stratify breast and gastroesophageal cancer patients for HER2-targeting therapies. ADAPTs (albumin-binding domain derived affinity proteins) are a new type of small (46-59 amino acids) proteins useful as probes for molecular imaging. The aim of this first-in-human study was to evaluate biodistribution, dosimetry, and safety of the HER2-specific 99mTc-ADAPT6.METHODS: Twenty-nine patients with primary breast cancerwere included. In 22 patients with HER2-positive (n = 11) or HER2-negative (n = 11) histopathology an intravenous injection with 385±125 MBq 99mTc-ADAPT6 was performed, randomized to an injected protein mass of either 500 µg (n = 11) or 1000 µg (n = 11). Planar scintigraphy followed by SPECT imaging was performed after 2, 4, 6 and 24 h. An additional cohort (n = 7) was injected with 165±29 MBq (injected protein mass 250 µg) and imaging was performed after 2 h only.RESULTS: Injections of 99mTc-ADAPT6 at all injected mass levels were well tolerated and not associated with adverse effects. 99mTc-ADAPT6 cleared rapidly from blood and most other tissues. The normal organs with the highest accumulation were kidney, liver and lung. Effective doses were 0.009±0.002 and 0.010±0.003 mSv/MBq for injected protein masses of 500 and 1000 µg, respectively. Injection of 500 µg resulted in excellent discrimination between HER2-positive and HER2-negative tumors already 2 h after injection (tumor-to-contralateral breast ratio was 37±19 vs 5±2, p<0.01). The tumor-to-contralateral breast ratios for HER2-positive tumors were significantly (p<0.05) higher for injected mass of 500 µg than for both 250 and 1000 µg.CONCLUSION: Injections of 99mTc-ADAPT6 are safe and associated with low absorbed and effective doses. Protein dose of 500 µg is preferable for discrimination between tumors with high and low expression of HER2. Further studies are justified to evaluate if 99mTc-ADAPT6 can be used as an imaging probe for stratification of patients for HER2-targeting therapy in the areas where PET imaging is not readily available.
|
|
| 6. |
- Bragina, Olga, et al.
(författare)
-
Phase I Trial of 99mTc-(HE)3-G3, a DARPin-Based Probe for Imaging of HER2 Expression in Breast Cancer
- 2022
-
Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 63:4, s. 528-535
-
Tidskriftsartikel (refereegranskat)abstract
- Radionuclide molecular imaging of human epidermal growth factor receptor type 2 (HER2) expression may enable a noninvasive discrimination between HER2-positive and HER2-negative breast cancers for stratification of patients for HER2-targeted treatments. DARPin (designed ankyrin repeat proteins) G3 is a small (molecular weight, 14 kDa) scaffold protein with picomolar affinity to HER2. The aim of this first-in-humans study was to evaluate the safety, biodistribution, and dosimetry of 99mTc-(HE)3-G3.Methods: Three cohorts of patients with primary breast cancer (each including at least 4 patients with HER2-negative and 5 patients with HER2-positive tumors) were injected with 1,000, 2,000, or 3,000 μg of 99mTc-(HE)3-G3 (287 ± 170 MBq). Whole-body planar imaging followed by SPECT was performed at 2, 4, 6, and 24 h after injection. Vital signs and possible side effects were monitored during imaging and up to 7 d after injection.Results: All injections were well tolerated. No side effects were observed. The results of blood and urine analyses did not differ before and after studies. 99mTc-(HE)3-G3 cleared rapidly from the blood. The highest uptake was detected in the kidneys and liver followed by the lungs, breasts, and small intestinal content. The hepatic uptake after injection of 2,000 or 3,000 μg was significantly (P < 0.05) lower than the uptake after injection of 1,000 μg. Effective doses did not differ significantly between cohorts (average, 0.011 ± 0.004 mSv/MBq). Tumor–to–contralateral site ratios for HER-positive tumors were significantly (P < 0.05) higher than for HER2-negative at 2 and 4 h after injection.Conclusion: Imaging of HER2 expression using 99mTc-(HE)3-G3 is safe and well tolerated and provides a low absorbed dose burden on patients. This imaging enables discernment of HER2-positive and HER2-negative breast cancer. Phase I study data justify further clinical development of 99mTc-(HE)3-G3.
|
|
| 7. |
- Chernov, Vladimir, et al.
(författare)
-
Phase I Trial of [Tc-99m]Tc-maSSS-PEG(2)-RM26, a Bombesin Analogue Antagonistic to Gastrin-Releasing Peptide Receptors (GRPRs), for SPECT Imaging of GRPR Expression in Malignant Tumors
- 2023
-
Ingår i: Cancers. - : MDPI. - 2072-6694. ; 15:6
-
Tidskriftsartikel (refereegranskat)abstract
- The gastrin-releasing peptide receptor (GRPR) is overexpressed in prostate cancer (PCa) and in hormone-driven breast cancer (BCa). The aim of this phase I clinical trial was to evaluate safety, biodistribution, and dosimetry after the administration of the recently developed GRPR-targeting antagonistic bombesin analogue [Tc-99m]Tc-maSSS-PEG(2)-RM26 in PCa and BCa patients. Planar and whole-body SPECT/CT imaging was performed in six PCa patients and seven BCa patients 2, 4, 6, and 24 h post the intravenous administration of 40 mu g of [Tc-99m]Tc-maSSS-PEG(2)-RM26 (600-700 MBq). No adverse events or pathological changes were observed. The rapid blood clearance of [Tc-99m]Tc-maSSS-PEG(2)-RM26 was observed with predominantly hepatobiliary excretion. The effective doses were 0.0053 +/- 0.0007 for male patients and 0.008 +/- 0.003 mSv/MBq for female patients. The accumulation of [Tc-99m]Tc-maSSS-PEG(2)-RM26 in tumors was observed in four out of six PCa and in seven out of seven BCa patients. In four BCa patients, a high uptake of the agent into the axillary lymph nodes was detected. Immunohistochemistry revealed positive GRPR expression in 60% of primary PCa, 71.4% of BCa tumors, and 50% of examined BCa lymph nodes. In conclusion, a single administration of [Tc-99m]Tc-maSSS-PEG(2)-RM26 was safe and well tolerated. [Tc-99m]Tc-maSSS-PEG(2)-RM26 SPECT may be useful for tumor detection in PCa and BCa patients, pending further studies.
|
|
| 8. |
|
|
| 9. |
- Oroujeni, Maryam, PhD, 1982-, et al.
(författare)
-
Preclinical Evaluation of Tc-99m-ZHER2:41071, a Second-Generation Affibody-Based HER2-Visualizing Imaging Probe with a Low Renal Uptake
- 2021
-
Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 22:5
-
Tidskriftsartikel (refereegranskat)abstract
- Radionuclide imaging of HER2 expression in tumours may enable stratification of patients with breast, ovarian, and gastroesophageal cancers for HER2-targeting therapies. A first-generation HER2-binding affibody molecule [Tc-99m]Tc-ZHER2:V2 demonstrated favorable imaging properties in preclinical studies. Thereafter, the affibody scaffold has been extensively modified, which increased its melting point, improved storage stability, and increased hydrophilicity of the surface. In this study, a second-generation affibody molecule (designated ZHER2:41071) with a new improved scaffold has been prepared and characterized. HER2-binding, biodistribution, and tumour-targeting properties of [Tc-99m]Tc-labelled ZHER2:41071 were investigated. These properties were compared with properties of the first-generation affibody molecules, [Tc-99m]Tc-ZHER2:V2 and [Tc-99m]Tc-ZHER2:2395. [Tc-99m]Tc-ZHER2:41071 bound specifically to HER2 expressing cells with an affinity of 58 +/- 2 pM. The renal uptake for [Tc-99m]Tc-ZHER2:41071 and [Tc-99m]Tc-ZHER2:V2 was 25-30 fold lower when compared with [Tc-99m]Tc-ZHER2:2395. The uptake in tumour and kidney for [Tc-99m]Tc-ZHER2:41071 and [Tc-99m]Tc-ZHER2:V2 in SKOV-3 xenografts was similar. In conclusion, an extensive re-engineering of the scaffold did not compromise imaging properties of the affibody molecule labelled with Tc-99m using a GGGC chelator. The new probe, [Tc-99m]Tc-ZHER2:41071 provided the best tumour-to-blood ratio compared to HER2-imaging probes for single photon emission computed tomography (SPECT) described in the literature so far. [Tc-99m]Tc-ZHER2:41071 is a promising candidate for further clinical translation studies.
|
|
| 10. |
- Vorobyeva, Anzhelika, et al.
(författare)
-
Comparative Evaluation of Radioiodine and Technetium-Labeled DARPin 9_29 for Radionuclide Molecular Imaging of HER2 Expression in Malignant Tumors
- 2018
-
Ingår i: Contrast Media & Molecular Imaging. - : WILEY-HINDAWI. - 1555-4309 .- 1555-4317.
-
Tidskriftsartikel (refereegranskat)abstract
- High expression of human epidermal growth factor receptor 2 (HER2) in breast and gastroesophageal carcinomas is a predictive biomarker for treatment using HER2-targeted therapeutics (antibodies trastuzumab and pertuzumab, antibody-drug conjugate trastuzumab DM1, and tyrosine kinase inhibitor lapatinib). Radionuclide molecular imaging of HER2 expression might permit stratification of patients for HER2-targeting therapies. In this study, we evaluated a new HER2-imaging probe based on the designed ankyrin repeat protein (DARPin) 9_29. DARPin 9_29 was labeled with iodine-125 by direct radioiodination and with [Tc-99m] Tc(CO)(3) using the C-terminal hexahistidine tag. DARPin 9_29 preserved high specificity and affinity of binding to HER2-expressing cells after labeling. Uptake of [I-125] I-DARPin 9_29 and [Tc-99m] Tc(CO)(3)-DARPin 9_29 in HER2-positive SKOV-3 xenografts in mice at 6 h after injection was 3.4 +/- 0.7 % ID/g and 2.9 +/- 0.7 % ID/g, respectively. This was significantly (p < 0.00005) higher than the uptake of the same probes in HER2-negative Ramos lymphoma xenografts, 0.22 +/- 0.09 % ID/g and 0.30 +/- 0.05 % ID/g, respectively. Retention of [I-125] I-DARPin 9_29 in the lung, liver, spleen, and kidneys was appreciably lower compared with [Tc-99m] Tc(CO)(3)-DARPin 9_29, which resulted in significantly (p < 0.05) higher tumor-to-organ ratios. The biodistribution data were confirmed by SPECT/CT imaging. In conclusion, radioiodine is a preferable label for DARPin 9_29.
|
|
