Sreekanth Dittakavi

Vodobatinib (K0706) is a novel, orally bioavailable Bcr-Abl 1 tyrosine kinase inhibitor designed to overcome resistance mutations such as T3151 in chronic myeloid leukemia. While its clinical efficacy and safety are under investigation, there is limited information on vodobatinib preclinical absorption, distribution, metabolism, and excretion properties and tissue distribution. The objective of this study is to evaluate vodobatinib solubility in phosphate buffer and biorelevant media, metabolic stability in liver microsomes and hepatocytes across species, permeability using MDCK-MDR1 cells, plasma protein binding via equilibrium dialysis, CYP phenotyping and CYP inhibition. Tissue distribution was assessed in male Sprague–Dawley rats following oral administration (2.0 mg/kg), with plasma and tissue samples collected over a 24-hour period. Vodobatinib exhibited poor solubility in phosphate buffer (2.5 µM), but showed improved solubility in biorelevant media. It demonstrated high metabolic stability in liver microsomes and hepatocytes of rats and dogs, with moderate stability in humans. Permeability studies indicated low efflux liability. Plasma protein binding was extensive (>99.8%) across species. Metabolism was primarily mediated by CYP3A4 (≈70%), with minor involvement from CYP2C19 and CYP2D6. CYP inhibition was weak to moderate, suggesting a low potential for drug–drug interactions. Vodobatinib showed high distribution to the liver, intestines, and kidneys, with low brain penetration. Vodobatinib demonstrates a favorable preclinical absorption, distribution, metabolism, and excretion profile, with high metabolic stability, minimal efflux liability, and selective tissue distribution. These findings support its continued clinical development in chronic myeloid leukemia and potentially other Bcr-Abl 1 driven malignancies.

Vodobatinib is a third‐generation Bcr‐Abl 1 inhibitor, being used in chronic myeloid leukemia treatment. Herein, we report a validated LC–MS/MS method for quantifying vodobatinib from rat dried blood spot (DBS) as per FDA guidelines. Methanol was used as a solvent to extract vodobatinib from the DBS discs. We used an isocratic method with a flow rate of 0.80 mL/min in an Atlantis dC₁₈ (50 × 4.6 mm, 3.0 μm) column with a 2.00 min run time. The retention of vodobatinib and the I.S. was ~1.15 and 1.05 min. The MS/MS ion transitions monitored for vodobatinib and I.S. were m/z 454.20 → 270.05 and 309.15 → 251.15, respectively. The linearity range was 1.04–1039 ng/mL. All the evaluated validation parameters met the acceptance criteria. Hematocrit levels of 35% and 50% yielded consistent concentrations at both low and high QC levels, with accuracy of 1.00%–1.03% and precision below 10%, indicating no hematocrit effect. For intravenous dosing, AUC_0–∞ was 9475 ng·h/mL (DBS) versus 10,109 ng·h/mL (plasma), and for oral dosing, C_max values were 568 ng/mL (DBS) versus 544 ng/mL (plasma). Oral bioavailability was nearly identical between matrices (98.7% for DBS vs. 97.9% for plasma), confirming the reliability of DBS sampling for PK studies of vodobatinib.

Vodobatinib is a Bcr‐Abl 1 inhibitor, currently entering into Phase 2 clinical trials as a potential drug to treat glioblastoma patients. In the present work, a validated high‐performance liquid chromatography (HPLC) detection method for the quantification of vodobatinib in rat plasma was established. Sample preparation involved liquid–liquid extraction method. The chromatographic separation of vodobatinib and the IS was accomplished on an XBridge C₁₈ column using 10 mM ammonium acetate and acetonitrile in gradient condition. The flow‐rate and injection volume were 0.8 mL/min and 20 μL, respectively. The eluent was detected at 310 nm. Vodobatinib and the IS eluted at 7.5 and 5.9 min, respectively, with a total run time of 10 min. Validation tests were performed according to FDA requirements. The established method showed good linearity in the range of 50.5–6534 ng/mL. Interday and intraday coefficients of variations were < 5.11%. Stability studies, dilution integrity, and incurred sample reanalysis met the acceptance criteria. Subsequently, the validated HPLC method was used to study the disposition kinetics of vodobatinib in rats.

A highly sensitive and rapid LC–MS/MS method was developed and validated for the quantification of dexamethasone in rat plasma and brain tissue. Protein precipitation method was used for sample preparation. The separation of dexamethasone and the IS (labetalol) was achieved on an Atlantis dC₁₈ column using an isocratic mobile phase (10 mM ammonium formate and acetonitrile, 25/75, v/v) delivered at 0.7 mL/min flow‐rate. Dexamethasone and the IS were eluted at 1.03 and 1.06 min, respectively. The MS/MS transitions monitored were m/z 393.100 → 373.100 (dexamethasone) and 329.100 → 91.100 (IS). Method validation was performed as per FDA guidelines and all parameters met the acceptance criteria. The assay was validated with a quantification range of 0.05–1046 ng/mL in both matrices. The intraday and interday precision for were in the range of 2.62–7.28 and 2.76%–6.98% and 2.24–6.85 and 2.97%–6.37%, in plasma and brain tissue, respectively. Dexamethasone was stable in a series of stability conditions in both matrices. Post‐intravenous administration to rats, dexamethasone concentrations in plasma and brain tissue were quantifiable up to 24 and 10 h, respectively. Dexamethasone half‐life was ~2.30 h. Dexamethasone exhibited low clearance and moderate volume of distribution in plasma but in brain tissue the clearance and volume of distribution were high.

Paxalisib is a pan‐PI3K and mTOR inhibitor, currently entering into Phase II clinical trials as a potential drug to treat glioblastoma patients. We report the development and validation of a high‐performance liquid chromatography (HPLC) method for the quantitation of paxalisib in mouse plasma as per the US Food and Drug Administration regulatory guidelines. From the mouse plasma, paxalisib and the internal standard (IS; filgotinib) were extracted using ethyl acetate as an extraction solvent. The chromatographic separation of paxalisib and the IS was accomplished on a Symmetry C₁₈ (250 × 4.6 mm, 5.0 μm) column maintained at 40°C using 10 mm ammonium formate and acetonitrile in gradient conditions at a 0.8 ml/min flow‐rate. The injection volume was 20 μl. The elution was monitored using a photo‐diode array detector set at λ_max 280 nm. Paxalisib and the IS eluted at 6.5 and 5.9 min, respectively with a total run time of 10 min. The calibration curve was linear over the range of 111–4,989 ng/ml. Inter‐ and intraday precision and accuracy, stability studies, dilution integrity and incurred sample reanalysis were investigated and the results met the acceptance criteria. The validated HPLC method was extended to assess the pharmacokinetic parameters of paxalisib in mice.

Copanlisib is a dual PI3K‐δ inhibitor, used in follicular lymphoma treatment. In this research, we report a validated LC–MS/MS method for quantifying copanlisib from a mouse dried blood spot (DBS). We validated the method in line with the guidelines of the US Food and Drug Administration. The liquid–liquid extraction technique was used to extract copanlisib from the DBS discs. We used an Atlantis dC₁₈ column and isocratic mobile phase for the chromatographic separation of copanlisib and the internal standard (idelalisib). The flow was 0.90 ml/min. Under the optimized chromatographic conditions, the retentions of copanlisib and the internal standard were 0.98 and 0.93 min, respectively. Each injection total run time was 2.50 min. The MS/MS ion transitions monitored were m/z 481.31 → 128.00 and 416.10 → 176.10 for copanlisib and the internal standard (IS) idelalisib, respectively. We have used a broad calibration range (1.01–4,797 ng/ml) with a determination coefficient (r²) of 0.997. All of the evaluated parameters met the acceptance criteria. Hematocrit did not influence the DBS copanlisib concentrations. We have used the validated method to derive the intravenous pharmacokinetic parameters by quantifying copanlisib in mouse plasma.

In this study, we report the development and validation of an LC–tandem mass spectrometry method for the simultaneous quantitation of bendamustine and copanlisib in mouse plasma as per the US FDA regulatory guidelines. The sample processing involves extraction of bendamustine and copanlisib along with internal standard (IS; warfarin) from 50 μL mouse plasma using a liquid–liquid extraction method. The chromatographic separation of bendamustine, copanlisib and the IS was achieved on an Atlantis dC₁₈ column using an isocratic mobile phase (5 mM ammonium acetate:methanol, 20:80 v/v). Bendamustine, copanlisib and the IS eluted at 0.88, 1.39 and 0.74 min, respectively, with a total run time of 2.5 min. The calibration curve ranged from 3.99–2996 and 4.33–3248 ng/mL for bendamustine and copanlisib, respectively. Inter‐ and intra‐day precision and accuracy, stability in processed samples and upon storage, dilution integrity and incurred sample reanalysis were investigated for both the analytes. The intra‐ and inter‐day precisions were in the ranges of 2.01%–5.05% and 2.74%–6.13% and 1.98%–7.64 and 8.62%–9.04% for bendamustine and copanlisib, respectively. Stability studies showed that both analytes were stable on bench top for 6 h, in auto‐sampler for 24 and at −80°C for 30 days. The validated method was successfully applied to a pharmacokinetic study in mice.

AMG 510 is the first‐in‐class KRAS^G12C inhibitor, currently in phase 2 clinical trials as an orphan drug to treat non‐small cell lung cancer patients. We developed and validated a sensitive, selective, and high‐throughput HPLC‐MS/MS method for the quantitation of AMG 510 in mouse plasma per the regulatory guideline of the US Food and Drug and Administration. AMG 510 and the IS (MRTX‐1257) were extracted from mouse plasma using tert‐butyl methyl ether and chromatographed using an isocratic mobile phase (0.2% formic acid:acetonitrile; 25:75, v/v) at a flow rate of 0.65 mL/min on an Atlantis dC₁₈ column. AMG 510 and the IS eluted at ~0.95 and 0.73 min, respectively. AMG 510 and the IS were detected by positive electrospray ionization in multiple reaction monitoring using transition pair (Q1 → Q3) m/z 561.1 → 134.1 and m/z 566.5 → 98.2, respectively. Excellent linearity was achieved in the concentration range of 1.08–5040 ng/mL (r > 0.0996). No matrix effect and carryover were observed. Intra‐ and inter‐day accuracies and precisions were within the acceptance range. AMG 510 was demonstrated to be stable under the tested storage conditions. This novel method has been applied to a pharmacokinetic study in mice.

Phosphatidylinositol 3‐kinase (PI3K) inhibitors are a novel class of anticancer drugs that are approved to treat various malignancies. We report the development and validation of a HPLC method for the simultaneous quantitation of three PI3K inhibitors, namely copanlisib, duvelisib and idelalisib, in rat plasma as per the regulatory guidelines of the United States Food and Drug Administration. The method involves extraction of copanlisib, duvelisib and idelalisib along with an internal standard (IS; filgotinib) from rat plasma (100 μL) using a liquid–liquid extraction process. The chromatographic separation of the analytes was achieved using step‐wise gradient elution on a Hypersil Gold C₁₈ column. The UV detection wavelength was set at λ_max = 280 nm. Copanlisib, duvelisib, idelalisib and the IS eluted at 7.16, 12.6, 11.9 and 9.86 min, respectively, with a total run time of 15 min. The calibration curve ranged from 50 to 5000 ng/mL for all the analytes. Inter‐ and intra‐day precision and accuracy, stability studies, dilution integrity and incurred sample reanalysis were investigated for all three analytes, and the results met the acceptance criteria. The validated HPLC method was successfully applied to a pharmacokinetic study in rats.

Idelalisib is a selective and second-generation PI3K-δ inhibitor, approved for the treatment of non-Hodgkin lymphoma and chronic lymphocytic leukemia. In this paper, we present a fully validated dried blood spot (DBS) method for the quantitation of idelalisib from mice blood using an LC-MS/MS, which was operated under multiple reaction monitoring mode. To the punched DBS discs, acidified methanol enriched with internal standard (IS; larotrectinib) was added and extracted using tert-butyl methyl ether as an extraction solvent with sonication. Chromatographic separation of idelalisib and the IS was achieved on an Atlantis dC₁₈ column using a mixture of 10 mM ammonium formate:acetonitrile (25:75, v/v). The flow-rate and injection volume were 0.80 mL/min and 2.0 µL, respectively. Idelalisib and the IS were eluted at ~0.98 and 0.93 min, respectively and the total run time was 2.00 min. Idelalisib and the IS were analyzed using positive ion scan mode and parent-daughter mass to charge ion (m/z) transition of 416.1→176.1 and 429.1→342.1, respectively was used for the quantitation. The calibration range was 1.01−4 797 ng/mL. No matrix effect and carry over were observed. Haematocrit did not influence DBS idelalisib concentrations. All the validation parameters met the acceptance criteria. The applicability of the validated method was shown in a mice pharmacokinetic study. Received: 05 August 2020 Accepted: 30 August 2020 Publication Date: 29 September 2020 (online) © 2020. Thieme. All rights reserved. © Georg Thieme Verlag KG Stuttgart · New York