Early Circulating Tumor DNA Dynamics and Efficacy of Lorlatinib in Patients With Treatment-Naive, Advanced, ALK-Positive NSCLC.

INTRODUCTION: Circulating tumor DNA (ctDNA) has been used as a biomarker for prognostication and response to treatment. Here, we evaluate ctDNA as a potential biomarker for response to lorlatinib, a third-generation ALK tyrosine kinase inhibitor in patients with treatment-naive, advanced, ALK-positive NSCLC in the ongoing phase 3 CROWN study (NCT03052608). METHODS: Molecular responses were calculated using mean variant allele frequency (VAF), longitudinal mean change in VAF (dVAF), and ratio to baseline. Efficacy assessments (progression-free survival [PFS] and objective response rate) were paired with individual patient ctDNA and analyzed for association. RESULTS: Compared with baseline, mean VAF at week 4 was decreased in both treatment arms. Considering all detected somatic variants, a reduction in dVAF (≤0) was associated with a longer PFS in the lorlatinib arm. The hazard ratio (HR) for a dVAF less than or equal to 0 versus more than 0 was 0.50 (95% confidence interval [CI]: 0.23-1.12) in the lorlatinib arm. A similar association was not observed for crizotinib (HR = 1.00, 95% CI: 0.49-2.03). Comparing molecular responders with nonresponders, patients treated with lorlatinib who had a molecular response had longer PFS (HR = 0.37, 95% CI: 0.16-0.85); patients treated with crizotinib who had a molecular response had similar PFS as those without a molecular response (HR = 1.48, 95% CI: 0.67-3.30). CONCLUSIONS: In patients with treatment-naive, advanced, ALK-positive NSCLC, early ctDNA dynamics predicted better outcome with lorlatinib but not with crizotinib. These results suggest that ctDNA may be used to monitor and potentially predict efficacy of lorlatinib treatment.

Asian Subgroup Analysis of the Randomized Phase 3 CROWN Study of First-Line Lorlatinib Versus Crizotinib in Advanced ALK-Positive NSCLC.

Introduction: Lorlatinib is a potent, third-generation inhibitor of ALK. In the planned interim analysis of the ongoing, phase 3, randomized, global CROWN trial (NCT03052608), lorlatinib resulted in significantly longer progression-free survival than crizotinib in patients with previously untreated, advanced, ALK-positive NSCLC. Here, we present a subgroup analysis of Asian patients in the CROWN study. Methods: Patients received lorlatinib 100 mg once daily or crizotinib 250 mg twice daily. The primary end point was progression-free survival assessed by blinded independent central review. Objective response rate (ORR), intracranial ORR, safety, and select biomarkers were secondary end points. Results: At data cutoff (September 20, 2021), 120 patients were included in the Asian intention-to-treat subgroup (lorlatinib n = 59; crizotinib n = 61). At 36 months, 61% (95% confidence interval [CI]: 47-72) and 25% (95% CI: 12-41) of patients in the lorlatinib and crizotinib groups, respectively, were alive without disease progression (hazard ratio for disease progression by blinded independent central review or death: 0.40; 95% CI: 0.23-0.71). ORR was 78% (95% CI: 65-88) versus 57% (95% CI: 44-70) for patients treated with lorlatinib and crizotinib, respectively. In patients with measurable, nonmeasurable, or both measurable and nonmeasurable brain metastases at baseline, intracranial ORR was 73% (95% CI: 39-94) versus 20% (95% CI: 4-48) for patients treated with lorlatinib and crizotinib, respectively. The definition of nonmeasurable brain metastases is: a brain lesion less than 10 mm in MRI scan is defined as nonmeasurable brain metastasi based on RECIST criteria (Clinical trial evaluation criteria). Hypercholesterolemia, hypertriglyceridemia, and edema were the most frequently reported adverse events with lorlatinib. Conclusions: Lorlatinib efficacy and safety in the Asian subgroup of CROWN were consistent with those in the overall population.

Plain language summary of the CROWN study comparing lorlatinib with crizotinib for people with untreated non-small cell lung cancer.

This is a summary of a research study (known as a clinical trial) called CROWN. The study tested two medicines called lorlatinib and crizotinib in participants with untreated non-small cell lung cancer that had spread to other parts of their body. All those who took part had changes in a gene called ALK, which is involved in cell growth. In total, 296 participants from 23 countries took part. Half the participants took lorlatinib and half took crizotinib. After participants started taking lorlatinib or crizotinib, they were checked regularly to see if their tumors had grown or spread to other parts of their body (known as tumor progression) and to monitor any side effects. After 1 year of treatment, the participants who took lorlatinib were twice as likely to be alive with no tumor growth as the participants who took crizotinib. More participants who took lorlatinib had cancer that shrank (76%) compared with the participants who took crizotinib (58%). This was also true of the participants whose cancer had spread to their brain. The most common side effects in participants who took lorlatinib were increases in the amount of cholesterol and triglycerides (a type of fat) in their blood, swelling, weight gain, nerve damage, unclear thoughts, and diarrhea. Among the participants who took crizotinib, the most common side effects were diarrhea, feeling like you want to throw up, sight problems, swelling, vomiting, changes in liver function, and feeling tired. Overall, the CROWN study showed that fewer participants with advanced ALK+ non-small cell lung cancer died or had tumor growth with lorlatinib compared with crizotinib treatment. ClinicalTrials.gov NCT number: NCT03052608.

Neurotrophin/Trk receptor signaling mediates C/EBPalpha, -beta and NeuroD recruitment to immediate-early gene promoters in neuronal cells and requires C/EBPs to induce immediate-early gene transcription.

BACKGROUND: Extracellular signaling through receptors for neurotrophins mediates diverse neuronal functions, including survival, migration and differentiation in the central nervous system, but the transcriptional targets and regulators that mediate these diverse neurotrophin functions are not well understood. RESULTS: We have identified the immediate-early (IE) genes Fos, Egr1 and Egr2 as transcriptional targets of brain derived neurotrophic factor (BDNF)/TrkB signaling in primary cortical neurons, and show that the Fos serum response element area responds to BDNF/TrkB in a manner dependent on a combined C/EBP-Ebox element. The Egr1 and Egr2 promoters contain homologous regulatory elements. We found that C/EBPalpha/beta and NeuroD formed complexes in vitro and in vivo, and were recruited to all three homologous promoter regions. C/EBPalpha and NeuroD co-operatively activated the Fos promoter in transfection assays. Genetic depletion of Trk receptors led to impaired recruitment of C/EBPs and NeuroD in vivo, and elimination of Cebpa and Cebpb alleles reduced BDNF induction of Fos, Egr1 and Egr2 in primary neurons. Finally, defective differentiation of cortical dendrites, as measured by MAP2 staining, was observed in both compound Cebp and Ntrk knockout mice. CONCLUSION: We here identify three IE genes as targets for BDNF/TrkB signaling, show that C/EBPalpha and -beta are recruited along with NeuroD to target promoters, and that C/EBPs are essential mediators of Trk signaling in cortical neurons. We show also that C/EBPs and Trks are required for cortical dendrite differentiation, consistent with Trks regulating dendritic differentiation via a C/EBP-dependent mechanism. Finally, this study indicates that BDNF induction of IE genes important for neuronal function depends on transcription factors (C/EBP, NeuroD) up-regulated during neuronal development, thereby coupling the functional competence of the neuronal cells to their differentiation.