Zanubrutinib for treatment-naïve and relapsed/refractory chronic lymphocytic leukaemia: long-term follow-up of the phase I/II AU-003 study

The phase I/II AU-003 study in patients with treatment-naïve (TN) or relapsed/refractory (R/R) chronic lymphocytic leukaemia/small lymphocytic lymphoma demonstrated that zanubrutinib therapy results in clinically meaningful and durable responses with acceptable safety and tolerability. We report updated safety and efficacy data for 123 patients with a median follow-up of 47·2 months. Patients received zanubrutinib 160 mg twice daily (81 patients), 320 mg once daily (40), or 160 mg once daily (two). Discontinuations due to adverse events or disease progression were uncommon. The overall response rate (ORR) was 95·9% (TN, 100%; R/R, 95%) with 18·7% achieving complete response (CR). Ongoing response at 3 years was reported in 85·7%. The ORR in patients with del(17p)/tumour protein p53 mutation was 87·5% (CR 16·7%). The 2- and 3-year progression-free survival estimates were 90% (TN, 90%; R/R, 91%) and 83% (TN, 81%; R/R, 83%) respectively. The most reported Grade ≥3 adverse events were neutropenia (15·4%), pneumonia (9·8%), hypertension (8·9%) and anaemia (6·5%). The annual incidence of atrial fibrillation, major haemorrhage, Grade ≥3 neutropenia and Grade ≥3 infection decreased over time. With a median follow-up of ~4 years, responses remain clinically meaningful and durable and long-term tolerability to zanubrutinib therapy continues.

Abstract OT1-01-04: A phase 2, open-label study of imprime PGG (Imprime), a novel beta glucan, with pembrolizumab (Pembro) in chemotherapy-resistant metastatic triple negative breast cancer (TNBC)

By blocking the interaction of PD-L1 with PD-1, immune checkpoint inhibitors (CPI) can unleash specific, anti-cancer killing function of activated cytotoxic T cells in patients (pts) for whom there is evidence of an ongoing anti-cancer immune response (PD-L1 expression and/or activated T cells within the tumor bed). Single agent CPI therapy has provided substantial clinical benefit to pts with multiple cancer types. Though effective, response rates are typically limited (˜15-30% of pts depending on tumor type) and therapy fails to benefit the majority of pts. For these pts there is often limited or no evidence of an ongoing T cell-based immune response. Agents that stimulate the anti-cancer immune response may be particularly promising in expanding the clinical responsiveness to CPI therapies. Imprime is a novel beta glucan derived from Saccharomyces acting mechanistically as a pathogen-associated molecular pattern (PAMP) or non-self danger signal, to awaken and activate the innate immune system. Imprime drives a cascade of immune activating events activating tumor-specific cytotoxic T cells. Imprime treatment elicits repolarization of the immunosuppressive microenvironment while activating the maturation of antigen presenting cells. Imprime has significantly enhanced the efficacy of CPI therapy in preclinical tumor models. In humans, Imprime-mediated innate immune activation requires the formation of an immune complex with naturally-occurring anti-beta glucan antibodies (ABA). Formation of this complex is dependent upon sufficient ABA levels. Imprime is now being studied in combination with pembro (KEYTRUDA®), a humanized mAb against PD-1 which has been previously studied in TNBC pts.This phase 2 study explores the treatment combination in pts with metastatic TNBC who progressed following at least one line of chemotherapy and pts with metastatic melanoma who progressed following CPI therapy with sufficient pre-treatment ABA levels (˜50% of screened patients). The study is a Simon 2-stage design. Specific to the TNBC tumor type, a sample size of 12 pts in Stage 1 is planned. Criteria to advance to Stage 2 are ≤4 GR 3/4 AEs and ≥2 objective responses in TNBC. An additional 30 TNBC pts may be enrolled in Stage 2. Main eligibility criteria are metastatic TNBC after chemotherapy in the metastatic setting and serum ABA ≥20 µg/mL. The primary endpoints are ORR and safety; secondary endpoints are TTR, CRR, DoR, PFS, and OS. Efficacy will be analyzed for ORR and CRR as point estimates with 95% CI and for PFS, OS, DoR and TTR as descriptive summaries. Safety parameters will be summarized. Exploratory endpoints include ORR and PFS based on irRECIST. This study aims to collect pre- and early on-treatment tumor (6 wks post-1st dose) biopsies and peripheral blood to assess the impact of the treatment combination on immune activating events in the periphery and at the tumor site. As of June 2017, 11 sites were open and 4 pts were in treatment. The trial is sponsored by Biothera Pharmaceuticals, Inc. in collaboration with Merck & Co. (ClinicalTrials.gov NCT02981303) For information, contact Richard D. Huhn, MD, Biothera Med Dir at rhuhn@biothera.com or 651-256-4657.

Citation Format: O'Day SJ, Stopeck AT, Huhn RD, Gargano MA, Prathikanti R, Ma B, Mattson PM, Lowe JR, Bose N, Ertelt KE, Ottoson NC, Uhlik MT, Graff JR, Chisamore MJ. A phase 2, open-label study of imprime PGG (Imprime), a novel beta glucan, with pembrolizumab (Pembro) in chemotherapy-resistant metastatic triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-01-04.

Abstract LB-A31: Imprime PGG (Imprime) plus pembrolizumab (PEM): a phase 2 immunotherapeutic combination in patients selected for an Imprime-specific biomarker

Imprime PGG (Imprime) is a novel immunotherapeutic that acts as a non-self danger signal to activate the innate immune system and coordinate an adaptive immune system response. In multiple preclinical tumor models, Imprime significantly enhances anti-tumor efficacy of multiple immune checkpoint inhibitors (CPI). Mechanistically, Imprime directly binds to innate immune effector cells via the formation of an immune complex with naturally-occurring anti-β glucan antibodies (ABA). This immune complex is required for Imprime to activate innate effector functions, e.g. monocyte and dendritic cell activation, and enhanced cytokine production. In a recently completed healthy volunteer study, activation of innate immune cell functions was demonstrated after intravenous (IV) infusion of Imprime in subjects with pre-treatment [Tx] ABA levels >20 µg/ml. In ex vivo human donor blood studies, whole blood from subjects with low (e.g., insufficient) ABA failed to show innate immune activation unless rescued by the addition of purified ABA (ABA from the serum of high ABA donors) or commercial immune globulin. Retrospective analyses of data from previous clinical trials showed that higher pre-Tx ABA levels correlated with enhanced overall survival in patients (pts) treated with Imprime. Collectively, these data support the hypothesis that ABA are essential to the therapeutic benefit of Imprime. A phase 2 clinical trial combining Imprime (4 mg/kg weekly IV) with PEM (200 mg, q3w) has begun in metastatic melanoma pts who have failed a CPI and in CPI naïve-triple negative breast cancer (TNBC) pts who have failed chemotherapy. Pts are screened for sufficient ABA (>20 μg/ml) by ELISA. Pre- and on- Tx biopsies at 6 wks and at time of response/progression or end of Tx are requested to assess immune cells at the tumor site by multi-channel immunofluorescence. Blood samples are collected pre- and post- Imprime infusion on Day 1 of each treatment cycle for the first 6 cycles and q4 cycle thereafter. The first TNBC pt had a pre-Tx ABA of 31 µg/ml. Following 6 wks of Tx, the pt’s total target lesion mass was reduced >40%. Partial response continued at 12, 18 and 24 wks (>50% reduction vs baseline). A biopsy of a remaining pelvic lesion after 18 wks Tx revealed primarily fibrotic tissue. Blood samples showed evidence of innate immune activation including increased expression of MCP-1, IL-8, chemokines targeting CCR5 and CXCR3 that are associated with enhanced T cell infiltration and effector function. The first melanoma pt (pre-Tx ABA 42 µg/ml) showed a modest increase in lesion size at 12 wks (+12% versus baseline). Pre- and on-Tx (6 wk) biopsy material (from two different lesion locations) was obtained for multichannel immunofluorescence. The pre-Tx biopsy tumor sample was primarily devoid of immune cells. In contrast, the on-Tx biopsy tumor sample indicates extensive infiltration of the tumor bed by CD8 and CD4 T cells, and innate immune cells. Previous Imprime clinical and ex vivo data suggest that sufficient ABA may be important for Imprime-mediated innate immune activation. Early clinical observations in ABA pre-selected patients support the notion that Imprime may provide benefit in combination with PEM in these two populations.

Citation Format: Steven O'Day, Nandita Bose, Mark Uhlik, Radha Prathikanti, Ben Harrison, Steven Leonardo, Richard Huhn, Nadine Ottoson, Xiaohong Qiu, Richard Walsh, Paulette Mattson, Mable Ma, Katie Ertelt, Jamie Lowe, Michele A. Gargano, Michael Chisamore, Bruno Osterwalder, Jeremy Graff. Imprime PGG (Imprime) plus pembrolizumab (PEM): a phase 2 immunotherapeutic combination in patients selected for an Imprime-specific biomarker [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-A31.

A multicenter, open-label, phase II study of PGG beta-glucan and pembrolizumab in patients (pts) with advanced melanoma (MEL) following progression on treatment with checkpoint inhibitors (CPI) or triple negative breast cancer (TNBC) failing front-line chemotherapy for metastatic disease

TPS3105

Background: Imprime PGG (Imprime) is a Pathogen- Associated Molecular Pattern that enhances innate immune cell killing, counteracts immune suppression and triggers activation and maturation of antigen presenting cells. Imprime’s ability to trigger a coordinated innate and adaptive immune response is critical for enhancing the efficacy of CPIs in several pre-clinical tumor models. We are now exploring the combination of PGG beta-glucan and Pembrolizumab, a humanized mAb against programmed death receptor-1 (PD-1) in the clinic. In previous trials, Pembro yielded a 33% ORR and 23 mo mOS in 655 pts with advanced MEL and an 18.5% ORR and 11.2 mo mOS in 27 evaluable pts with metastatic/recurrent TNBC (Ribas et al., 2016; Nanda et al., 2016). Pre-treatment levels of anti-beta glucan antibodies (ABA) are correlated with pt response to Imprime. Methods: This Phase 2 study is enrolling ABA positive pts with advanced MEL following progression on treatment with a CPI or metastatic TNBC failing front-line chemotherapy. The study is a Simon optimal 2-stage design with sample size of 12 pts of each tumor type in Stage 1. If response and AE criteria (≤ 4 [or ≤ 33%] pts with grade 3/4 in Cycle 1) for each tumor type are met, an additional 17 pts with MEL and 30 pts with TNBC will be enrolled in Stage 2. Primary endpoints of the study are ORR (based on RECIST 1.1) and safety. Secondary endpoints include TTR, CRR, DoR, PFS, and OS. PK data will be profiled. Exploratory endpoints include ORR and PFS based on irRECIST, analysis of an ABA biomarker, immune cell activation markers, and changes in the tumor immune microenvironment. Screening and enrollment are underway in the US. Biothera Pharmaceuticals, Inc. is sponsoring the trial (ClinicalTrials.gov NCT02981303) under a collaborative agreement with Merck. Clinical trial information: NCT02981303.

Preference for monthly darbepoetin alfa dosing in patients with chronic kidney disease not receiving dialysis

OBJECTIVE

To determine patient preference for once-weekly Epoetin alfa versus once-monthly (QM) darbepoetin alfa in patients with chronic kidney disease (CKD) not receiving dialysis.

METHODS

AMPS (Aranesp Monthly Preference Study) consisted of two studies of similar design, each with a 2-week screening/baseline period, a 20-week QM darbepoetin alfa dosing period, and an 8-week follow-up period. Patients aged > or = 18 years had a nephrologist-reported diagnosis of CKD but were not receiving dialysis, and were required to have at least two hemoglobin levels within 10-12 g/dL and to have been receiving a stable dose (< 25% change) of once-weekly or once-every-other-weekly Epoetin alfa for at least 8 weeks. At week 21, patients could continue on QM darbepoetin alfa or revert back to their previous Epoetin alfa regimen. The primary analysis assessed patient preference at week 21 for QM darbepoetin alfa versus previous once-weekly Epoetin alfa.

RESULTS

AMPS enrolled 442 patients: 54% were female, 67% were Caucasian, and mean (SD) age was 68.3 (13.5) years. At week 21, 346 patients remained on study. Of the patients converted from once-weekly Epoetin alfa, 86% (138/161) preferred darbepoetin alfa QM, and of all patients who expressed a preference, regardless of previous Epoetin alfa dosing frequency, 96% (305/319) preferred QM darbepoetin alfa. Mean (SD) hemoglobin at week 29 of the study was similar to mean hemoglobin at baseline (for those who completed the study and were receiving QM darbepoetin alfa at week 29: 11.2 [1.1] g/dL at week 29 versus 11.4 [0.7] g/dL at baseline). QM darbepoetin alfa was well tolerated.

CONCLUSION

These data show that the majority of study patients preferred QM darbepoetin alfa to more frequent Epoetin alfa, and that QM darbepoetin alfa maintained hemoglobin levels at week 29 and was well tolerated over the study period. The single-item questionnaire could be a potential limitation of this study and further investigation with a multi-question instrument may be helpful in confirming these results.

Darbepoetin alfa administration to achieve and maintain target hemoglobin levels for 1 year in patients with chronic kidney disease

OBJECTIVE

To assess the efficacy and safety of every-other-week darbepoetin alfa therapy in treating anemia and maintaining hemoglobin levels for 1 year in patients with chronic kidney disease (CKD) who were not undergoing dialysis and who had not previously received erythropolesis-stimulating proteins (ESPs).

PATIENTS AND METHODS

This multicenter 52-week study (evaluation period, weeks 20-32), a subanalysis of the Simplify the Treatment of Anemia with Aranesp study, enrolled patients with CKD who were not receiving dialysis (creatinine clearance < or =70 mL/min or estimated glomerular filtration rate [GFR] < or =60 mL/min). Patients evaluated in this analysis were not receiving ESPs, had hemoglobin concentrations less than 11 g/dL, and had transferrin saturation of 20% or higher during screening. Patients Initiated every-other-week darbepoetin alfa therapy at 0.75 microg/kg, with the dose subsequently titrated to maintain hemoglobin levels not to exceed 12 g/dL. The first study participant was enrolled on February 4, 2002, and the last participant completed the study on March 31, 2004.

RESULTS

The analysis included 911 patients (mean [SD] age, 66.4 [14.2] years; 54.3% female; 55.3% white). The least squares mean evaluation hemoglobin concentration was 11.54 g/dL (95% confidence interval, 11.47-11.61 g/dL), and the change from baseline was 1.6 g/dL (95% confidence interval, 1.5-1.7 g/dL). The mean (SD) every-other-week darbepoetin alfa dose during evaluation was 44.5 (33.7) microg. Iron supplementation was administered to 573 patients (62.9%) during the study. Darbepoetin alfa was well tolerated throughout the study period.

CONCLUSION

Darbepoetin alfa initiated every other week safely and effectively treated anemia and maintained hemoglobin for 1 year in patients with CKD who were not undergoing dialysis and who were not receiving prior ESP therapy.

Darbepoetin alfa administered every other week maintains hemoglobin levels over 52 weeks in patients with chronic kidney disease converting from once-weekly recombinant human erythropoietin: results from simplify the treatment of anemia with Aranesp (STAAR)

BACKGROUND/AIM

Darbepoetin alfa, an effective treatment for anemia of chronic kidney disease (CKD), can be administered at extended intervals. Simplify the Treatment of Anemia with Aranesp (STAAR), a multicenter, 52-week study, was conducted to assess the efficacy of darbepoetin alfa administered subcutaneously every other week (Q2W) in maintaining hemoglobin (Hb) in CKD patients not receiving dialysis.

METHODS

This is a subgroup analysis of subjects converted from once-weekly (QW) recombinant human erythropoietin (rHuEPO; US Aranesp package insert) and who received up to 52 weeks of darbepoetin alfa therapy (evaluation period 20-32 weeks). Enrolled subjects had a creatinine clearance < or = 70 ml/min or an estimated glomerular filtration rate < or = 60 ml/min and transferrin saturation > or = 20%. Darbepoetin alfa doses were titrated to maintain Hb levels < or = 12 g/dl. The primary endpoint was mean Hb during evaluation.

RESULTS

There were 524 subjects enrolled in the study who were previously receiving rHuEPO QW. Mean Hb +/- standard deviation was 11.2 +/- 1.27 g/dl at baseline, and the least squares mean +/- SE was 11.4 +/- 0.04 during evaluation. The mean +/- SD Q2W darbepoetin alfa dose was 49.7 +/- 21.9 microg at baseline and 48.9 +/- 35.5 microg at evaluation. Darbepoetin alfa was well tolerated.

CONCLUSIONS

Study subjects with CKD receiving QW rHuEPO were effectively converted to Q2W darbepoetin alfa, which was well tolerated. Hb levels were maintained over 52 weeks without a significant change in darbepoetin alfa dose.