Lorlatinib in Previously Treated Alk-Positive Metastatic Nsclc

Patients with ALK-positive metastatic non-small cell lung cancer (mNSCLC) have benefited significantly from the evolution of targeted therapies, yet treatment decisions become increasingly challenging once disease progresses after second-generation ALK tyrosine kinase inhibitors (TKIs). New findings from a phase IV study provide additional evidence supporting the use of lorlatinib in this setting, confirming efficacy and safety outcomes observed in earlier clinical development.

Lorlatinib was initially approved by the European Medicines Agency on the basis of results from the pivotal phase I/II study NCT01970865 for patients whose disease had progressed following prior ALK-targeted therapy. However, because relatively few patients in the original development program had previously received second-generation ALK inhibitors such as alectinib or ceritinib, investigators launched a post-approval phase IV trial to further evaluate lorlatinib in this treatment population.

The open-label study enrolled adults with ALK-positive mNSCLC whose disease had progressed after first-line treatment with either alectinib or ceritinib. Participants received lorlatinib at a dose of 100 mg once daily. The primary endpoint was confirmed objective response rate (ORR) assessed by independent central review, while secondary endpoints included duration of response (DOR), progression-free survival (PFS), intracranial ORR, and safety outcomes.

Among the 71 patients treated, the majority (85%) had previously received alectinib, while the remaining 15% had received ceritinib. Median duration of lorlatinib treatment was 9.7 months, although some patients remained on therapy for more than three years.

The study achieved its primary endpoint, demonstrating a confirmed ORR of 42% (95% CI, 31%–55%). Importantly, the durability of those responses appeared substantial. After a median response follow-up of 18 months, median DOR had not yet been reached. Investigators estimated that 65% of responding patients would remain in response for at least 12 months. Clinical benefit was also reflected in progression-free survival. Median PFS reached 12.2 months (95% CI, 6.9–22.1), with approximately 51% of patients remaining progression-free at one year.

CNS involvement was also evaluated in the study. Thirty patients presented with CNS metastases at baseline. Within this subgroup, lorlatinib achieved an intracranial ORR of 47% (95% CI, 28%–66%), demonstrating antitumor activity in patients with CNS metastases. The safety profile observed in the phase IV trial was generally consistent with prior experience. Treatment-emergent adverse events (TEAEs) of any grade occurred in 97% of patients, while grade 3 or higher events were reported in 39%. The most commonly observed adverse events included hypercholesterolemia (59%), hypertriglyceridemia (56%), edema (46%), fatigue (27%), and peripheral neuropathy (21%).

Serious TEAEs occurred in 32% of participants. Adverse events prompted dose reductions in 14% of patients and treatment discontinuation in 13%. Notably, no patients discontinued treatment because of treatment-related adverse events.

Taken together, the results provide an important confirmation of lorlatinib’s clinical activity in patients whose disease progresses after frontline treatment with alectinib or ceritinib. The response rates, durability of benefit, progression-free survival outcomes, and intracranial activity remained consistent with findings from the earlier pivotal phase I/II study that supported regulatory approval.

As treatment sequencing continues to evolve for ALK-positive mNSCLC, these phase IV data help address a key evidence gap by specifically evaluating patients previously treated with second-generation ALK inhibitors. The findings reinforce lorlatinib’s role in this setting and support the conclusion that lorlatinib continued to show clinically meaningful benefit in patients with previously treated ALK-positive mNSCLC.