Safety and activity of alectinib against systemic disease and brain metastases in patients with crizotinib-resistant ALK-rearranged non-small-cell lung cancer (AF-002JG): results from the dose-finding portion of a phase 1/2 study.

BACKGROUND: Patients with non-small-cell lung cancer (NSCLC) and ALK rearrangements generally have a progression-free survival of 8-11 months while on treatment with the ALK inhibitor crizotinib. However, resistance inevitably develops, with the brain a common site of progression. More potent ALK inhibitors with consistently demonstrable CNS activity and good tolerability are needed urgently. Alectinib is a novel, highly selective, and potent ALK inhibitor that has shown clinical activity in patients with crizotinib-naive ALK-rearranged NSCLC. We did a phase 1/2 study of alectinib to establish the recommended phase 2 dose of the drug and examine its activity in patients resistant or intolerant to crizotinib. METHODS: We enrolled patients with ALK-rearranged NSCLC who progressed on or were intolerant to crizotinib. We administered various oral doses of alectinib (300-900 mg twice a day) during the dose-escalation portion of the study (phase 1), to ascertain the recommended dose for phase 2. We used Response Evaluation Criteria in Solid Tumors criteria (version 1.1) to investigate the activity of alectinib in all patients with a baseline scan and at least one post-treatment scan (CT or MRI), with central radiological review of individuals with brain metastases. We assessed safety in all patients who received at least one dose of alectinib. Here, we present data for the phase 1 portion of the study, the primary objective of which was to establish the recommended phase 2 dose; phase 2 is ongoing. This trial is registered at ClinicalTrials.gov, number NCT01588028. FINDINGS: 47 patients were enrolled. Alectinib was well tolerated, with the most common adverse events being fatigue (14 [30%]; all grade 1-2), myalgia (eight [17%]; all grade 1-2), and peripheral oedema (seven [15%] grade 1-2, one [2%] grade 3). Dose-limiting toxic effects were recorded in two patients in the cohort receiving alectinib 900 mg twice a day; one individual had grade 3 headache and the other had grade 3 neutropenia. The most common grade 3-4 adverse events were increased levels of γ-glutamyl transpeptidase (two [4%]), a reduction in the number of neutrophils (two [4%]), and hypophosphataemia (two [4%]). Three patients reported four grade 4 serious adverse events that were deemed unrelated to alectinib: acute renal failure; pleural effusion and pericardial effusion; and brain metastasis. At data cut-off (median follow-up 126 days [IQR 84-217]), 44 patients could be assessed for activity. Investigator-assessed objective responses were noted in 24 (55%) patients, with a confirmed complete response in one (2%), a confirmed partial response in 14 (32%), and an unconfirmed partial response in nine (20%). 16 (36%) patients had stable disease; the remaining four (9%) had progressive disease. Of 21 patients with CNS metastases at baseline, 11 (52%) had an objective response; six (29%) had a complete response (three unconfirmed) and five (24%) had a partial response (one unconfirmed); eight (38%) patients had stable disease and the remaining two (10%) had progressive disease. Pharmacokinetic data indicated that mean exposure (AUC0-10) after multiple doses of alectinib (300-600 mg twice a day) was dose-dependent. INTERPRETATION: Alectinib was well tolerated, with promising antitumour activity in patients with ALK-rearranged NSCLC resistant to crizotinib, including those with CNS metastases. On the basis of activity, tolerability, and pharmacokinetic data, we chose alectinib 600 mg twice a day as the recommended dose for phase 2. FUNDING: Chugai Pharmaceuticals, F Hoffmann La-Roche.

Alectinib induced CNS radiation necrosis in an ALK+NSCLC patient with a remote (7 years) history of brain radiation.

Alectinib is a second generation ALK inhibitor that has significant clinical activity in central nervous system (CNS) metastases in anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC). Pseudoprogression (PsP) due to radiation necrosis during alecitnib treatment of central nervous system (CNS) metastases from ALK-rearranged NSCLC as been reported. Hence, distinguishing radiation-related PsP from alectinib-induced radiographic changes is important to avoid erroneous early trial discontinuation and abandonment of an effective treatment. However, it remains difficult to assess casuality of radiation necrosis is related to recent direct radiation or induced by alectinib treatment or both. It is also unknown how long from previous radiation can alectinib still induce radiation necrosis. Here we reported a crizotinib-refractory ALK-positive NSCLC patient who develop radiation necrosis in one of his metastatic CNS lesions after approximately 12 months of alectinib treatment who otherwise had on-going CNS response on alectinib. His most recent radiation to his CNS metastases was 7 years prior to the start of alectinib. This case illustrates that in the setting of pror CNS radiation, given the significant clinical activity of alectinib in CNS metastases in ALK-positive NSCLC patients the risk of CNS radiation necrosis remains long after previous radiation to the CNS metastases has been completed and can occur after durable response of treatment.

ALK F1174V mutation confers sensitivity while ALK I1171 mutation confers resistance to alectinib. The importance of serial biopsy post progression.

Many acquired resistant mutations to the anaplastic lymphoma kinase (ALK) gene have been identified during treatment of ALK-rearranged non-small cell lung cancer (NSCLC) patients with crizotinib, ceritinib, and alectinib. These various acquired resistant ALK mutations confer differential sensitivities to various ALK inhibitors and may provide guidance on how to sequence the use of many of the second generation ALK inhibitors. We described a patient who developed an acquired ALK F1174V resistant mutation on progression from crizotinib that responded to alectinib for 18 months but then developed an acquired ALK I1171S mutation to alectinib. Both tumor samples had essentially the same genomic profile by comprehensive genomic profiling otherwise. This is the first patient report that demonstrates ALK F1174V mutation is sensitive to alectinib and further confirms missense acquired ALK I1171 mutation is resistant to alectinib. Sequential tumor re-biopsy for comprehensive genomic profiling (CGP) is important to appreciate the selective pressure during treatment with various ALK inhibitors underpinning the evolution of the disease course of ALK+NSCLC patients while on treatment with the various ALK inhibitors. This approach will likely help inform the optimal sequencing strategy as more ALK inhibitors become available. This case report also validates the importance of developing structurally distinct ALK inhibitors for clinical use to overcome non-cross resistant ALK mutations.

Choroidal metastasis response to crizotinib in a ROS1-rearranged NSCLC patient.

OBJECTIVES: Choroidal metastases are uncommon metastasis from non-small cell lung cancer (NSCLC). With improved survival from the use of targeted therapy against actionable driver mutation driven NSCLC, the incidence of choroidal metastases seems to be increasing. Recently, there are several case reports of choroidal metastases in patients with anaplastic lymphoma kinase (ALK)-driven NSCLC one of which the patient's choroidal metastases had responded to crizotinib, multi-targeted tyrosine kinase inhibitor against ALK/ROS1/MET. Similarly ROS1-rearranged NSCLC has very similar clinicopathologic characteristics as ALK-rearranged NSCLC and crizotinib has demonstrated significant clinical activity against ROS1-rearranged NSCLC. MATERIALS AND METHODS: Here in this report we presented a patient with ROS1-rearranged NSCLC that presented with choroidal metastases that did not respond to initial chemotherapy but had a rapid and complete response to crizotinib. CONCLUSIONS: Although likely to be exceeding rare, choroidal metastases from ROS1-rearranged NSCLC can be successfully treated with crizotinib similar to choroidal metastases from ALK-rearranged NSCLC can be successfully treated from another case report.

Radiation necrosis presenting as pseudoprogression (PsP) during alectinib treatment of previously radiated brain metastases in ALK-positive NSCLC: Implications for disease assessment and management.

OBJECTIVES: Radiation necrosis presenting as pseudoprogression (PsP) is relatively common after radiation and temozolomide (TMZ) treatment in glioblastoma multiforme (GBM), especially among patients with GBM that harbors intrinsic increased responsiveness to TMZ (methylated O6-methylguanine-DNA methyltransferase [MGMT] promoter). Alectinib is a second generation ALK inhibitor that has significant CNS activity against brain metastases in anaplastic lymphoma kinase (ALK)-rearranged (ALK+) non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: We report 2 ALK+ NSCLC patients who met RECIST criteria for progressive disease by central radiologic review due to increased in size from increased contrast enhancement in previously stereotactically radiated brain metastases with ongoing extra-cranial response to alectinib. In both patients alectinib was started within 4 months of completing stereotactic radiosurgery (SRS). The enlarging lesions in both patients were resected and found to have undergone extensive necrosis with no residual tumor pathologically. PsP was incorrectly classified as progressive disease even by central independent imaging review. CONCLUSIONS: Treatment-related necrosis of previously SRS-treated brain metastasis during alectinib treatment can present as PsP. It may be impossible to distinguish PsP from true disease progression without a pathologic examination from resected sample. High degree of clinical suspicion, close monitoring and more sensitive imaging modalities may be needed to distinguish PsP versus progression in radiated brain lesions during alectinib treatment especially if there is no progression extra-cranially.

I1171 missense mutation (particularly I1171N) is a common resistance mutation in ALK-positive NSCLC patients who have progressive disease while on alectinib and is sensitive to ceritinib.

OBJECTIVES: Acquired resistance mutations to anaplastic lymphoma kinase (ALK) inhibitors such as crizotinib and alectinib have been documented in non-small cell lung cancer (NSCLC) patients harboring ALK rearrangement (ALK+). Of note I1171T/N/S mutations in the ALK kinase domain have recently been described by several groups to confer resistance to alectinib, a second-generation ALK inhibitor. Additionally one of these reports demonstrated one ALK+ NSCLC patient harboring an I1171T acquired mutation has responded to ceritinib, another second-generation ALK inhibitor. MATERIALS AND METHODS: We reported the presence of an ALK I1171N resistance mutation from comprehensive genomic profiling from a liver biopsy of a progressing metastatic lesion in an ALK+ patient on alectinib after an initial partial response. The patient then responded to ceritinib 750 mg orally once daily but required dose reduction to 600 mg once daily. She initially had grade 3 elevation of liver enzymes from crizotinib necessitating the original switch to alectinib but experienced no transaminase elevations with alectinib or ceritinib. CONCLUSIONS: This is the fifth patient case to date demonstrating that ALK I1171 mutation confers resistance to alectinib and the second reported case of ALK I1171 mutation being sensitivity to ceritinib. Substitutions of isoleucine at amino acid 1171 in the ALK kinase domain may distinguish which second generation ALK inhibitor will be effective after crizotinib failure. This case also provides evidence that transaminase elevations is likely a unique adverse event associated with crizotinib and unlikely a "class" effect involving all ALK inhibitors.

Identification of a novel TMEM106B-ROS1 fusion variant in lung adenocarcinoma by comprehensive genomic profiling.

OBJECTIVES: ROS1-rearranged non-small cell lung cancer (NSCLC) is a unique molecularly defined yet heterogeneous subset of NSCLC. To date 12 known fusion partners of ROS1 in NSCLC have been reported. While crizotinib, a multi-targeted ALK/ROS1/MET tyrosine kinase inhibitor (TKI), has demonstrated significant clinical activity in ROS1-rearranged NSCLC, no companion diagnostic assay has been approved for the detection of ROS1-rearrange NSCLC by the US FDA. Comprehensive genomic profiling (CGP), a subtype of clinical next-generation sequencing (NGS), offers a uniquely comprehensive and convenient approach to detect the ever-increasing and "druggable" receptor-kinase rearrangements being discovered in lung cancer. MATERIALS AND METHODS: We identified a novel ROS1 fusion variant (TMEM106B-ROS1) in a stage IV adenocarcinoma of the lung never-smoker female patient during routine genomic profiling (FoundationOne). This novel TMEM106B-ROS1 fusion variant is generated by the fusion of exons 1-3 of TMEMB106B on chromosome 7p21 to the exons 35-43 of ROS1 on chromosome 6q22. The predicted TMEM106-ROS1 protein product contains 540 amino acids comprising of the N-terminal amino acids 1-73 of TMEMB106 and C-terminal amino acids of 1881-2341 of ROS1. Although there is no predicted "coiled-coil" domain in the N-terminal domain of TMEM106B, the N-terminal domain of TMEM106B is involved in homo- and hetero-dimerization with other TMEM106 family members. CONCLUSIONS: TMEM106B-ROS1 is a novel ROS1 fusion variant in NSCLC identified by comprehensive genomic profiling and should be included in any ROS1 detecting assay that depends on identifying the corresponding fusion partners such as reverse transcriptase-polymerase chain reaction (RT-PCR).