SUMMARY: The FDA on March 3, 2021, granted regular approval to LORBRENA® (Lorlatinib) for patients with metastatic Non Small Cell Lung Cancer (NSCLC) whose tumors are Anaplastic Lymphoma Kinase (ALK)-positive, as detected by an FDA-approved test. The FDA also approved the Ventana ALK (D5F3) CDx Assay (Ventana Medical Systems, Inc.) as a companion diagnostic for LORBRENA®. Lung cancer is the leading cause of cancer death in both men and women, and accounts for about 14% of all new cancers and 25% of all cancer deaths. The American Cancer Society estimates that for 2021, about 235,760 new cases of lung cancer will be diagnosed and 131,880 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Of the three main subtypes of NSCLC, 30% are Squamous Cell Carcinomas (SCC), 40% are Adenocarcinomas and 10% are Large Cell Carcinomas. With changes in the cigarette composition and decline in tobacco consumption over the past several decades, Adenocarcinoma now is the most frequent histologic subtype of lung cancer.
The discovery of chromosomal rearrangements of the Anaplastic Lymphoma Kinase (ALK) gene in some patients with advanced NSCLC and adenocarcinoma histology, and their sensitivity to ALK inhibitors, paved the way to the development of small-molecule ALK Tyrosine Kinase Inhibitors. It has become clear that appropriate, molecularly targeted therapy for tumors with a molecular abnormality, results in the best outcomes. According to the US Lung Cancer Mutation Consortium (LCMC), two thirds of patients with advanced adenocarcinoma of the lung, have a molecular driver abnormality. The most common oncogenic drivers in patients with advanced adenocarcinoma of the lung are, KRAS in 25%, EGFR in 21% and ALK in 8%, as well as other mutations in BRAF, HER2, AKT1 and fusions involving RET and ROS oncogenes. These mutations are mutually exclusive, and the presence of two simultaneous mutations, are rare.
ALK inhibitors include first-generation XALKORI® (Crizotinib) and second-generation ALK inhibitors such as ZYKADIA® (Ceritinib), ALECENSA® (Alectinib) and ALUNBRIG® (Brigatinib). Despite the improved efficacy of second-generation ALK inhibitors, recurrent disease due to drug resistance including CNS disease progression, can still develop.
LORBRENA® is a novel third-generation ALK inhibitor that is more potent than second-generation inhibitors, and has the broadest coverage of ALK resistance mutations that have been identified. LORBRENA® crosses the blood-brain barrier and has marked intracranial activity in previously treated patients with baseline CNS disease, including leptomeningeal disease. LORBRENA® received accelerated approval by the FDA in November 2018 for the second or third-line treatment of ALK-positive metastatic NSCLC. However, the efficacy of LORBRENA®, as compared with that of XALKORI®, as first line treatment for advanced ALK-positive NSCLC, has been unclear.
The CROWN trial is a global, open label, randomized, Phase 3 study, in which LORBRENA® was compared with XALKORI®, in patients with previously untreated ALK-positive advanced NSCLC. In this study, 296 treatment naïve advanced NSCLC patients were randomly assigned 1:1 to receive LORBRENA® 100 mg orally once daily (N=149) or XALKORI® 250 mg orally twice daily (N=147) in cycles of 28 days. Treatment was continued until disease progression or unacceptable toxic effects. Eligible patients were required to have ALK-positive tumors detected by the Ventana ALK (D5F3) CDx assay. Patients with asymptomatic treated or untreated CNS metastases were eligible and had to have at least one extracranial measurable target lesion that had not been previously irradiated. Patients were stratified according to the presence of brain metastases and ethnic group (Asian or non-Asian) and crossover between the treatment groups was not permitted. The Primary end point was Progression Free Survival (PFS) as assessed by Blinded Independent Central Review (BICR). Secondary end points included independently assessed Objective Response Rate (ORR) and intracranial response.
At a planned interim analysis, treatment with LORBRENA® resulted in statistically significant and clinically meaningful improvement in PFS as assessed by BICR, with a Hazard Ratio of 0.28 (P<0.001), corresponding to a 72% reduction in the risk of disease progression or death. The median PFS was not estimable in the LORBRENA® arm and was 9.3 months for those treated with XALKORI®. The percentage of patients who were alive without disease progression at 12 months was 78% in the LORBRENA® group and 39% in the XALKORI® group, and the Hazard Ratio favored LORBRENA® over XALKORI® across all prespecified patient subgroups. The Overall Survival data were immature at the PFS analysis.
The confirmed ORR was 76% with LORBRENA® and 58% with XALKORI®. About 70% of the patients who received LORBRENA® and 27% of those who received XALKORI® had a response that lasted at least 12 months. Additionally, treatment with LORBRENA® was associated with increased intracranial activity compared with XALKORI®. Among patients presenting with measurable brain metastases, the intracranial ORR was 82% with LORBRENA® and 23% with XALKORI®, with a intracranial Complete Response rate of 71% and 8%, respectively. The duration of intracranial response was 12 months or more in 79% and 0% of patients in the LORBRENA® and XALKORI® groups, respectively. The most common adverse events with LORBRENA® were hyperlipidemia, edema, weight gain, peripheral neuropathy, and cognitive effects.
It was concluded that treatment LORBRENA® resulted in a significantly longer Progression Free Survival and a higher frequency of intracranial response, compared to XALKORI®, among patients with previously untreated advanced ALK-positive NSCLC.
First-Line Lorlatinib or Crizotinib in Advanced ALK-Positive Lung Cancer. Shaw AT, Bauer TM, de Marinis F, et al. N Engl J Med 2020; 383:2018-2029.
