Clinical Pharmacology for Lorbrena
Mechanism Of Action
Lorlatinib is a kinase inhibitor with in vitro activity against ALK and ROS1 as well as TYK1, FER, FPS, TRKA, TRKB, TRKC, FAK, FAK2, and ACK. Lorlatinib demonstrated in vitro activity against multiple mutant forms of the ALK enzyme, including some mutations detected in tumors at the time of disease progression on crizotinib and other ALK inhibitors.
In mice subcutaneously implanted with tumors harboring EML4 fusions with either ALK variant 1 or ALK mutations, including the G1202R and I1171T mutations detected in tumors at the time of disease progression on ALK inhibitors, administration of lorlatinib resulted in antitumor activity. Lorlatinib also demonstrated anti-tumor activity and prolonged survival in mice implanted intracranially with EML4-ALK-driven tumor cell lines. The overall antitumor activity of lorlatinib in in vivo models was dose-dependent and correlated with inhibition of ALK phosphorylation.
Pharmacodynamics
Exposure-response relationships for Grade 3 or 4 hypercholesterolemia and for any Grade 3 or 4 adverse reaction were observed at steady-state exposures achieved at the recommended dosage, with higher probability of the occurrence of adverse reactions with increasing lorlatinib exposure.
Cardiac Electrophysiology
In 295 patients who received LORBRENA at the recommended dosage of 100 mg once daily and had an ECG measurement in Study B7461001, the maximum mean change from baseline for PR interval was 16.4 ms (2-sided 90% upper confidence interval [CI] 19.4 ms). Among the 284 patients with PR interval <200 ms at baseline, 14% had PR interval prolongation ≥200 ms after starting LORBRENA. The prolongation of PR interval occurred in a concentration-dependent manner. Atrioventricular block occurred in 1% of patients.
In 275 patients who received LORBRENA at the recommended dosage in the activity-estimating portion of Study B7461001, no large mean increases from baseline in the QTcF interval (i.e., >20 ms) were detected.
Pharmacokinetics
Steady-state lorlatinib maximum plasma concentration (Cmax) increases proportionally and AUC increased slightly less than proportionally over the dose range of 10 mg to 200 mg orally once daily (0.1 to 2 times the recommended dosage). At the recommended dosage, the mean (coefficient of variation [CV] %) Cmax was 577 ng/mL (42%) and the AUC0-24h was 5650 ng·h/mL (39%) in patients with cancer. Lorlatinib oral clearance increased at steady-state compared to single dose, indicating autoinduction.
Absorption
The median lorlatinib Tmax was 1.2 hours (0.5 to 4 hours) following a single oral 100 mg dose and 2 hours (0.5 to 23 hours) following 100 mg orally once daily at steady-state.
The mean absolute bioavailability is 81% (90% CI 75.7%, 86.2%) after oral administration compared to intravenous administration.
Effect of Food
There was no clinically significant effect on lorlatinib pharmacokinetics following administration of LORBRENA with a high fat, high calorie meal (approximately 1000 calories with 150 calories from protein, 250 calories from carbohydrate, and 500 to 600 calories from fat).
Distribution
Lorlatinib was 66% bound to plasma proteins at a concentration of 2.4 μM. The blood-to-plasma ratio was 0.99, in vitro. The mean (CV%) steady-state volume of distribution (Vss) was 305 L (28%) following a single intravenous dose.
Elimination
The mean plasma half-life (t½) of lorlatinib was 24 hours (40%) after a single oral 100 mg dose of LORBRENA. The mean oral clearance (CL/F) was 11 L/h (35%) following a single oral 100 mg dose and increased to 18 L/h (39%) at steady-state, suggesting autoinduction.
Metabolism
Lorlatinib is metabolized primarily by CYP3A4 and UGT1A4, with minor contribution from CYP2C8, CYP2C19, CYP3A5, and UGT1A3, in vitro.
In plasma, a benzoic acid metabolite (M8) of lorlatinib resulting from the oxidative cleavage of the amide and aromatic ether bonds of lorlatinib accounted for 21% of the circulating radioactivity. The oxidative cleavage metabolite, M8, is pharmacologically inactive.
Excretion
Following a single oral 100 mg dose of radiolabeled lorlatinib, 48% of the radioactivity was recovered in urine (<1% as unchanged) and 41% in feces (about 9% as unchanged).
Specific Populations
No clinically significant differences in lorlatinib pharmacokinetics were observed based on age (19 to 85 years), sex, race/ethnicity, body weight, mild to moderate renal impairment (CLcr 30 to 89 mL/min, estimated by Cockcroft-Gault), mild hepatic impairment (total bilirubin ≤ ULN and AST > ULN or total bilirubin > 1 to 1.5 × ULN and any AST), or metabolizer phenotypes for CYP3A5 and CYP2C19. The effect of moderate to severe hepatic impairment (total bilirubin ≥ 1.5 × ULN with any AST) on lorlatinib pharmacokinetics is unknown [see Use In Specific Populations].
Patients With Severe Renal Impairment
Following administration of a single oral 100 mg dose of LORBRENA, lorlatinib AUCinf increased by 42% in subjects with severe renal impairment (CLcr 15 to <30 mL/min, estimated by Cockcroft-Gault) compared to subjects with normal renal function (CLcr ≥ 90 mL/min, estimated by Cockcroft-Gault). The pharmacokinetics of lorlatinib have not been studied in patients with end-stage renal disease requiring hemodialysis.
Drug Interaction Studies
Clinical Studies And Model-Informed Approaches
Effect of Strong CYP3A Inducers on Lorlatinib
Rifampin (a strong CYP3A inducer that also activates PXR) 600 mg once daily for 8 days (Days 1 to 8) coadministered with a single oral 100 mg dose of LORBRENA on Day 8 reduced the mean lorlatinib AUCinf by 85% and Cmax by 76%. Grade 2 to 4 increases in ALT or AST occurred within 3 days. Grade 4 ALT or AST elevations occurred in 50%, Grade 3 ALT or AST elevations in 33%, and Grade 2 ALT or AST elevations occurred in 8% of subjects. ALT and AST returned to within normal limits within 7 to 34 days (median 15 days) [see DRUG INTERACTIONS].
Effect of Moderate CYP3A Inducers on Lorlatinib
Modafinil (a moderate CYP3A inducer) decreased AUCinf by 23% and decreased Cmax by 22% of a single oral 100 mg dose of LORBRENA [see DRUG INTERACTIONS].
Effect of Strong CYP3A Inhibitors on Lorlatinib
Itraconazole (a strong CYP3A inhibitor) increased AUCinf by 42% and increased Cmax by 24% of a single oral 100 mg dose of LORBRENA [see DRUG INTERACTIONS].
Effect of Fluconazole on Lorlatinib
Fluconazole is predicted to increase steady-state AUCtau and Cmax of lorlatinib by 59%, and 28%, respectively, following concomitant oral administration of 100 mg of LORBRENA once daily and 200 mg fluconazole once daily [see DRUG INTERACTIONS].
Effect of Moderate CYP3A Inhibitors on Lorlatinib
No clinically significant effect on steady-state lorlatinib pharmacokinetics is predicted when used concomitantly with verapamil or erythromycin.
Effect of Lorlatinib on CYP3A Substrates
LORBRENA 150 mg orally once daily for 15 days decreased AUCinf by 64% and Cmax by 50% of a single oral 2 mg dose of midazolam (a sensitive CYP3A substrate) [see DRUG INTERACTIONS].
Effect of Lorlatinib on CYP2B6 Substrates
LORBRENA 100 mg orally once daily for 15 days decreased AUCinf by 25% and Cmax by 27% of a single oral 100 mg dose of bupropion (a sensitive CYP2B6 substrate).
Effect of Lorlatinib on CYP2C9 Substrates
LORBRENA 100 mg orally once daily for 15 days decreased AUCinf by 43% and Cmax by 15% of a single oral 100 mg dose of tolbutamide (a sensitive CYP2C9 substrate).
Effect of Lorlatinib on UGT1A Substrates
LORBRENA 100 mg orally once daily for 15 days decreased AUCinf by 45% and Cmax by 28% of a single oral 100 mg dose of acetaminophen (a UGT1A substrate).
Effect of Lorlatinib on P-gp Substrates
LORBRENA 100 mg orally once daily for 15 days decreased AUCinf by 67% and Cmax by 63% of a single oral 60 mg dose of fexofenadine (a P-gp substrate) [see DRUG INTERACTIONS].
Effect of Acid-Reducing Agents on Lorlatinib
Concomitant use of a proton pump inhibitor, rabeprazole, did not have a clinically significant effect on lorlatinib pharmacokinetics.
In Vitro Studies
Effect of Lorlatinib on CYP Enzymes
Lorlatinib is a time-dependent inhibitor as well as an inducer of CYP3A and activates PXR, with the net effect in vivo being induction. Lorlatinib induces CYP2B6 and activates the human constitutive androstane receptor (CAR). Lorlatinib and the major circulating metabolite, M8, do not inhibit CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, or CYP2D6. M8 does not inhibit CYP3A.
M8 does not induce CYP1A2, CYP2B6, or CYP3A.
Effects of Lorlatinib on UDP-glucuronosyltransferase (UGT)
Lorlatinib and M8 do not inhibit UGT1A1, UGT1A4, UGT1A6, UGT1A9, UGT2B7, or UGT2B15.
Effect of Lorlatinib on Transporter Systems
Lorlatinib is an inhibitor of P-gp and activates PXR (potential to induce P-gp), with the net effect in vivo being induction. Lorlatinib inhibits organic cation transporter (OCT)1, organic anion transporter (OAT)3, multidrug and toxin extrusion (MATE)1, and intestinal breast cancer resistance protein (BCRP). Lorlatinib does not inhibit organic anion transporting polypeptide (OATP)1B1, OATP1B3, OAT1, OCT2, MATE2K, or systemic BCRP. M8 does not inhibit P-gp, BCRP, OATP1B1, OATP1B3, OAT1, OAT3, OCT1, OCT2, MATE1, or MATE2K.
Animal Toxicology And/Or Pharmacology
Distended abdomen, skin rash, and increased cholesterol and triglycerides occurred in animals. These findings were accompanied by hyperplasia and dilation of the bile ducts in the liver and acinar atrophy of the pancreas in rats at 15 mg/kg/day and in dogs at 2 mg/kg/day (approximately 8 and 0.5 times, respectively, the human exposure at the recommended dose of 100 mg based on AUC). All effects were reversible within the recovery period.
Clinical Studies
Previously Untreated ALK-Positive Metastatic NSCLC (CROWN Study)
The efficacy of LORBRENA for the treatment of patients with ALK-positive NSCLC who had not received prior systemic therapy for metastatic disease was established in an open-label, randomized, active-controlled, multicenter study (Study B7461006; NCT03052608). Patients were required to have an ECOG performance status of 0-2 and ALK-positive NSCLC as identified by the VENTANA ALK (D5F3) CDx assay. Neurologically stable patients with treated or untreated asymptomatic CNS metastases, including leptomeningeal metastases, were eligible. Patients were required to have finished radiation therapy, at least 2 weeks (for stereotactic or partial radiation) or 4 weeks (for whole brain irradiation) prior to randomization.
Patients with severe acute or chronic psychiatric conditions, including recent (within the past year) or active suicidal ideation or behavior, were excluded. Patients were randomized 1:1 to receive LORBRENA 100 mg orally once daily or crizotinib 250 mg orally twice daily. Randomization was stratified by ethnic origin (Asian vs. non-Asian) and the presence or absence of CNS metastases at baseline. Treatment on both arms was continued until disease progression or unacceptable toxicity. The major efficacy outcome measure was progression-free survival (PFS) as determined by Blinded Independent Central Review (BICR) according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 (v1.1). Additional efficacy outcome measures were overall survival (OS) and tumor assessment related data by BICR, including overall response rate (ORR), and duration of response (DOR). In patients with measurable CNS metastases at baseline, additional outcome measures were intracranial overall response rate (IC-ORR) and intracranial duration of response (IC-DOR) by BICR.
A total of 296 patients were randomized to LORBRENA (n=149) or crizotinib (n=147). The demographic characteristics of the overall study population were: median age 59 years (range: 26 to 90 years), age ≥65 years (35%), 59% female, 49% White, 44% Asian, and 0.3% Black. The ECOG performance status at baseline was 0 or 1 in 96% of patients. The majority of patients had adenocarcinoma (95%) and never smoked (59%). CNS metastases were present in 26% (n=78) of patients: of these, 30 patients had measurable CNS lesions.
Efficacy results from Study B7461006 as assessed by BICR are summarized in Table 6 and Figure 1. Results demonstrated a significant improvement in PFS for the LORBRENA arm over the crizotinib arm. At the data cutoff point OS data was not mature.
Table 6 Efficacy Results in Study B7461006 (CROWN)
| Efficacy Parameter |
LORBRENA
N=149 |
Crizotinib
N=147 |
| Progression-free survival |
| Number of events, n (%) |
41 (28%) |
86 (59%) |
| Progressive disease, n (%) |
32 (22%) |
82 (56%) |
| Death, n (%) |
9 (6%) |
4 (3%) |
| Median, months (95% CI)a |
NE (NE, NE) |
9.3 (7.6, 11.1) |
| Hazard ratio (95% CI)b |
0.28 (0.19, 0.41) |
| p-value* |
<0.0001 |
| Overall response rate |
| Overall response rate (95% CI)c |
76% (68, 83) |
58% (49, 66) |
| Complete response |
3% |
0% |
| Partial response |
73% |
58% |
| Duration of response |
| Number of responders, n |
113 |
85 |
| Median, months (Range) |
NE (0.9, 31.3) |
11 (1.1, 27.5) |
| Response duration ≥6 months, n (%) |
101 (89%) |
53 (62%) |
| Response duration ≥12 months, n (%) |
79 (70%) |
23 (27%) |
| Response duration ≥18 months, n (%) |
34 (30%) |
9 (11%) |
Abbreviations: CI=confidence interval; N=number of patients; NE=not estimable; PFS=progression free survival.
* p-value based on 1-sided stratified log-rank test.
a Based on the Brookmeyer and Crowley method.
b Hazard ratio based on Cox proportional hazards model.
c Using exact method based on binomial distribution. |
Figure 1: Kaplan-Meier Plot of Progression-Free Survival by BICR in Study B7461006 (CROWN)
The results of prespecified exploratory analyses of intracranial response rate in 30 patients with measurable CNS lesions at baseline as assessed by BICR are summarized in Table 7.
Table 7 Intracranial Response Rate in Patients with Measurable Intracranial Lesions in CROWN
| Intracranial Tumor Response Assessment |
LORBRENA
N=17 |
Crizotinib
N=13 |
| Intracranial response rate (95% CI)a |
82% (57, 96) |
23% (5, 54) |
| Complete response |
71% |
8% |
| Duration of response |
| Number of responders, n |
14 |
3 |
| Response duration ≥12 months, n (%) |
11 (79%) |
0 |
Abbreviations: CI=confidence interval; N/n=number of patients.
a Using exact method based on binomial distribution. |
ALK-Positive Metastatic NSCLC Previously Treated With An ALK Kinase Inhibitor
The efficacy of LORBRENA was demonstrated in a subgroup of patients with ALK-positive metastatic NSCLC previously treated with one or more ALK kinase inhibitors who were enrolled in a non-randomized, doseranging and activity-estimating, multi-cohort, multicenter study (Study B7461001; NCT01970865). Patients included in this subgroup were required to have metastatic disease with at least 1 measurable target lesion according to RECIST v1.1, ECOG performance status of 0 to 2, and documented ALK rearrangement in tumor tissue as determined by fluorescence in situ hybridization (FISH) assay or by Immunohistochemistry (IHC), and received LORBRENA 100 mg orally once daily. Patients with asymptomatic CNS metastases, including patients with stable or decreasing steroid use within 2 weeks prior to study entry, were eligible. Patients with severe, acute, or chronic psychiatric conditions including suicidal ideation or behavior were excluded. In addition, for patients with ALK-positive metastatic NSCLC, the extent and type of prior treatment was specified for each individual cohort (see Table 8). The major efficacy outcome measures were ORR and intracranial ORR, according to RECIST v1.1, as assessed by Independent Central Review (ICR) committee. Data were pooled across all subgroups listed in Table 8. Additional efficacy outcome measures included DOR, and intracranial DOR.
A total of 215 patients were enrolled across the subgroups in Table 8. The distribution of patients by type and extent of prior therapy is provided in Table 8. The demographic characteristics across all 215 patients were: 59% female, 51% White, 34% Asian, and the median age was 53 years (29 to 85 years) with 18% of patients ≥65 years. The ECOG performance status at baseline was 0 or 1 in 96% of patients. All patients had metastatic disease and 95% had adenocarcinoma. Brain metastases as identified by ICR were present in 69% of patients; of these, 60% had received prior radiation to the brain and 60% (n=89) had measurable disease per ICR.
Table 8 Extent of Prior Therapy in the Subgroup of Patients with Previously Treated ALK-Positive Metastatic NSCLC in Study B7461001
| Extent of prior therapy |
Number of patients |
| Prior crizotinib and no prior chemotherapya |
29 |
| Prior crizotinib and 1-2 lines of prior chemotherapya |
35 |
| Prior ALK inhibitor (not crizotinib) with or without prior chemotherapya |
28 |
| Two prior ALK inhibitors with or without prior chemotherapya |
75 |
| Three prior ALK inhibitors with or without prior chemotherapya |
48 |
| Total |
215 |
Abbreviations: ALK=anaplastic lymphoma kinase; NSCLC=non-small cell lung cancer.
a Chemotherapy administered in the metastatic setting. |
Efficacy results for Study B7461001 are summarized in Tables 9 and 10.
Table 9 Efficacy Results in Study B7461001
| Efficacy Parameter |
Overall
N=215 |
| Overall response ratea (95% CI)b |
48% (42, 55) |
| Complete response |
4% |
| Partial response |
44% |
| Duration of response |
|
| Median, monthsc (95% CI) |
12.5 (8.4, 23.7) |
Abbreviations: CI=confidence interval; N=number of patients.
a Per Independent Central Review.
b Using exact method based on binomial distribution.
c Estimated using the Kaplan-Meier method. |
An assessment of intracranial ORR and the duration of response for CNS metastases in the subgroup of 89 patients in Study B7461001 with baseline measurable lesions in the CNS according to RECIST v1.1 are summarized in Table 10. Of these, 56 (63%) patients received prior brain radiation, including 42 patients (47%) who completed brain radiation treatment at least 6 months before starting treatment with LORBRENA.
Table 10 Intracranial Response Rate in Patients with Measurable Intracranial Lesions in Study B7461001
| Efficacy Parameter |
Intracranial
N=89 |
| Intracranial response ratea (95% CI)b |
60% (49, 70) |
| Complete response |
21% |
| Partial response |
38% |
| Duration of response |
|
| Median, monthsc (95% CI) |
19.5 (12.4, NR) |
Abbreviations: CI=confidence interval; N=number of patients; NR=not reached.
a Per Independent Central Review.
b Using exact method based on binomial distribution.
c Estimated using the Kaplan-Meier method. |
In exploratory analyses conducted in subgroups defined by prior therapy, the response rates to LORBRENA were:
- ORR = 39% (95% CI: 30, 48) in 119 patients who received crizotinib and at least one other ALK inhibitor, with or without prior chemotherapy
- ORR = 31% (95% CI: 9, 61) in 13 patients who received alectinib as their only ALK inhibitor, with or without prior chemotherapy
- ORR = 46% (95% CI: 19, 75) in 13 patients who received ceritinib as their only ALK inhibitor, with or without prior chemotherapy