Citations

348 Background: Patients (pts) with mUC have few treatment options beyond the second-line setting. HER2 gene amplification has been reported in a minority of pts with UC, but there have been anecdotal reports of the activity of HER2-targeted agents. MyPathway is a multi-basket study evaluating the efficacy and safety of targeted therapies in non-indicated tumor types harboring relevant molecular alterations. We present preliminary data for pts with HER2-positive mUC receiving HER2-targeted treatment with pertuzumab + trastuzumab. Methods: MyPathway (NCT02091141) is an open-label, multicenter, phase IIA study. Pts in this subset analysis had refractory mUC with HER2 amplification or putative activating mutations by gene sequencing, FISH, or IHC. Pts received standard doses of pertuzumab + trastuzumab without chemotherapy until disease progression or unacceptable toxicity. The primary endpoint is investigator-assessed overall response rate (RECIST v1.1). Results: As of July 31, 2016, 12 pts with platinum-resistant HER2-positive mUC (HER2-amplified, n=9; HER2-mutated, n=3) have been enrolled. At a median follow-up of 5.4 (range 0.9–14.5) mos, 1 pt had complete response (CR, ongoing at 12.5 mos), 2 had partial responses (PR; duration of response, 3.7 and 5.5 mos), and 2 had stable disease (SD) for >4 mos (Table). Safety was consistent with the product labels. Conclusions: Preliminary results indicate that the combination of pertuzumab + trastuzumab has activity in previously treated HER2-amplified mUC, including a durable CR in a pt with peritoneal metastases. Accrual to MyPathway is ongoing. Clinical trial information: NCT02091141. [Table: see text]

166 Background: T-DM1 is an antibody-drug conjugate composed of trastuzumab, a stable linker, and the cytotoxic agent DM1. Few T-DM1 data are available in settings approximating clinical practice. We present safety and efficacy data from T-PAS, an expanded access study of T-DM1 in patients (pts) with previously treated HER2-positive MBC. Methods: T-PAS is a US multicenter study of T-DM1 (3.6 mg/kg q3w) in HER2-positive (IHC 3+ or FISH/CISH+) locally advanced or MBC. Key eligibility criteria: prior anthracycline and taxane; prior capecitabine or 5-FU and ≥2 HER2-directed agents (including trastuzumab and lapatinib) for MBC; LVEF ≥50%. Primary endpoint: safety; secondary endpoint: investigator-assessed objective response rate (ORR) in pts with measurable disease. Safety was assessed on day 1 of each cycle; ECHO/MUGA scans were every 12 weeks. Results: This analysis includes 215 pts enrolled in May 2010–Sep 2011 (data cutoff 7/31/2012). Pts received a median of 7 prior systemic MBC therapies (range 1–23) with a median cumulative anthracycline dose of 240 mg/m2(range 6–2645). At baseline, median LVEF was 60% and 50% of pts had investigator-reported cardiovascular disease. Median follow-up was 5.9 months (range 0.1–25.3); median T-DM1 duration was 5.0 months (range 0–23) with 15.8% receiving >18 cycles. ORR was 25.6% (42/164). Rate of grade ≥3 AEs was 43.7% and of SAEs of any grade was 18.1%. Most common all-grade AEs were fatigue (50.7%), nausea (36.3%), and headache (24.2%). Most common grade ≥3 AEs were thrombocytopenia (7.9%), fatigue (4.7%), and increased aspartate aminotransferase and anemia (each 3.7%). There were no grade ≥3 bleeding events. Cardiac dysfunction (primarily asymptomatic decreases in LVEF) was reported in 8 pts (3.7%); 4 were grade ≥3, 3 resulting in T-DM1 discontinuation. Conclusions: In this study that more closely reflects the real-world setting, the safety profile of T-DM1 was similar to that previously reported in conventional clinical trials, with no new safety signals. In this pretreated population (median of 7 prior therapies for HER2-positive MBC), significant activity was observed. Clinical trial information: NCT01120561.

Abstract Background: Central nervous system (CNS) metastases are observed in up to half of patients with HER2-positive metastatic breast cancer (MBC), with incidence likely to continue to rise due to longer survival through improved systemic treatments. While radiotherapy-based approaches can be effective, there are potential short- and long-term toxicities, and patients frequently progress. CNS response to existing systemic therapies has been generally poor, and there is a high unmet need with no approved treatment for CNS metastases in HER2-positive MBC. Combination of the HER2-targeted monoclonal antibodies trastuzumab and pertuzumab provides a more comprehensive blockade of HER2 than either antibody alone, and data from the phase III CLEOPATRA trial suggest that adding pertuzumab to trastuzumab and docetaxel may delay onset of CNS disease. Trastuzumab concentrations in the CNS are increased under conditions of an impaired blood–brain barrier (BBB) and subtherapeutic levels in the CNS may be related to insufficient dosing rather than inability to cross the BBB. The PATRICIA trial is evaluating the addition of pertuzumab with high-dose trastuzumab to a patient's current systemic treatment for HER2-positive MBC patients with CNS progression post-radiotherapy and stable systemic disease. Study design: In this US-based, phase II, open-label, single-arm study, patients will receive intravenous pertuzumab (840 mg loading dose followed by 420 mg every 3 weeks) in combination with intravenous high-dose trastuzumab (6 mg/kg weekly) in addition to their current systemic therapy (except for ado-trastuzumab emtansine or lapatinib) until disease progression or unacceptable toxicity. Eligibility criteria: Patients aged ≥18 years with confirmed HER2-positive MBC with new and/or progressive CNS lesions >60 days after whole-brain radiotherapy or stereotactic radiosurgery for CNS metastases, performance status 0–1, and stable systemic disease will be eligible. Patients must have a baseline left ventricular ejection fraction (LVEF) ≥50%, no significant history of cardiac disease or current use of anthracyclines, life expectancy >12 weeks, and not be pregnant or lactating. Aims: The primary efficacy endpoint will be objective response rate (ORR) in the CNS, assessed by the investigator using RANO–BM criteria. Secondary endpoints will include duration of CNS response, progression-free survival (CNS and/or non-CNS), overall survival, and safety. Pharmacokinetic and patient-reported outcomes will also be evaluated. LVEF will be assessed throughout treatment and follow-up. An interim analysis will be performed when 15 patients have completed 2 cycles, and the study will be stopped if no clinical benefit (complete response, partial response, or stable disease in the CNS) is seen or if two or more patients have congestive heart failure events related to trastuzumab or pertuzumab. Statistical methods: The recruitment target is 40 patients; with 35 evaluable, the 95% confidence interval around an estimated ORR of 20% will be 8.4–36.9%. The trial opens for accrual in Q3 2015. Citation Format: Lin NU, Pegram MD, Lai C, Lacasia A, Stein A, Yoo B, Perez EA. An open-label, single-arm, phase II study of pertuzumab with high-dose trastuzumab for the treatment of central nervous system progression post-radiotherapy in patients with HER2-positive metastatic breast cancer (PATRICIA). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-01-04.

Amyotrophic lateral sclerosis (ALS) is a devastating, fatal neurologic disease that primarily affects spinal cord anterior horn cells and their axons for which there is no treatment. Here we report the use of a recombinant natural human IgM that binds to the surface of neurons and supports neurite extension, rHIgM12, as a therapeutic strategy in murine models of human ALS. A single 200 µg intraperitoneal dose of rHIgM12 increases survival in two independent genetic-based mutant SOD1 mouse strains (SOD1G86R and SOD1G93A) by 8 and 10 days, delays the onset of neurologic deficits by 16 days, delays the onset of weight loss by 5 days, and preserves spinal cord axons and anterior horn neurons. Immuno-overlay of thin layer chromatography and surface plasmon resonance show that rHIgM12 binds with high affinity to complex gangliosides GD1a and GT1b. Addition of rHIgM12 to neurons in culture increases α-tubulin tyrosination levels, suggesting an alteration of microtubule dynamics. We previously reported that a single peripheral dose of rHIgM12 preserved neurologic function in a murine model of demyelination with axon loss. Because rHIgM12 improves three different models of neurologic disease, we propose the IgM may act late in the cascade of neuronal stress and/or death by a broad mechanism.

Abstract Purpose: Oncolytic herpes simplex viruses (oHSV) represent a promising therapy for glioblastoma (GBM), but their clinical success has been limited. Early innate immune responses to viral infection reduce oHSV replication, tumor destruction, and efficacy. Here, we characterized the antiviral effects of macrophages and microglia on viral therapy for GBM. Experimental Design: Quantitative flow cytometry of mice with intracranial gliomas (±oHSV) was used to examine macrophage/microglia infiltration and activation. In vitro coculture assays of infected glioma cells with microglia/macrophages were used to test their impact on oHSV replication. Macrophages from TNFα-knockout mice and blocking antibodies were used to evaluate the biologic effects of TNFα on virus replication. TNFα blocking antibodies were used to evaluate the impact of TNFα on oHSV therapy in vivo. Results: Flow-cytometry analysis revealed a 7.9-fold increase in macrophage infiltration after virus treatment. Tumor-infiltrating macrophages/microglia were polarized toward a M1, proinflammatory phenotype, and they expressed high levels of CD86, MHCII, and Ly6C. Macrophages/microglia produced significant amounts of TNFα in response to infected glioma cells in vitro and in vivo. Using TNFα-blocking antibodies and macrophages derived from TNFα-knockout mice, we discovered TNFα-induced apoptosis in infected tumor cells and inhibited virus replication. Finally, we demonstrated the transient blockade of TNFα from the tumor microenvironment with TNFα-blocking antibodies significantly enhanced virus replication and survival in GBM intracranial tumors. Conclusions: The results of these studies suggest that FDA approved TNFα inhibitors may significantly improve the efficacy of oncolytic virus therapy. Clin Cancer Res; 21(14); 3274–85. ©2015 AACR.