A Phase 1 Drug-Drug Interaction Study Between Brigatinib and the CYP3A Substrate Midazolam in Patients With ALK-Positive or ROS1-Positive Solid Tumors.

Brigatinib is a next-generation anaplastic lymphoma kinase (ALK) inhibitor approved for the treatment of patients with ALK-positive (ALK+) non-small cell lung cancer (NSCLC). A phase 1 drug-drug interaction study was conducted to evaluate the effect of multiple-dose administration of brigatinib on the single-dose pharmacokinetics of midazolam, a sensitive cytochrome P450 3A substrate. In cycle 1, patients with ALK+ or ROS1+ solid tumors, including NSCLC, received a single 3-mg dose of midazolam as an oral solution alone on day 1 and then coadministered with brigatinib on day 21 (brigatinib 90 mg once daily on days 2-8; 180 mg once daily on days 9-28). After cycle 1, patients could continue to receive brigatinib in 28-day treatment cycles. The primary study objective was to characterize the effect of brigatinib 180 mg once daily on midazolam pharmacokinetics. The secondary objective was to assess safety. Exploratory efficacy endpoints included objective response rate and progression-free survival. Brigatinib was generally well tolerated, and safety data were consistent with the known safety profile. Among the 10 patients with ALK+ NSCLC, the confirmed objective response rate was 30% and median progression-free survival was 7.2 months. Coadministration of brigatinib reduced midazolam maximum observed plasma concentration by ≈16% (geometric least-squares mean ratio, 0.836 [90%CI, 0.662-1.056]) and area under the plasma concentration-time curve from time 0 to infinity by ≈26% (geometric least-squares mean ratio, 0.741 [90%CI, 0.600-0.915]). Thus, brigatinib is a weak inducer of cytochrome P450 3A in vivo.

Long-Term Efficacy and Safety of Brigatinib in Crizotinib-Refractory ALK+ NSCLC: Final Results of the Phase 1/2 and Randomized Phase 2 (ALTA) Trials.

Introduction: We report brigatinib long-term efficacy and safety from phase 1/2 and phase 2 (ALTA) trials in ALK-rearrangement positive (ALK+) NSCLC. Methods: The phase 1/2 study evaluated brigatinib 30 to 300 mg/d in patients with advanced malignancies. ALTA randomized patients with crizotinib-refractory ALK+ NSCLC to brigatinib 90 mg once daily (arm A) or 180 mg once daily (7-d lead-in at 90 mg; arm B). Results: In the phase 1/2 study, 79 of 137 brigatinib-treated patients had ALK+ NSCLC; 71 were crizotinib pretreated. ALTA randomized 222 patients (n = 112 in arm A; n = 110 in arm B). Median follow-up at phase 1/2 study end (≈5.6 y after last patient enrolled) was 27.7 months; at ALTA study end (≈4.4 y after last patient enrolled), 19.6 months (A) and 28.3 months (B). Among patients with ALK+ NSCLC in the phase 1/2 study, median investigator-assessed progression-free survival (PFS) was 14.5 months (95% confidence interval [CI]: 10.8-21.2); median overall survival was 47.6 months (28.6-not reached). In ALTA, median investigator-assessed PFS was 9.2 months (7.4-11.1) in arm A and 15.6 months (11.1-18.5) in arm B; median independent review committee (IRC)-assessed PFS was 9.9 (7.4-12.8) and 16.7 (11.6-21.4) months, respectively; median overall survival was 25.9 (18.2-45.8) and 40.6 (32.5-not reached) months, respectively. Median intracranial PFS for patients with any brain metastases was 12.8 (9.2-18.4) months in arm A and 18.4 (12.6-23.9) months in arm B. No new safety signals were identified versus previous analyses. Conclusions: Brigatinib exhibited sustained long-term activity and PFS with manageable safety in patients with crizotinib-refractory ALK+ NSCLC.

Brigatinib Versus Crizotinib in ALK Inhibitor-Naive Advanced ALK-Positive NSCLC: Final Results of Phase 3 ALTA-1L Trial.

INTRODUCTION: In the phase 3 study entitled ALK in Lung cancer Trial of brigAtinib in 1st Line (ALTA-1L), which is a study of brigatinib in ALK inhibitor-naive advanced ALK-positive NSCLC, brigatinib exhibited superior progression-free survival (PFS) versus crizotinib in the two planned interim analyses. Here, we report the final efficacy, safety, and exploratory results. METHODS: Patients were randomized to brigatinib 180 mg once daily (7-d lead-in at 90 mg once daily) or crizotinib 250 mg twice daily. The primary end point was a blinded independent review committee-assessed PFS. Genetic alterations in plasma cell-free DNA were assessed in relation to clinical efficacy. RESULTS: A total of 275 patients were enrolled (brigatinib, n = 137; crizotinib, n = 138). At study end, (brigatinib median follow-up = 40.4 mo), the 3-year PFS by blinded independent review committee was 43% (brigatinib) versus 19% (crizotinib; median = 24.0 versus 11.1 mo, hazard ratio [HR] = 0.48, 95% confidence interval [CI]: 0.35-0.66). The median overall survival was not reached in either group (HR = 0.81, 95% CI: 0.53-1.22). Posthoc analyses suggested an overall survival benefit for brigatinib in patients with baseline brain metastases (HR = 0.43, 95% CI: 0.21-0.89). Detectable baseline EML4-ALK fusion variant 3 and TP53 mutation in plasma were associated with poor PFS. Brigatinib exhibited superior efficacy compared with crizotinib regardless of EML4-ALK variant and TP53 mutation. Emerging secondary ALK mutations were rare in patients progressing on brigatinib. No new safety signals were observed. CONCLUSIONS: In the ALTA-1L final analysis, with longer follow-up, brigatinib continued to exhibit superior efficacy and tolerability versus crizotinib in patients with or without poor prognostic biomarkers. The suggested survival benefit with brigatinib in patients with brain metastases warrants future study.

Platform for induction and maintenance of transgene-free hiPSCs resembling ground state pluripotent stem cells.

Cell banking, disease modeling, and cell therapy applications have placed increasing demands on hiPSC technology. Specifically, the high-throughput derivation of footprint-free hiPSCs and their expansion in systems that allow scaled production remains technically challenging. Here, we describe a platform for the rapid, parallel generation, selection, and expansion of hiPSCs using small molecule pathway inhibitors in stage-specific media compositions. The platform supported efficient and expedited episomal reprogramming using just OCT4/SOX2/SV40LT combination (0.5%-4.0%, between days 12 and 16) in a completely feeder-free environment. The resulting hiPSCs are transgene-free, readily cultured, and expanded as single cells while maintaining a homogeneous and genomically stable pluripotent population. hiPSCs generated or maintained in the media compositions described exhibit properties associated with the ground state of pluripotency. The simplicity and robustness of the system allow for the high-throughput generation and rapid expansion of a uniform hiPSC product that is applicable to industrial and clinical-grade use.

Optimized surface markers for the prospective isolation of high-quality hiPSCs using flow cytometry selection.

hiPSC derivation and selection remains inefficient; with selection of high quality clones dependent on extensive characterization which is not amenable to high-throughput (HTP) approaches. We recently described the use of a cocktail of small molecules to enhance hiPSC survival and stability in single cell culture and the use of flow cytometry cell sorting in the HTP-derivation of hiPSCs. Here we report an enhanced protocol for the isolation of bona fide hiPSCs in FACS-based selection using an optimized combination of cell surface markers including CD30. Depletion of CD30(+) cells from reprogramming cultures almost completely abolished the NANOG and OCT4 positive sub-population, suggesting it is a pivotal marker of pluripotent cells. Combining CD30 to SSEA4 and TRA-1-81 in FACS greatly enhanced specificity and efficiency of hiPSC selection and derivation. The current method allows for the efficient and automated, prospective isolation of high-quality hiPSC from the reprogramming cell milieu.

Striated organelle, a cytoskeletal structure positioned to modulate hair-cell transduction.

The striated organelle (SO), a cytoskeletal structure located in the apical region of cochlear and vestibular hair cells, consists of alternating, cross-linked, thick and thin filamentous bundles. In the vestibular periphery, the SO is well developed in both type I and type II hair cells. We studied the 3D structure of the SO with intermediate-voltage electron microscopy and electron microscope tomography. We also used antibodies to α-2 spectrin, one protein component, to trace development of the SO in vestibular hair cells over the first postnatal week. In type I cells, the SO forms an inverted open-ended cone attached to the cell membrane along both its upper and lower circumferences and separated from the cuticular plate by a dense cluster of exceptionally large mitochondria. In addition to contacts with the membrane and adjacent mitochondria, the SO is connected both directly and indirectly, via microtubules, to some stereociliary rootlets. The overall architecture of the apical region in type I hair cells--a striated structure restricting a cluster of large mitochondria between its filaments, the cuticular plate, and plasma membrane--suggests that the SO might serve two functions: to maintain hair-cell shape and to alter transduction by changing the geometry and mechanical properties of hair bundles.