Cross-validation of a mass spectrometricbased method for the therapeutic drug monitoring of irinotecan: implementation of matrix-assisted laser desorption/ ionization mass spectrometry in pharmacokinetic measurements Eleonora Calandra, Bianca Posocco, Sara Crotti, Elena Marangon, Luciana Giodini, et al. Analytical and Bioanalytical Chemistry ISSN 1618-2642 Anal Bioanal Chem DOI 10.1007/s00216-016-9634-5
1 23
Your article is protected by copyright and all rights are held exclusively by SpringerVerlag Berlin Heidelberg. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com”.
1 23
Author's personal copy Anal Bioanal Chem DOI 10.1007/s00216-016-9634-5
RESEARCH PAPER
Cross-validation of a mass spectrometric-based method for the therapeutic drug monitoring of irinotecan: implementation of matrix-assisted laser desorption/ionization mass spectrometry in pharmacokinetic measurements Eleonora Calandra 1 & Bianca Posocco 2 & Sara Crotti 1 & Elena Marangon 2 & Luciana Giodini 2 & Donato Nitti 3 & Giuseppe Toffoli 2 & Pietro Traldi 1,4 & Marco Agostini 1,3,5
Received: 2 March 2016 / Revised: 2 May 2016 / Accepted: 12 May 2016 # Springer-Verlag Berlin Heidelberg 2016
Abstract Irinotecan is a widely used antineoplastic drug, mostly employed for the treatment of colorectal cancer. This drug is a feasible candidate for therapeutic drug monitoring due to the presence of a wide inter-individual variability in the pharmacokinetic and pharmacodynamic parameters. In order to determine the drug concentration during the administration protocol, we developed a quantitative MALDI-MS method using CHCA as MALDI matrix. Here, we demonstrate that MALDI-TOF can be applied in a routine setting for therapeutic drug monitoring in humans offering quick and accurate results. To reach this aim, we cross validated, according to FDA and EMA guidelines, the MALDI-TOF method in comparison with a standard LC-MS/MS method, applying it for the quantification of 108 patients’ plasma samples from a clinical trial. Standard curves for irinotecan were linear (R2 ≥ 0.9842) over the concentration ranges between 300 and 10,000 ng/mL and showed good back-calculated accuracy
* Sara Crotti
[email protected] 1
Lab. NIB, Pediatric Research Institute, Città della Speranza, Corso Stati Uniti 4, 35127 Padua, Italy
2
Experimental and Clinical Pharmacology Division, Department of Translational Research, IRCCS-National Cancer Institute, Via Franco Gallini 2, 33081 Aviano, Italy
3
Surgical Clinic, Department of Surgical, Oncological and Gastroenterological Sciences, University of Padova, Via Nicolo Giustiniani 2, 35128 Padua, Italy
4
IENI CNR, Corso Stati Uniti 4, 35127 Padua, Italy
5
Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Avenue, Houston, TX 77030, USA
and precision. Intra- and inter-day precision and accuracy, determined on three quality control levels were always 20 %), the LLOQ resulted higher in the case of MALDI-TOF, with respect to the LCMS/MS method (300 and 10 ng/mL, respectively). This higher limit of quantification can surely have an impact on the fidelity of representation of the late elimination phase; nevertheless, this is not the case of therapeutic drug monitoring, which is performed during the drug administration. In this case, the linearity range of 300–10,000 ng/mL results satisfactory to cover the expected clinical concentration range.
6379.41 ± 520.23 9090.55 ± 369.12
Selected reaction monitoring, 587.4 → 124.2 for CPT-11 and 349.2 → 305.1 for IS
The absence of an interfering signal due to endogenous plasma species was assessed for the MALDI method depositing six different blank plasma samples after deproteinization. Figure 1 reports one of the six deproteinized blank plasma samples (panels a and d), a deproteinized plasma sample with the addition of IS (panels b and e) and a deproteinized plasma sample at the LLOQ (panels c and f). Observing the figure, no molecular ionic species coming nor from plasma neither from CHCA matrix were present in the m/z region where the protonated species related to irinotecan and IS are expected. Pharmacokinetic analysis In order to cross-validate the MALDI method, a total of 108 clinical samples were analysed with the newly developed MALDI method as well as by using the LC-MS/MS method currently employed in the clinical study. All CPT-11 concentrations measured were within the range of linearity of both methods, so there was no need for a further dilution step. The set of patients’ plasma samples used for this crossvalidation study was chosen in order to evaluate the possibility to use the MALDI method to perform pharmacokinetic measures of CPT-11. The pharmacokinetic profile of CPT-11 alone was assessed at the first chemotherapy treatment in which BV was administered 50 h after the start of CPT-11 infusion, whereas CPT-11 pharmacokinetics in combination with BV was performed during the second treatment of the first cycle (i.e. when BV was administered before CPT-11 dosage). In the first set of measures, we analysed samples from different patients in
Author's personal copy E. Calandra et al.
Fig. 1 MALDI-TOF mass spectra in the m/z ranges of camptothecin and irinotecan (CPT-11) of one of the six deproteinized blank plasma samples (a and d), deproteinized plasma sample with the addition of IS (b and e) and deproteinized plasma sample at the LLOQ (c and f)
which BV was administered 50 h after the start of CPT-11 infusion. Analysed samples were collected during the first 9 h of the treatment (i.e. BV was not present in the samples). In more than 70 % of the total amount of clinical samples analysed for the cross-validation study, we obtained a percentage difference between the two methods within 20 %. Figure 2 Fig. 2 Pharmacokinetic profiles of two patients receiving 260 (a) and 310 mg/m2 (b) of irinotecan as intravenous infusion. Solid lines indicate concentrations found by MALDI-TOF measurements; dashed lines indicate concentrations found by LC-MS/MS measurements
shows the comparison between the plasma concentrationversus-time curves of CPT-11 obtained with both MALDI and LC-MS/MS methods, in two patients receiving 260 (panel a) and 310 mg/m2 (panel b) of irinotecan as a 2-h continuous intravenous infusion during the first chemotherapy cycle. As shown in this figure, we obtained a good reproducibility
Author's personal copy MALDI-TOF for the irinotecan pharmacokinetic measurements Fig. 3 Plasma concentrationversus-time profiles of CPT-11 in one patient receiving 370 mg/m2 of irinotecan during the I and II administration of the first therapy cycle. a shows the pharmacokinetic profile evaluated in the absence of BV and b in the presence of the co-administration of BV. Solid lines indicate concentrations found by MALDITOF measurements, whilst dashed lines indicate concentrations found by LC-MS/ MS measurements
between the CPT-11 plasma concentrations found. The percentage differences were within −12.5 and 15.3 % in all the plasma time points for patient A and less than 17 % in 80 % of the total amount of patient B plasma samples. The second set of samples was chosen to study if BV when present in the samples could influence the measures of CPT-11 (i.e. in the case of treatment in which BV is administered just before the FOLFIRI regimen). Figure 3 shows two pharmacokinetic curves related to the same patient treated following the FOLFIRI regimen without (panel A) and with (panel B) the co-administration of BV. As shown in Fig. 3, a quite good overlapping between pharmacokinetic curves has been obtained and the agreement between CPT-11 levels obtained by the two analytical methods shows no influence by the presence of BV with the MALDI method. In panel A of Fig. 3, related to the administration of CPT-11 without BV, it is noted that the presence of a point in the curve where the absolute concentration of irinotecan calculated with the LC-MS/MS method and with the MALDI-TOF method appears different. Nevertheless, the presence of this difference in the
concentration measure, the calculated pharmacokinetic parameters, using the data coming from the two different methods, was not affected and presented a maximum difference in the parameters of 8.7 %. In particular, the mean percent difference for each parameter is 1.3 % in the determination of Cmax, −2.0 % for AUClast, 3.3 % for AUCinf, 7.8 % for t1/2, 5.4 % for Vz and −3.3 % for Cl. At the same manner, we observed that the presence of BV does not influence the CPT11 measurement concentrations (Fig. 3B), and also, in this case, the pharmacokinetic parameters calculated using MALDI data well correlate with the ones calculated with LC-MS/MS data, and the overall percent difference remain
