ALBERT

Description: Introduction: PI3Kδ signaling is critical for the proliferation, survival and homing/tissue retention of malignant B cells. Idelalisib is a first-in-class, highly selective, oral inhibitor of PI3Kδ recently approved for the treatment of relapsed CLL in combination with R. This report summarizes the long-term follow-up of the Phase 1 combination experience of idelalisib with anti-CD20 antibodies. Methods: This Phase 1 study evaluated idelalisib for relapsed/refractory CLL continuously given at 100 mg BID (4 of the pts receiving R) or 150 mg BID (all other pts) in combination with a total of 8 infusions of rituximab (R, 375 mg/m2 weekly x 8), or a total of 12 infusions of ofatumumab (O, 300mg initial dose either on Day 1 or Day 2 relative to the first dose of idelalisib, then 1,000 mg weekly x 7, then 1,000 mg every 4 wks x 4). Pts on treatment after 48 weeks were eligible to continue idelalisib on an extension study. Clinical response was evaluated according to published criteria (Hallek 2008; Cheson 2012). Results: 40 pts (12F/28M) with a median (range) age of 66 (43-87) years and a WHO performance status of 0 (24, 60%) or 1 (16, 40%) were enrolled. 19 pts received idelalisib in combination with R and 21 with O. Adverse disease characteristics (n, %) included Rai Stage III/IV (20, 50%), bulky lymphadenopathy (23, 58%), refractory disease (15, 38%), multiple prior therapies (median 2, range: 1-9). Almost all pts (39, 98%) had at least 1 prior therapy containing R, and 3 of the 21 pts (14%) receiving idelalisib + O had received prior O. 63% of the pts receiving idelalisib + R, and 48% of the pts receiving idelalisib + O were refractory to R. Prior therapies also included alkylating agents (31, 78%, [bendamustine: 20, 50%]) and purine analogs (31, 78%, [fludarabine: 28, 70%]). Data available from 39 pts showed that 11 (28%) pts had evidence of del(17p) and/or TP53 mutations and 30 (75%) had unmutated IGHV. As of 7/15/2014, the median (range) treatment duration was 18 (0-44) months. 23 (58%) pts have completed the primary study and enrolled into the extension study. Primary reasons for study discontinuation (as reported by investigators) included disease progression (14, 35%), adverse events (AEs) (12, 30%), investigator request (3, 8%), withdrawal of consent (n=1), BMT (n=1). There were a total of 8 deaths on study: 2 deaths occurred after disease progression, and 6 pts died because of AEs (all assessed as unrelated/unlikely related to idelalisib by investigators). A total of 4 pts (10%) were continuing idelalisib treatment on the extension study at time of analysis. Selected treatment-emergent AEs (any Grade/≥Gr 3, regardless of causality) included diarrhea/colitis (55%/23%), cough (40%/3%), pyrexia (40%/3%), dyspnea (30%/3%), fatigue (25%/0%) nausea (25%/0%), rash (20%/0%), pneumonia (20%/18%), and pneumonitis (8%/5%). Elevation of liver transaminases (TA, any Grade/≥Gr 3) was seen in 30%/10%. Re-exposure to idelalisib after resolution of TA elevation generally was successful; only 1 patient discontinued the study because of (recurrent) TA elevation. Other AEs leading to study discontinuation and reported as possibly/probably related to idelalisib included diarrhea/colitis (4, 10%), pyrexia (n=1), interstitial lung disease (n=1), pneumonia (n=1), rash (n=1), psoriasis (n=1). Secondary malignancies leading to discontinuation (all reported as unrelated) were breast cancer (n=1), recurrent colon cancer (n=1), AML (n=1). There was no obvious overall difference in the toxicity reported for pts receiving idelalisib with rituximab compared to those with ofatumumab. The ORR (N=40) was 83% (33/40), with 2 CRs (5%) reported. Median PFS (N=40) and duration of response (DOR) (n=33) were 24 months. Median (range) time to response was 1.9 (range 1.7-16.9) months. Median overall survival (OS) has not been reached with a KM estimate for OS of 80% at 24 months. For the 11 pts with del(17p) and/or TP53 mutations, the response rate was 73%, and the median PFS and DOR were 20 and 24 months, respectively. Conclusions: Combinations of idelalisib with anti-CD20 antibodies such as R or O represent non-cytotoxic regimens with acceptable safety profiles and considerable activity resulting in durable tumor control in pts with relapsed/refractory CLL, including those with high risk factors such as del(17p) or TP53 mutations. A Phase 3 trial evaluating the efficacy of idelalisib in combination with ofatumumab is ongoing (NCT01659021). Disclosures Furman: Gilead Sciences: Research Funding. Off Label Use: Zydelig is a kinase inhibitor indicated for the treatment of patients with: 1) Relapsed chronic lymphocytic leukemia (CLL), in combination with rituximab, in patients for whom rituximab alone would be considered appropriate therapy due to other co-morbidities; 2) Relapsed follicular B-cell non-Hodgkin lymphoma (FL) in patients who have received at least two prior systemic therapies; and 3) Relapsed small lymphocytic lymphoma (SLL) in patients who have received at least two prior systemic therapies.. de Vos:Gilead Sciences: Research Funding. Barrientos:Gilead Sciences: Research Funding. Schreeder:Gilead Sciences: Research Funding. Flinn:Gilead Sciences: Research Funding. Sharman:Gilead Sciences: Research Funding. Boyd:Gilead Sciences: Research Funding. Fowler:Gilead Sciences: Research Funding. Leonard:Gilead Sciences: Research Funding. Rai:Gilead Sciences: Research Funding. Kim:Gilead Sciences: Employment, Equity Ownership. Viggiano:Gilead Sciences: Employment, Equity Ownership. Jahn:Gilead Sciences: Employment, Equity Ownership. Coutre:Gilead Sciences: Research Funding.

Description: Introduction: Longitudinal changes in health-related quality of life (HRQoL) are important in patients with chronic lymphocytic leukemia (CLL). GIBB (NCT02320487) is an open-label, single-arm phase II study of obinutuzumab (GA101; G) in combination with bendamustine (G-Benda) in patients with previously untreated CLL. A previous report from the GIBB study demonstrated an investigator-assessed objective response rate of 89.2%, a complete response rate of 49.0%, and no unexpected safety signals with G-Benda (Sharman et al. J Clin Oncol 2017). Here we report the final HRQoL data over 3 years from the GIBB study. Methods: Enrolled patients received G-Benda by intravenous infusion over six 28-day cycles: G 100mg on Day (D)1, 900mg on D2, and 1000mg on D8 and D15 of Cycle (C)1, then 1000mg on D1 of C2-6; benda 90mg/m2 on D2-3 of C1, and on D1-2 of C2-6. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) includes a global health status measure, 5 functional scales (physical, emotional, cognitive, social, and role functioning), 8 symptom scales/items (fatigue, nausea and vomiting, pain, dyspnea, insomnia, appetite loss, constipation, and diarrhea), and an item on financial difficulties (Aaronson et al. J Natl Cancer Inst 1993). The EORTC Quality of Life Questionnaire-Chronic Lymphocytic Leukemia 16 (QLQ-CLL16) is a 16-item module, specific to CLL, containing 4 multi-item scales (fatigue, treatment side effects, disease symptoms, and infection) and 2 single items (social activities and future health worries). Both questionnaires were completed by patients on C1D1 (baseline), C3D1, and C6D1, at the end of induction (EOI) treatment (defined as +28 days from C6D1 or early treatment termination visit), at the response visit (defined as 2-3 months after the EOI treatment for all patients who received study treatment and had not experienced disease progression), and every 3 months thereafter at follow-up visits for up to 2 years. In total, there were 14 timepoints where data were collected. HRQoL scores were linear transformed to a 0-100-point scale. Mean baseline scores and mean score changes from baseline at each visit were evaluated. A threshold of ≥10-point change in score represents a clinically meaningful difference. For symptoms, negative change scores from baseline reflect an improvement in symptom burden. For global health status and functioning, positive change scores from baseline reflect improvements. Results: The trial enrolled 102 patients. Median age was 61 years and 68.4% of patients were male. Ninety-eight patients (96%) completed a questionnaire at baseline and at least 1 other questionnaire during a follow-up visit. Questionnaire completion rates at 14 time points ranged from 96% at baseline to 66% at 27 months follow-up (Table 1). According to the EORTC QLQ-C30 (Figure 1), improvements were observed for global health status at all follow-up visits, and clinically meaningful improvements were observed at the response visit, 3 months follow-up, and 27 months follow-up. Clinically meaningful improvements in role functioning were observed at EOI and persisted throughout the 27-month follow-up. For fatigue, clinically meaningful improvements were observed at every visit starting from the end of treatment (EOT) visit. Improvements were also observed for insomnia with mean reductions from baseline ≥10 points at various time points during follow-up. There was no worsening in other patient-reported symptoms or functional status over time. Similarly, with the EORTC QLQ-CLL16 (Figure 2), clinically meaningful improvements in symptoms were observed for fatigue, disease symptoms, and future health worries during treatment, at the EOT and/or throughout the follow-up. The largest improvement was observed for fatigue (-24.7) at the 24-month follow-up and future health worries (-25.4) at the 27-month follow-up. Conclusions: We previously reported that G-Benda is an effective regimen for first-line treatment of CLL with no unexpected safety signals. The HRQoL data from the GIBB trial suggest that G-Benda treatment consistently improved patient HRQoL over time. Several clinically meaningful improvements were observed in HRQoL, including global health status, functioning, symptoms, and future health worries. Disclosures Danilov: AstraZeneca: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; TG Therapeutics: Consultancy; MEI: Research Funding; Bristol-Meyers Squibb: Research Funding; Verastem Oncology: Consultancy, Other: Travel Reimbursement , Research Funding; Takeda Oncology: Research Funding; Genentech: Consultancy, Research Funding; Bristol-Meyers Squibb: Research Funding; Takeda Oncology: Research Funding; Aptose Biosciences: Research Funding; Aptose Biosciences: Research Funding; Janssen: Consultancy; Pharmacyclics: Consultancy; Bayer Oncology: Consultancy, Research Funding; Celgene: Consultancy; Pharmacyclics: Consultancy; Janssen: Consultancy; Curis: Consultancy; Seattle Genetics: Consultancy; Verastem Oncology: Consultancy, Other: Travel Reimbursement , Research Funding; Gilead Sciences: Consultancy, Research Funding; Bayer Oncology: Consultancy, Research Funding; Curis: Consultancy; Seattle Genetics: Consultancy; MEI: Research Funding; TG Therapeutics: Consultancy; Celgene: Consultancy; Gilead Sciences: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Abbvie: Consultancy; Abbvie: Consultancy. Yimer:AstraZeneca: Speakers Bureau; Janssen: Speakers Bureau; Seattle Genetics: Honoraria; Celgene: Honoraria; Clovis Oncology: Equity Ownership; Puma Biotechnology: Equity Ownership; Amgen: Consultancy. Boxer:Gerson Lerman: Consultancy; Best Doctors: Consultancy; Takeda: Honoraria, Speakers Bureau; AbbVie: Honoraria, Speakers Bureau. Burke:Celgene: Consultancy; Gilead: Consultancy; Roche/Genentech: Consultancy. Babu:Genentech: Research Funding. Li:Genentech: Employment; Roche: Equity Ownership. Mun:Genentech: Employment, Equity Ownership. Trask:Genentech: Employment, Equity Ownership. Masaquel:Roche: Equity Ownership; Genentech: Employment. Sharman:Acerta: Consultancy, Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; TG Therapeutics: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding. OffLabel Disclosure: GAZYVA (obinutuzumab) is a CD20-directed cytolytic antibody and is indicated: in combination with chlorambucil, for the treatment of patients with previously untreated chronic lymphocytic leukemia; in combination with bendamustine followed by GAZYVA monotherapy, for the treatment of patients with follicular lymphoma (FL) who relapsed after, or are refractory to, a rituximab-containing regimen

Description: Signal transduction plays a key role in cell survival, and changes to signaling are frequently implicated in tumor initiation and progression. We sought to identify abnormal variation in signaling network activity within primary tumor samples obtained prior to treatment from patients with follicular lymphoma (FL). We previously showed that altered B cell receptor (BCR) signaling distinguishes tumor B cells from the non-malignant host B cells in FL tumors. Here we extend this approach and use flow cytometry to measure 648 signaling events in live lymphoid cells from more than 25 lymphoma specimens and healthy controls. We combined 9 previously identified BCR stimulation conditions with inputs from CD40, interleukin 4, interferons (IFNs), and more than 10 other environmental cues that govern the development and activity of lymphocytes. Fluorescent cell barcoding allowed simultaneous staining and analysis of phospho-protein activation under all 27 stimulation conditions within a single tube. The activation of key phospho-protein nodes throughout lymphocyte signaling networks, including Syk, Erk1/2, Btk, Src family kinases, cCbl, p38, NFkB, Akt, Stat1, Stat3, Stat6, and Stat5, was measured under each of the 27 stimulation conditions. Measurements of phospho-protein responses to stimulation were combined with detection of the Bcl-2 oncogene, B and T cell lineage markers in each cell. This panel allowed us to characterize signaling in the heterogeneous cell subsets found within each patient’s tumor sample. Tumor B cells, host tumor infiltrating T cells, non-malignant B cells were all distinguished by contrasting signaling profiles. In some cases, subsets of tumor B cells with differences in signaling network topology were observed within the tumor B cell population. This result suggests that signaling can distinguish between tumor sub-clones and could be used to measure tumor heterogeneity. As previously reported, little variation in signaling was observed among healthy peripheral blood B and T cell samples from different individuals. Abnormally low host T cell signaling was commonly observed within the tumor infiltrating T cells infiltrating FL tumors. Further analysis of tumor T cell subsets indicated that a high proportion of infiltrating T cells expressed CD4 and FoxP3. Taken together, these results support the hypothesis that FL tumor B cells promote suppressed signaling in the T cells of the patient and may modulate the immune response against the tumor. In FL tumor B cells, BCR and IFN signaling frequently triggered Stat5 phosphorylation, but not Stat1 phosphorylation. These results are consistent with the hypothesis that Stat5 initiates genetic programs that support cancer cell survival and proliferation, whereas Stat1 promotes immunogenicity and cooperates with the p53 tumor suppressor protein. In contrast with healthy B cells, loss of the response to CD40L, altered PKC signaling, and variable responses to BCR crosslinking were all seen in FL tumor B cells. The patterns of abnormal signaling we observed in tumor B cells and tumor infiltrating T cells suggest that measuring the activity of key signaling network nodes can identify targets for therapeutic attention in FL.

Description: Key Points Obinutuzumab monotherapy demonstrates an increased ORR with 2000 mg over 1000 mg, but no difference in progression-free survival. No meaningful difference was observed in the overall safety profile across the 2 treatment arms.

Description: Background: Spleen tyrosine kinase (Syk) is a mediator of B-cell receptor signaling in normal and transformed B-cells. Entospletinib is an orally bioavailable, selective inhibitor of Syk. Methods: This Phase 2 trial is evaluating entospletinib 800 mg BID in a study of 204 patients with previously treated lymphoid malignancies. Tumor imaging was planned at weeks 8, 16, 24 and then every 12. Tumor response was assessed per Cheson 2007 criteria. Results: A cohort of 69 patients with iNHL (41 follicular lymphoma [FL], 11 lymphoplasmacytoid lymphoma [LPL], 17 marginal zone lymphoma [MZL]) are included in this analysis. Median age was 66 years (range 41 - 89). 58% were male. The median number of prior treatments (Rxs) regimens was 3 (range 1- 14). Prior Rxs included anti-CD20 antibodies (rituximab 99%, ofatumumab 4%), alkylating agents (90%; bendamustine 51%) and anthracyclines (35%). Baseline risk factors: Ann Arbor Stg III-IV (70%), Gr 3a FL (29%), FLIPI ≥3 (34%). Median duration of Rx was 16 weeks with 10 patients continuing on Rx. Entospletinib was generally well tolerated. The most common TEAEs (any Grade/≥Gr 3, independent of causality) were fatigue (54%/13%), nausea (49%/4%), diarrhea(36%/0%), vomiting (26%/0%), headache (23%/1%), pyrexia (23%/3%), decreased appetite (22%/0%), constipation (22%/1%) and common laboratory abnormalities were increased AST (33%/15%), increased ALT (41%/19%), increased total bilirubin (32%/16%), anemia (36%/13%) and neutropenia (38%/13%). 4 patients died while on study from progressive disease. At the time of this analysis, 66 of 69 patients have been treated through first response assessment (1 patient ongoing not reaching first response assessment, 1 patient discontinued due to AE and 1 patient withdrew consent prior to it). 38 out of 61 (62%) patients evaluable for SPD experienced reduced tumor burden, with median duration of Rx 28 weeks (range 4-92). 9/61 (15%) achieved a decrease of ≥ 50% in SPD. The ORR was 13.0% (95% CI: 6.1%, 23.3%), with 7 patients achieving a PR, one LPL patient achieving MR and one patient achieving a CR. Forty-one patients (59.4%) had stable disease. The primary end point of 24 weeks PFS was 48.9% (95% CI: 34.6%, 61.7%). Median PFS was 5.5 months (95% CI: 4.4 months, 8.2 months). There were 39 patients (56.5%) with events of disease progression. Conclusions: Entospletinib monotherapy given with this dose and schedule was well tolerated and demonstrated activity in patients with advanced relapsed iNHL, including those with poor prognostic features. Further development of entospletinib in iNHL will focus on the development of combination approaches with chemotherapy and targeted agents. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Sharman: Calistoga: Honoraria; Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; TG Therapeutics, Inc.: Research Funding; Celgene Corporation: Consultancy, Research Funding; Roche: Research Funding; Janssen: Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding. Off Label Use: Management of CLL/SLL and follicular lymphoma. Kolibaba:Takeda Pharmaceuticals International Co.: Research Funding; Genentech: Research Funding; Seattle Genetics, Inc.: Research Funding; Celgene: Research Funding; Pharmacyclics: Research Funding; Acerta: Research Funding; Janssen: Research Funding; GSK: Research Funding; Gilead: Consultancy, Research Funding; TG Therapeutics: Research Funding. Abella:Gilead: Employment. Eng:Gilead: Employment. He:Gilead Sciences: Employment. Hu:gilead: Employment. Yasenchak:Seattle Genetics, Inc.: Research Funding.

Description: Introduction: Rituximab-CHOP (R-CHOP) has resulted in significantly improved outcomes for patients (pts) with untreated DLBCL. Despite this progress, approximately 30% of pts are not cured with R-CHOP, especially those with high risk disease as defined by the IPI. Polatuzumab vedotin (PoV) is an antibody drug conjugate (ADC) designed for the targeted delivery of the potent microtubule inhibitor MMAE to cells expressing CD79b. Because ADCs may possess a therapeutic index superior to that of many systemically administered chemotherapies, PoV has the potential to replace vincristine with a targeted agent and potentially increase the potency of the standard R-CHOP regimen. We report preliminary results from the dose-escalation portion of this Phase Ib/II study of PoV combined with rituximab, cyclophosphamide, doxorubicin, and prednisone (R-CHP) (ClinicalTrials.gov NCT01992653). Methods: This multicenter, open-label study will evaluate the safety, tolerability, and pharmacokinetics of escalating doses of PoV with standard doses of R-CHP. Adults, ages 60-80 years, with newly diagnosed or relapsed/refractory B-cell NHL were given PoV intravenously 1.0, 1.4, or 1.8 mg/kg with R-CHP every 21 days for a total of 6 or 8 cycles. Doses were escalated in a 3+3 design based on dose limiting toxicity assessment during cycle 1. Assessments for anti-tumor activity were performed following 4 cycles of study treatment (tx) and at the end of study tx (EOT). Results: 13 pts (46% male) enrolled in the R-CHP + PoV dose-escalation phase of the study. Median age was 68 years (range 60-73). Pts had untreated DLBCL (n=10), relapsed FL (n=2), and untreated MZL (n=1). At baseline, pts had stage I/II (5), III/IV (8) disease and ECOG status of 1-2 (6). Of 10 DLBCL pts, 4 had age adjusted IPI (aaIPI) 2, and 6 had aaIPI 0-1. At the time of this report, all pts in the 1.0 mg/kg (n=3), 1.4 mg/kg (n=3) and 4 of 7 pts in the 1.8 mg/kg cohort completed study tx. The most common adverse events (AEs) in 〉3 pts were nausea (8), fatigue (7), diarrhea (6), neutropenia (5), dizziness (4), peripheral neuropathy (PN; 4), and insomnia (4). Across all dose levels, 8 pts had a total of 18 grade (Gr) 3/4 AEs including neutropenia (10), thrombocytopenia (1), febrile neutropenia, pneumonia (2 each), DVT, PE, and ophthalmic herpes zoster (1 each). Six pts experienced a serious AE (SAE). Four pts in the 1.8 mg/kg cohort had SAEs: 1 pt with Gr 2 dysphagia (not attributed to tx), 1 pt with Gr 4 pulmonary embolism (PE) and neutropenia and Gr 3 pneumonia (all tx-related), 1 pt with 2 episodes of Gr 4 neutropenia (tx-related that investigator deemed life-threatening), and 1 pt with Gr 4 pneumonia (not attributed to tx). The PE event was determined to be a DLT by the investigator. This pt had a concurrent event of deep vein thrombosis (non-serious). Seven of 13 pts experienced PN (Gr 1 [n=6] and Gr 2 [n=1]). The pt who had the Gr 2 PN received 2.4 mg/kg of PoV with R-CHP in error for 4 cycles and had additional risk factors for PN including history of diabetes mellitus, prior vincristine therapy. One tx discontinuation due to AE occurred due to Gr 2 PN in this pt who received PoV 2.4 mg/kg. One pt had a dose reduction for Gr 3 neutropenia. No deaths were reported. Of the 10 pts with DLBCL, 8 were assessed for interim response by PET/CT: 5 CR [1 at 1.0 mg/kg, 3 at 1.4 mg/kg, and 1 at 1.8 mg/kg], 3 PR [1 at 1.0 mg/kg and 2 at 1.8 mg/kg]). Two of 10 had not completed 3 cycles of tx and therefore not assessable for interim response. At the EOT, 7 were assessed for response: 5 CR (1 at 1.0 mg/kg, 3 at 1.4 mg/kg, and 1 at 1.8 mg/kg), 1 PR (at 1.0 mg/kg), 1 unevaluable (at 1.8 mg/kg). The 3 other pts were not assessed because they did not have a PET scan at EOT. Of the 2 pts with FL: one had SD (1.0 mg/kg) and one was not evaluable at the time of this report (2.4 mg/kg) at the EOT. One pt with MZL had CR at the EOT, then progressed at month 3 follow-up with biopsy proven transformed DLBCL. Conclusions: Early results show that PoV plus R-CHP has an acceptable safety profile in pts with previously untreated DLBCL. The PoV doses tested (1.0, 1.4, and 1.8 mg/kg) in this study showed acceptable toxicity in previous studies with relapsed NHL pts. Although the protocol-specified MTD was not formally reached, the recommended phase 2 dose of PoV was established at 1.8 mg/kg based on the overall safety and tolerability profile at that dose. The study's Phase 2 PoV+R-CHP expansion and the Phase Ib PoV+obinutuzumab-CHP dose escalation are ongoing. Disclosures Bartlett: AstraZeneca: Research Funding; Janssen: Research Funding; ImaginAb: Research Funding; Pharmacyclics: Research Funding; Genentech, Inc.: Research Funding; Pfizer: Research Funding; Novartis: Research Funding; Millennium: Research Funding; Celgene: Research Funding; Medimmune: Research Funding; Seattle Genetics: Consultancy, Research Funding; Gilead: Consultancy. Off Label Use: Polatuzumab vedotin is an investigational agent and not approved for DLBCL. Chen:Genentech, Inc.: Consultancy, Other: Advisory Board; Seattle Genetics: Consultancy, Other: Advisory Board; Janssen: Consultancy, Other: Advisory Board; Gilead: Consultancy, Other: Advisory Board. Kolibaba:Seattle Genetics: Research Funding; TG Therapeutics: Research Funding; GSK: Research Funding; Acerta: Research Funding; Genentech, Inc.: Research Funding; Novartis: Research Funding; Cell therapeutics: Research Funding; Celgene: Research Funding; Janssen: Research Funding; Gilead: Consultancy, Research Funding; Amgen: Research Funding; Pharmacyclics: Research Funding. Jones:Genentech, Inc.: Employment. Hirata:Genentech, Inc.: Employment, Equity Ownership. Sharman:TG Therapeutics, Inc.: Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene Corporation: Consultancy, Research Funding; Roche: Research Funding; Janssen: Research Funding; Calistoga: Honoraria.

Description: Background Entospletinib (GS-9973) is an orally bioavailable, selective inhibitor of spleen tyrosine kinase (Syk). Syk is a mediator of B-cell receptor signaling in normal and transformed B-cells. Targeting the B-cell receptor (BCR) signaling pathway has been a successful therapeutic strategy for chronic lymphocytic leukemia (CLL), with both ibrutinib, an inhibitor of BTK (BTKi) and idelalisib, an inhibitor of PI3Kdelta (PI3Ki), approved for this indication. Entospletinib activity in CLL was recently reported, and preclinical data suggested that entospletinib may be effective even in the context of resistance to BTK therapy, including that conferred by activation of PLCγ2. (Liu, Blood -2015-02-626846) Methods GS-US-339-0102 is an ongoing phase2 trial of entospletinib in CLL and NHL (NCT01799889). The study protocol was amended to add 40 patients in each of 2 CLL cohorts who have been previously treated with BCR signaling pathway (BTK/PI3K) inhibitors. These patients were treated with entospletinib monotherapy (400mg BID) and evaluated using modified Hallek/IWG-CLL criteria every 2-3 months as previously described in Sharman, Blood 2015:125(5). Results As of July 20, 2015, 8 patients with preceding BCR pathway signaling inhibitor treatment have been enrolled, 5 with preceding BTKi therapy (4 with ibrutinib, 1 with AVL-292) and 3 with preceding PI3Ki therapy (idelalisib). The median duration of preceding BTKi treatment was 51 weeks (range 2-85 weeks) and the median duration of preceding PI3Ki treatment was 106 weeks (range 74-168 weeks). Two patients had progressed on prior BTKi and 2 were intolerant (cause missing for 1 patient), while 2 patients progressed on PI3Ki and 1 was intolerant. All 5 patients with preceding BTKi and 2 out of 3 patients with prior PI3Ki remain on entospletinib treatment. Of the 5 patients who were previously treated with BTKi, the ongoing duration of treatment with entospletinib is 8, 8, 13, 25, and 39 weeks. For the 3 patients with preceding PI3Ki, two patients have ongoing treatment of 18 and 26 weeks; one patient stopped treatment and died after 23 weeks due to a cardiac arrest that is not believed to be related to the study drug. The most common treatment-emergent AEs (N=number; any Grade/≥Gr 3, independent of causality) were decreased appetite (3/0), contusion (2/0), dyspepsia (2/0), fatigue (2/0), dehydration (1/1), cardiac arrest (1/1); common laboratory abnormalities were anemia (5/1), neutropenia (4/1), thrombocytopenia (3/2), increased lipase (1/1). Early responses were seen with entospletinib treatment (3 partial response (PR), 1 stable disease, & 3 patients were too early to evaluate) and 1 PD. PR occurred in 1 BTKi and 2 PI3Ki previously treated patients. One patient with preceding PI3Ki developed progressive disease after 8 weeks. Conclusions Early experience from this trial with ongoing enrollment demonstrates that entospletinib has clinical activity following therapy with either BTKi or PI3Ki. No additional safety signals were seen from earlier studies. Additional investigation of treatment with entospletinib following progression with B-cell receptor signaling pathway inhibitors is warranted. Disclosures Sharman: Celgene Corporation: Consultancy, Research Funding; TG Therapeutics, Inc.: Research Funding; Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pharmacyclics: Consultancy, Honoraria, Research Funding; Roche: Research Funding; Calistoga: Honoraria; Janssen: Research Funding. Shustov:Celegene, BMS: Consultancy, Honoraria, Research Funding. Smith:celegene, spectrum, genentech: Honoraria. Boyd:US Oncology: Research Funding; Celgene: Speakers Bureau; Genentech, Inc.: Research Funding. Kolibaba:Gilead: Consultancy, Research Funding; Seattle Genetics, Inc.: Research Funding; Acerta: Research Funding; Celgene: Research Funding; Genentech: Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; GSK: Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; TG Therapeutics: Research Funding. Abella:Gilead: Employment. He:Gilead Sciences: Employment. Eng:Gilead: Employment. Hu:gilead: Employment. Reddy:gilead: Employment. Mitra:Gilead: Employment. Yasenchak:Seattle Genetics, Inc.: Research Funding.

Description: Background: Spleen tyrosine kinase (Syk) is a mediator of B-cell receptor signaling in normal and transformed B-cells. GS-9973 is an orally bioavailable, selective inhibitor of Syk. Methods: This Phase 2 trial enrolled 41 patients with CLL and 15 patients with SLL treated with GS-9973 800 mg BID. Tumor imaging occurred at weeks 8, 16, 24 and then every 12. Response was independently evaluated according to Hallek 2008 as modified by Cheson 2012 for patients with CLL and Cheson 2007 for patients with SLL. Primary endpoint for the study was PFS at 24 weeks. Results: The median ages of CLL and SLL patients were 73 (range 51-89) and 70 (range 57-84), respectively. 68% of CLL subjects and 60% of SLL subjects were male. Ten patients had 17p deletions/TP53 mutations and 17 had SF3B1 or NOTCH1 mutation, or 11q22.3 deletion. The median number of prior regimens for CLL was 2 (range 1-8) and for SLL was 2 (range 1-10). Prior therapies included anti-CD20 antibodies (98%), alkylating agents (86%, [bendamustine 63%]) and fludarabine (66%). 12 CLL and 6 SLL patients are still on treatment; the median duration of treatment for all CLL and SLL patients was 36 weeks The most common treatment emergent AEs (any Grade/≥Gr 3, independent of causality) were fatigue (70%/7%), nausea (54%/2%), diarrhea(48%/0%), cough(34%/0%), dizziness (32%/2%), headache (29%/0%), pyrexia (29%/0%), decreased appetite (27%/2%), upper respiratory tract infection(27%/0%), constipation (23%/0%). Common laboratory abnormalities were increased AST (30%/5%), increased ALT (43%/4%), increased total bilirubin (41%/16%), anemia (50%/7%) and neutropenia (54%/29%). Forty-nine patients were treated for at least 8 weeks and 54 patients had ≥ 1 efficacy assessment, two patients discontinued prior to the first response assessment, one due to AE and one withdrew consent. Per investigator assessment, 51 out of 52 (98%) patients evaluable for SPD experienced reduced tumor bulk; 38 (73%) achieved a decrease of ≥ 50%. The ORR was 62.5% (95% CI: 48.6%, 75.1%), with 35 patients achieving a PR and no subject achieving a CR. Thirteen patients (23.2%) had stable disease. The primary end point of 24 weeks PFS was 72.3% (95% CI: 57.1%, 83.0%). Median PFS was 20.5 months (95% CI: 7.7 months, not reached). There were 24 patients (42.9%) with events, 22 (39%) with disease progression and two deaths (4%) attributed to septic pneumonia and pseudomonal infection which was unrelated to entospletinib by investigator assessment. Among the 35 responding patients, median DOR was 21.3 months (95% CI: 13.2 months, not reached). Results of an independent response assessment are pending and will be presented. Entospletinib was well tolerated and demonstrated substantial activity in patients with CLL, and SLL including those with poor prognostic features. Entospletinib activity seems comparable to that reported by other approved BCR pathway inhibitors with the median PFS reported for Idela of 15.8 months (Blood. 2014;123(22):3390-3397) and Ibrutinib reported 42.6% overall response rate and a PFS of 70-80% @ 12 months (ibrutinib PI) Current studies plans include studying Entospletinib in combination therapy. Figure 1. Figure 1. Figure 2. Figure 2. Figure 3. Figure 3. Disclosures Sharman: Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Roche: Research Funding; Calistoga: Honoraria; Pharmacyclics: Consultancy, Honoraria, Research Funding; Celgene Corporation: Consultancy, Research Funding; TG Therapeutics, Inc.: Research Funding; Janssen: Research Funding. Kolibaba:Janssen: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; TG Therapeutics: Research Funding; GSK: Research Funding; Celgene: Research Funding; Acerta: Research Funding; Seattle Genetics, Inc.: Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; Gilead: Consultancy, Research Funding. Abella:Gilead: Employment. Di Paolo:Gilead Sciences: Employment, Equity Ownership. Eng:Gilead: Employment. Hu:gilead: Employment. He:Gilead Sciences: Employment. Reddy:gilead: Employment. Yasenchak:Seattle Genetics, Inc.: Research Funding.

Description: Background: PTLDs are typically B-cell neoplasms occurring as uncommon but serious complications of reduced T-cell immune surveillance associated with organ transplantation. RIS benefits only a subset of PTLD patients and cytotoxic therapy may be poorly tolerated. Therefore, in October 1998 we initiated a prospective study of rituximab in patients who failed or were unable to receive RIS and now report mature results. Methods: Patients with CD20+ PTLD were eligible if they had failed to completely respond to RIS or RIS was contraindicated and had Karnofsky performance status 〉60, age 3–70 years (y), measurable disease, and no change in immunosuppression for at least 2 weeks and no cytotoxic therapy within 4 weeks. Rituximab was given as 375 mg/m2 weekly x 4 with disease evaluation at 1, 3, 6, 9, 12 and 18 months. Response data, survival curves, and the impact of clinical and pathological factors were evaluated. Results: 24 of 26 enrolled pt were eligible and evaluable. Median age was 42y with 5

Description: The majority of pts with newly diagnosed CLL are classified with Rai stage 0 or 1 disease and typically experience an indolent clinical course. However, little is known regarding the reasons for initiating therapy in this population or patterns of initial treatment in the contemporary era of our practicing community. We utilized data from the Connect CLL registry, a US-based multi-center, prospective observational cohort study that is aimed at understanding patterns of CLL management without a study-specific intervention. Eligible pts were adults with a clinical diagnosis of CLL who initiated therapy ≤2 months prior to enrollment, and were enrolled from academic (n=155), community (n=1311), or government (n=28) sites between 2010-2014. Descriptive statistics were applied to examine data on demographics, baseline characteristics, treatment selection, early treatment outcomes, and reasons for initiating therapy that were reported for pts with Rai 0/1 CLL receiving first-line therapy. Multivariable logistic regression models were constructed to evaluate predictors of complete response (CR) and event-free survival (EFS) defined as the occurrence of the first of disease progression, relapse or death within 24 months of enrollment. Among 684 pts who received first-line therapy at enrollment and for whom Rai stage was available, 363 had Rai 0/1 CLL. This group had a median age of 68 years (range 41-90); 94% were white, 60% male, 98% insured, and 93% were treated in community practices; 47% had Rai stage 0 disease (54% Binet A); 33% had ≥1 constitutional symptoms; 96% had ECOG performance status of 0 or 1; 35% had conventional cytogenetics and 53% had FISH analysis performed. Among pts for whom cytogenetic or FISH analysis were performed, 159 (72%) were abnormal, of them 37 pts (23%) had del(11q), 104 pts (65%) had del(13q), 33 pts (21%) had trisomy 12, and 20 pts (13%) had del(17p) by conventional cytogenetics and/or FISH, including 8% with del(17p) by FISH. The median time from diagnosis to initiation of therapy was 2.5 years (range 0-20 years) for Rai 0/1 pts compared with 0.5 years for pts enrolled with Rai stage ≥2 (range 0-32). The most common reasons for initiating therapy (with 〉1 reason possible) in Rai 0/1 CLL were: bulky or progressive or lymphadenopathy (40%), progressive lymphocytosis (39%), any disease-related symptom (weight loss, fatigue, fever, night sweats; 28%), anemia (20%), and thrombocytopenia (15%); 42% of pts had 〉1 reason for initiation. The most common first-line regimens used in this cohort were: fludarabine/cyclophosphamide/rituximab (FCR; 29%), bendamustine/rituximab (BR; 20%), and rituximab alone (12%). Of the 317 pts who either responded to treatment during the first 24 months of enrollment or were followed ≥24 months, 143 pts (45%) achieved CR (investigator assessed as per protocol) and 264 (83%) achieved CR or partial response. Female gender (odds ratio [OR] = 2.22), treatment with BR or FCR (OR = 3.41), and time from diagnosis to therapy (OR = 0.92; with each year increase in time from diagnosis to initiation of therapy, relative odds of CR decreases by 8%), were independent predictors of CR. Of the 311 evaluable pts, 82 pts (26%) experienced an EFS event during the 24 months on study, of which 19 (23%) were deaths and 48 (59%) were progressions. Age ≥75 years (OR = 4.46), lymphocytosis as a reason for therapy initiation (OR = 1.89), and male gender (OR = 1.73) were independent predictors of an EFS event within 24 months. The Connect CLL registry represents the largest comprehensive prospective cohort of CLL pts collected from multiple practices across the US. In concordance with other studies, pts with Rai 0/1 initiated therapy approximately 2.5 years following CLL diagnosis and included a cohort of pts with poor prognostic FISH characteristics. Although chemoimmunotherapy was associated with a significantly higher likelihood of CR, progressive lymphocytosis as a reason for initiating therapy (and not any form of treatment) was more likely to predict an early EFS event. Approaches using novel agents or combination therapies aimed towards addressing pts with progressive lymphocytosis should be considered in future studies. Disclosures Flowers: Seattle Genetics: Consultancy; OptumRx: Consultancy; AbbVie: Research Funding; Pharmacyclics: Research Funding; Gilead Sciences: Research Funding; Genentech: Research Funding; AbbVie: Research Funding; Celegene: Other: Unpaid consultant, Research Funding; Spectrum: Research Funding; Onyx Pharmaceuticals: Research Funding; Spectrum: Research Funding; Acerta: Research Funding; Gilead Sciences: Research Funding; Janssen: Research Funding; Infinity Pharmaceuticals: Research Funding; Infinity Pharmaceuticals: Research Funding; Janssen: Research Funding; Millennium/Takeda: Research Funding; Onyx Pharmaceuticals: Research Funding; Pharmacyclics: Research Funding; Acerta: Research Funding; Millennium/Takeda: Research Funding. Nabhan:Celgene Corporation: Honoraria, Research Funding. Kay:Pharmacyclics: Research Funding; Genentech: Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Hospira: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero Pharma: Research Funding. Mato:AbbVie: Consultancy, Research Funding; Janssen: Consultancy; Celgene Corporation: Consultancy, Research Funding; Pronai Pharmaceuticals: Research Funding; Pharmacyclics: Consultancy, Research Funding; TG Therapeutics: Research Funding; Gilead: Consultancy, Research Funding; Genentech: Consultancy. Lamanna:Genentech-Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Infinity: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Grinblatt:Celgene Corporation: Consultancy, Honoraria, Speakers Bureau. Kipps:Pharmacyclics Abbvie Celgene Genentech Astra Zeneca Gilead Sciences: Other: Advisor; Pharmacyclics Abbvie Celgene Genentech Astra Zeneca Gilead Sciences: Other: Advisor. Kozloff:Roche: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Genentech: Consultancy, Speakers Bureau; AbbVie: Consultancy. Sullivan:Celgene Corporation: Employment, Equity Ownership. Flick:Celgene Corporation: Employment, Equity Ownership. Kiselev:Celgene Corporation: Consultancy. Bhushan:Celgene Corporation: Employment, Equity Ownership. Swern:Celgene Corporation: Employment, Equity Ownership. Sharman:TG Therapeutics, Inc.: Research Funding; Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Research Funding; Calistoga: Honoraria; Celgene Corporation: Consultancy, Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Roche: Research Funding.