Purpose: This study investigated the efficacy and safety of oral PARP inhibitor veliparib, plus carboplatin and etoposide in patients with treatment-naïve, extensive-stage small cell lung cancer (ED-SCLC).Patients and Methods: Patients were randomized 1:1:1 to veliparib [240 mg twice daily (BID) for 14 days] plus chemotherapy followed by veliparib maintenance (400 mg BID; veliparib throughout), veliparib plus chemotherapy followed by placebo (veliparib combination only), or placebo plus chemotherapy followed by placebo (control). Patients received 4-6 cycles of combination therapy, then maintenance until unacceptable toxicity/progression. The primary endpoint was progression-free survival (PFS) with veliparib throughout versus control.Results: Overall (N ¼ 181), PFS was improved with veliparib throughout versus control [hazard ratio (HR), 0.67; 80% confidence interval (CI), 0.50-0.88; P ¼ 0.059]; median PFS was 5.8 and 5.6 months, respectively. There was a trend toward improved PFS with veliparib throughout versus control in SLFN11-positive patients (HR, 0.6; 80% CI, 0.36-0.97). Median overall survival (OS) was 10.1 versus 12.4 months in the veliparib throughout and control arms, respectively (HR, 1.43; 80% CI, 1.09-1.88). Grade 3/4 adverse events were experienced by 82%, 88%, and 68% of patients in the veliparib throughout, veliparib combination-only and control arms, most commonly hematologic.Conclusions: Veliparib plus platinum chemotherapy followed by veliparib maintenance demonstrated improved PFS as firstline treatment for ED-SCLC with an acceptable safety profile, but there was no corresponding benefit in OS. Further investigation is warranted to define the role of biomarkers in this setting.

Serotonin is thought to contribute to the syncopal-like response that develops during severe blood loss by inhibiting presympathetic neurons of the rostroventrolateral medulla (RVLM). Here, we tested whether serotonin cells activated during hypotensive hemorrhage, i.e., express the protein product of the immediate early gene c-Fos, are critical for the normal sympathetic response to blood loss in unanesthetized rats. Serotonin-immunoreactive cells of the raphe obscurus and raphe magnus, parapyramidal cells of the B3 region, subependymal cells of the ventral parapyramidal region, and cells of the ventrolateral periaqueductal gray region were activated by hypotensive hemorrhage, but not by hypotension alone. In contrast to findings in anesthetized animals, lesion of hindbrain serotonergic cells sufficient to produce >80% loss of serotonin nerve terminal immunoreactivity in the RVLM accelerated the sympatholytic response to blood loss, attenuated recovery of sympathetic activity after termination of hemorrhage, and exaggerated metabolic acidosis. Hindbrain serotonin lesion also attenuated ventilatory and sympathetic responses to stimulation of central chemoreceptors but increased spontaneous arterial baroreflex sensitivity and decreased blood pressure variability. A more global neurotoxic lesion that also eliminated tryptophan hydroxylase-immunoreactive cells of the ventrolateral periaqueductal gray region had no further effect on the sympatholytic response to blood loss. Together, the data indicate that serotonin cells of the caudal hindbrain contribute to compensatory responses following blood loss that help maintain oxygenation of peripheral tissue in the unanesthetized rat. This effect may be related to facilitation of chemoreflex responses to acidosis.

PURPOSE Squamous non–small-cell lung cancer (sqNSCLC) is genetically complex with evidence of DNA damage. This phase III study investigated the efficacy and safety of poly (ADP-ribose) polymerase inhibitor veliparib in combination with conventional chemotherapy for advanced sqNSCLC ( NCT02106546 ). PATIENTS AND METHODS Patients age ≥ 18 years with untreated, advanced sqNSCLC were randomly assigned 1:1 to carboplatin and paclitaxel with veliparib 120 mg twice daily (twice a day) or placebo twice a day for up to six cycles. The primary end point was overall survival (OS) in the veliparib arm versus the control arm in current smokers, based on phase II findings. Archival tumor samples were provided for biomarker analysis using a 52-gene expression histology classifier (LP52). RESULTS Overall, 970 patients were randomly assigned to carboplatin and paclitaxel plus either veliparib (n = 486) or placebo (n = 484); 57% were current smokers. There was no significant OS benefit with veliparib in current smokers, with median OS 11.9 versus 11.1 months (hazard ratio [HR], 0.905; 95% CI, 0.744 to 1.101; P = .266). In the overall population, OS favored veliparib; median OS was 12.2 versus 11.2 months (HR, 0.853; 95% CI, 0.747 to 0.974), with no difference in progression-free survival (median 5.6 months per arm). In patients with biomarker-evaluable tumor samples (n = 360), OS favored veliparib in the LP52-positive population (median 14.0 v 9.6 months; HR, 0.66; 95% CI, 0.49 to 0.89), but favored placebo in the LP52-negative population (median 11.0 v 14.4 months; HR, 1.33; 95% CI, 0.95 to 1.86). No new safety signals were observed in the experimental arm. CONCLUSION In current smokers with advanced sqNSCLC, there was no therapeutic benefit of adding veliparib to first-line chemotherapy. The LP52 signature may identify a subgroup of patients likely to derive benefit from veliparib with chemotherapy.

3013 Background: ABBV-621 is a potent tumor-necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor agonist fusion protein that induces apoptotic cell death, particularly in DR4/5 expressing tumor models. Methods: Patients (pts) with previously treated solid tumors and ECOG 0–2 were administered ABBV-621 (2.5–15 mg/kg IV) on day (D) 1 (dose level [DL] 1) or D1D8 (DL2 and beyond) of each 21-day cycle. Dose escalation (DE) was guided by a Bayesian continual reassessment method. In addition to PK studies, blood-based PD markers of apoptosis (M30, M65) and drug binding were assessed. Results: As of 14 December 2018, 57 pts were enrolled in the DE portion, of which 30% had pancreatic, 23% colorectal cancer, and 47% other tumor types; 13 were KRAS mutant. Median age was 61 yrs. 60% were male; pts had a median of 4 prior regimens (range 1–10). Pts per DL: 2.5 (5 on D1, 16 on D1D8), 3.75 (12), 5 (6), 6.5 (6), 8.5 (4), 11 (4), and 15 mg/kg (4). Median duration of ABBV-621 exposure was 2 cycles (range 1–11). Seven pts had dose-limiting toxicities: respiratory failure (5 mg/kg; Grade 5, the only treatment-related death), blood bilirubin increased (3.75, 6.5 mg/kg), nausea (3.75 mg/kg), fatigue (3.75 mg/kg), increased ALT (2.5, 3.75, 6.5, 15 mg/kg), and increased AST (6.5 mg/kg). Summary of AEs is shown in Table. Clinical trial information: NCT03082209. A partial response (duration 20 weeks) was observed in a pt with pancreatic cancer (2.5 mg/kg D1D8). 27 pts had stable disease (6 pts for > 12 weeks). ABBV-621 PK was linear (mean ± SD clearance was 1.79 mL/h/kg ± 0.44) with a terminal half-life of 36.7 ± 5.55 h (n = 49). ABBV-621 bound to decoy receptors on neutrophils for up to 168 h; the duration of binding was dose-dependent. M30 and M65 increased at 8, 24, and 48 h following ABBV-621, but effect was independent of dose. Conclusions: ABBV-621 shows evidence of antitumor activity and effect on blood-based markers of apoptosis, with acceptable toxicity (MTD not reached). NCT03082209.[Table: see text]

Eftozanermin alfa (eftoza), a second-generation tumor necrosis factor-related apoptosis-inducing ligand receptor (TRAIL-R) agonist, induces apoptosis in tumor cells by activation of death receptors 4/5. This phase 1 dose-escalation/dose-optimization study evaluated the safety, pharmacokinetics, pharmacodynamics, and preliminary activity of eftoza in patients with advanced solid tumors. Patients received eftoza 2.5–15 mg/kg intravenously on day 1 or day 1/day 8 every 21 days in the dose-escalation phase, and 1.25–7.5 mg/kg once-weekly (QW) in the dose-optimization phase. Dose-limiting toxicities (DLTs) were evaluated during the first treatment cycle to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Pharmacodynamic effects were evaluated in circulation and tumor tissue. A total of 105 patients were enrolled in the study (dose-escalation cohort, n = 57; dose-optimization cohort, n = 48 patients [n = 24, colorectal cancer (CRC); n = 24, pancreatic cancer (PaCA)]). In the dose-escalation cohort, seven patients experienced DLTs. MTD and RP2D were not determined. Most common treatment-related adverse events were increased alanine aminotransferase and aspartate aminotransferase levels, nausea, and fatigue. The one treatment-related death occurred due to respiratory failure. In the dose-optimization cohort, three patients (CRC, n = 2; PaCA, n = 1) had a partial response. Target engagement with regard to receptor saturation, and downstream apoptotic pathway activation in circulation and tumor were observed. Eftoza had acceptable safety, evidence of pharmacodynamic effects, and preliminary anticancer activity. The 7.5-mg/kg QW regimen was selected for future studies on the basis of safety findings, pharmacodynamic effects, and biomarker modulations. (Trial registration number: NCT03082209 (registered: March 17, 2017)).