Hainsworth, John D.

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]

653 Background: Next-generation sequencing often reveals potentially actionable molecular alterations; however, data on approved targeted therapies in non-indicated tumors are limited. MyPathway (NCT02091141) evaluates agents targeting the HER2, EGFR, BRAF, or Hedgehog (Hh) pathways in tumors for which these therapies are not currently indicated. Here, we present early response data for patients with GI tumors. Methods: Eligible patients had metastatic tumors with potentially actionable genomic alterations, identified by a CLIA-certified lab, and progression on standard therapy. Based on the identified alteration, patients received standard doses of trastuzumab + pertuzumab (HER2), erlotinib (EGFR), vemurafenib (BRAF), or vismodegib (Hh). Response was evaluated by the investigator using RECIST v1.1. Results: As of Aug 21, 2015, 96 patients had enrolled, 36 of whom (38%) had GI tumors with the following alterations: HER2 (n=28 [22 amplifications, 5 activating mutations, 1 both]), BRAF (n=4), Hh (n=2 [2 PTCH-1 mutations]), and EGFR (n=2). Patients had a median of 4 (range, 1–8) prior lines of therapy. Tumor types and interim best response data are shown below. Among all evaluable patients with GI tumors (n=26), 5 have had a PR to targeted therapy (duration 3–10+ months). Conclusions: Targetable molecular alterations were found in a variety of GI tumors, resulting in clinical benefit from targeted treatments that would not have otherwise been realized. These early results support this molecular testing strategy. Accrual to the trial continues; based on activity observed, the HER2-positive colorectal cancer cohort will be expanded to ≥30 patients. Additional data will be presented at the meeting. Clinical trial information: NCT02091141. [Table: see text]

PurposeThe optimal management of stage I follicular lymphoma, according to consensus guidelines, is based on uncontrolled experiences of select institutions. Diverse treatment approaches are used despite guidelines that recommend radiation therapy (XRT).Patients and MethodsWe analyzed outcomes of patients with stage I follicular lymphoma enrolled onto the National LymphoCare database.ResultsOf 471 patients with stage I follicular lymphoma, 206 patients underwent rigorous staging as defined by both a bone marrow aspirate and biopsy and an imaging study (a computed tomography [CT] scan of the whole body, a positron emission tomography [PET]/CT scan, or both). Rigorously staged patients had superior progression-free survival (PFS) compared with nonrigorously staged patients (hazard ratio [HR], 0.63). Treatments given to rigorously staged patients were rituximab/chemotherapy (R-chemo; 28%), XRT (27%), observation (17%), systemic therapy + XRT (13%), rituximab monotherapy (12%), and other (3%). With a median follow-up of 57 months for PFS, there were 44 progression events (in 21% of patients) for rigorously staged patients. For these patients, PFS was significantly improved with either R-chemo or systemic therapy + XRT compared with patients receiving XRT alone after adjustment for histology, LDH, and the presence of B symptoms. There were no differences in overall survival.ConclusionIn this largest, prospectively enrolled group of patients with stage I follicular lymphoma, variable treatment approaches resulted in similar excellent outcomes, which challenges the paradigm that XRT should be standard for this presentation.

Purpose Optimal therapy of follicular lymphoma (FL) is not defined. We analyzed a large prospective cohort study to identify current demographics and patterns of care of FL in the United States. Patients and Methods The National LymphoCare Study is a multicenter, longitudinal, observational study designed to collect information on treatment regimens and outcomes for patients with newly diagnosed FL in the United States. Patients were enrolled between 2004 and 2007. There is no study-specific prescribed treatment regimen or intervention. Results Two thousand seven hundred twenty-eight subjects were enrolled at 265 sites, including the 80% of patients enrolled from nonacademic sites. Using the Follicular Lymphoma International Prognostic Index (FLIPI), three distinct groups independent of histologic grade could be defined. Initial therapeutic strategy was: observation, 17.7%; rituximab monotherapy, 13.9%; clinical trial 6.1%; radiation therapy, 5.6%; chemotherapy only, 3.2%; chemotherapy plus rituximab, 51.9%. Chemotherapy plus rituximab regimens were: rituximab plus cyclophosphamide, doxorubicin, vincristine, prednisone, 55.0%; rituximab plus cyclophosphamide, vincristine, and prednisone, 23.1%; rituximab plus fludarabine based, 15.5%; other, 6.4%. The choice to initiate therapy rather than observe was associated with age, FLIPI, stage, and grade (P < .01). Significant differences in treatment (P < .01) across regions of the United States were noted. Contrary to practice guidelines, treatment of stage I FL frequently omits radiation therapy. Conclusion Widely disparate therapeutic approaches are utilized for FL. Initial therapy is deferred in a small subset of patients. There is no single standard of care for the treatment of de novo FL, although antibody use is ubiquitous when therapy is initiated. These disparate approaches to the initial care of patients with FL render a heterogeneous group of patients at relapse.

Purpose To evaluate the efficacy and safety of arsenic trioxide monotherapy in patients with myelodysplastic syndromes (MDS). Patients and Methods Patients received arsenic trioxide (0.25 mg/kg/d) on 5 consecutive days per week for 2 weeks, followed by 2 weeks’ rest (one cycle). Two patient cohorts were established according to International Prognostic Scoring System risk category: lower-risk (low or intermediate-1) or higher-risk MDS (intermediate-2 or high). For lower-risk MDS, hematologic improvement (HI) was the primary response end point. For higher-risk MDS, additional end points included complete or partial remission. Based on the expected time to response, patients receiving two or more cycles were prospectively evaluated. Results Hematologic adverse events included neutropenia, thrombocytopenia, and febrile neutropenia. Two patients died during the study due to treatment-related toxicities. Most common grade 3/4 nonhematologic events were pneumonia, fatigue, hemorrhage, pain, and dyspnea. Among patients who received one or more doses (n = 70) or completed two or more cycles (n = 51), the HI rates were 34% and 39% in lower-risk patients, and 6% and 9% in higher-risk patients, respectively; the overall major HI rates were 20% and 22%. One higher-risk patient achieved a complete remission (3%). Major HIs were observed in all hematologic lineages; erythroid responses were the most common. Transfusion independence or reduction by ≥ 50% occurred in 33% of patients dependent on RBC transfusions. The overall median duration of HI was 6.8 months (range, 2 to 40 months). Conclusion Arsenic trioxide monotherapy has moderate activity against MDS, with a manageable adverse effect profile. The further study of arsenic trioxide in MDS, particularly in combination with other agents, is warranted.