Dose Optimization in Oncology Drug Development: An International Consortium for Innovation and Quality in Pharmaceutical Development White Paper.

The landscape of oncology drug development has witnessed remarkable advancements over the last few decades, significantly improving clinical outcomes and quality of life for patients with cancer. Project Optimus, introduced by the U.S. Food and Drug Administration, stands as a groundbreaking endeavor to reform dose selection of oncology drugs, presenting both opportunities and challenges for the field. To address complex dose optimization challenges, an Oncology Dose Optimization IQ Working Group was created to characterize current practices, provide recommendations for improvement, develop a clinical toolkit, and engage Health Authorities. Historically, dose selection for cytotoxic chemotherapeutics has focused on the maximum tolerated dose, a paradigm that is less relevant for targeted therapies and new treatment modalities. A survey conducted by this group gathered insights from member companies regarding industry practices in oncology dose optimization. Given oncology drug development is a complex effort with multidimensional optimization and high failure rates due to lack of clinically relevant efficacy, this Working Group advocates for a case-by-case approach to inform the timing, specific quantitative targets, and strategies for dose optimization, depending on factors such as disease characteristics, patient population, mechanism of action, including associated resistance mechanisms, and therapeutic index. This white paper highlights the evolving nature of oncology dose optimization, the impact of Project Optimus, and the need for a tailored and evidence-based approach to optimize oncology drug dosing regimens effectively.

Evaluation of the Effect of Lorlatinib on CYP2B6, CYP2C9, UGT, and P-Glycoprotein Substrates in Patients with Advanced Non-Small Cell Lung Cancer.

BACKGROUND AND OBJECTIVE: Lorlatinib is a tyrosine kinase inhibitor approved for the treatment of advanced anaplastic lymphoma kinase-positive non-small cell lung cancer. This study assessed the effect of steady-state lorlatinib on the metabolic enzymes cytochrome P450 (CYP) 2B6, CYP2C9, and uridine 5'-diphospho-glucuronosyltransferase (UGT) and the P-glycoprotein (P-gp) transporter. METHODS: Thirty-two patients received a single oral dose of a probe drug on Day - 2 to determine the pharmacokinetics of the probe drug alone. Starting on Day 1, patients received 100 mg oral lorlatinib daily. On Day 15, a single oral dose of the probe drug was administered concurrently with lorlatinib. Pharmacokinetic parameters for these probe substrates were assessed. RESULTS: Plasma exposures of all probe substrates were reduced by lorlatinib compared with the probe alone. The greatest reduction in area under the plasma concentration-time curve from time zero to infinity (AUC∞) and maximum (peak) plasma drug concentration (Cmax) (67% and 63% decrease, respectively) was observed with the P-gp probe substrate fexofenadine. Lorlatinib coadministration also decreased the AUC∞ and Cmax of bupropion (CYP2B6 probe substrate) by 25% and 27%, tolbutamide (CYP2C9 probe substrate) by 43% and 15%, and acetaminophen (UGT probe substrate) by 45% and 28%, respectively. CONCLUSIONS: Lorlatinib is a net moderate inducer of P-gp and a weak inducer of CYP2B6, CYP2C9, and UGT after steady state is achieved with daily dosing. Medications that are P-gp substrates with a narrow therapeutic window should be avoided in patients taking lorlatinib; no dose modifications are needed with substrates of CYP2B6, CYP2C9, or UGT. CLINICALTRIALS: gov: NCT01970865.

A literature review of liver function test elevations in rifampin drug-drug interaction studies.

Although rifampin drug-drug interaction (DDI) studies are routinely conducted, there have been instances of liver function test (LFT) elevations, warranting further evaluation. A literature review was conducted to identify studies in which combination with rifampin resulted in hepatic events and evaluate any similarities. Over 600 abstracts and manuscripts describing rifampin DDI studies were first evaluated, of which 30 clinical studies reported LFT elevations. Out of these, 11 studies included ritonavir in combination with other drug(s) in the rifampin DDI study. The number of subjects that were discontinued from treatment on these studies ranged from 0 to 71 (0-100% of subjects in each study). The number of subjects hospitalized for adverse events in these studies ranged from 0 to 41 (0-83.67% of subjects in each study). LFT elevations in greater than 50% of subjects were noted during the concomitant administration of rifampin with ritonavir-boosted protease inhibitors and with lorlatinib; with labeled contraindication due to observed hepatotoxicity related safety findings only for saquinavir/ritonavir and lorlatinib. In the lorlatinib and ritonavir DDI studies, considerable LFT elevations were observed rapidly, typically within 24-72 h following co-administration. A possible sequence effect has been speculated, where rifampin induction prior to administration of the combination may be associated with increased severity of the LFT elevations. The potential role of rifampin in the metabolic activation of certain drugs into metabolites with hepatic effects needs to be taken into consideration when conducting rifampin DDI studies, particularly those for which the metabolic profiles are not fully elucidated.

Evaluation of Lorlatinib Cerebrospinal Fluid Concentrations in Relation to Target Concentrations for Anaplastic Lymphoma Kinase (ALK) Inhibition.

Lorlatinib is a third-generation, brain-penetrant anaplastic lymphoma kinase (ALK) and c-ros oncogene 1 (ROS1) tyrosine kinase inhibitor (TKI) with robust intracranial activity in patients with ALK- or ROS1-positive non-small cell lung cancer (NSCLC). Data from the ongoing open-label, single-arm, multicenter, phase-1/2 study of lorlatinib in patients with metastatic ALK- or ROS1-positive NSCLC were used to further investigate the potential brain penetration of lorlatinib. Patients received escalating lorlatinib doses (10-200 mg once daily or 35-100 mg twice daily) or the approved dosing (100 mg daily). Plasma was collected from all patients, and cerebrospinal fluid (CSF) was collected at baseline and during the study from 5 patients with suspected or confirmed leptomeningeal carcinomatosis or carcinomatous meningitis. For those 5 patients, lorlatinib concentrations ranged from 2.64 to 125 ng/mL in the CSF and from 12.7 to 457 ng/mL in the plasma; free plasma concentrations ranged from 4.318 to 155.385 ng/mL. The CSF/free plasma ratio was 0.77 (R2  = 0.96 and P < .001). Using a post-hoc population pharmacokinetic model, the average steady-state unbound plasma concentration of lorlatinib was derived and the CSF concentration was estimated for all patients. Known minimum efficacy concentrations (Ceff ) for wild-type and mutated (L1196M and G1202R) ALK were used to derive central nervous system (CNS) Ceff . Estimated CNS concentrations exceeded the derived CNS Ceff values in all patients for wild-type ALK and the ALK L1196M mutation, and in 35.8% of patients for the ALK G1202R mutation. Projected lorlatinib CNS concentrations were consistent with the high intracranial response rates reported in clinical trials and provide further evidence of the potent CNS penetration of lorlatinib.

A Phase I Study to Evaluate the Pharmacokinetics and Safety of Lorlatinib in Adults with Mild, Moderate, and Severe Renal Impairment.

BACKGROUND AND OBJECTIVES: Lorlatinib is approved (100 mg once daily [QD]) for the treatment of patients with anaplastic lymphoma kinase- (ALK) positive metastatic non-small cell lung cancer. This study evaluated the impact of varying degrees of renal impairment on the safety and pharmacokinetics of lorlatinib. METHODS: Participants were assigned to mild, moderate, and severe renal impairment groups and to a matching normal renal function group based on absolute estimated glomerular filtration rate (eGFR, based on the Modification of Diet in Renal Disease equation and adjusted for body surface area [BSA]) and were evaluated for pharmacokinetics and safety. RESULTS: A total of 29 participants (5 with severe renal impairment; 8 each with moderate and mild impairment and normal renal function) were enrolled and received a single dose of lorlatinib 100 mg. One of the participants with severe renal impairment had end-stage renal disease with a baseline absolute eGFR of 10.3 mL/min. No serious adverse events (AEs) were reported. Eighteen AEs, all mild or moderate in severity, were reported by 12 participants (5, 2, 4, and 1 in the normal, mild, moderate, and severe groups, respectively). Area under the plasma concentration-time profile from time zero extrapolated to infinity (AUCinf) for lorlatinib was increased by 4%, 19%, and 41% in the mild, moderate, and severe renal impairment groups, respectively, compared with the normal renal function cohort. CONCLUSION: Lorlatinib 100 mg was well tolerated. As participants with mild and moderate renal impairment did not experience clinically meaningful increases in lorlatinib exposure, no lorlatinib dose adjustment is recommended in these populations. Patients with severe renal impairment are recommended to reduce the starting dose of lorlatinib from 100 mg QD to 75 mg QD. GOV IDENTIFIER: NCT03542305 (available May 31, 2018 on clinicaltrials.gov).

Evaluation of the absolute oral bioavailability of the anaplastic lymphoma kinase/c-ROS oncogene 1 kinase inhibitor lorlatinib in healthy participants.

PURPOSE: Lorlatinib is a third-generation tyrosine kinase inhibitor currently approved for the treatment of anaplastic lymphoma kinase (ALK)-positive metastatic non-small cell lung cancer. This open-label, phase 1, randomized two-sequence, two-treatment, two-period, crossover study investigated the absolute oral bioavailability of lorlatinib in healthy participants. METHODS: Eligible participants were randomized to receive two treatments in one of two sequences: lorlatinib 100 mg single oral dose followed by lorlatinib 50 mg intravenous (IV) dose, or lorlatinib IV dose followed by lorlatinib oral dose, each with at least a 10-day washout between successive lorlatinib doses. Blood samples for pharmacokinetics were collected for up to 144 hours (h) after dosing. Validated liquid chromatographic-tandem mass spectrometry was used to determine plasma concentrations of lorlatinib and its benzoic acid metabolite PF-06895751. RESULTS: In total, 11 participants were enrolled (mean age 37.6 years, all male). The adjusted geometric mean (90% confidence interval) for the absolute oral bioavailability was 80.78% (75.73-86.16%). Using non-compartmental analysis, the estimated arithmetic mean elimination plasma half-life of lorlatinib was 25.5 and 27.0 h after the oral and IV doses, respectively. No deaths, serious adverse events (AEs), or severe AEs were reported, and most treatment-emergent AEs were mild in severity, with two events of transaminase increase of moderate severity. All treatment-emergent AEs were resolved by the end of the study. CONCLUSION: Both oral and IV lorlatinib were well-tolerated in healthy participants and oral lorlatinib is highly bioavailable after oral administration.

Phase 1 Study Evaluating the Effects of the Proton Pump Inhibitor Rabeprazole and Food on the Pharmacokinetics of Lorlatinib in Healthy Participants.

Lorlatinib is approved worldwide as treatment for anaplastic lymphoma kinase-positive and c-ros oncogene 1-positive non-small cell lung cancer. The objectives of this phase 1, open-label crossover study (NCT02569554) in healthy adult participants were to determine (1) the effects of the proton pump inhibitor (PPI) rabeprazole on lorlatinib pharmacokinetics (PK), (2) the effects of a high-fat meal on lorlatinib PK, and (3) the relative bioavailability of an oral solution to tablet formulation of lorlatinib under fasted conditions. Participants were followed on-study for ≥50 days after the first dose of lorlatinib. Participants received treatments over 4 periods, with a washout of ≥10 days between consecutive lorlatinib doses. Twenty-seven participants were enrolled and received lorlatinib, and all were assessed for PK and safety. Results showed no effect of multiple doses of rabeprazole on the total plasma exposure of a single oral dose of lorlatinib 100-mg tablets. The results also indicated that a high-fat meal had no effect on lorlatinib PK after a single 100-mg oral dose. In addition, the relative bioavailability of lorlatinib oral solution compared with lorlatinib tablets was complete (approximately 108%). The safety profile of lorlatinib was consistent with that reported in previous studies, and most treatment-related adverse events were mild to moderate. These data indicate that lorlatinib can be administered with drugs that modify gastric acid, including PPIs, without restriction. These results also confirm that lorlatinib can be administered regardless of food intake.

The Effect of Modafinil on the Safety and Pharmacokinetics of Lorlatinib: A Phase I Study in Healthy Participants.

BACKGROUND AND OBJECTIVE: Lorlatinib is a third-generation tyrosine kinase inhibitor approved for the second-line treatment of patients with advanced anaplastic lymphoma kinase-positive non-small cell lung cancer. Lorlatinib is metabolized by cytochrome P450 (CYP) 3A and contraindicated with strong CYP3A inducers because of significant transaminase elevation. This phase I, open-label, two-period study evaluated the impact of a moderate CYP3A inducer, modafinil, on the safety and pharmacokinetics of lorlatinib. METHODS: Healthy participants received single-dose oral lorlatinib (50 mg [n = 2], 75 mg [n = 2], or 100 mg [n = 2 + 10 in an expanded cohort]) in Period 1 followed by modafinil 400 mg/day (days 1-19) and single-dose lorlatinib (day 15, same dose as previous) both orally in Period 2. Blood samples were collected for 120 h after each dose of lorlatinib. RESULTS: Of 16 participants, ten completed the study; six participants, all in the expanded 100-mg cohort, discontinued because of adverse events during the modafinil lead-in dosing period. Single doses of lorlatinib 50-100 mg were well tolerated when administered alone and in the presence of steady-state modafinil. Of the ten participants who completed the study, all had transaminase values within normal limits during the combination of lorlatinib with modafinil. The ratios of the adjusted geometric means (90% confidence interval) for lorlatinib area under the plasma concentration-time profile extrapolated to infinity and maximum plasma concentration were 76.69% (70.15-83.83%) and 77.78% (65.92-91.77), respectively, when lorlatinib 100 mg was co-administered with steady-state modafinil compared with lorlatinib administration alone. CONCLUSION: Lorlatinib 100 mg may be safely co-administered with moderate CYP3A inducers. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT03961997; registered 23 May, 2019.

Pharmacokinetics of Lorlatinib After Single and Multiple Dosing in Patients with Anaplastic Lymphoma Kinase (ALK)-Positive Non-Small Cell Lung Cancer: Results from a Global Phase I/II Study.

BACKGROUND: Lorlatinib demonstrated efficacy (including intracranial activity) in patients with anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC) in a phase I/II study (NCT01970865). BACKGROUND AND OBJECTIVE: This analysis describes the pharmacokinetics (PK) of lorlatinib following single and multiple dosing. METHODS: This ongoing, multicenter, open-label, single-arm, phase I/II trial enrolled patients with ALK-positive or c-ros oncogene 1 (ROS1)-positive advanced NSCLC. In phase I, patients received escalating doses of lorlatinib (10-200 mg orally once daily) and twice-daily doses of 35, 75, and 100 mg in continuous 21-day cycles. In phase II, lorlatinib was administered at a starting dose of 100 mg once daily in continuous 21-day cycles. Parameters investigated included the potential for lorlatinib to inhibit/induce cytochrome P450 (CYP) 3A; the absorption/metabolism of lorlatinib and its major metabolite PF-06895751; and differences in these parameters between Asian and non-Asian patients. RESULTS: Data were available for 54 patients from phase I and 275 patients from phase II. Lorlatinib plasma exposure increased dose proportionally after single doses of 10-200 mg, and slightly less than dose proportionally after multiple doses. Lorlatinib clearance increased following multiple dosing compared with single dosing, indicating autoinduction. The area under the concentration-time curve from time zero to time τ (the dosing interval; AUCτ) of PF-06895751 was approximately 80% higher than that of lorlatinib after multiple dosing. Lorlatinib exhibited brain penetration. Furthermore, no overt differences in single- and multiple-dose PK parameters between the Asian and non-Asian patients were observed. CONCLUSIONS: Lorlatinib is highly brain penetrant and exhibits autoinduction after multiple dosing. There appears to be no inherent differences in lorlatinib PK between healthy subjects and cancer patients, or between Asian and non-Asian patients. ClinicalTrials.gov NCT01970865.

Liver Toxicity Observed With Lorlatinib When Combined With Strong CYP3A Inducers: Evaluation of Cynomolgus Monkey as a Nonclinical Model for Assessing the Mechanism of Combinational Toxicity.

Lorlatinib is a potent small-molecule anaplastic lymphoma kinase inhibitor approved for the treatment of patients with nonsmall cell lung cancer. In a drug-drug interaction study in healthy human participants, liver enzyme elevations were observed when a single 100 mg dose of lorlatinib was administered after multiple doses of rifampin, a strong cytochrome P450 (CYP) 3A inducer and a pregnane X receptor (PXR) agonist. A series of in vitro and in vivo studies were conducted to evaluate potential mechanisms for the observed clinical toxicity. To investigate the involvement of CYP3A and/or PXR in the observed liver toxicity, studies were conducted in cynomolgus monkeys administered lorlatinib alone or with coadministration of multiple doses of known CYP3A inducers that are predominantly PXR agonists (rifampin, St. John's wort) or predominantly constitutive androstane receptor agonists (carbamazepine, phenytoin) and a net CYP3A inhibitory PXR agonist (ritonavir). Results from the investigative studies identified cynomolgus monkeys as a pharmacologically relevant nonclinical model, which recapitulated the elevated liver function test results observed in humans. Furthermore, liver toxicity was only observed in this model when lorlatinib was coadministered with strong CYP3A inducers, and the effects were not restricted to, or exclusively dependent upon, a PXR activation mechanism. These results generated mechanistic insights on the liver enzyme elevations observed in the clinical drug-drug interaction study and provided guidance on appropriate product safety label for lorlatinib.

Population pharmacokinetic model with time-varying clearance for lorlatinib using pooled data from patients with non-small cell lung cancer and healthy participants.

Lorlatinib, a selective inhibitor of anaplastic lymphoma kinase (ALK) and c-ROS oncogene 1 (ROS1) tyrosine kinase, is indicated for the treatment of ALK-positive metastatic non-small cell lung cancer (NSCLC) following progression on crizotinib and at least one other ALK inhibitor, or alectinib/ceritinib as the first ALK inhibitor therapy for metastatic disease. The population pharmacokinetics (PopPK) of lorlatinib was conducted by nonlinear mixed effects modeling of data from 330 patients with ALK-positive or ROS1-positive NSCLC and 95 healthy participants from six phase I studies in healthy volunteers; demographic, metabolizer phenotype, and patient prognostic factors were evaluated as covariates. Lorlatinib plasma PK was well-characterized by a two-compartment model with sequential zero-order and first-order absorption and a time-varying induction of clearance. Single dose clearance was estimated to be 9.04 L/h. Assuming that the metabolic auto-induction of lorlatinib reaches saturation in ~ 5 half-lives, clearance was estimated to approach a maximum of 14.5 L/h at steady-state after a period of ~ 7.25 days. The volume of distribution of the central compartment was estimated to be 121 L and the first-order absorption rate constant was estimated to be 3.1 h-1 . Baseline albumin and lorlatinib total daily dose were significant covariates on lorlatinib clearance. Use of proton pump inhibitors was found to be a significant covariate on the lorlatinib absorption rate constant. These factors were assessed to have no clinically meaningful impact on lorlatinib plasma exposure, and no dose adjustments are considered necessary based on the examined covariates.

Correction to: The Effect of Rifampin on the Pharmacokinetics and Safety of Lorlatinib: Results of a Phase One, Open-Label, Crossover Study in Healthy Participants.

In the original article, the reference 4 has been published and cited incorrectly.

Metabolism, Excretion, and Pharmacokinetics of Lorlatinib (PF-06463922) and Evaluation of the Impact of Radiolabel Position and Other Factors on Comparability of Data Across 2 ADME Studies.

While an initial clinical absorption, distribution, metabolism, and excretion (ADME) study (Study 1; N = 6) with 100 mg/100 µCi [14 C]lorlatinib, radiolabeled on the carbonyl carbon, confirmed that the primary metabolic pathways for lorlatinib are oxidation (N-demethylation, N-oxidation) and N-glucuronidation, it also revealed an unanticipated, intramolecular cleavage metabolic pathway of lorlatinib, yielding a major circulating benzoic acid metabolite (M8), and an unlabeled pyrido-pyrazole substructure. Concerns regarding the fate of unknown metabolites associated with this intramolecular cleavage pathway led to conduct of a second ADME study (Study 2; N = 6) of identical design but with the radiolabel positioned on the pyrazole ring. Results were similar with respect to the overall mass balance, lorlatinib plasma exposures, and metabolic profiles in excreta for the metabolites that retained the radiolabel in both studies. Differences were observed in plasma total radioactivity exposures (2-fold area under the plasma concentration-time curve from time 0 to infinity difference) and relative ratios of the percentage of dose recovered in urine vs feces (48% vs 41% in Study 1; 28% vs 64% in Study 2). In addition, an approximately 3-fold difference in the mean molar exposure ratio of M8 to lorlatinib was observed for values derived from metabolic profiling data relative to those derived from specific bioanalytical methods (0.5 vs 1.4 for Studies 1 and 2, respectively). These interstudy differences were attributed to a combination of factors, including alteration of radiolabel position, orthogonal analytical methodologies, and intersubject variability, and illustrate that results from clinical ADME studies are not unambiguous and should be interpreted within the context of the specific study design considerations.

Brain Penetration of Lorlatinib: Cumulative Incidences of CNS and Non-CNS Progression with Lorlatinib in Patients with Previously Treated ALK-Positive Non-Small-Cell Lung Cancer.

BACKGROUND: Lorlatinib is a potent, third-generation ALK/ROS1 tyrosine kinase inhibitor (TKI) designed to penetrate the blood-brain barrier. OBJECTIVE: We report the cumulative incidence of central nervous system (CNS) and non-CNS progression with lorlatinib in patients with ALK-positive non-small-cell lung cancer (NSCLC) previously treated with ALK TKIs. PATIENTS AND METHODS: In an ongoing phase II study (NCT01970865), 198 patients with ALK-positive NSCLC with ≥ 1 prior ALK TKI were enrolled into expansion cohorts (EXP) based on treatment history. Patients received lorlatinib 100 mg once daily. Patients were analyzed for progressive disease, categorized as CNS or non-CNS progression, by independent central review. Cumulative incidence probabilities were calculated adopting a competing risks approach. RESULTS: Fifty-nine patients received crizotinib as their only prior ALK TKI (EXP2-3A); cumulative incidence rates (CIRs) of CNS and non-CNS progression were both 22% at 12 months in patients with baseline CNS metastases (n = 37), and CIR of non-CNS progression at 12 months was higher versus that for CNS progression in patients without baseline CNS metastases [43% vs. 9% (n = 22)]. In patients who received ≥ 1 prior second-generation ALK TKI [EXP3B-5 (n = 139)], CIR of non-CNS progression at 12 months was higher versus that for CNS progression in patients both with and without baseline CNS metastases (35% vs. 23% (n = 94) and 55% vs. 12% (n = 45), respectively). CONCLUSIONS: Lorlatinib showed substantial intracranial activity in patients with pretreated ALK-positive NSCLC, with or without baseline CNS metastases, whose disease progressed on crizotinib or second-generation ALK TKIs. CLINICALTRIALS. GOV IDENTIFIER: NCT01970865.

The Effect of Rifampin on the Pharmacokinetics and Safety of Lorlatinib: Results of a Phase One, Open-Label, Crossover Study in Healthy Participants.

INTRODUCTION: Lorlatinib is a third-generation tyrosine kinase inhibitor approved for the treatment of anaplastic lymphoma kinase (ALK)-positive metastatic non-small cell lung cancer; cytochrome P450 (CYP) 3A plays an important role in the metabolism of lorlatinib. METHODS: This phase 1, open-label, two-period, crossover study estimated the effect of oral rifampin (a strong CYP3A inducer) on the pharmacokinetics and safety of oral lorlatinib (NCT02804399). Healthy participants received single-dose lorlatinib 100 mg in period 1 followed by rifampin 600 mg/day (days 1-12) and single-dose lorlatinib 100 mg (day 8) in period 2. Blood samples were collected for 120 h after each dose of lorlatinib. RESULTS: When a single dose of lorlatinib was administered during daily dosing with rifampin (period 2), the area under the plasma concentration-time profile extrapolated to infinity (AUCinf) and maximum plasma concentration (Cmax) of lorlatinib were 14.74% [90% confidence interval (CI) 12.78%, 17.01%] and 23.88% (90% CI 21.58%, 26.43%), respectively, of those in period 1 (lorlatinib alone). A single dose of lorlatinib was well tolerated in period 1, but elevations in transaminase values were observed in all participants (grade 2-4 in 11 participants) within 1-3 days after a single dose of lorlatinib was administered with ongoing rifampin in period 2. Rifampin dosing was therefore halted. Transaminase levels subsequently returned to normal (median time to recovery: 15 days). No elevations in bilirubin were observed. CONCLUSIONS: The addition of a single dose of lorlatinib to daily dosing with rifampin significantly reduced lorlatinib plasma exposure relative to a single dose of lorlatinib administered alone and was associated with severe but self-limiting transaminase elevations in all healthy participants. These observations support the contraindication in the product label against concomitant use of lorlatinib with all strong CYP3A inducers. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02804399.

The effect of itraconazole on the pharmacokinetics of lorlatinib: results of a phase I, open-label, crossover study in healthy participants.

Background The third-generation tyrosine kinase inhibitor lorlatinib is approved for the treatment of ALK-positive metastatic NSCLC. CYP3A plays a major role in lorlatinib metabolism; therefore, a drug-drug interaction study was warranted to evaluate the impact of the strong CYP3A inhibitor, itraconazole, on lorlatinib plasma exposure. Methods This phase 1, open-label, 2-period, crossover study estimated the effects of itraconazole on the plasma pharmacokinetics and safety of lorlatinib in healthy participants (NCT02838264). Single-dose lorlatinib 50 mg (n = 2), 75 mg (n = 2) and 100 mg (n = 12) was administered in Period 1. In Period 2, itraconazole oral solution 200 mg/day was administered on Days 1-11, and single-dose lorlatinib on Day 5. Blood samples were collected up to 168 h after lorlatinib dosing. Results During daily dosing with itraconazole (Period 2), the ratios of the adjusted geometric means for area under the plasma concentration-time profile extrapolated to infinity (AUCinf) and maximum plasma concentration (Cmax) of single-dose lorlatinib 100 mg were 141.79% (90% confidence interval, 128.71%, 156.21%) and 124.39% (110.20%, 140.41%), respectively, compared with Period 1 (lorlatinib alone). Lorlatinib was well tolerated alone and with itraconazole. No serious adverse events or withdrawals were reported. Conclusions Co-administration of itraconazole and lorlatinib increased the plasma exposure of lorlatinib relative to lorlatinib alone in healthy participants. Therefore, concomitant use of lorlatinib with strong CYP3A inhibitors should be avoided. If this combination is unavoidable, the starting dose of lorlatinib should be reduced from 100 mg to 75 mg.

Lack of effect of smoking status on axitinib pharmacokinetics in patients with non-small-cell lung cancer.

PURPOSE: Axitinib, a tyrosine kinase inhibitor targeting vascular endothelial growth factor receptors 1-3, is approved for second-line treatment of advanced renal cell carcinoma. Axitinib is partially metabolized by cytochrome P450 1A2, which is induced by chronic heavy smoking. The effect of smoking on axitinib pharmacokinetics was evaluated in a non-small-cell lung cancer (NSCLC) patient population with a large number of active and ex-smokers. METHODS: Data were pooled from six clinical studies-serial pharmacokinetics from two healthy volunteer studies (n = 58) and sparse pharmacokinetics from four NSCLC studies (n = 152)-for a nonlinear mixed effects modeling (NONMEM v7.2) analysis. Demographics, smoking status, liver and renal function status, and Eastern Cooperative Oncology Group performance status were tested as covariates. RESULTS: There were 83 (40%) active smokers and 56 (27%) ex-smokers in the pooled dataset. Axitinib pharmacokinetics was adequately described with a linear, two-compartment model with a lagged first-order absorption. Final parameter estimates (inter-individual variability) were 16.1 L/h (59.1%) and 45.3 L (54.4%) for systemic clearance (CL) and central volume of distribution (Vc), respectively. Smoking status was found not to alter CL or Vc. Asian ethnicity and body weight were significant covariates for Vc, but were not considered clinically relevant since individual values of Vc for Asians were within the range of non-Asians. CONCLUSIONS: Based on this analysis, smoking status does not affect area under plasma concentration-time curve, and thus no dose adjustment is required for smokers.

Effect of Renal Impairment on the Pharmacokinetics and Safety of Axitinib.

BACKGROUND: Axitinib, an inhibitor of vascular endothelial growth factor (VEGF) receptors, is approved as second-line treatment for advanced renal cell carcinoma (RCC). Agents targeting the VEGF pathway may induce renal toxicities, which may be influenced by pre-existing renal dysfunction. OBJECTIVE: The objective was to characterize axitinib pharmacokinetics and safety in patients with renal impairment. PATIENTS AND METHODS: Effect of renal function (baseline creatinine clearance [CrCL]) on axitinib clearance was evaluated in a population pharmacokinetic model in 207 patients with advanced solid tumors who received a standard axitinib starting dose, and in 383 healthy volunteers. Axitinib safety according to baseline CrCL was assessed in previously treated patients with RCC (n = 350) who received axitinib in the phase 3 AXIS study. RESULTS: Median axitinib clearance was 14.0, 10.7, 12.3, 7.81, and 12.6 L/h, respectively, in individuals with normal renal function (≥90 ml/min; n = 381), mild renal impairment (60-89 ml/min; n = 139), moderate renal impairment (30-59 ml/min; n = 64), severe renal impairment (15-29 ml/min; n = 5), and end-stage renal disease (<15 ml/min; n = 1). The population pharmacokinetic model adequately predicted axitinib clearance in individuals with severe renal impairment or end-stage renal disease. Grade ≥3 adverse events (AEs) were reported in 63 % of patients with normal renal function or mild impairment, 77 % with moderate impairment, and 50 % with severe impairment; study discontinuations due to AEs were 10 %, 11 %, and 0 %, respectively. CONCLUSIONS: Axitinib pharmacokinetics and safety were similar regardless of baseline renal function; no starting-dose adjustment is needed for patients with pre-existing mild to severe renal impairment.