Clinical and Radiographic Response of Leptomeningeal and Brain Metastases to Encorafenib and Binimetinib in a Patient With BRAF V600E-Mutated Lung Adenocarcinoma

Leptomeningeal Metastasis from Non-Small Cell Lung Cancer and Current Landscape of Treatments

Leptomeningeal metastasis (LM), also known as leptomeningeal carcinomatosis (LC), is a devastating complication of metastatic cancer that occurs when neoplastic cells invade the meningeal space. Diagnosis of LM remains challenging given the heterogeneous signs and symptoms at presentation and requires thorough neurological examination, cerebrospinal fluid (CSF) analysis, and MRI of the brain and spine with gadolinium. Detecting neoplastic cells in the CSF is the gold standard for diagnosing leptomeningeal metastases; however, it has low sensitivity and may require multiple CSF samples. New emerging technologies, such as liquid biopsy of CSF, have increased sensitivity and specificity for detecting circulating tumor cells in CSF. The management of LM in patients with NSCLC requires an individualized multidisciplinary approach. Treatment options include surgery for ventricular shunt placement, radiation therapy to bulky or symptomatic disease sites, systemic or intrathecal chemotherapy, molecularly targeted agents, and, more recently, immunotherapy. Targeting actionable mutations in LM from NSCLC, such as EGFR tyrosine kinase inhibitors or anaplastic lymphoma kinase gene rearrangement inhibitors, has shown encouraging results in terms of disease control and survival. Although there are limited data regarding the use of immunotherapy in LM, immunotherapy has produced promising results in several case reports. In this review, we focused on the epidemiology, pathophysiology, clinical presentation, diagnosis, and current treatment strategies, with a special emphasis on novel agents, including targeted therapies and immunotherapy of LM in patients with NSCLC.

COLUMBUS 5-Year Update: A Randomized, Open-Label, Phase III Trial of Encorafenib Plus Binimetinib Versus Vemurafenib or Encorafenib in Patients With BRAF V600-Mutant Melanoma

PURPOSE

Combination treatment with BRAF and MEK inhibitors has demonstrated benefits on progression-free survival (PFS) and overall survival (OS) and is a standard of care for the treatment of advanced BRAF V600-mutant melanoma. Here, we report the 5-year update from the COLUMBUS trial (ClinicalTrials.gov identifier: NCT01909453).

METHODS

Patients with locally advanced unresectable or metastatic BRAF V600-mutant melanoma, untreated or progressed after first-line immunotherapy, were randomly assigned 1:1:1 to encorafenib 450 mg once daily plus binimetinib 45 mg twice daily, vemurafenib 960 mg twice daily, or encorafenib 300 mg once daily. An updated analysis was conducted 65 months after the last patient was randomly assigned.

RESULTS

Five hundred seventy-seven patients were randomly assigned: 192 to encorafenib plus binimetinib, 191 to vemurafenib, and 194 to encorafenib. The 5-year PFS and OS rates with encorafenib plus binimetinib were 23% and 35% overall and 31% and 45% in those with normal lactate dehydrogenase levels, respectively. In comparison, the 5-year PFS and OS rates with vemurafenib were 10% and 21% overall and 12% and 28% in those with normal lactate dehydrogenase levels, respectively. The median duration of response with encorafenib plus binimetinib was 18.6 months, with disease control achieved in 92.2% of patients. In comparison, the median duration of response with vemurafenib was 12.3 months, with disease control achieved in 81.2% of patients. Long-term follow-up showed no new safety concerns, and results were consistent with the known tolerability profile of encorafenib plus binimetinib. Interactive visualization of the data presented in this article is available at COLUMBUS dashboard.

CONCLUSION

In this 5-year update of part 1 of the COLUMBUS trial, encorafenib plus binimetinib treatment demonstrated continued long-term benefits and a consistent safety profile in patients with BRAF V600-mutant melanoma.

Targeting Infrequent Driver Alterations in Non-Small Cell Lung Cancer

The discovery of oncogenic driver mutations led to the development of targeted therapies with non-small cell lung cancer (NSCLC) being a paradigm for precision medicine in this setting. Nowadays, the number of clinical trials focusing on targeted therapies for uncommon drivers is growing exponentially, emphasizing the medical need for these patients. Unfortunately, similar to what is observed with most targeted therapies directed against a driver oncogene, the clinical response is almost always temporary and acquired resistance to these drugs invariably emerges. Here, we review the biology of infrequent genomic actionable alterations in NSCLC as well as the current and emerging therapeutic options for these patients. Mechanisms leading to acquired drug resistance and future challenges in the field are also discussed.

Leptomeningeal Metastases in Non-small Cell Lung Cancer: Optimal Systemic Management in NSCLC With and Without Driver Mutations

OPINION STATEMENT

As a devastating complication of non-small cell lung cancer (NSCLC), the incidence of leptomeningeal metastasis (LM) is rising, largely due to overall longer survival of NSCLC, especially in patients with targetable molecular driver mutations. There is no clear consensus on the optimal management of LM. This review will cover recent advances in diagnosis, monitoring, and treatment of LM in NSCLC. In LM without oncogene drivers, systemic chemotherapy, intrathecal therapy, and radiation have modestly improved the clinical outcomes. Emerging data have also suggested encouraging activity of immunotherapy. At the same time, in LM with sensitizing EGFR mutations, osimertinib should be considered regardless of T790M status. Pulse erlotinib, afatinib, and newer agents with improved CNS penetration have also shown benefits. Moreover, accumulating evidences support potential benefits of molecularly targeted therapy in ALK-rearranged and other oncogene-driven NSCLC with LM. Future studies are warranted to better define the underlying mechanism, to optimize the clinical management, and to improve patient outcomes.