ALK Inhibitor Alectinib Research Articles

Absorption, distribution, metabolism and excretion (ADME) of the ALK inhibitor alectinib: results from an absolute bioavailability and mass balance study in healthy subjects

1. Alectinib is a highly selective, central nervous system-active small molecule anaplastic lymphoma kinase inhibitor.2. The absolute bioavailability, metabolism, excretion and pharmacokinetics of alectinib were studied in a two-period single-sequence crossover study. A 50 μg radiolabelled intravenous microdose of alectinib was co-administered with a single 600 mg oral dose of alectinib in the first period, and a single 600 mg/67 μCi oral dose of radiolabelled alectinib was administered in the second period to six healthy male subjects.3. The absolute bioavailability of alectinib was moderate at 36.9%. Geometric mean clearance was 34.5 L/h, volume of distribution was 475 L and the hepatic extraction ratio was low (0.14).4. Near-complete recovery of administered radioactivity was achieved within 168 h post-dose (98.2%) with excretion predominantly in faeces (97.8%) and negligible excretion in urine (0.456%). Alectinib and its major active metabolite, M4, were the main components in plasma, accounting for 76% of total plasma radioactivity. In faeces, 84% of dose was excreted as unchanged alectinib with metabolites M4, M1a/b and M6 contributing to 5.8%, 7.2% and 0.2% of dose, respectively.5. This novel study design characterised the full absorption, distribution, metabolism and excretion properties in each subject, providing insight into alectinib absorption and disposition in humans.

BMET-18ASSESSING CENTRAL NERVOUS SYSTEM (CNS) RESPONSE TO ALECTINIB IN TWO PHASE II STUDIES OF PRE-TREATED ALK+ NON-SMALL CELL LUNG CANCER (NSCLC): RECIST VERSUS RANO CRITERIA

BACKGROUND: CNS progression results in frequent treatment failure for ALK+ NSCLC patients receiving the ALK inhibitor crizotinib. CNS efficacy is important in assessing new ALK inhibitors and accurate assessment of response/progression is vital in determining treatment efficacy. Data from two phase II studies in pre-treated ALK+ NSCLC were pooled to examine the CNS efficacy of the highly selective ALK inhibitor alectinib, using both Response Evaluation Criteria in Solid Tumors (RECIST) and Response Assessment in Neuro-Oncology (RANO) criteria to evaluate brain metastases. METHODS: The phase II, single-arm, multicenter studies both enrolled ALK+ NSCLC patients aged ≥18 years who had previously received crizotinib. NP28761 was conducted in North America only (NCT01871805); NP28673 was a global study (NCT01801111). All patients in both studies received 600mg oral alectinib twice daily. Patients underwent imaging at baseline to assess CNS metastases and CNS response was determined by an independent review committee (IRC) according to RECIST v1.1 or RANO criteria. RESULTS: Fifty-one patients had baseline measurable CNS disease by IRC according to RECIST v1.1, and 43 according to RANO criteria. The CNS objective response rate (ORR) was 60.8% by RECIST (95% CI 46.1–74.2; 9 CNS complete responses [CRs]; CNS disease control rate [DCR] 90.2%) and 51.2% by RANO (95% CI 35.5–66.7; 5 CNS CRs; CNS DCR 83.7%). Responses by RECIST included both confirmed and unconfirmed responses; those by RANO had to be confirmed. Median duration of CNS response was 9.1 months with RECIST (95% CI 5.8–NE; 39% of responders with event) and 9.1 months with RANO (95% CI 7.4–NE; 36% of responders with event). CONCLUSION: Alectinib demonstrated promising and durable efficacy in the CNS for ALK+ NSCLC patients previously treated with crizotinib, regardless of the assessment criteria used. Updated results from a later cut-off, plus correlative data and additional analyses, will be presented.

Induction of PD-L1 Expression by the EML4-ALK Oncoprotein and Downstream Signaling Pathways in Non-Small Cell Lung Cancer.

Therapies targeted to the immune checkpoint mediated by PD-1 and PD-L1 show antitumor activity in a subset of patients with non-small cell lung cancer (NSCLC). We have now examined PD-L1 expression and its regulation in NSCLC positive for the EML4-ALK fusion gene. The expression of PD-L1 at the protein and mRNA levels in NSCLC cell lines was examined by flow cytometry and by reverse transcription and real-time PCR analysis, respectively. The expression of PD-L1 in 134 surgically resected NSCLC specimens was evaluated by immunohistochemical analysis. The PD-L1 expression level was higher in NSCLC cell lines positive for EML4-ALK than in those negative for the fusion gene. Forced expression of EML4-ALK in Ba/F3 cells markedly increased PD-L1 expression, whereas endogenous PD-L1 expression in EML4-ALK-positive NSCLC cells was attenuated by treatment with the specific ALK inhibitor alectinib or by RNAi with ALK siRNAs. Furthermore, expression of PD-L1 was downregulated by inhibitors of the MEK-ERK and PI3K-AKT signaling pathways in NSCLC cells positive for either EML4-ALK or activating mutations of the EGFR. Finally, the expression level of PD-L1 was positively associated with the presence of EML4-ALK in NSCLC specimens. Our findings that both EML4-ALK and mutant EGFR upregulate PD-L1 by activating PI3K-AKT and MEK-ERK signaling pathways in NSCLC reveal a direct link between oncogenic drivers and PD-L1 expression.

Abstract 5122: In vivo imaging models of bone and brain metastases and pleural carcinomatosis developed using a novel human EML4-ALK lung cancer cell line, A925LPE3

Abstract Introduction:EML4-ALK lung cancer accounts for approximately 3%-7% of non-small cell lung cancer cases. Crizotinib, an ALK tyrosine kinase inhibitor, shows dramatic clinical efficacy with a response rate of approximately 60%-80% in EML4-ALK NSCLC patients. However, almost all patients who strongly responded to crizotinib acquired resistance over time. Recently, new generation ALK-TKIs such as alectinib and ceritinib have been approved for treatment of ALK-rearranged NSCLC patients, and it is now clear that resistance may also develop against this class of inhibitors. To investigate the molecular mechanism underlying tumor progression and targeted drug sensitivity/resistance in EML4-ALK lung cancer, clinically relevant animal models are indispensable. Methods: A human lung adenocarcinoma cell line A925L, which expresses an EML4-ALK gene fusion (variant 5a, E2:A20), established from a surgical specimen obtained from a Japanese male patient. We further established highly tumorigenic A925LPE3 cells with luciferase gene transfection, which also have the EML4-ALK gene fusion. A925LPE3 cells were injected into the right thoracic cavity for the pleural carcinomatosis model, into the tibia for the bone metastasis model, and into the right striatum for the brain metastasis model. After inoculation, the quantity of tumors and the quality of bones were tracked in live mice by repeated noninvasive optical imaging of tumor-specific luciferase activity using the IVIS Lumina XR Imaging System. Results: In this study, we found that A925L and A925LPE3 cell lines are sensitive to the ALK inhibitors crizotinib and alectinib. By using A925LPE3 cells we established in vivo imaging models for pleural carcinomatosis, bone metastasis, and brain metastasis, all of which are significant clinical concerns of advanced EML4-ALK lung cancer. Interestingly, crizotinib caused tumors to shrink in the pleural carcinomatosis model, but not in bone and brain metastasis models, while alectinib showed remarkable efficacy in all three models, indicative of the clinical efficacy of these ALK inhibitors. Conclusions: Our in vivo imaging models of multiple organ sites may provide useful resources to analyze further the pathogenesis of EML4-ALK lung cancer and its response and resistance to ALK inhibitors in various organ microenvironments. Citation Format: Shigeki Nanjo, Shinji Takeuchi, Kenji Kita, Koji Fukuda, Mitsutoshi Nakada, Hiroshi Nishihara, Seiji Yano. In vivo imaging models of bone and brain metastases and pleural carcinomatosis developed using a novel human EML4-ALK lung cancer cell line, A925LPE3. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5122. doi:10.1158/1538-7445.AM2015-5122

Abstract 3309: Co-inhibition of ALK and EGFR and/or c-MET on cell growth and response to radiation in ALK-positive NSCLC cells

Abstract ALK (anaplastic lymphoma kinase), EGFR (epidermal growth factor receptor) and c-MET are molecular drivers for a subset of non-small cell lung cancers (NSCLC). Approximately 4-7% of NSCLCs carry the EML4-ALK chromosomal rearrangement. We identified overexpression of EGFR and c-MET in EML4-ALK-positive NSCLC cell lines H3122 and H2228. ALK, EGFR, and c-MET may function cooperatively to modulate tumor growth, stress response, and survival in EML4-ALK-positive cells and co-inhibition may favorably impact tumor control. We therefore investigated the effects of co-inhibition of ALK and EGFR or c-MET on cell survival and response to radiation in EML4-ALK-positive NSCLC cells. Compared with ALK-negative cell lines (H226, A549 and H520), the ALK-positive cell lines (H3122, H2228) were highly sensitive to the ALK inhibitors crizotinb, ceritinib and alectinib, although with differing sensitivity to radiation. Crizotinib, ceritinib and alectinib sensitized H3122 and H2228 to radiation, as evaluated by clonogenic assay. However, knockdown of ALK by siRNA in H3122 and H2228, or overexpression of EML4-ALK in NIH-3T3 cells, had only moderate effects on radiosensitivity. Simultaneous knockdown of ALK and MET, or ALK and EGFR, increased radiosensitivity as assessed by clonogenic survival in H3122 and H2228 cells, while also increasing inhibitory effects on cell growth and proliferation. These results were confirmed in cells treated with the combination of ceritinib and su11274 (c-MET inhibitor) or with ceritinib and erlotinib (EGFR inhibitor). We further assessed the impact of drug alone or in combination with radiation on cell cycle, cell survival and DNA damage repair pathways. To further evaluate ALK function in the cellular response to radiation in NSCLC, we are developing EML4-ALK stable expression cell lines. Evaluation of drug-radiation interactions in xenograft model systems are also under consideration. These data indicate that co-inhibition of ALK and EGFR or c-MET can enhance growth inhibitory effects in ALK-positive cells and augment radiosensitivity in-vitro, suggesting the potential value for ALK inhibitors combined with EGFR/c-MET-targeting for therapeutic benefit in ALK-positive NSCLC patients with or without radiation. Citation Format: Chunrong Li, Shyhmin Huang, Fang Ma, Eric A. Armstrong, David Francis, Lauryn Werner, Paul M. Harari. Co-inhibition of ALK and EGFR and/or c-MET on cell growth and response to radiation in ALK-positive NSCLC cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3309. doi:10.1158/1538-7445.AM2015-3309

Efficacy and safety of the ALK inhibitor alectinib in ALK+ non-small-cell lung cancer (NSCLC) patients who have failed prior crizotinib: An open-label, single-arm, global phase 2 study (NP28673).

8008 Background: The ALK inhibitor crizotinib is approved for patients (pts) with ALK-rearranged (ALK+) NSCLC, but most pts progress within a year and CNS progression is common. The NP28673 study (...

A phase II, open-label, multicenter study of the ALK inhibitor alectinib in an ALK+ non-small-cell lung cancer (NSCLC) U.S./Canadian population who had progressed on crizotinib (NP28761).

8019 Background: Crizotinib is an approved treatment for patients (pts) with ALK-rearranged (ALK+) NSCLC. However, progression on crizotinib, particularly in the CNS, frequently occurs within a yea...

A phase I/II study with a CNS-penetrant, selective ALK inhibitor alectinib in ALK-rearranged non-small cell lung cancer (ALK+ NSCLC) patients (pts): Updates on progression free survival (PFS) and safety results from AF-001JP.

8061 Background: Alectinib, a CNS-penetrant, selective ALK inhibitor with a novel scaffold, was granted approval in Japan 2014, since it showed good efficacy and tolerability in ALK+ NSCLC pts with...

Alectinib for the treatment of ALK-positive stage IV non-small cell lung cancer

Our increased understanding of the molecular subsets of non-small cell lung cancer (NSCLC) has led to the development of highly effective targeted therapies. In particular, the outcomes of patients with advanced NSCLC driven by the EML4-ALK fusion protein, which comprise 3-5% of cases, have remarkably improved with the use of crizotinib, an oral multi-tyrosine kinase inhibitor that targets ALK. However, patients inevitably develop progression while on crizotinib due to various mechanisms of resistance. Alectinib is a novel oral small molecule that inhibits ALK with high potency and selectivity, and demonstrates promising antitumor effects in NSCLC. Preclinical studies have shown that it is also active against several mutant forms of ALK that confer resistance to crizotinib, including the gatekeeper mutation L1196M. Moreover, an objective response rate of over 90% was observed in a phase I trial. Due to the impressive results of early phase studies, alectinib was approved for the treatment of advanced ALK-positive NSCLC in Japan, while it has been granted a breakthrough therapy designation by the FDA. A phase III trial is currently ongoing. This review will describe the biology and significance of ALK rearrangements in NSCLC, ALK inhibition by crizotinib and mechanisms of resistance, as well as the preclinical and clinical evidence for the novel ALK inhibitor alectinib.

Two novel ALK mutations mediate acquired resistance to the next-generation ALK inhibitor alectinib.

The first-generation ALK tyrosine kinase inhibitor (TKI) crizotinib is a standard therapy for patients with ALK-rearranged non-small cell lung cancer (NSCLC). Several next-generation ALK-TKIs have entered the clinic and have shown promising activity in crizotinib-resistant patients. As patients still relapse even on these next-generation ALK-TKIs, we examined mechanisms of resistance to the next-generation ALK-TKI alectinib and potential strategies to overcome this resistance. We established a cell line model of alectinib resistance, and analyzed a resistant tumor specimen from a patient who had relapsed on alectinib. We developed Ba/F3 models harboring alectinib-resistant ALK mutations and evaluated the potency of other next-generation ALK-TKIs in these models. We tested the antitumor activity of the next-generation ALK-TKI ceritinib in the patient with acquired resistance to alectinib. To elucidate structure-activity relationships of ALK mutations, we performed computational thermodynamic simulation with MP-CAFEE. We identified a novel V1180L gatekeeper mutation from the cell line model and a second novel I1171T mutation from the patient who developed resistance to alectinib. Both ALK mutations conferred resistance to alectinib as well as to crizotinib, but were sensitive to ceritinib and other next-generation ALK-TKIs. Treatment of the patient with ceritinib led to a marked response. Thermodynamics simulation suggests that both mutations lead to distinct structural alterations that decrease the binding affinity with alectinib. We have identified two novel ALK mutations arising after alectinib exposure that are sensitive to other next-generation ALK-TKIs. The ability of ceritinib to overcome alectinib-resistance mutations suggests a potential role for sequential therapy with multiple next-generation ALK-TKIs.

Abstract 754: Selective ALK inhibitor alectinib (CH5424802/RO5424802) with potent antitumor activity in models of crizotinib resistance, including intracranial metastases

Abstract Purpose: EML4-ALK has been implicated as a driver oncogene and a therapeutic target in non-small cell lung cancer (NSCLC). The clinical efficacy of the ALK inhibitor crizotinib has been demonstrated in ALK fusion-positive NSCLC; however, resistance to crizotinib certainly occurs through ALK secondary mutations in clinical use. In addition, brain metastases are frequent sites of initial failure in patients because crizotinib has poor penetration of the central nervous system. This study aimed to clarify the efficacy of ALK inhibitor alectinib (CH5424802/RO5424802) in models of crizotinib-resistant ALK mutant tumors and intracranial tumors. Experimental Design: The antitumor activity of alectinib was evaluated in subcutaneous xenograft tumor models of Ba/F3 cells expressing mutated EML4-ALK, and in intracranial tumor implantation models of EML4-ALK-positive NSCLC NCI-H2228. Results: Alectinib had kinase inhibitory activity against some ALK mutations, including G1269A, and blocked tumor growth driven by a mutant of EML4-ALK in vitro and in vivo. In intracranial tumor implantation mouse models, alectinib resulted in regression of NCI-H2228 tumor in brain and provided a survival benefit. Alectinib is not a substrate for P-glycoprotein efflux transporter in vitro and showed a high brain-to-plasma ratio in rat. Additionally, alectinib led to tumor size reduction in the subcutaneous NCI-H2228 xenograft tumor that had failed to regress fully during treatment with crizotinib. Conclusions: Alectinib was effective against most EML4-ALK mutations and showed potent efficacy against intracranial ALK-positive tumor. Thus, alectinib might provide therapeutic opportunities for crizotinib-treated patients with ALK secondary mutations and brain metastases. Citation Format: Tatsushi Kodama, Toshiyuki Tsukaguchi, Masami Hasegawa, Miyuki Yoshida, Kenji Takanashi, Osamu Kondoh, Hiroshi Sakamoto. Selective ALK inhibitor alectinib (CH5424802/RO5424802) with potent antitumor activity in models of crizotinib resistance, including intracranial metastases. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 754. doi:10.1158/1538-7445.AM2014-754

Alectinib Is Active in Crizotinib-Resistant ALK-Rearranged NSCLC

Abstract The next-generation ALK inhibitor alectinib overcomes acquired crizotinib resistance in NSCLC.

Selective ALK inhibitor alectinib with potent antitumor activity in models of crizotinib resistance

The clinical efficacy of the ALK inhibitor crizotinib has been demonstrated in ALK fusion-positive NSCLC; however, resistance to crizotinib certainly occurs through ALK secondary mutations in clinical use. Here we examined the efficacy of a selective ALK inhibitor alectinib/CH5424802 in models of crizotinib resistance. Alectinib led to tumor size reduction in EML4-ALK-positive xenograft tumors that failed to regress fully during the treatment with crizotinib. In addition, alectinib inhibited the growth of some EML4-ALK mutant-driven tumors, including the G1269A model. These results demonstrated that alectinib might provide therapeutic opportunities for crizotinib-treated patients with ALK secondary mutations.