Lung cancer patients with a specific genetic alteration lived longer and were protected against metastasis to the brain when treated early with the drug lorlatinib (Lorbrena), according to a study led by researchers at Massachusetts General Hospital (MGH), published in the New England Journal of Medicine (NEJM).
Non-small-cell lung cancer (NSCLC) accounts for 87% of all cases of lung cancer. Some 5% of NSCLC cases are ALK-positive, which means they have a genetic abnormality in the anaplastic lymphoma kinase gene. ALK-positive NSCLC, which is not associated with smoking, is a particularly aggressive form of lung cancer.
"When ALK is turned on abnormally, it's like stepping on the gas pedal — it drives uncontrolled proliferation and survival of cancer cells," says investigator Dr Alice Shaw, who was formerly director of the Center for Thoracic Cancers at MGH and led the study. Notably, ALK-positive patients tend to be 10 to 15 years younger than other lung cancer patients. They are also at high risk for developing brain metastasis.
A new class of drugs that block ALK, known as ALK inhibitors, was discovered in 2008. "Turning off ALK with an ALK inhibitor is like putting on the brakes," agrees Dr Justin Gainor, of the Mass General Cancer Center, who worked with Shaw on the study. "It can lead to rapid killing of cancer cells and cause tumors to shrink dramatically." Both first and second generation ALK inhibitors have been developed, including crizotinib (Xalkori), alectinib (Alecensa), and brigatinib (Alunbrig), which can be very effective, but patients eventually relapse. What's more, patients treated with these drugs can still develop metastatic spread of cancer to the brain.
Lorlatinib belongs to a third-generation of this drug class and is even more effective at blocking ALK. It's currently approved by the Food and Drug Administration for treating ALK-positive patients whose cancer has progressed despite taking older-generation ALK inhibitors.
Shaw and her co-investigators wanted to know if lorlatinib improved the likelihood of long-term remission in ALK-positive patients when administered as first-line therapy. To find out, she and colleagues at 104 medical centers in 23 countries recruited 296 patients with advanced, previously untreated ALK-positive NSCLC. Half of the patients received lorlatinib, while the remainder were treated with crizotinib, which was the standard of care for these patients when the trial began.
The results were striking. Compared to patients who received crizotinib, those given lorlatinib had a 72% reduction in the risk of cancer progression or death. Importantly, lorlatinib also reduced the risk of new or recurrent brain metastases by 93%. Serious side effects were more common in the lorlatinib group, but more than half were increases in blood cholesterol and triglycerides, which were manageable with medication.
The investigators will continue to follow patients in this study to track their long-term outcomes, but "these results support lorlatinib as a potential first-line option for ALK-positive patients," says Shaw.
Title: First-Line Lorlatinib or Crizotinib in Advanced ALK-Positive Lung Cancer
List of authors:
Alice T. Shaw, M.D., Ph.D., Todd M. Bauer, M.D., Filippo de Marinis, M.D., Ph.D., Enriqueta Felip, M.D., Ph.D., Yasushi Goto, M.D., Ph.D., Geoffrey Liu, M.D., Julien Mazieres, M.D., Ph.D., Dong-Wan Kim, M.D., Ph.D., Tony Mok, M.D., Anna Polli, B.Sc., Holger Thurm, M.D., Anna M. Calella, Ph.D., et al., for the CROWN Trial Investigators
Journal and Date: The New England Journal of Medicine, November 19, 2020
Lorlatinib, a third-generation inhibitor of anaplastic lymphoma kinase (ALK), has antitumor activity in previously treated patients with ALK-positive non–small-cell lung cancer (NSCLC). The efficacy of lorlatinib, as compared with that of crizotinib, as first-line treatment for advanced ALK-positive NSCLC is unclear.
We conducted a global, randomized, phase 3 trial comparing lorlatinib with crizotinib in 296 patients with advanced ALK-positive NSCLC who had received no previous systemic treatment for metastatic disease. The primary end point was progression-free survival as assessed by blinded independent central review. Secondary end points included independently assessed objective response and intracranial response. An interim analysis of efficacy was planned after approximately 133 of 177 (75%) expected events of disease progression or death had occurred.
The percentage of patients who were alive without disease progression at 12 months was 78% (95% confidence interval [CI], 70 to 84) in the lorlatinib group and 39% (95% CI, 30 to 48) in the crizotinib group (hazard ratio for disease progression or death, 0.28; 95% CI, 0.19 to 0.41; P<0.001). An objective response occurred in 76% (95% CI, 68 to 83) of the patients in the lorlatinib group and 58% (95% CI, 49 to 66) of those in the crizotinib group; among those with measurable brain metastases, 82% (95% CI, 57 to 96) and 23% (95% CI, 5 to 54), respectively, had an intracranial response, and 71% of the patients who received lorlatinib had an intracranial complete response. The most common adverse events with lorlatinib were hyperlipidemia, edema, increased weight, peripheral neuropathy, and cognitive effects. Lorlatinib was associated with more grade 3 or 4 adverse events (mainly altered lipid levels) than crizotinib (in 72% vs. 56%). Discontinuation of treatment because of adverse events occurred in 7% and 9% of the patients, respectively.
In an interim analysis of results among patients with previously untreated advanced ALK-positive NSCLC, those who received lorlatinib had significantly longer progression-free survival and a higher frequency of intracranial response than those who received crizotinib. The incidence of grade 3 or 4 adverse events was higher with lorlatinib than with crizotinib because of the frequent occurrence of altered lipid levels. (Funded by Pfizer; CROWN ClinicalTrials.gov number, NCT03052608.)
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