Pembrolizumab plus dinaciclib in patients with hematologic malignancies: the phase 1b KEYNOTE-155 study

Preclinical data demonstrated that combining an anti-programmed cell death 1 (PD-1) inhibitor with a CDK9 inhibitor provided enhanced antitumor activity with no significant toxicities, suggesting this combination may be a potential therapeutic option. The multicohort, phase 1 KEYNOTE-155 study evaluated the safety and antitumor activity of the PD-1 inhibitor pembrolizumab plus the CDK9 inhibitor dinaciclib in patients with relapsed or refractory (rr) chronic lymphocytic leukemia (CLL), diffuse large B-cell lymphoma (DLBCL) and multiple myeloma (MM). Patients enrolled were ≥18 years of age with a confirmed diagnosis of CLL, DLBCL, or MM. The study included 2 phases: a dose-evaluation phase to determine dose-limiting toxicities and a signal-detection phase. Patients received pembrolizumab 200 mg every 3 weeks plus dinaciclib 7 mg/m2 on day 1 and 10 mg/m2 on day 8 of cycle 1 and 14 mg/m2 on days 1 and 8 of cycles 2 and later. Primary endpoint was safety, and a key secondary endpoint was objective response rate (ORR), Seventy-two patients were enrolled and received ≥1 dose of study treatment (CLL, n = 17; DLBCL, n = 38; MM, n = 17). Pembrolizumab plus dinaciclib was generally well tolerated and produced no unexpected toxicities. The ORRs were 29.4% (5/17, rrCLL), 21.1% (8/38, rrDLBCL), and 0% (0/17, rrMM), respectively. At data cutoff, all 72 patients had discontinued treatment, 38 (52.8%) because of progressive disease. These findings demonstrate activity with combination pembrolizumab plus dinaciclib and suggest that a careful and comprehensive approach to explore anti-PD-1 and CDK9 inhibitor combinations is warranted. Clinical trial registration: ClinicalTrials.gov, NCT02684617

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Inhibition of Syk with fostamatinib disodium has significant clinical activity in non-Hodgkin lymphoma and chronic lymphocytic leukemia

Blood ◽

10.1182/blood-2009-08-236471 ◽

2010 ◽

Vol 115 (13) ◽

pp. 2578-2585 ◽

Cited By ~ 541

Author(s):

Jonathan W. Friedberg ◽

Jeff Sharman ◽

John Sweetenham ◽

Patrick B. Johnston ◽

Julie M. Vose ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Hodgkin Lymphoma ◽

Cell Lymphoma ◽

Phase 1 ◽

Objective Response ◽

B Cell Lymphoma ◽

Lymphocytic Leukemia ◽

Primary Tumors ◽

Non Hodgkin Lymphoma

AbstractCertain malignant B cells rely on B-cell receptor (BCR)–mediated survival signals. Spleen tyrosine kinase (Syk) initiates and amplifies the BCR signal. In in vivo analyses of B-cell lymphoma cell lines and primary tumors, Syk inhibition induces apoptosis. These data prompted a phase 1/2 clinical trial of fostamatinib disodium, the first clinically available oral Syk inhibitor, in patients with recurrent B-cell non-Hodgkin lymphoma (B-NHL). Dose-limiting toxicity in the phase 1 portion was neutropenia, diarrhea, and thrombocytopenia, and 200 mg twice daily was chosen for phase 2 testing. Sixty-eight patients with recurrent B-NHL were then enrolled in 3 cohorts: (1) diffuse large B-cell lymphoma (DLBCL), (2) follicular lymphoma (FL), and (3) other NHL, including mantle cell lymphoma (MCL), marginal zone lymphoma (MZL), mucosa-associated lymphoid tissue lymphoma, lymphoplasmacytic lymphomas, and small lymphocytic leukemia/chronic lymphocytic leukemia (SLL/CLL). Common toxicities included diarrhea, fatigue, cytopenias, hypertension, and nausea. Objective response rates were 22% (5 of 23) for DLBCL, 10% (2 of 21) for FL, 55% (6 of 11) for SLL/CLL, and 11% (1/9) for MCL. Median progression-free survival was 4.2 months. Disrupting BCR-induced signaling by inhibiting Syk represents a novel and active therapeutic approach for NHL and SLL/CLL. This trial was registered at www.clinicaltrials.gov as #NCT00446095.

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Phase 1/2 study of cirmtuzumab and ibrutinib in mantle cell lymphoma (MCL) or chronic lymphocytic leukemia (CLL).

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.7556 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. 7556-7556

Author(s):

Hun Ju Lee ◽

Michael Y. Choi ◽

Tanya Siddiqi ◽

Jacqueline Claudia Barrientos ◽

William G. Wierda ◽

...

Keyword(s):

Phase 1 ◽

Single Agent ◽

Objective Response ◽

Median Number ◽

Lymphocytic Leukemia ◽

Synergistic Activity ◽

Best Response ◽

Car T ◽

Treatment Naïve

7556 Background: Cirmtuzumab (Cirm) is a humanized monoclonal antibody that inhibits the tumor promoting activity of ROR1 and had demonstrated additive/synergistic activity with many anti-cancer agents including ibrutinib (Ibr). Methods: Patients (Pts) with relapsed or refractory (RR) MCL or treatment naïve (TN) or RR CLL were enrolled. In Part 1 (Dose Escalation), doses of Cirm IV q2wks x5 then q4wks of 2-16 mg/kg and 300 or 600 mg were examined. Safety of Cirm alone was assessed during the first 28 days, then Ibr was started at approved doses for each indication. Cirm 600 mg IV q2wks x3 then q4wks in combination with Ibr starting day 0 was chosen as the recommended dosing regimen for use in Part 2 (Expansion) and Part 3 (CLL only, Cirm/Ibr vs. Ibr alone). Results: Twelve evaluable MCL pts were enrolled into Part 1, and 5 into Part 2. Median number of prior regimens was 2 (1-5), including pts relapsing after Ibr (4), auto-SCT (3), auto-SCT/ allo-SCT (1), auto-SCT/CAR-T (1). In CLL, 34 evaluable pts (12 TN and 22 RR) enrolled into Part 1 (18) or Part 2 (16). At least 74% of CLL pts in Parts 1 and 2 were high risk as determined by unmutated IGHV, del17p, and/or del11q. In Part 3, 22 evaluable pts received Cirm/Ibr (15) or Ibr (7). As of the 30OCT2020 safety cut-off for MCL and CLL, common TEAEs (all grades) included diarrhea (41%), contusion (39%), fatigue (39%), URI (31%), hypertension (25%) arthralgia (23%). Grade ≥3 neutropenia was 13% and thrombocytopenia 1%. There were no Cirm dose reductions or discontinuations for toxicity. Overall, Cirm did not appear to negatively impact the safety of Ibr. Efficacy (MCL): As of the 02FEB2021 efficacy cutoff, the best response of 17 evaluable pts in Parts 1 and 2 included an objective response rate (ORR) of 82%, 41% CR/CMR, 41% PR, 12% SD, and 6% PD. CR/CMR remain durable from 8-28+ mos. Most responses occurred rapidly after ̃3 mos of Cirm/Ibr. Notably, responses were achieved in all pts who received prior SCT+/- CAR-T (4CR, 1PR) or prior Ibr (2CR, 2PR). At a median follow-up of 14.6 mos, the median PFS (mPFS) had not been reached (NR) (95% CI: 17.5, NA). Efficacy (CLL): The best response of 34 evaluable pts in Parts 1 and 2 included 91% ORR, 3% CR, 88% PR/PR-L, 9% SD, 0% PD. In Part 3, both arms achieved 100% ORR (all PRs). At a median follow-up of 20.2 mos, the mPFS was NR (95% CI: NA, NA), and the PFS estimate at 24 months was 95% for R/R, and 87% for TN, respectively, for evaluable CLL pts receiving Cirm/Ibr. Conclusions: Cirm/Ibr is a well-tolerated, active regimen in both MCL and CLL. For MCL, the mPFS of NR (95% CI: 17.5, NA) and CRR (41%), with all CRs remaining without PD, compare favorably to mPFS of 12.8 mos (95% CI 8.5-16.6) and CRR (20%) reported for single agent Ibr (Rule 2017). For CLL, the high ORR and PFS are encouraging, particularly for RR CLL. The study is ongoing, with MCL enrollment expanded to study Cirm + Ibr in pts who have had a suboptimal response to an Ibr regimen, or who have failed other approved BTKi agents. Clinical trial information: NCT03088878.

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Bone Marrow Lymphoid Niche Adaptation to Mature B Cell Neoplasms

Frontiers in Immunology ◽

10.3389/fimmu.2021.784691 ◽

2021 ◽

Vol 12 ◽

Author(s):

Erwan Dumontet ◽

Stéphane J. C. Mancini ◽

Karin Tarte

Keyword(s):

Bone Marrow ◽

B Cells ◽

B Cell ◽

Tumor Cells ◽

Stromal Cells ◽

Therapeutic Option ◽

B Cell Lymphoma ◽

Lymphocytic Leukemia ◽

Niche Adaptation ◽

Functional Features

B-cell non-Hodgkin lymphoma (B-NHL) evolution and treatment are complicated by a high prevalence of relapses primarily due to the ability of malignant B cells to interact with tumor-supportive lymph node (LN) and bone marrow (BM) microenvironments. In particular, progressive alterations of BM stromal cells sustain the survival, proliferation, and drug resistance of tumor B cells during diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and chronic lymphocytic leukemia (CLL). The current review describes how the crosstalk between BM stromal cells and lymphoma tumor cells triggers the establishment of the tumor supportive niche. DLBCL, FL, and CLL display distinct patterns of BM involvement, but in each case tumor-infiltrating stromal cells, corresponding to cancer-associated fibroblasts, exhibit specific phenotypic and functional features promoting the recruitment, adhesion, and survival of tumor cells. Tumor cell-derived extracellular vesicles have been recently proposed as playing a central role in triggering initial induction of tumor-supportive niches, notably within the BM. Finally, the disruption of the BM stroma reprogramming emerges as a promising therapeutic option in B-cell lymphomas. Targeting the crosstalk between BM stromal cells and malignant B cells, either through the inhibition of stroma-derived B-cell growth factors or through the mobilization of clonal B cells outside their supportive BM niche, should in particular be further evaluated as a way to avoid relapses by abrogating resistance niches.

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The phase 3 DUO trial: duvelisib vs ofatumumab in relapsed and refractory CLL/SLL

Blood ◽

10.1182/blood-2018-05-850461 ◽

2018 ◽

Vol 132 (23) ◽

pp. 2446-2455 ◽

Cited By ~ 87

Author(s):

Ian W. Flinn ◽

Peter Hillmen ◽

Marco Montillo ◽

Zsolt Nagy ◽

Árpád Illés ◽

...

Keyword(s):

B Cell ◽

Phase 1 ◽

Randomized Study ◽

Progression Free Survival ◽

Hematologic Malignancies ◽

Lymphocytic Leukemia ◽

Primary Study ◽

Effective Treatment Option ◽

Phase 3 ◽

Dual Inhibitor

Abstract Duvelisib (also known as IPI-145) is an oral, dual inhibitor of phosphatidylinositol 3-kinase δ and γ (PI3K-δ,γ) being developed for treatment of hematologic malignancies. PI3K-δ,γ signaling can promote B-cell proliferation and survival in clonal B-cell malignancies, such as chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). In a phase 1 study, duvelisib showed clinically meaningful activity and acceptable safety in CLL/SLL patients. We report here the results of DUO, a global phase 3 randomized study of duvelisib vs ofatumumab monotherapy for patients with relapsed or refractory (RR) CLL/SLL. Patients were randomized 1:1 to oral duvelisib 25 mg twice daily (n = 160) or ofatumumab IV (n = 159). The study met the primary study end point by significantly improving progression-free survival per independent review committee assessment compared with ofatumumab for all patients (median, 13.3 months vs 9.9 months; hazard ratio [HR] = 0.52; P < .0001), including those with high-risk chromosome 17p13.1 deletions [del(17p)] and/or TP53 mutations (HR = 0.40; P = .0002). The overall response rate was significantly higher with duvelisib (74% vs 45%; P < .0001) regardless of del(17p) status. The most common adverse events were diarrhea, neutropenia, pyrexia, nausea, anemia, and cough on the duvelisib arm, and neutropenia and infusion reactions on the ofatumumab arm. The DUO trial data support duvelisib as a potentially effective treatment option for patients with RR CLL/SLL. This trial was registered at www.clinicaltrials.gov as #NCT02004522.

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Antitumor activity of dostarlimab in patients with mismatch repair-deficient/microsatellite instability–high tumors: A combined analysis of two cohorts in the GARNET study.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.2564 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. 2564-2564

Author(s):

Dominique Berton ◽

Susana N. Banerjee ◽

Giuseppe Curigliano ◽

Sara Cresta ◽

Hendrik-Tobias Arkenau ◽

...

Keyword(s):

Antitumor Activity ◽

Microsatellite Instability ◽

Mismatch Repair ◽

Solid Tumors ◽

Phase 1 ◽

Objective Response ◽

Low Grade ◽

Open Label ◽

Tumor Types

2564 Background: Dostarlimab is an investigational, humanized programmed death 1 (PD-1) receptor monoclonal antibody that blocks interaction with the PD-1 ligands, PD-L1 and PD-L2. GARNET (NCT02715284) is a phase 1 study assessing the antitumor activity and safety of dostarlimab monotherapy in patients with solid tumors. Methods: This multicenter, open-label, single-arm study is being conducted in 2 parts: dose escalation and expansion. Here we report on the 2 expansion cohorts that enrolled mismatch repairdeficient/microsatellite instabilityhigh (dMMR/MSI-H) patients. Cohort A1 enrolled patients with advanced or recurrent dMMR/MSI-H endometrial cancer (EC), and cohort F enrolled patients with advanced or recurrent dMMR/MSI-H or POLε-hypermutated non-EC solid tumors, mainly gastrointestinal (GI) tumors (99 [93.4%] had GI tumors, including 69 [65.1%] with colorectal cancer). Patients received 500 mg IV of dostarlimab every 3 weeks for 4 cycles, then 1000 mg IV every 6 weeks until disease progression or discontinuation. The primary endpoints were objective response rate (ORR) and duration of response (DOR) by RECIST v1.1. Here we report ORR and DOR, by individual cohort and as an overall population, in patients with dMMR tumors identified by immunohistochemistry testing. Results: For this interim analysis, an efficacy analysis was performed for the patients who had baseline measurable disease and ≥6 months of follow-up in the study (N = 209). The ORR was 41.6% (95% CI, 34.9%48.6%) for the combined A1+F dMMR cohorts (Table). Responses were durable, and median DOR has not been reached in either cohort (median follow-up: cohort A1, 16.3 months; cohort F, 12.4 months). A total of 267 patients were included in the safety population (all patients who received ≥1 dose; cohort A1, N = 126; cohort F, N = 141). Treatment-related adverse events (TRAEs) were consistent across tumor types. Overall, the most frequently reported any-grade TRAEs were asthenia (13.9%), diarrhea (13.5%), and fatigue (11.2%). The most common grade ≥3 TRAEs were anemia (2.2%), lipase increased (1.9%), alanine aminotransferase increased (1.1%), and diarrhea (1.1%). No deaths were attributed to dostarlimab. Conclusions: Dostarlimab demonstrated durable antitumor activity in patients with dMMR solid tumors, with consistent antitumor activity seen across endometrial and nonendometrial tumor types. The safety profile was manageable, with no new safety signals detected. Most TRAEs were low grade and were similar across cohorts. Clinical trial information: NCT02715284. [Table: see text]

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Combination strategies to overcome resistance to the BCL2 inhibitor venetoclax in hematologic malignancies

Cancer Cell International ◽

10.1186/s12935-020-01614-z ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

XiaoYan Yue ◽

Qingxiao Chen ◽

JingSong He

Keyword(s):

Intracellular Signaling ◽

B Cell Lymphoma ◽

Hematologic Malignancies ◽

The United States ◽

Resistance Mechanisms ◽

Lymphocytic Leukemia ◽

Bcl2 Family ◽

Combination Strategies ◽

United States Food ◽

Major Factors

Abstract Venetoclax has been approved by the United States Food and Drug Administration since 2016 as a monotherapy for treating patients with relapsed/refractory chronic lymphocytic leukemia having 17p deletion. It has led to a breakthrough in the treatment of hematologic malignancies in recent years. However, unfortunately, resistance to venetoclax is inevitable. Multiple studies confirmed that the upregulation of the anti-apoptotic proteins of the B-cell lymphoma 2 (BCL2) family mediated by various mechanisms, such as tumor microenvironment, and the activation of intracellular signaling pathways were the major factors leading to resistance to venetoclax. Therefore, only targeting BCL2 often fails to achieve the expected therapeutic effect. Based on the mechanism of resistance in specific hematologic malignancies, the combination of specific drugs with venetoclax was a clinically optional treatment strategy for overcoming resistance to venetoclax. This study aimed to summarize the possible resistance mechanisms of various hematologic tumors to venetoclax and the corresponding clinical strategies to overcome resistance to venetoclax in hematologic malignancies.

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Parsaclisib, a potent and highly selective PI3Kδ inhibitor, in patients with relapsed or refractory B-cell malignancies

Blood ◽

10.1182/blood-2018-08-867499 ◽

2019 ◽

Vol 133 (16) ◽

pp. 1742-1752 ◽

Cited By ~ 27

Author(s):

Andres Forero-Torres ◽

Radhakrishnan Ramchandren ◽

Abdulraheem Yacoub ◽

Michael S. Wertheim ◽

William J. Edenfield ◽

...

Keyword(s):

Respiratory Failure ◽

B Cell ◽

Cell Lymphoma ◽

Phase 1 ◽

Objective Response ◽

B Cell Lymphoma ◽

Janus Kinase ◽

B Cell Malignancies ◽

Once Daily ◽

Grade 3

Abstract This phase 1/2 study assessed parsaclisib (INCB050465), a next-generation, potent, and highly selective phosphatidylinositol 3-kinase δ (PI3Kδ) inhibitor, in patients with relapsed or refractory B-cell malignancies, alone or in combination with a Janus kinase 1 inhibitor (itacitinib) or chemotherapy (rituximab, ifosfamide, carboplatin, and etoposide). Seventy-two patients received parsaclisib monotherapy (5-45 mg once daily). Expansion doses were 20 and 30 mg once daily; intermittent dosing at 20 mg (once daily for 9 weeks, then once weekly) was explored. No dose-limiting toxicities were identified, and maximum tolerated dose was not reached. Most common nonhematologic treatment-emergent adverse events (TEAEs) were diarrhea/colitis (36%), nausea (36%), fatigue (31%), and rash (31%). Grade 3/4 neutropenia occurred in 19% of patients. Serious TEAEs (>2 patients) were diarrhea/colitis (n = 9), pyrexia (n = 4), hypotension (n = 3), and sepsis (n = 3). Aspartate and alanine transaminase elevations occurring before treatment discontinuation were grade 1, except 1 grade 3 event each, secondary to sepsis. Two patients experienced 3 fatal parsaclisib-unrelated TEAEs (respiratory failure; respiratory failure and sepsis). In non-Hodgkin lymphoma (NHL), objective response rates to monotherapy were 71% in follicular lymphoma, 78% in marginal zone lymphoma, 67% in mantle cell lymphoma, and 30% in diffuse large B-cell lymphoma; 93% of responses occurred at first assessment (∼9 weeks). Parsaclisib has demonstrated antitumor activity in relapsed or refractory B-cell NHL with the potential for improved long-term patient outcomes. Phase 2 studies in relapsed or refractory B-cell NHL subtypes are ongoing. This trial was registered at www.clinicaltrials.gov as #NCT02018861.

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Venetoclax for Patients With Chronic Lymphocytic Leukemia With 17p Deletion: Results From the Full Population of a Phase II Pivotal Trial

Journal of Clinical Oncology ◽

10.1200/jco.2017.76.6840 ◽

2018 ◽

Vol 36 (19) ◽

pp. 1973-1980 ◽

Cited By ~ 101

Author(s):

Stephan Stilgenbauer ◽

Barbara Eichhorst ◽

Johannes Schetelig ◽

Peter Hillmen ◽

John F. Seymour ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Complete Remission ◽

Median Time ◽

Objective Response Rate ◽

Response Rate ◽

Objective Response ◽

Progression Free Survival ◽

B Cell Lymphoma ◽

Lymphocytic Leukemia ◽

Free Survival

Purpose Venetoclax is an orally bioavailable B-cell lymphoma 2 inhibitor. US Food and Drug Administration and European Medicines Agency approval for patients with 17p deleted relapsed/refractory chronic lymphocytic leukemia [del(17p) CLL] was based on results from 107 patients. An additional 51 patients were enrolled in a safety expansion cohort. Extended analysis of all enrolled patients, including the effect of minimal residual disease (MRD) negativity on outcome, is now reported. Patients and Methods Overall, 158 patients with relapsed/refractory or previously untreated (n = 5) del(17p) CLL received venetoclax 400 mg per day after an initial dose ramp up. Responses were based on 2008 International Workshop on Chronic Lymphocytic Leukemia criteria, with monthly physical exams and blood counts. Computed tomography scan was mandatory at week 36, after which assessment made was by clinical evaluation. Marrow biopsy was performed when complete remission was suspected. MRD was assessed by flow cytometry. Results Patients had a median of two prior therapies (range, zero to 10 therapies), 71% had TP53 mutation, and 48% had nodes that were ≥ 5 cm. Median time on venetoclax was 23.1 months (range, 0 to 44.2 months) and median time on study was 26.6 months (range, 0 to 44.2 months). For all patients, investigator-assessed objective response rate was 77% (122 of 158 patients; 20% complete remission) and estimated progression-free survival at 24 months was 54% (95% CI, 45% to 62%). For 16 patients who received prior kinase inhibitors, objective response rate was 63% (10 of 16 patients) and 24-month progression-free survival estimate was 50% (95% CI, 25% to 71%). By intent-to-treat analysis, 48 (30%) of 158 patients achieved MRD below the cutoff of 10−4 in blood. Common grade 3 and 4 adverse events were hematologic and managed with supportive care and/or dose adjustments. Conclusion Venetoclax achieves durable responses and was well tolerated in patients with del(17p) CLL. A high rate of blood MRD < 10−4 was achieved in this high-risk population.

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Safety and efficacy of ofatumumab, a fully human monoclonal anti-CD20 antibody, in patients with relapsed or refractory B-cell chronic lymphocytic leukemia: a phase 1-2 study

Blood ◽

10.1182/blood-2007-09-111781 ◽

2008 ◽

Vol 111 (3) ◽

pp. 1094-1100 ◽

Cited By ~ 265

Author(s):

Bertrand Coiffier ◽

Stéphane Lepretre ◽

Lars Møller Pedersen ◽

Ole Gadeberg ◽

Henrik Fredriksen ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Adverse Events ◽

Partial Remission ◽

Phase 1 ◽

Objective Response ◽

Median Number ◽

Maximum Tolerated Dose ◽

Lymphocytic Leukemia ◽

Safety And Efficacy ◽

Anti Cd20

Abstract Safety and efficacy of the fully human anti-CD20 monoclonal antibody, ofatumumab, was analyzed in a multicenter dose-escalating study including 33 patients with relapsed or refractory chronic lymphocytic leukemia. Three cohorts of 3 (A), 3 (B), and 27 (C) patients received 4, once weekly, infusions of ofatumumab at the following doses: (A) one 100 mg and three 500 mg; (B) one 300 mg and three 1000 mg; (C) one 500 mg and three 2000 mg. Sixty-seven percent of the patients were Binet stage B, and the median number of previous treatments was 3. The maximum tolerated dose was not reached. The majority of related adverse events occurred at first infusion, and the number of adverse events decreased at each subsequent infusion. Seventeen (51%) of 33 patients experienced infections, 88% of them of grade 1-2. One event of interstitial pneumonia was fatal; all other cases resolved within one month. The response rate of cohort C was 50% (13/26), one patient having a nodular partial remission and 12 patients partial remission. In conclusion, ofatumumab was found to be well tolerated in patients with chronic lymphocytic leukemia (CLL) in doses up to 2000 mg. Preliminary data on safety and objective response are encouraging and support further studies on the role of ofatumumab in CLL patients. This trial was registered at www.clinicaltrials.gov as no. NCT00093314.

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Navitoclax (ABT-263) Plus Fludarabine/Cyclophosphamide/Rituximab (FCR) or Bendamustine/Rituximab (BR): A Phase 1 Study In Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia (CLL)

Blood ◽

10.1182/blood.v116.21.2455.2455 ◽

2010 ◽

Vol 116 (21) ◽

pp. 2455-2455 ◽

Cited By ~ 4

Author(s):

Thomas J. Kipps ◽

William G. Wierda ◽

Jeffrey A. Jones ◽

Lode J. Swinnen ◽

Jianning Yang ◽

...

Keyword(s):

Bone Marrow ◽

Chronic Lymphocytic Leukemia ◽

Dose Escalation ◽

Research Funding ◽

Phase 1 ◽

B Cell Lymphoma ◽

Lymphocytic Leukemia ◽

Cell Transplant ◽

Phase 2 ◽

Anti Tumor Activity

Abstract Abstract 2455 Background: Navitoclax (ABT-263), a novel, orally bioavailable, small molecule, binds with high affinity (Ki ≤1nM) to Bcl-2, Bcl-xL, and Bcl-w, promoting apoptosis. In vitro, navitoclax shows potent targeted cytotoxicity (EC50 ≤ 1μM) against T and B lymphoid malignancies that over-express Bcl-2. A phase 1 trial demonstrated oral navitoclax monotherapy to be well-tolerated and to have anti-tumor activity in patients (pts) with chronic lymphocytic leukemia (CLL). However, thrombocytopenia (TCP) was the dose-limiting toxicity (DLT). Phase 3 studies showed improved outcomes in CLL pts with the fludarabine/cyclophosphamide/rituximab (FCR) combination, and a phase 2 trial showed bendamustine/rituximab (BR) to be effective for pts with relapsed or refractory CLL. Navitoclax enhanced R (monotherapy and in combination with chemotherapy) efficacy in preclinical models of B-cell lymphoma. Methods: This is an ongoing, international, phase 1 dose-escalation study to evaluate the safety and pharmacokinetics (PK) of oral navitoclax in combination with FCR (Arm A) or BR (Arm B) in pts with relapsed/refractory CLL. Secondary objectives are efficacy endpoints (PFS, ORR, TTP, OS, duration of response). Eligible pts had measurable disease, ECOG performance score ≤1, ANC ≥100/μL, platelets ≥100,000/mm3, and hemoglobin ≥9.0 g/dL. Preliminary results are reported. After obtaining informed consent, pts were assigned to Arm A or Arm B based on physician preference, each consisting of 28-day dose-escalation cycles with once-daily, pre-infusion, navitoclax treatment on Days 3–5 of Cycle 1 and Days 1–3 of subsequent cycles. In both arms, R was 375 mg/m2 on Day 1 of Cycle 1; and 500 mg/m2 on Day 2 of Cycle 2 and on Day 1 of subsequent cycles. In Arm A, F 25 mg/m2 and C 175 mg/m2 were dosed on Days 2–4 in Cycles 1 and 2, and on Days 1–3 in subsequent cycles. In Arm B, B was dosed at 70 mg/m2 on Days 2 and 3 of Cycles 1 and 2, and on Days 1 and 2 in subsequent cycles. Navitoclax starting dose was 110 mg daily. Dose escalation to the next cohort (200 mg) was according to a continuous reassessment model. Tumor responses were evaluated using NCI-WG 1996 criteria. Pts could continue on navitoclax therapy for 1 yr in the absence of progressive disease or significant toxicity. Results: As of July 2010, 7 pts enrolled in the initially prioritized Arm B (BR+navitoclax); all completed the first cohort of 110 mg (median age 60 yr [range 55–72]). Study sites are currently enrolling pts in Arm A (FCR+navitoclax); 2 pts have enrolled to date. The median number of prior therapies was 2 (range 1–7). One pt had a DLT of elevated AST (Arm B, 110 mg cohort) and 1 pt had a DLT of neutropenic fever (Arm A, 110 mg cohort). In Arm B, neither TCP nor neutropenia have been DLTs. For the 7 pts with navitoclax-related AEs, the most common were diarrhea (3 pts), nausea (5 pts), and fatigue (3 pts). Seven pts remain on study; 2 pts discontinued due to disease progression and 2 withdrew per physician preference. In Arm B, preliminary antitumor best responses were assessable in 4 pts who received 2 cycles; 1 CRi in a pt with del17p- (based on lymph node [LN] response and no morphologic evidence of CLL in the bone marrow), 2 unconfirmed CRs (based on LN response and no bone marrow at this time), and 1 PR in a pt with del17p- (this pt subsequently received an allogeneic stem cell transplant). Preliminary PK results for the Arm B 110 mg cohort indicated that navitoclax PK was similar in Cycle 1 (navitoclax+BR) and Cycle 2 (navitoclax alone), and appeared comparable to PK in the navitoclax monotherapy study. Conclusions: Early results show that the combination of navitoclax with BR is well-tolerated, without DLTs of TCP or neutropenia, and show evidence of anti-tumor activity. Data are limited in the FCR portion of the study. The maximum tolerated dose of navitoclax has not been reached. Accrual is ongoing and following completion of the dose-escalation components of this study, expanded cohorts of pts will be assessed using the recommended phase 2 dose of navitoclax to further assess the tolerability and dose, and to continue to explore for efficacy signals in combinations. Preliminary data in combination with BR are encouraging. Disclosures: Kipps: Abbott Laboratories: Research Funding; Genentech/Roche: Research Funding. Wierda: Abbott: Research Funding; Genentech: Honoraria, Speakers Bureau. Jones: Glaxo Smith-Kline: Consultancy; Abbott: Research Funding. Swinnen: Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding. Yang: Abbott: Employment. Cui: Abbott: Employment. Busman: Abbott: Employment. Krivoshik: Abbott: Employment. Enschede: Abbott: Employment. Humerickhouse: Abbott: Employment.

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