Lorlatinib

Introduction Overview

Generic Name

lorlatinib

Brand Name

Lorbrena

Dosage Form

oral tablet (100 mg; 25 mg)

Drug Class

Multikinase inhibitors

Pharmacokinetics

Absorption:
Lorlatinib is administered orally and exhibits good bioavailability. It is absorbed in the gastrointestinal tract after oral administration, with plasma concentrations reaching adequate systemic levels to exert its pharmacologic effect. Food intake does not significantly affect the absorption of lorlatinib, allowing dosing with or without food. The Tmax (time to reach maximum plasma concentration) typically occurs within a few hours post-dose, facilitating once-daily dosing in clinical use. Despite its oral formulation, lorlatinib's absorption parameters ensure therapeutic doses rapidly achieve systemic exposure necessary for inhibiting ALK and ROS1 kinases in cancer cells.

Distribution:
Lorlatinib demonstrates extensive distribution throughout the body, including penetration across the blood-brain barrier (BBB). This characteristic is particularly important in the treatment of non-small cell lung cancer (NSCLC) with brain metastases, as the drug needs to reach intracranial tumor sites to be effective. The volume of distribution is fairly large, signifying extensive tissue binding. Plasma protein binding of lorlatinib is high, limiting free drug in circulation but maintaining prolonged plasma levels. The ability of lorlatinib to distribute into the central nervous system (CNS) surpasses that of earlier generation ALK inhibitors, supported by preclinical and clinical data, and explains its efficacy in controlling CNS disease.

Metabolism:
Lorlatinib is predominantly metabolized in the liver via cytochrome P450 enzymes, primarily CYP3A4, with minor contributions from CYP2C8. This metabolism results in several inactive metabolites. The CYP3A4-mediated metabolism indicates potential for significant drug-drug interactions, as inducers or inhibitors of CYP3A4 can alter lorlatinib plasma levels, affecting efficacy and toxicity. Additionally, lorlatinib itself may affect the metabolism of other drugs by modulating enzyme activity. The hepatic metabolism is crucial for the drug's clearance and requires monitoring in patients with hepatic impairment, as reduced metabolic clearance may increase drug exposure and toxicity.

Elimination:
Lorlatinib and its metabolites are primarily eliminated via the hepatobiliary route, with fecal excretion being the principal pathway. Renal excretion plays a minimal role in lorlatinib elimination. The elimination half-life supports once-daily dosing and the maintenance of steady-state plasma concentrations through chronic treatment. Clinical studies have documented that impaired hepatic function can prolong elimination half-life and increase drug exposure; hence, dose adjustments may be necessary in patients with moderate to severe hepatic impairment. The elimination kinetics are consistent with the clinical dosing regimen and the necessity to avoid accumulation leading to toxicity.

Dosage Forms

Available Dosage Forms:
Lorlatinib is available as oral tablets in two dose strengths:
- 25 mg tablets
- 100 mg tablets
The tablets are designed to be swallowed whole and must not be crushed, chewed, or broken to ensure proper pharmacokinetic profile.

Dosages for Adults and Adolescents:
The standard approved adult dose for treating ALK-positive metastatic non-small cell lung cancer (NSCLC) is 100 mg taken orally once daily. This dosing continues until disease progression or unacceptable toxicity occurs. The dosing regimen is designed to optimize efficacy while managing side effect profiles. There is limited dosing information for pediatric populations, as clinical approval and studies primarily address adult patients with metastatic NSCLC.

Specific Patient Populations:
In patients with hepatic impairment, dosing adjustments may be required due to metabolism primarily via the liver. There are no specific formulations for pediatric or geriatric populations; dosing is individualized based on tolerance and clinical response. Because lorlatinib can cause significant side effects, dose modifications may be necessary based on toxicity grades, such as adjusting or temporarily interrupting dosing in renal or hepatic dysfunction settings and in patients experiencing CNS-related side effects. The oral tablet formulation is ideal for outpatient treatment, facilitating chronic administration in approved indications.

Mechanism Of Action

Lorlatinib is a potent, selective inhibitor of anaplastic lymphoma kinase (ALK) and ROS1 tyrosine kinases, enzymes that are aberrantly activated due to chromosomal rearrangements in certain non-small cell lung cancers. By competitively binding to the ATP-binding sites of ALK and ROS1, lorlatinib prevents phosphorylation and activation of downstream signaling pathways essential for tumor cell growth, survival, and proliferation.

At the molecular level, lorlatinib effectively overcomes resistance mutations that limit the efficacy of earlier generation ALK inhibitors like crizotinib. Its binding affinity accommodates mutated forms of ALK, including those harboring the G1202R mutation that confers resistance, therefore expanding its clinical utility in patients with progressed disease after prior ALK inhibitor therapies.

Cellularly, lorlatinib inhibits proliferation and induces apoptosis in ALK-positive tumor cells by blocking signaling cascades such as the PI3K/AKT/mTOR and MAPK pathways. Additionally, lorlatinib's ability to cross the blood-brain barrier allows it to inhibit ALK-driven tumor cell growth within the central nervous system, a common site of metastasis in NSCLC.

Comparatively, lorlatinib demonstrates a broader spectrum of activity against resistant ALK mutations and better CNS penetration than first- and second-generation ALK inhibitors. Clinical trials have shown that lorlatinib achieves significant tumor regression in patients with metastatic NSCLC who have failed previous ALK-targeted therapies, supporting its role as a third-generation ALK inhibitor with enhanced efficacy and target selectivity.

Pharmacological Actions

Selective inhibition of anaplastic lymphoma kinase (ALK) tyrosine kinase activity.
Inhibition of ROS1 tyrosine kinase, another driver mutation in NSCLC.
Blockade of downstream signaling pathways crucial for tumor cell proliferation and survival, including PI3K/AKT/mTOR and MAPK pathways.
Ability to overcome resistance mutations in ALK, including G1202R and other mutations resistant to earlier ALK inhibitors.
Effective penetration of the blood-brain barrier, enabling treatment of CNS metastases.
Induction of apoptosis and inhibition of tumor progression in ALK-positive tumors.
Long half-life supporting once-daily oral administration and sustained kinase inhibition.
Metabolism primarily via CYP3A4, with potential modulation of drug metabolizing enzymes.
Multikinase inhibitor class targeting multiple kinases, though primarily ALK and ROS1.
Exhibits competitive ATP binding to kinase domains leading to inhibition of phosphorylation.
Anti-proliferative effects specific to cancer cells harboring ALK or ROS1 rearrangements.
Modulation of immune tumor microenvironment has not been demonstrated; acts primarily through kinase inhibition.
Demonstrates higher potency and selectivity relative to first and second-generation ALK inhibitors.
Minimal off-target kinase inhibition reduces adverse effects related to non-specific kinase inhibition.
Pharmacodynamic effects correlating with clinical tumor regression in NSCLC patients.

Therapeutic Or Clinical Uses

Treatment of ALK-positive metastatic non-small cell lung cancer (NSCLC) in adult patients.
Indicated for patients with disease progression on crizotinib and at least one other ALK inhibitor or who have received alectinib or ceritinib as first ALK inhibitor therapy.
Management of NSCLC with CNS metastases due to central nervous system penetration capability.
Used as third-line or later therapy in ALK-positive NSCLC refractory to previous ALK inhibitors.
Oral investigational use in clinical trials for other tumors harboring ALK or ROS1 rearrangements.
For patients who have failed prior therapies, offers an option with improved CNS efficacy.
May serve as a second-line targeted therapy alternative in advanced NSCLC harboring ALK mutations.
Improves progression-free survival in ALK-positive NSCLC patients compared to chemotherapy.
Part of personalized medicine approach based on biomarker testing for ALK gene rearrangement.
Used to delay disease progression and improve quality of life in advanced NSCLC patients.
Provides therapeutic benefit in patients with limited options due to resistance mutations.
Facilitates outpatient management of metastatic NSCLC with oral dosing regimen.
Adjuvant use is under investigation but currently limited to metastatic settings.
Shown to have durable responses in clinical trials with manageable safety profile.
Can be combined with supportive care to manage side effects and enhance patient compliance.

Side Or Adverse Effects

Peripheral edema characterized by swelling of hands, arms, legs, and feet.
Peripheral neuropathy presenting as numbness, tingling, or burning sensations in extremities.
Mood changes including depression, irritability, and mood swings.
Fatigue and tiredness impacting daily functioning.
Weight gain noted in some patients during treatment.
Joint pain or arthralgia, sometimes interfering with mobility.
Diarrhea varying from mild to moderate severity.
Cognitive effects such as memory and speech difficulties reported.
Hallucinations or unusual changes in thought processes or behavior.
Respiratory symptoms including dry cough, wheezing, or sudden chest pain.
Increased cholesterol and triglyceride levels requiring monitoring and management.
Risk of severe allergic reactions including hives and anaphylaxis.
Seizures reported, especially in patients with a prior history of seizure disorder.
Potential liver enzyme elevations necessitating hepatic function monitoring.
Cardiac conduction abnormalities such as atrioventricular (AV) block in susceptible patients.

Precautions

Inform healthcare provider of existing heart problems, such as AV block, before starting therapy.
Monitor liver function regularly due to hepatic metabolism and potential liver toxicity.
Screen for and manage hyperlipidemia, as lorlatinib can increase cholesterol and triglycerides.
Use caution in patients with lung diseases or breathing difficulties.
Careful psychiatric evaluation and monitoring for mood changes or depressive symptoms.
Avoid use during pregnancy due to potential for fetal harm and congenital anomalies.
Use effective contraception during and after treatment (6 months post-dose for women, 3 months for men).
Advise male patients that fertility may be affected; recommend contraception even if fertility is preserved.
Do not breastfeed during treatment and for at least 7 days after last dose.
Avoid concomitant use of St. John’s wort and other strong CYP3A inducers or inhibitors.
Adjust or interrupt dose in patients experiencing severe adverse effects, including CNS toxicity.
Regular neurologic assessments recommended for early detection of cognitive or neuropathic symptoms.
Educate patients on signs of allergic reactions and instruct immediate medical consultation if symptoms occur.
Monitor QT interval and ECG as cardiac conduction may be impacted in susceptible patients.
Maintain hydration and general supportive care during treatment to mitigate side effects.

Warnings

Lorlatinib can cause severe mood alterations, including depression and suicidal ideation.
Risk of seizures especially in patients with a history or predisposition to seizure disorders.
Potential for serious allergic reactions requiring immediate discontinuation and treatment.
Can cause fetal harm; contraindicated in pregnancy unless no alternative therapy is available.
May reduce effectiveness of hormonal contraceptives; alternative methods of contraception should be used.
Risk of hepatotoxicity necessitates regular liver function monitoring.
Avoid abrupt discontinuation without physician guidance to prevent disease progression.
CNS toxicities including cognitive and speech impairments require close clinical monitoring.
Hypersensitivity reactions including urticaria and angioedema have been reported.
Drug interactions can alter lorlatinib levels causing toxicity or therapeutic failure.
Progression of cardiac conduction abnormalities may occur; patients with preexisting conduction disease at risk.
Patients should avoid herbal supplements like St. John’s wort due to interaction potential.
Use caution in patients with pulmonary conditions as respiratory adverse events can be severe.
Should only be used in patients with confirmed ALK gene rearrangements positive NSCLC.
Potential for permanent discontinuation if intolerable side effects develop.

Contraindication

Known hypersensitivity to lorlatinib or any component of the formulation.
Pregnancy due to risk of fetal harm and congenital malformations.
Use in breastfeeding women due to potential for serious adverse reactions in infants.
Patients with severe uncontrolled cardiac conduction abnormalities without pacemaker support.
Concomitant use with strong CYP3A4 inducers that significantly reduce lorlatinib plasma concentration.
Patients with known severe hepatic impairment without dose adjustment or close monitoring.
History of severe allergic reactions to multikinase inhibitors similar to lorlatinib.
Use in patients without confirmed ALK or ROS1 genetic markers for NSCLC.
Patients unable to comply with contraception requirements during and after treatment.
Concomitant use with drugs highly sensitive to CYP3A4 metabolism with narrow therapeutic indices without monitoring.

Drug Interactions

Strong CYP3A4 inducers (e.g., rifampin, carbamazepine) can decrease lorlatinib plasma levels reducing efficacy.
Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin) can increase lorlatinib plasma levels increasing toxicity risk.
Lorlatinib may reduce the effectiveness of hormonal contraceptives including pills, patches, injections, implants, and vaginal rings.
Co-administration with St. John’s wort is contraindicated due to significant induction of CYP3A4 enzyme.
Drugs metabolized by CYP3A4 with narrow therapeutic windows may have altered levels when given with lorlatinib.
Potential additive CNS effects with other neuroactive drugs increasing risk of seizures or mood changes.
Caution with other multikinase inhibitors or chemotherapy agents due to overlapping toxicities.
Lorlatinib may affect P-glycoprotein substrates, altering distribution and elimination of certain drugs.
Interaction with anticoagulants may require closer monitoring of coagulation parameters.
Concomitant use with strong acid reducers may affect absorption but clinical significance is unclear.
Potential interaction with lipid-lowering agents as lorlatinib can induce hyperlipidemia requiring medication adjustments.
Avoid concurrent use with other drugs known to prolong QT interval due to additive cardiac risk.
Interactions with immunosuppressants or immunotherapies have not been fully characterized; caution advised.
Drugs affecting CNS function (e.g., benzodiazepines) may increase CNS adverse effects when used with lorlatinib.
Potential for altered metabolism when coadministered with drugs impacting UDP-glucuronosyltransferase enzymes.

Preparations Of The Drug

Lorlatinib is supplied as oral tablets formulated for daily administration.
Available strengths include 25 mg and 100 mg tablets enabling flexible dosing.
Tablets should be stored at room temperature away from moisture and heat.
Tablets are to be swallowed whole with water; crushing or chewing is not recommended.
Packaging includes child-resistant containers to prevent accidental ingestion.
Accompanying patient information leaflets detail dosing instructions and safety information.
Supplied by specialized pharmaceutical manufacturers under brand name Lorbrena.
No parenteral or intravenous formulations currently available.
Not recommended for compounding into alternate dosage forms due to stability and bioavailability concerns.
Distribution requires adherence to handling standards for oncology medications.
Shelf-life and storage conditions conform to standard practices for oral kinase inhibitors.
Packaging includes warnings on teratogenic risk and necessity for contraception.
Accompanied by medication guides emphasizing adherence and potential drug interactions.
Prescription-only medication with distribution limited to oncology pharmacies.
Manufactured under stringent quality controls ensuring purity and potency.