Phase I/Ib Study of the Efficacy and Safety of Buparlisib and Ibrutinib Therapy in MCL, FL, and DLBCL with Serial Cell-Free DNA Monitoring

PURPOSE

Activation of Bruton tyrosine kinase (BTK) and phosphatidylinositol-3-kinase (PI3K) represent parallel, synergistic pathways in lymphoma pathogenesis. As predominant PI3Kδ inhibition is a possible mechanism of tumor escape, we proposed a clinical trial of dual BTK and pan-PI3K inhibition.

PATIENTS AND METHODS

We conducted a single-center phase I/Ib trial combining a BTK inhibitor (ibrutinib) and a pan-PI3K inhibitor (buparlisib) in 37 patients with relapsed/refractory (R/R) B-cell lymphoma. Buparlisib and ibrutinib were administered orally, once daily in 28-day cycles until progression or unacceptable toxicity. The clinical trial is registered with clinicaltrials.gov, NCT02756247.

RESULTS

Patients with mantle cell lymphoma (MCL) receiving the combination had a 94% overall response rate (ORR) and 33-month median progression-free survival; ORR of 31% and 20% were observed in patients with diffuse large B-cell lymphoma and follicular lymphoma, respectively. The maximum tolerated dose was ibrutinib 560 mg plus buparlisib 100 mg and the recommended phase II dose was ibrutinib 560 mg plus buparlisib 80 mg. The most common grade 3 adverse events were rash/pruritis/dermatitis (19%), diarrhea (11%), hyperglycemia (11%), and hypertension (11%). All grade mood disturbances ranging from anxiety, depression, to agitation were observed in 22% of patients. Results from serial monitoring of cell-free DNA samples corresponded to radiographic resolution of disease and tracked the emergence of mutations known to promote BTK inhibitor resistance.

CONCLUSIONS

BTK and pan-PI3K inhibition in mantle cell lymphoma demonstrates a promising efficacy signal. Addition of BCL2 inhibitors to a BTK and pan-PI3K combination remain suitable for further development in mantle cell lymphoma.

Prephase rituximab/prednisone therapy and aging-related, pro-inflammatory cytokine milieu in older, vulnerable patients with newly diagnosed diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) predominantly affects older adults with suboptimal therapeutic outcomes due to increased treatment-related mortality and toxicities in vulnerable patients, clinically defined by geriatric impairments such as functional limitation, multimorbidity, or cognitive deficits. In this prospective pilot study, we evaluated a rituximab/prednisone prephase treatment strategy in 33 older, vulnerable patients with newly diagnosed DLBCL, defined by either age ≥70 years or age 60-70 years with Karnofsky performance scale (KPS) <80. A single dose of rituximab 375 mg/m² between 3-10 days and oral prednisone for at least 5 days prior to the first dose of chemoimmunotherapy was administered. All patients completed prephase treatment and all but one commenced anthracycline-based chemoimmunotherapy. Only one early cycle death occurred. Toxicity events, defined by either unplanned hospitalization, unplanned dose reduction/delay, or chemotherapy discontinuation, occurred in 22 patients (67%). Sixteen patients (48%) experienced grade 3 or higher non-hematologic toxicities and/or grade 4 or higher hematologic toxicities. With a median follow-up of 4.4 years, both 5-year progression-free survival and overall survival were at 81% (95% confidence interval: 69-96). Importantly, we found that phenotypic impairments in basic and instrumental activities of daily living, physical function, mobility, KPS, and Cancer and Aging Research Group chemotherapy toxicity risk score were significantly associated with senescence-associated, proinflammatory cytokine milieu which was readily reversed with prephase treatment, potentially explaining its clinical effectiveness. Prephase therapy with rituximab/prednisone should be considered for all older, vulnerable DLBCL patients prior to curative intent, anthracycline-based chemoimmunotherapy. This trial was registered as clinicaltrials gov. Identifier: NCT 89028394.

Positron-emission tomography-based staging reduces the prognostic impact of early disease progression in patients with follicular lymphoma

BACKGROUND

Previous studies reported that early progression of disease (POD) after initial therapy predicted poor overall survival (OS) in patients with follicular lymphoma (FL). Here, we investigated whether pre-treatment imaging modality had an impact on prognostic significance of POD.

METHODS

In this retrospective study, we identified 1088 patients with grade I-IIIA FL; of whom, 238 patients with stage II-IV disease were initially treated with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP), and 346 patients were treated with rituximab-based chemotherapy. Patients (N = 484) from the FOLL05 study served as an independent validation cohort. We risk-stratified patients based on pre-treatment radiographic imaging (positron-emission tomography [PET] versus computed tomography [CT]) and early POD status using event-defining and landmark analyses. A competing risk analysis evaluated the association between early POD and histologic transformation.

RESULTS

In the discovery cohort, patients with POD within 24 months (PFS24) of initiating R-CHOP therapy had a 5-year OS of 57.6% for CT-staged patients compared with 70.6% for PET-staged patients. In the validation cohort, the 5-year OS for patients with early POD was 53.9% and 100% in CT- and PET-staged patients, respectively. The risk of histologic transformation in patients whose disease progressed within one year of initiating therapy was higher in CT-staged patients than in PET-staged patients (16.7% versus 6.3%, respectively), which was associated with a 9.7-fold higher risk of death.

CONCLUSION

In FL, pre-treatment PET staging reduced the prognostic impact of early POD compared with CT staging. Patients with early POD and no histologic transformation have an extended OS with standard therapy.

Paradigms for Precision Medicine in Epichaperome Cancer Therapy

Alterations in protein-protein interaction networks are at the core of malignant transformation but have yet to be translated into appropriate diagnostic tools. We make use of the kinetic selectivity properties of an imaging probe to visualize and measure the epichaperome, a pathologic protein-protein interaction network. We are able to assay and image epichaperome networks in cancer and their engagement by inhibitor in patients' tumors at single-lesion resolution in real time, and demonstrate that quantitative evaluation at the level of individual tumors can be used to optimize dose and schedule selection. We thus provide preclinical and clinical evidence in the use of this theranostic platform for precision medicine targeting of the aberrant properties of protein networks.

In Vivo PET Assay of Tumor Glutamine Flux and Metabolism: In-Human Trial of 18F-(2S,4R)-4-Fluoroglutamine

Purpose To assess the clinical safety, pharmacokinetics, and tumor imaging characteristics of fluorine 18-(2S,4R)-4-fluoroglutamine (FGln), a glutamine analog radiologic imaging agent. Materials and Methods This study was approved by the institutional review board and conducted under a U.S. Food and Drug Administration-approved Investigational New Drug application in accordance with the Helsinki Declaration and the Health Insurance Portability and Accountability Act. All patients provided written informed consent. Between January 2013 and October 2016, 25 adult patients with cancer received an intravenous bolus of FGln tracer (mean, 244 MBq ± 118, <100 μg) followed by positron emission tomography (PET) and blood radioassays. Patient data were summarized with descriptive statistics. FGln biodistribution and plasma amino acid levels in nonfasting patients (n = 13) were compared with those from patients who fasted at least 8 hours before injection (n = 12) by using nonparametric one-way analysis of variance with Bonferroni correction. Tumor FGln avidity versus fluorodeoxyglucose (FDG) avidity in patients with paired PET scans (n = 15) was evaluated with the Fisher exact test. P < .05 was considered indicative of a statistically significant difference. Results FGln PET depicted tumors of different cancer types (breast, pancreas, renal, neuroendocrine, lung, colon, lymphoma, bile duct, or glioma) in 17 of the 25 patients, predominantly clinically aggressive tumors with genetic mutations implicated in abnormal glutamine metabolism. Acute fasting had no significant effect on FGln biodistribution and plasma amino acid levels. FGln-avid tumors were uniformly FDG-avid but not vice versa (P = .07). Patients experienced no adverse effects. Conclusion Preliminary human FGln PET trial results provide clinical validation of abnormal glutamine metabolism as a potential tumor biomarker for targeted radiotracer imaging in several different cancer types. ^© RSNA, 2018 Online supplemental material is available for this article. Clinical trial registration no. NCT01697930.

Venetoclax (VEN) in patients with relapsed/refractory non-Hodgkin lymphoma (NHL)

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Background: VEN is a selective orally bioavailable BCL-2 inhibitor. The dose-escalation Phase 1 study of VEN in 106 patients (pts) with relapsed/refractory NHL reported an ORR of 44%. Most pts had diffuse large B-cell/follicular lymphoma; we report on updated results in pts with less common NHL subtypes. Methods: VEN was administered and continued until progressive disease (PD)/unacceptable toxicity, in dose cohorts ranging from 300–1200 mg. Adverse events (AEs) were assessed by NCI-CTCAE v4.0 and response by 2007 Cheson IWG response criteria, utilizing CT scans beginning at wk 6. Results: 35 of 106 pts had mantle cell lymphoma (MCL, n=28), marginal zone lymphoma (MZL, n=3) or Waldenström macroglobulinemia (WM, n=4). Most common all grade treatment emergent AEs were nausea (51%), diarrhea (49%) and fatigue (34%); grade 3/4 AEs in >10% of pts were neutropenia and anemia (17% each). Laboratory TLS was reported in a single pt (bulky MCL). MCL pts (median age: 72 years) had received a median of 3 (1–7) prior treatments (tx). Median time from start of prior tx to start of VEN was 13 mo (2–148) and time on VEN was 11 mo (0.2–42). ORR was 75%, 6 pts (21%) achieved CR and remain on study (DORs: 25–40 mo). One pt with a PR proceeded to elective allogeneic stem cell transplant and remained disease free at last protocol defined follow-up (24 mo after coming off study). Median PFS was 11 mo and DOR was 15 mo. MZL pts (median age: 63 years) had received a median of 4 (2–6) prior tx. Time from start of prior tx to start of VEN was 8, 14, 73 mo and time on VEN was 5, 1, 35 mo. One pt (6 prior tx) received VEN for <1 mo due to progressive cytopenias; 1 pt (4 prior tx) achieved a PR with VEN at wk 6 but had PD at wk 16; 1 pt (2 prior tx) achieved PR at wk 6 and is the only pt to remain on study (DOR:32 mo). WM pts (median age: 67 years) had a median of 4 (3–5) prior tx. Time from start of prior tx to start of VEN was 5, 18, 33, 67 mo and time on VEN was 42, 17, 54, 20 mo. All pts achieved PR (at wks 6 [n=2], 16 and 36), with DORs of 11, 12, 38 and 50+ mo (latter is ongoing and remains on study). Conclusions: VEN monotherapy has a tolerable safety profile in MCL, MZL and WM pts. ORR were high and most responses durable; median PFS and DOR suggest significant activity in MCL pts. Further investigation of VEN in each disease is indicated. Clinical trial information: NCT01328626.

Evidence of low incidence of myelodysplastic syndrome (MDS) in patients exposed to bendamustine treatment for chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL)

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Background: CLL/SLL is a treatable malignancy, which is responsive to therapies that include bendamustine. However, as with many alkylating agents, there is concern for the development of secondary malignancies and MDS after exposure to bendamustine. We evaluated the risk of MDS using electronic medical records from a geographically diverse cohort of cancer patients (pts). Methods: Pathologically confirmedCLL/SLL pts with any exposure to bendamustine were identified in the Flatiron Health database (FHD, Flatiron Health, New York [122016]). This is a longitudinal US-based cohort with > 1.5 million cancer pts drawn from over 250 cancer clinics. Pts with bendamustine exposure and no history of MDS or other malignancy were included. Pts were followed longitudinally to identify incident cases of secondary malignancies or MDS. Results: Of 3140 CLL/SLL pts in the analytic cohort, 1022 met inclusion criteria. Median follow-up after bendamustine exposure was 1.7 years. Overall, 8% received bendamustine monotherapy, 84% received combination therapy, and 8% received cycles of bendamustine monotherapy and combination therapy. Of the 1022 pts, 205 (20%) had prior antineoplastic exposure, a risk factor for MDS. During the follow-up period, five pts developed MDS (0.48% of the bendamustine-exposed cohort), one of whom had prior antineoplastic exposure. Conclusions: This real-world study demonstrated that pts received bendamustine overwhelmingly as combination therapy, and 20% had prior antineoplastic exposure. MDS related to alkylators and purine analogs can have a latency of > 3 years; in this study a minority (~20%) of pts had > 3 years of follow-up. Thus, longer follow-up is required to draw definitive conclusions regarding the risk. Nevertheless, the FHD provides a source of oncology data for studying long-term outcomes of cancer pts, which have historically been difficult to capture in epidemiological studies. At a median of 1.7 years after exposure, the current study identified a low risk of MDS after controlling for potential confounders.

Phase I dose escalation of ibrutinib and buparlisib in relapsed/refractory diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), and follicular lymphoma (FL)

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Background: In vitro studies of BTK and PI3K inhibitors demonstrate synergy in non-Hodgkin lymphoma (NHL). We embarked on a phase I/Ib investigator-initiated clinical trial evaluating the combination of ibrutinib (BTK inhibitor) and buparlisib (pan-PI3K inhibitor) in relapsed/refractory (R/R) NHL. The completed dose escalation is reported. Methods: Patients (pts) were eligible if they had R/R DLBCL, MCL, or FL with ECOG≤2 and adequate organ function. Ibrutinib and buparlisib were given daily by mouth on a 28-day cycle. Dose reductions were permitted after cycle 1. Tumor response was based on Lugano Classification however CR required both PET resolution and ≥ PR by CT. Results: As of Dec 16, 2016, 13 pts were enrolled and evaluated for toxicity (DLBCL 5, FL 2, MCL 6). Dose levels and DLT per table. Six pts discontinued treatment for disease progression (DLBCL 4, FL 2). Hematologic AE ≥ grade 3 are anemia (2), leukocytosis (2), and leukopenia (4). Relevant non-hematologic AEs of any grade ≥ 20% across all pts were fatigue (77%), diarrhea (62%), anorexia (54%), rash (46%), hyperbilirubinemia (46%), gastric reflux (46%), CMV reactivation (31%), mood change (31%), and hypertension (23%). Most common related grade 3/4 toxicity is rash (N = 3). No grade 5 toxicities noted. Serious adverse events (SAE) include: grade 2 pleural effusion and grade 2 nausea (N = 1), grade 1 fever with hospitalization (N = 1), grade 2 confusion and grade 4 hyponatremia (N = 1) were unrelated to therapy. Responses noted in 13 pts: MCL (N = 6: CR 4, PR 2), FL (N = 2: SD 2), DLBCL (N = 5: SD 1). One CR was a MCL pt with CR after 2 cycles on combination therapy and continues in remission on ibrutinib alone because of buparlisib toxicity. Conclusions: Combination of ibrutinib and buparlisib while generally well tolerated has predicted toxicities of both BTK and PI3K inhibitors. The recommended phase 2 dose is ibrutinib 560 mg and buparlisib 100 mg though dose reductions for tolerability may be needed for long term oral therapies. Promising efficacy is observed in MCL. Clinical trial information: NCT02756247. [Table: see text]

The PARP Inhibitor Veliparib Can Be Safely Added to Bendamustine and Rituximab and Has Preliminary Evidence of Activity in B-Cell Lymphoma

Purpose: The PARP inhibitor veliparib enhances the cytotoxicity of alkylating agents. This phase I study evaluated veliparib with the bifunctional alkylator bendamustine (VB) in patients with relapsed/refractory lymphoma, multiple myeloma, and solid malignancies, with a cohort expansion of VB with rituximab (VBR) in patients with B-cell lymphomas.Experimental Design: This dose-escalation study evaluated safety, pharmacokinetics, and preliminary efficacy of veliparib (20-400 mg twice a day, days 1-7 of 28-day cycle) and bendamustine (70 and 90 mg/m² intravenously, days 1 and 2). A cohort expansion was conducted, which combined veliparib and bendamustine at the maximum tolerated dose (MTD) with rituximab (375 mg/m², day 1) in patients with B-cell lymphomas. Thirty-four patients were treated in seven dose-escalation cohorts and seven patients in the dose-expansion cohort.Results: The MTD was veliparib 300 mg twice daily plus bendamustine 90 mg/m² Dose-limiting toxicities (DLT) were anemia, nausea, hypertension, and hyperhidrosis. Grade ≥3 toxicities included lymphopenia (87.8%), anemia (19.5%), neutropenia (12.2%), thrombocytopenia (9.8%), leukopenia (9.8%), nausea (7.3%), and hypophosphatemia (7.3%). Apparent veliparib clearance was slightly lower than previously reported. Of 14 patients with lymphoma evaluable for response, five of seven (71%) on VB and six of seven (86%) on VBR achieved objective response. One patient with multiple myeloma achieved partial response.Conclusions: VB and VBR were generally well-tolerated. VBR had preliminary clinical activity in patients with B-cell lymphoma, which warrants further investigation in a phase II trial. This trial was registered at www.clinicaltrials.gov as NCT01326702 Clin Cancer Res; 23(15); 4119-26. ©2017 AACR.

Inhibition of the Nuclear Export Receptor XPO1 as a Therapeutic Target for Platinum-Resistant Ovarian Cancer

Purpose: The high fatality-to-case ratio of ovarian cancer is directly related to platinum resistance. Exportin-1 (XPO1) is a nuclear exporter that mediates nuclear export of multiple tumor suppressors. We investigated possible clinicopathologic correlations of XPO1 expression levels and evaluated the efficacy of XPO1 inhibition as a therapeutic strategy in platinum-sensitive and -resistant ovarian cancer.Experimental Design: XPO1 expression levels were analyzed to define clinicopathologic correlates using both TCGA/GEO datasets and tissue microarrays (TMA). The effect of XPO1 inhibition, using the small-molecule inhibitors KPT-185 and KPT-330 (selinexor) alone or in combination with a platinum agent on cell viability, apoptosis, and the transcriptome was tested in immortalized and patient-derived ovarian cancer cell lines (PDCL) and platinum-resistant mice (PDX). Seven patients with late-stage, recurrent, and heavily pretreated ovarian cancer were treated with an oral XPO1 inhibitor.Results: XPO1 RNA overexpression and protein nuclear localization were correlated with decreased survival and platinum resistance in ovarian cancer. Targeted XPO1 inhibition decreased cell viability and synergistically restored platinum sensitivity in both immortalized ovarian cancer cells and PDCL. The XPO1 inhibitor-mediated apoptosis occurred through both p53-dependent and p53-independent signaling pathways. Selinexor treatment, alone and in combination with platinum, markedly decreased tumor growth and prolonged survival in platinum-resistant PDX and mice. In selinexor-treated patients, tumor growth was halted in 3 of 5 patients, including one with a partial response, and was safely tolerated by all.Conclusions: Taken together, these results provide evidence that XPO1 inhibition represents a new therapeutic strategy for overcoming platinum resistance in women with ovarian cancer. Clin Cancer Res; 23(6); 1552-63. ©2016 AACR.

A phase 1b dose expansion study of the pan-class I PI3K inhibitor buparlisib (BKM120) plus carboplatin and paclitaxel in PTEN deficient tumors and with dose intensified carboplatin and paclitaxel

Purpose We previously reported the phase I dose escalation study of buparlisib, a pan-class 1A PI3K inhibitor, combined with platinum/taxane-based chemotherapy in patients with advanced solid tumors. The combination was well tolerated and promising preliminary efficacy was observed in PTEN deficient tumors. This phase I dose expansion study now evaluates buparlisib plus high dose carboplatin and paclitaxel in unselected patients with advanced solid tumors and buparlisib plus standard dose carboplatin and paclitaxel in patients with PTEN deficient tumors (ClinicalTrials.gov, NCT01297452). Methods There were two expansion cohorts: Cohort A received continuous buparlisib (100 mg/daily) orally plus high dose carboplatin AUC 6 and paclitaxel 200 mg/m2; Cohort B treated patients with PTEN deficient tumors only and they received the recommended phase II dose (RP2D) of continuous buparlisib (100 mg/daily) orally plus standard dose carboplatin AUC 5 and paclitaxel 175 mg/m2. Both cohorts received chemotherapy intravenously on day 1 of the 21-day cycle with pegfilgrastim support. Primary endpoint in Cohort A was to evaluate the safety and tolerability of chemotherapy dose intensification with buparlisib and in Cohort B was to describe preliminary efficacy of the combination among patients with tumors harboring a PTEN mutation or homozygous deletion. Results 14 subjects were enrolled, 7 in Cohort A and 7 in Cohort B. Dose reductions were required in 5 (71%) and 3 (43%) patients, in cohort A and B respectively. Grade 3 adverse events in Cohort A included lymphopenia (n = 5 [71%]), hyperglycemia (n = 2, [29%]), diarrhea (n = 2, [29%]) and rash (n = 2, [29%]) and in cohort B included lymphopenia (n = 5 [71%]), hyperglycemia (n = 4 [57%]) and neutropenia (n = 2 [29%]. The mean number of cycles on protocol was 6. The overall objective response rate was 14% (2 /14). No objective responses were observed in the PTEN deficient cohort. Four out of 6 patients with stable disease (SD) had SD or better for ≥6 cycles, 2 of which had PTEN deficient tumors. Conclusion The addition of buparlisib to high dose carboplatin and paclitaxel was not tolerable. The combination did not reveal significant clinical activity amongst a small and heterogenous group of PTEN deficient tumors.

Phase I First-in-Human Study of Venetoclax in Patients With Relapsed or Refractory Non-Hodgkin Lymphoma

Purpose B-cell leukemia/lymphoma-2 (BCL-2) overexpression is common in many non-Hodgkin lymphoma (NHL) subtypes. A phase I trial in patients with NHL was conducted to determine safety, pharmacokinetics, and efficacy of venetoclax, a selective, potent, orally bioavailable BCL-2 inhibitor. Patients and Methods A total of 106 patients with relapsed or refractory NHL received venetoclax once daily until progressive disease or unacceptable toxicity at target doses from 200 to 1,200 mg in dose-escalation and safety expansion cohorts. Treatment commenced with a 3-week dose ramp-up period for most patients in dose-escalation cohorts and for all patients in safety expansion. Results NHL subtypes included mantle cell lymphoma (MCL; n = 28), follicular lymphoma (FL; n = 29), diffuse large B-cell lymphoma (DLBCL; n = 34), DLBCL arising from chronic lymphocytic leukemia (Richter transformation; n = 7), Waldenström macroglobulinemia (n = 4), and marginal zone lymphoma (n = 3). Venetoclax was generally well tolerated. Clinical tumor lysis syndrome was not observed, whereas laboratory tumor lysis syndrome was documented in three patients. Treatment-emergent adverse events were reported in 103 patients (97%), a majority of which were grade 1 to 2 in severity. Grade 3 to 4 events were reported in 59 patients (56%), and the most common were hematologic, including anemia (15%), neutropenia (11%), and thrombocytopenia (9%). Overall response rate was 44% (MCL, 75%; FL, 38%; DLBCL, 18%). Estimated median progression-free survival was 6 months (MCL, 14 months; FL, 11 months; DLBCL, 1 month). Conclusion Selective targeting of BCL-2 with venetoclax was well tolerated, and single-agent activity varied among NHL subtypes. We determined 1,200 mg to be the recommended single-agent dose for future studies in FL and DLBCL, with 800 mg being sufficient to consistently achieve durable response in MCL. Additional investigations including combination therapy to augment response rates and durability are ongoing.

First-in-Class, First-in-Human Phase I Study of Selinexor, a Selective Inhibitor of Nuclear Export, in Patients With Advanced Solid Tumors

Purpose This trial evaluated the safety, pharmacokinetics, pharmacodynamics, and efficacy of selinexor (KPT-330), a novel, oral small-molecule inhibitor of exportin 1 (XPO1/CRM1), and determined the recommended phase II dose. Patients and Methods In total, 189 patients with advanced solid tumors received selinexor (3 to 85 mg/m2) in 21- or 28-day cycles. Pre- and post-treatment levels of XPO1 mRNA in patient-derived leukocytes were determined by reverse transcriptase quantitative polymerase chain reaction, and tumor biopsies were examined by immunohistochemistry for changes in markers consistent with XPO1 inhibition. Antitumor response was assessed according Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 guidelines. Results The most common treatment-related adverse events included fatigue (70%), nausea (70%), anorexia (66%), and vomiting (49%), which were generally grade 1 or 2. Most commonly reported grade 3 or 4 toxicities were thrombocytopenia (16%), fatigue (15%), and hyponatremia (13%). Clinically significant major organ or cumulative toxicities were rare. The maximum-tolerated dose was defined at 65 mg/m2 using a twice-a-week (days 1 and 3) dosing schedule. The recommended phase II dose of 35 mg/m2 given twice a week was chosen based on better patient tolerability and no demonstrable improvement in radiologic response or disease stabilization compared with higher doses. Pharmacokinetics were dose proportional, with no evidence of drug accumulation. Dose-dependent elevations in XPO1 mRNA in leukocytes were demonstrated up to a dose level of 28 mg/m2 before plateauing, and paired tumor biopsies showed nuclear accumulation of key tumor-suppressor proteins, reduction of cell proliferation, and induction of apoptosis. Among 157 patients evaluable for response, one complete and six partial responses were observed (n = 7, 4%), with 27 patients (17%) achieving stable disease for ≥ 4 months. Conclusion Selinexor is a novel and safe therapeutic with broad antitumor activity. Further interrogation into this class of therapy is warranted.

The epichaperome is an integrated chaperome network that facilitates tumour survival

Transient, multi-protein complexes are important facilitators of cellular functions. This includes the chaperome, an abundant protein family comprising chaperones, co-chaperones, adaptors, and folding enzymes-dynamic complexes of which regulate cellular homeostasis together with the protein degradation machinery. Numerous studies have addressed the role of chaperome members in isolation, yet little is known about their relationships regarding how they interact and function together in malignancy. As function is probably highly dependent on endogenous conditions found in native tumours, chaperomes have resisted investigation, mainly due to the limitations of methods needed to disrupt or engineer the cellular environment to facilitate analysis. Such limitations have led to a bottleneck in our understanding of chaperome-related disease biology and in the development of chaperome-targeted cancer treatment. Here we examined the chaperome complexes in a large set of tumour specimens. The methods used maintained the endogenous native state of tumours and we exploited this to investigate the molecular characteristics and composition of the chaperome in cancer, the molecular factors that drive chaperome networks to crosstalk in tumours, the distinguishing factors of the chaperome in tumours sensitive to pharmacologic inhibition, and the characteristics of tumours that may benefit from chaperome therapy. We find that under conditions of stress, such as malignant transformation fuelled by MYC, the chaperome becomes biochemically 'rewired' to form a network of stable, survival-facilitating, high-molecular-weight complexes. The chaperones heat shock protein 90 (HSP90) and heat shock cognate protein 70 (HSC70) are nucleating sites for these physically and functionally integrated complexes. The results indicate that these tightly integrated chaperome units, here termed the epichaperome, can function as a network to enhance cellular survival, irrespective of tissue of origin or genetic background. The epichaperome, present in over half of all cancers tested, has implications for diagnostics and also provides potential vulnerability as a target for drug intervention.

A Phase I Study of the Cyclin-Dependent Kinase 4/6 Inhibitor Ribociclib (LEE011) in Patients with Advanced Solid Tumors and Lymphomas

PURPOSE

Ribociclib (an oral, highly specific cyclin-dependent kinase 4/6 inhibitor) inhibits tumor growth in preclinical models with intact retinoblastoma protein (Rb⁺). This first-in-human study investigated the MTD, recommended dose for expansion (RDE), safety, preliminary activity, pharmacokinetics, and pharmacodynamics of ribociclib in patients with Rb⁺ advanced solid tumors or lymphomas.

EXPERIMENTAL DESIGN

Patients received escalating doses of ribociclib (3-weeks-on/1-week-off or continuous). Dose escalation was guided by a Bayesian Logistic Regression Model with overdose control principle.

RESULTS

Among 132 patients, 125 received ribociclib 3-weeks-on/1-week-off and 7 were dosed continuously. Nine dose-limiting toxicities were observed among 70 MTD/RDE evaluable patients during cycle 1, most commonly neutropenia (n = 3) and thrombocytopenia (n = 2). The MTD and RDE were established as 900 and 600 mg/day 3-weeks-on/1-week-off, respectively. Common treatment-related adverse events were (all-grade; grade 3/4) neutropenia (46%; 27%), leukopenia (43%; 17%), fatigue (45%; 2%), and nausea (42%; 2%). Asymptomatic Fridericia's corrected QT prolongation was specific to doses ≥600 mg/day (9% of patients at 600 mg/day; 33% at doses >600 mg/day). Plasma exposure increases were slightly higher than dose proportional; mean half-life at the RDE was 32.6 hours. Reduced Ki67 was observed in paired skin and tumor biopsies, consistent with ribociclib-mediated antiproliferative activity. There were 3 partial responses and 43 patients achieved a best response of stable disease; 8 patients were progression-free for >6 months.

CONCLUSIONS

Ribociclib demonstrated an acceptable safety profile, dose-dependent plasma exposure, and preliminary signs of clinical activity. Phase I-III studies of ribociclib are under way in various indications. Clin Cancer Res; 22(23); 5696-705. ©2016 AACR.

Abstract CT085: Phase III randomized, double-blind, controlled studies of the PI3K inhibitor copanlisib in combination with rituximab or rituximab-based chemotherapy in subjects with relapsed indolent B-cell non-Hodgkin's lymphoma (iNHL): CHRONOS-3 and CHRONOS-4

Background: Patients with newly diagnosed iNHL generally receive rituximab (R) either alone or given with an alkylating agent (bendamustine, ie R-B) or a chemotherapy combination containing an alkylating agent (CHOP, ie R-CHOP). Patients progressing after 6 months or more from last treatment are considered to be R-sensitive and candidates for re-treatment, whether with R treatment alone if ineligible for treatment with an alkylating agent or with a different R-chemotherapy treatment compared to initial treatment. Copanlisib is a novel pan-Class I PI3K inhibitor with potent preclinical inhibitory activity against both PI3K-δ and PI3K-α isoforms. Copanlisib has activity as monotherapy in patients with relapsed or refractory iNHL (Dreyling et al., ASH 2014). Therefore, in two separate phase III studies in the second line setting, we seek to evaluate the efficacy and safety of copanlisib in combination with R or R-based chemotherapy; namely CHRONOS-3, copanlisib plus R versus placebo plus R; and CHRONOS-4, copanlisib plus chemotherapy (R-B or R-CHOP) versus chemotherapy alone. The primary endpoints are progression-free survival.

Methods: Patients must have histologically confirmed diagnosis of iNHL (including follicular lymphoma, marginal zone lymphoma (splenic, nodal, or extra-nodal), small lymphocytic lymphoma, or lymphoplasmacytoid lymphoma/Waldenström macroglobulinemia) and have previously received at least one line of therapy including rituximab and alkylating agents. Patients must be not refractory to rituximab during any prior line of therapy (response &lt;6 months). Patients contraindicated for chemotherapy in the second line setting or with a treatment-free interval after the last rituximab-based treatment of ?12 months are eligible for CHRONOS-3, whereas patients able to receive chemotherapy are eligible for CHRONOS-4.

For CHRONOS-3, patients will be randomized 2:1 to copanlisib (60 mg) or placebo administered intravenously on days 1, 8 and 15 of a 28-day cycle in combination with 375 mg/m2 of rituximab administered on days 1, 8, 15 and 22. Radiologic tumor assessment will be performed every 8, 12, or 24 weeks for years 1, 2, and 3, respectively.

For CHRONOS-4, there will be an initial safety run-in with 45 mg copanlisib with either R-B or R-CHOP and if well tolerated, 60 mg, on days 1, 8, and 15 of a 28-day cycle with B iv 90 mg/m2 days 1 and 2, or on days 1 and 8 of a 21-day cycle with CHOP per standard dosing. After the run-in phase, patients eligible to receive R-B or R-CHOP will be randomized 1:1 to either copanlisib or placebo and receive up to 6 cycles of R-B or R-CHOP after which they will receive either copanlisib or placebo as monotherapy. Radiologic tumor assessment will be performed every 12 weeks for years 1 and 2, and every 24 weeks years 3-5.

Citation Format: John F. Gerecitano, Pier L. Zinzani, HongXia Zheng, Rodrigo Ito, Paula Y. Tanaka, Katharina Mueller, Jason Yuan, Barrett H. Childs. Phase III randomized, double-blind, controlled studies of the PI3K inhibitor copanlisib in combination with rituximab or rituximab-based chemotherapy in subjects with relapsed indolent B-cell non-Hodgkin's lymphoma (iNHL): CHRONOS-3 and CHRONOS-4. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT085.

Targeting BCL2 with Venetoclax in Relapsed Chronic Lymphocytic Leukemia

BACKGROUND

New treatments have improved outcomes for patients with relapsed chronic lymphocytic leukemia (CLL), but complete remissions remain uncommon. Venetoclax has a distinct mechanism of action; it targets BCL2, a protein central to the survival of CLL cells.

METHODS

We conducted a phase 1 dose-escalation study of daily oral venetoclax in patients with relapsed or refractory CLL or small lymphocytic lymphoma (SLL) to assess safety, pharmacokinetic profile, and efficacy. In the dose-escalation phase, 56 patients received active treatment in one of eight dose groups that ranged from 150 to 1200 mg per day. In an expansion cohort, 60 additional patients were treated with a weekly stepwise ramp-up in doses as high as 400 mg per day.

RESULTS

The majority of the study patients had received multiple previous treatments, and 89% had poor prognostic clinical or genetic features. Venetoclax was active at all dose levels. Clinical tumor lysis syndrome occurred in 3 of 56 patients in the dose-escalation cohort, with one death. After adjustments to the dose-escalation schedule, clinical tumor lysis syndrome did not occur in any of the 60 patients in the expansion cohort. Other toxic effects included mild diarrhea (in 52% of the patients), upper respiratory tract infection (in 48%), nausea (in 47%), and grade 3 or 4 neutropenia (in 41%). A maximum tolerated dose was not identified. Among the 116 patients who received venetoclax, 92 (79%) had a response. Response rates ranged from 71 to 79% among patients in subgroups with an adverse prognosis, including those with resistance to fludarabine, those with chromosome 17p deletions (deletion 17p CLL), and those with unmutated IGHV. Complete remissions occurred in 20% of the patients, including 5% who had no minimal residual disease on flow cytometry. The 15-month progression-free survival estimate for the 400-mg dose groups was 69%.

CONCLUSIONS

Selective targeting of BCL2 with venetoclax had a manageable safety profile and induced substantial responses in patients with relapsed CLL or SLL, including those with poor prognostic features. (Funded by AbbVie and Genentech; ClinicalTrials.gov number, NCT01328626.).

A Positive Prospective Trial of Antibiotic Therapy in Advanced Stage, Non-Bulky Indolent Lymphoma

BACKGROUND

We have prospectively studied a three month course of clarithromycin (substituted by Prevpac^®, lansoprazole/ amoxicillin/ clarithromycin, in the first two wks when stool H pylori+) for non-bulky, advanced stage indolent lymphoma. These patients are often candidates for expectant monitoring and it is during this period that a window of opportunity may exist to identify and treat associated infections.

METHODS

All previously untreated patients with a new diagnosis of indolent lymphoma (FL and non-FL) meeting GELF criteria were treated with 12 weeks of clarithromycin. There were 32 evaluable patients, 4 of whom had stool H pylori.

RESULTS

At one month post-antibiotic therapy, we have observed lymphoma responses in 7 of 32 patients (21.9%). Two additional patients had objective response during followup (28.1% overall response). The median treatment free survival for antibiotic responders is 69.9 months and for non-responders, 30.6 months (p = 0.019).

CONCLUSION

Three response patterns have been noted, perhaps suggestive of an immune-mediated response -- prompt PET negative; flair with delayed PET negative response; and gradual continuous improvement. This prospective study appears promising, may be a step toward developing a lymphoma prevention strategy by reducing "antigen drive," and deserves further clinical/biological study. http://clinicaltrials.gov/show/NCT00461084.

Abstract 5444: Development of a noninvasive assay to determine drug concentration in tumor during hsp90 inhibitor therapy

As molecularly targeted agents assume a more prominent role in anticancer therapy there is a growing need to determine in a noninvasive manner whether the target is being engaged and to what extent such drug-target binding results in desirable effects. We address this need in the context of Hsp90, a target of significant value and one in critical need for such assessment tools, by combining a novel chemical tool selective for tumor Hsp90 with PET imaging and mathematical modeling. The chemical tool is [124I]-PU-H71, the iodine-124 radiolabeled analog of the potent Hsp90 inhibitor PU-H71, which can be administered in tracer quantities for PET imaging. The resulting diagnostic, PU-PET, has been optimized and validated preclinically in mouse models of cancer and then translated to the clinic. The exquisite design of this assay is based on three essential concepts as it relates to the target (Hsp90) as well as to the PET tracer (124I-PU-H71). First, the target is “oncogenic” Hsp90 and has been shown by numerous biochemical and pharmacokinetic studies to have a strong affinity for inhibitors and a very low koff resulting in selective and prolonged retention in tumor. Secondly, the tracer incorporates a 124I in place of the naturally occurring 127I in the structure of PU-H71 and therefore there is no change in the chemical structure. This feature in a PET tracer intended as a companion diagnostic is unprecedented and ensures that the PK properties are identical to the therapeutic agent (PU-H71). Finally, the radionuclide 124I has a four-day half-life and thus is well-suited to monitor the extended tumor retention profile observed for Hsp90 inhibitors. We here demonstrate that this PET assay informs on Hsp90 targeting in individual tumors in real time and provides accurate tumor drug concentrations for at least four chemically distinct Hsp90 drugs. In contrast, we find that plasma pharmacokinetics is not predictive of intratumor parameters and therefore provides limited value in estimating target engagement. Using PU-PET we demonstrate that at least one Hsp90 inhibitor exhibits tumor targeting and retention in humans, delivering and retaining therapeutic, micromolar, concentrations at safe doses. PU-PET is currently being evaluated in Phase 0/1 (NCT01269593) clinical trials as a noninvasive companion diagnostic to determine intratumoral concentration as well as to identify those patients who would best benefit from Hsp90 inhibitor therapy. This diagnostic assay is intended to be incorporated into future Phase 2 clinical trials in order to preselect those patients who would most likely benefit from Hsp90 inhibitor treatment.

Citation Format: Tony Taldone, Nagavarakishore Pillarsetty, Mark PS Dunphy, John F. Gerecitano, Eloisi Caldas-Lopes, Brad Beattie, Radu I. Peter, Yanlong Kang, Anna Rodina, Pengrong Yan, Erica M. DaGama Gomes, Alexander Bolaender, Christina Pressl, Blesida Punzalan, Anson Ku, Thomas Ku, Smit Shah, Mohammad Uddin, Mei H. Chen, Elmer Santos, Jacek Koziorowski, Adriana Corben, Shanu Modi, Komal Jhaveri, Oscar Lin, Efsevia Vakiani, Yelena Janjigian, Pat Zanzonico, Clifford Hudis, Steven M. Larson, Jason S. Lewis, Gabriela Chiosis. Development of a noninvasive assay to determine drug concentration in tumor during hsp90 inhibitor therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5444. doi:10.1158/1538-7445.AM2015-5444

Phase I/II trial of vorinostat with rituximab, cyclophosphamide, etoposide and prednisone as palliative treatment for elderly patients with relapsed or refractory diffuse large B-cell lymphoma not eligible for autologous stem cell transplantation

The standard treatment of relapsed/refractory diffuse large B-cell lymphoma (DLBCL) in frail elderly patients has not been established. A variation was made on rituximab (R), cyclophosphamide (C), etoposide (E), procarbazine and prednisone (P), substituting vorinostat (V) for procarbazine. Patients ≥aged 60 years with relapsed/refractory DLBCL, not candidates for autologous stem cell transplantation, were treated R-CVEP [R 375 mg/m(2) intravenously (IV), day 1; C 600 mg/m(2) IV days 1, 8: E 70 mg/m(2) IV day 1, 140 mg/m(2) days 2, 3 orally (PO); V (300 vs. 400 mg) PO and P 60 mg/m(2) PO days 1-10] every 28 d for six cycles. Quality of life (QoL) was assessed in addition to response. Thirty patients (median age 76 years, 69-88) were enrolled (one died before treatment). Maximum tolerated dose (MTD) for V was 300 mg. For 23 patients at MTD (six phase I + 17 phase II), two were discontinued for toxicity, one withdrew consent, eight achieved complete response (35%), five achieved partial response (22%) and seven progressed (25%). Median overall survival was 17·5 months. Median progression-free survival was 9·2 months. Nine patients are alive. QoL declined during treatment but improved above baseline for patients who completed treatment. In conclusion, R-CVEP was tolerated at MTD and produced durable responses with improved QoL.

Heat shock protein 90 inhibitors in the treatment of cancer: current status and future directions

INTRODUCTION

Heat shock protein 90 (HSP90) serves as a critical facilitator for oncogene addiction. There has been augmenting enthusiasm in pursuing HSP90 as an anticancer strategy. In fact, since the initial serendipitous discovery that geldanamycin (GM) inhibits HSP90, the field has rapidly moved from proof-of-concept clinical studies with GM derivatives to novel second-generation inhibitors.

AREAS COVERED

The authors highlight the current status of the second-generation HSP90 inhibitors in clinical development. Herein, the authors note the lessons learned from the completed clinical trials of first- and second-generation inhibitors and describe various assays attempting to serve for a more rational implementation of these agents to cancer treatment. Finally, the authors discuss the future perspectives for this promising class of agents.

EXPERT OPINION

The knowledge gained thus far provides perhaps only a glimpse at the potential of HSP90 for which there is still much work to be done. Lessons from the clinical trials suggest that HSP90 therapy would advance at a faster pace if patient selection and tumor pharmacokinetics of these drugs were better understood and applied to their clinical development. It is also evident that combining HSP90 inhibitors with other potent anticancer therapies holds great promise not only due to synergistic antitumor activity but also due to the potential of prolonging or preventing the development of drug resistance.

Safety and antitumor activity of selinexor (KPT-330), a first-in-class, oral XPO1 selective inhibitor of nuclear export: A phase I study expanded with colon cancer cohort

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Background: Tumor suppressor proteins (TSPs) are inactivated by their export from the nucleus by Exportin1 (XPO1/CRM1). The oral selective inhibitor of nuclear export selinexor (KPT-330)restores the nuclear localization and function of TSPs and shows a broad anti-tumor activity in animal models. Here we report on the treatment of a subset of patients (pts) with metastatic colorectal cancer (CRC) in a phase I trial of selinexor. Methods: Objectives were to determine the recommended phase 2 dose, evaluate safety, pharmacokinetics (PK), pharmacodynamics (PD), and tumor response (RECIST 1.1) of selinexor administered in two different schedules with 8 or 10 doses in a 28-day cycle. An expansion cohort of 15 pts with CRC was planned. Results: Twenty-seven pts with CRC were treated across eight doses (3-40 mg/m2) including 15 pts in the expansion cohort (30-35 mg/m2). Median age was 61 yrs and median number of prior regimens was 4. MTD of the 10-dose schedule was 30 mg/m2. MTD for the 8-dose schedule has not been reached. Thirteen pts experienced drug related gr 3-4 adverse events (AEs) including fatigue (n = 6), hyponatremia (n = 5), thrombocytopenia (n = 3), anorexia (n = 3), dehydration (n = 2), anemia (n = 2), hyperglycemia (n = 1), pulmonary embolism (n = 1), and hypotension (n = 1). The most common gr 1-2 drug related AEs were nausea (74 %), anorexia (67 %), fatigue (67 %), vomiting (59 %), dysgeusia (52 %), and weight loss (48 %). Cmax increased with dose to ≈ 1.4 µM with T½ of 4.0 – 7.4 hrs. Significant increases (2-20x) in PD marker XPO1 mRNA in circulating leukocytes were observed at all doses. Analysis of tumor biopsies confirmed nuclear localization of TSPs and induction of apoptosis following selinexor. CEA decreased in 4 of 12 pts. One pt had a partial response at 23 mg/m2, 6 patients had stable disease ≥8 weeks, and 3 patients had stable disease ≥24 weeks in 25 evaluable pts Conclusions: Preliminary signals of antitumor activity in CRC pts were observed. Selinexor is generally well tolerated and prolonged drug exposure is feasible. Selinexor induces Exportin in leucocytes and apoptosis in tumor biopsies with restoration of the nuclear location of TSPs. Clinical trial information: NCT01607905.

Using 124I-PU-H71 PET imaging to predict intratumoral concentration in patients on a phase I trial of PU-H71

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Background: PU-H71 is a Heat Shock Protein 90 inhibitor that can be labeled with 124I without altering its biochemical properties. Intratumoral drug concentration can be calculated based on 124I-PU-H71 (*PU-H71) region of interest analysis and dilution principle. A microdose pilot study has shown uptake of *PU-H71 in a variety of tumors. *PU-H71 PET is currently being used to estimate intratumoral concentrations in subjects on our phase I study. Methods: Patients with previously treated solid tumors or lymphoma are eligible for this phase 1 trial. PU-H71 is given twice-weekly for 2 weeks each 21 days at escalating dose levels. A mix of *PU-H71 and unlabeled PU-H71 is given during cycle 2 followed by serial PET imaging. Patients on the pilot study are administered a microdose of *PU-H71 alone, followed by serial PET scans. Intratumoral PUH-71 concentration is measured directly in optional pre- and post- treatment core needle tumor biopsies (CNB). Results: To date, 13 patients have received PU-H71 on the phase I trial. Of these, 10 have undergone *PU-H71 PET imaging. 4 imaged patients also volunteered for CNBs, with results reported in the table. Of the 10 patients who underwent *PU-H71 imaging in the phase 1 study, 5 also underwent prior *PU-H71 imaging in the microdose pilot. Intratumoral concentrations as calculated in the pilot and phase I studies were in close concordance. Conclusions: *PU-H71 can be used to visualize PU-H71 uptake in a variety of solid tumors and lymphoma, and *PU-H71 PET scans can be used to estimate intratumoral concentrations of PU-H71. Direct intratumoral measurements of PU-H71 correlate reasonably closely with concentrations calculated from *PU-H71 PET imaging. Further refinement of this imaging tool will allow quantitative assessment of PU-H71 uptake in tumors during the ongoing phase I trial. Clinical trial information: NCT01393509. [Table: see text]

Infectious disease associations in advanced stage, indolent lymphoma (follicular, FL, and nonfollicular, nFL): A prospective trial of antibiotic therapy

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Background: The antigen-drive association of gastric MALT with H. pylori (HP) is well recognized. Successful antibiotic (Ab) can result in lymphoma remission. We have studied a 3 mo course of clarithromycin (substituting lansoprazole/amoxicillin/clarithromycin, Prevpak, in the first 2 wks if HP +) in non-bulky, advanced stage indolent lymphoma as the first step to such a lymphoma treatment/prevention strategy. Methods: Patients with new diagnosis indolent lymphoma (FL and nFL), stages II (abdominal), III and IV fulfilling GELF criteria for observation were eligible. Stool HP done in all patients. Hepatitis B and C positive excluded. All patients had CT and PET prior to and 1 mo post Ab. Results: 32 evaluable patients were enrolled: 14 females, 18 males; median age, 53.5 years (36- 81); 22 FL, 10 nFL; stage II (2), III (16), and IV (14). HP + patients: 4 (3 FL, 1 nFL). We have observed lymphoma responses 1 mo post Ab in 7 of 32 (Table). With continued followup post Ab, best response to date in 9 of 32: PET CR ( 2 FL; 2 nFL); CT CR/PR ( 1/3 FL, 1/0 nFL). Median followup for all patients, 23.7 mos; and for those not needing lymphoma treatment, 54.9 mos. To date, no patient with PET CR has required lymphoma treatment (22.5+ to 62.8+ mos). Among 22 with FL, 8 have progressed, 3 had histologic transformation, possibly suggesting a different biology. Conclusions: H pylori eradication/3 mos clarithromycin has achieved lymphoma responses in advanced stage indolent lymphoma. PET negative CRs have been durable for 22.5 – 62.8 + mos following Ab alone. This prospective study may be a first step toward developing a lymphoma prevention strategy and deserves further clinical/biological study. Clinical trial information: NCT00461084. [Table: see text]

Updated results of a phase I first-in-human study of the BCL-2 inhibitor ABT-199 (GDC-0199) in patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL)

7018

Background: Targeting BCL-2 is a promising strategy for treating CLL, including disease refractory to fludarabine (F), or with (del(17p). ABT-199 is a selective BCL-2 inhibitor with >500-fold higher affinity for BCL-2 (Ki<0.10 nM) than for BCL-XL (Ki=48 nM). Methods: Objectives of this Ph I dose-escalation study include evaluations of safety, pharmacokinetics and preliminary efficacy of ABT-199 in patients (pts) with R/R CLL. A single oral dose was given followed by 6 days off drug, before continuous once daily dosing. After cohort 1, the initial dose was reduced and daily dosing modified to include a 2 or 3 step dose-escalation to the target dose for each cohort. Results: As of January 11, 2013, 56 pts have been enrolled; median age 67 y (range 36-86); 41 males; median 3.5 prior therapies (range 1-10). 16 (29%) had del(17p) and 18 (32%) F-refractory CLL. Median follow up is 6.3 months (range 0.03-16.5); 7 pts have been on study for more than 1 yr. 13 pts discontinued; 7 due to PD, 6 for other reasons: tumor lysis syndrome (TLS; 2), other illness (2), thromboembolic event (1), consent withdrawal (1). The most common non-hematological AEs (>15% pts) were nausea (36%), diarrhea (30%), fatigue (25%), upper respiratory tract infection (23%), and cough (16%). Grade 3/4 AEs occurring in > 5 pts were neutropenia 21(38%), thrombocytopenia 6 (11%) and TLS 5 (9%). TLS occurred in 3/3 pts in cohort 1 and 2/53 pts with the modified stepped dosing schedule (DLTs). Additionally, 1 fatal AE occurred within 48 hrs of dose-escalation to 1200 mg in a pt with laboratory evidence of TLS (DLT). 46 of 54 pts (85%) evaluable for efficacy achieved a response to ABT-199; 7 (13%) a CR or CR with incomplete count recovery and 39 (72%) a PR (30 confirmed by consecutive scans). 14/16 (88%) and 12/16 (75%) of pts with del(17p) and F-refractory CLL, respectively, achieved at least a PR. Conclusions: ABT-199 is highly active achieving a 85% overall response rate in R/R CLL, independent of high risk markers such as del(17p) and F-refractory disease. Additional dosing and scheduling modifications are currently being explored to minimize the risk of TLS. Clinical trial information: NCT01328626.

Updated results of a phase I first-in-human study of the BCL-2 inhibitor ABT-199 (GDC-0199) in patients with relapsed/refractory non-Hodgkin lymphoma (NHL)

8520

Background: BCL-2 is highly expressed in NHL, including mantle cell lymphoma (MCL), and is a promising therapeutic target as it is involved in NHL pathogenesis and mediates resistance to many cytotoxics. ABT-199 is a second generation inhibitor with 500-fold higher affinity for BCL-2 (Ki<0.10 nM) than BCL-XL (Ki=48 nM). Methods: Objectives of this Ph 1 dose-escalation study include evaluations of safety, pharmacokinetics and preliminary efficacy in patients (pts) with relapsed or refractory (R/R) NHL. A single oral dose (50-400 mg) was administered followed by 6 days off drug prior to the initiation of continuous once daily dosing. Due to concerns of potential tumor lysis syndrome (TLS), a 2 to 3 wk lead-in period with step-wise escalation to the target cohort dose was implemented. Dose cohorts up to 900 mg have been evaluated to date. Results: As of January 2013, 31 pts have been enrolled (median age 68 y (range 35-85); 20 males; median prior therapies 3 (range 1-7). 13 (42%) and 4 (13%) had bulky adenopathy (>5 and >10 cm, respectively). The most common AEs (≥15% of patients) were nausea (36%), diarrhea (26%), dyspepsia, vomiting, fatigue, pyrexia and cough (16% each). Gr 3/4 AEs occurring in >1 patient were anemia, neutropenia (4 pts each), and febrile neutropenia (2 pts). Two of 14 pts in cohort 5 experienced DLTs at the target dose of 600 mg: Gr 3 febrile neutropenia and Gr 4 neutropenia. Although Gr 3/4 thrombocytopenia was observed in 3 pts, it was not dose dependent. Gr 3 TLS was seen after the initial dose in 1 pt with very bulky MCL (>10 cm). With a median follow-up of 5 months (range 0.5-15), 17 have discontinued: 13 due to PD, 2 due to AEs and 2 who received a BMT. Of the 29 pts evaluable for efficacy, the overall best response rate was 55% with 1 DLBCL pt achieving a CR and 15 (52%) a PR (8/8 MCL, 3/3 Waldenstrom macroglobulinemia, 2/7 follicular lymphoma and 2/7 DLBCL pts). Conclusions: ABT-199 is highly active in R/R NHL, particularly in MCL. Additional dosing and scheduling modifications are currently being explored to optimize the efficacy/safety profile of this active new agent. ABT-199 warrants further single-agent and combination trials in NHL. Clinical trial information: NCT01328626.

The impact of non-drug-related toxicities on the estimation of the maximum tolerated dose in phase I trials

The rate of observed dose-limiting toxicities (DLT) determines the maximum tolerated dose (MTD) in phase I trials. There are cases in which non-drug-related toxicities or other-cause toxicities (OCT) are flagged as DLTs, or vice versa, due to attribution errors. We aim to assess the impact of such errors on the final estimate of MTD. We compared the impact of attribution errors using 2 trial designs-the "3+3" dose-escalation scheme and the continual reassessment method (CRM). Two attribution errors are considered: when a DLT is classified as an OCT (type A error) and when an OCT is misclassified as a DLT (type B error). The impact of these errors on accuracy, patient safety, sample size, and study duration was evaluated by varying the probability of occurrence of each error through simulated trials. Under no errors, CRM is on average 35% more accurate than 3+3 in finding the true MTD. This improved accuracy is maintained in the presence of errors. At a 15% type B error rate, CRM recommends a dose within 2 levels of the true MTD 68% of the time, compared with 17% of the time using the 3+3 method. A DLT must be attributed as an OCT 30% of the time to increase the accuracy of 3+3; otherwise the method recommends a wrong dose approximately 75% of the time. CRM is more robust to toxicity attribution errors compared with the 3+3 as it uses information from all treated patients, leading to a more accurate MTD estimation at the frequency of attribution errors anticipated in phase I clinical trials.

A Phase I trial of the kinesin spindle protein (Eg5) inhibitor AZD4877 in patients with solid and lymphoid malignancies

BACKGROUND

This Phase I study assessed the safety and maximum tolerated dose (MTD) of the kinesin spindle protein inhibitor AZD4877 in patients with relapsed/refractory solid tumors and lymphoma.

METHODS

In this multicenter study, a standard 3 + 3 dose-escalation design was used. AZD4877 was given as an intravenous infusion on days 1, 4, 8 and 11 of each 21-day cycle. Responses were assessed with CT scans +/- PET after 6 and 12 weeks, then every 12 weeks while on therapy. An additional four patients with lymphoma were enrolled at the MTD.

RESULTS

29 patients were enrolled and 22 patients received at least one dose of AZD4877 and were evaluable for safety. The MTD was 11 mg. Dose-limiting toxicity was neutropenia (n = 2 patients, 15 mg cohort). The most common adverse events were grade 1/2 fatigue, nausea, neutropenia and dyspnea. AZD4877 exposure generally increased with dose, with mean elimination half-life approximately 16 h at the MTD. Pharmacodynamic analyses demonstrated moderate correlation between plasma drug concentrations at 6 or 24 h and monoaster formation in peripheral blood mononuclear cells (PBMCs).

CONCLUSIONS

AZD4877 is generally well-tolerated with pharmacodynamic evidence of target inhibition in circulating PBMCs.

Risk of skin rash with the proteasome inhibitor bortezomib: Updated systematic review and meta-analysis

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Background: Rash is a common, adverse event to the novel proteasome inhibitor bortezomib (Velcade). Indicated for the treatment of multiple myeloma and mantle cell lymphoma, bortezomib is the first proteasome inhibitor approved by regulatory agencies. Because the incidence of bortezomib-induced skin rash varies widely in published manuscripts, we performed a systematic literature review and meta-analysis to determine the incidence and overall risk. Methods: We searched PubMed and Web of Science databases and abstracts presented at the American Society of Clinical Oncology and The American Society of Hematology annual meetings (1998 to July 2011) to identify relevant clinical studies. Eligible studies included prospective clinical phase II and phase III trials, with data on the incidence of rash in patients taking 1.3mg/m2, 1.5mg/m2, or 1.6 mg/m2 of bortezomib intravenously either weekly or twice weekly. The incidence of rash and relative risk (RR) were calculated using random-effects or fixed-effects model, depending on the heterogeneity of included studies. Results: A total of 2,616 patients with various hematologic and solid malignancies from 35 clinical trials were included for analysis. Among patients receiving twice weekly bortezomib, the summary incidence of all-grade and high-grade rash were 18.8 % (95% CI: 14.9% to 23.5%) and 3.6 % (95% CI: 2.3% to 5.7%), respectively. We found no significant increase in all grade rash incidence with higher doses of bortezomib: 19.3 % (95% CI: 15% to 24.5%) and 20.8% (95% CI: 11.6% to 34.4%) for doses of 1.3 mg/m2 and 1.5 mg/m2, respectively. In addition, bortezomib was associated with an increased risk in both all grade (RR: 19.70, 95% CI: 8.73 to 44.44, p<0.001) and high-grade rash (RR: 5.35, 95% CI: 2.16 to 13.29, p<0.001), compared to controls. Weekly bortezomib is associated with lower risk of rash compared to twice weekly dosing (incidence 3.9% versus 18.8%, p=0.001). Conclusions: Bortezomib is associated with a significant risk of developing rash with a higher risk among patients receiving twice weekly dosage. Management of rash to bortezomib is critical to prevent a negative effect on quality of life and dose modifications, both of which affect clinical outcome.

Final results of phase I/II trial of vorinostat in combination with cyclophosphamide, etoposide, prednisone, and rituximab (R-CVEP) for elderly patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL)

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Background: Standard treatment of relapsed/refractory DLBCL in elderly patients who are not candidates for autologous stem cell transplantation (auSCT) has not been established. Cyclophosphamide (C), etoposide (E), prednisone (P) and procarbazine (CEPP) has been used by many clinicians based on limited data (Blood 76: 1293-98, 1990). Vorinostat (V) is a histone deacetylase inhibitor that is approved for relapsed cutaneous T-cell lymphoma and has activity in B-cell lymphomas. This trial defined the maximum tolerated dose (MTD) of V added to standard therapy and determined the response rate of this combination. Methods: Patients ≥age 60 with relapsed/refractory DLBCL not candidates for auSCT were enrolled on R-CVEP (R 375mg/m2 IV, d1; C 600mg/m2 d1 and 8, E 70mg/m2 IV d1, 140mg/m2 d2 and 3; V PO and Pred 60mg/m2 PO d1-10) every 28 days for 6 cycles. In the phase I component V was administered at doses of 300mg/d or 400mg/d for 10 days. The phase I was a 3 + 3 design and the phase II a two stage design requiring 8/20 complete responses (CR) for expansion. Assessment of response utilized end-of-treatment positron emission tomography (PET) (JCO 25: 579-86, 2007). Quality of life (QOL) was measured with the FACT-Lym v.4. Results: 27 pts. were enrolled. 1 died before treatment. For 26 pts: median age 76 yrs. (69-88), 14 females and 12 males, baseline PS (ECOG) 1 (0-2). Median follow-up for survivors: 9.2 mo. Phase I: 6 pts. at 300mg/d (no dose-limiting toxicity-DLT), 6 pts. at 400mg/d (2 grade 3 neutropenia = DLT). MTD 300mg/d x 10d. For 20 pts. at V 300mg/m2 (6 phase I + 14 phase II): 2 off study for toxicity, 1 withdrew consent, 6 CR (30%), 5 partial response (PR) (25%), 6 progressed (30%). Phenotypic overall responses (OR): germinal center (GC) 4/8 (2 CR), non-GC 6/10 (3 CR), transformed CLL 1/2 (1 CR). Median progression-free survival: 10 mo. QOL results will be presented. Conclusions: OR rate for V added to conventional chemotherapy and R was 55% (CR 30%, PR 25%) in relapsed/refractory DLBCL in elderly pts. not candidates for auSCT. This could provide a baseline for comparison with future clinical trials in this understudied population.

Augmenting advance care planning in poor prognosis cancer with a video decision aid: a preintervention-postintervention study

BACKGROUND

The authors tested whether an educational video on the goals of care in advanced cancer (life-prolonging care, basic care, or comfort care) helped patients understand these goals and had an impact on their preferences for resuscitation.

METHODS

A survey of 80 patients with advanced cancer was conducted before and after they viewed an educational video. The outcomes of interest included changes in goals of care preference and knowledge and consistency of preferences with code status.

RESULTS

Before viewing the video, 10 patients (13%) preferred life-prolonging care, 24 patients (30%) preferred basic care, 29 patients (36%) preferred comfort care, and 17 patients (21%) were unsure. Preferences did not change after the video, when 9 patients (11%) chose life-prolonging care, 28 patients (35%) chose basic care, 29 patients (36%) chose comfort care, and, 14 patients (18%) were unsure (P = .28). Compared with baseline, after the video presentation, more patients did not want cardiopulmonary resuscitation (CPR) (71% vs 62%; P = .03) or ventilation (80% vs 67%; P = .008). Knowledge about goals of care and likelihood of resuscitation increased after the video (P < .001). Of the patients who did not want CPR or ventilation after the video augmentation, only 4 patients (5%) had a documented do-not-resuscitate order in their medical record (kappa statistic, -0.01; 95% confidence interval, -0.06 to 0.04). Acceptability of the video was high.

CONCLUSIONS

Patients with advanced cancer did not change care preferences after viewing the video, but fewer wanted CPR or ventilation. Documented code status was inconsistent with patient preferences. Patients were more knowledgeable after the video, reported that the video was acceptable, and said they would recommend it to others. The current results indicated that this type of video may enable patients to visualize "goals of care," enriching patient understanding of worsening health states and better informing decision making.

Navitoclax, a targeted high-affinity inhibitor of BCL-2, in lymphoid malignancies: a phase 1 dose-escalation study of safety, pharmacokinetics, pharmacodynamics, and antitumour activity

BACKGROUND

Proteins of the BCL-2 family regulate clonal selection and survival of lymphocytes, and are frequently overexpressed in lymphomas. Navitoclax is a targeted high-affinity small molecule that inhibits the anti-apoptotic activity of BCL-2 and BCL-XL. We aimed to assess the safety and antitumour activity of navitoclax in patients with lymphoid tumours, and establish the drug's pharmacokinetic and pharmacodynamic profiles.

METHODS

In this phase 1 dose-escalation study, patients (aged ≥18 years) with relapsed or refractory lymphoid malignancies were enrolled and treated at seven sites in the USA between November, 2006, and November, 2009. A modified Fibonacci 3+3 design was used to assign patients to receive oral navitoclax once daily by one of two dosing schedules: intermittently for the first 14 days of a 21-day cycle (14/21) at doses of 10, 20, 40, 80, 110, 160, 225, 315, or 440 mg/day; or continuously for 21 days of a 21-day cycle (21/21) at doses of 200, 275, 325, or 425 mg/day. Study endpoints were safety, maximum tolerated dose, pharmacokinetic profile, pharmacodynamic effects on platelets and T cells, and antitumour activity. This trial is registered with ClinicalTrials.gov, number NCT00406809.

FINDINGS

55 patients were enrolled (median age 59 years, IQR 51-67), 38 to receive the 14/21 dosing schedule, and 17 to receive the 21/21 dosing schedule. Common toxic effects included grade 1 or 2 anaemia (41 patients), infection (39), diarrhoea (31), nausea (29), and fatigue (21); and grade 3 or 4 thrombocytopenia (29), lymphocytopenia (18), and neutropenia (18). On the intermittent 14/21 schedule, dose-limiting toxic effects were hospital admissions for bronchitis (one) and pleural effusion (one), grade 3 increase in aminotransferases (one), grade 4 thrombocytopenia (one), and grade 3 cardiac arrhythmia (one). To reduce platelet nadir associated with intermittent 14/21 dosing, we assessed a 150 mg/day lead-in dose followed by a continuous 21/21 dosing schedule. On the 21/21 dosing schedule, two patients did not complete the first cycle and were excluded from assessment of dose-limiting toxic effects; dose-limiting toxic effects were grade 4 thrombocytopenia (one), grade 3 increase in aminotransferases (one), and grade 3 gastrointestinal bleeding (one). Navitoclax showed a pharmacodynamic effect on circulating platelets and T cells. Clinical responses occurred across the range of doses and in several tumour types. Ten of 46 patients with assessable disease had a partial response, and these responders had median progression-free survival of 455 days (IQR 40-218).

INTERPRETATION

Navitoclax has a novel mechanism of peripheral thrombocytopenia and T-cell lymphopenia, attributable to high-affinity inhibition of BCL-XL and BCL-2, respectively. On the basis of these findings, a 150 mg 7-day lead-in dose followed by a 325 mg dose administered on a continuous 21/21 dosing schedule was selected for phase 2 study.

FUNDING

Abbott Laboratories, Genentech, and National Cancer Institute, National Institutes of Health.

A phase 1 dose escalation study of the safety and pharmacokinetics of the novel proteasome inhibitor carfilzomib (PR-171) in patients with hematologic malignancies

PURPOSE

Carfilzomib (formerly PR-171) is a novel proteasome inhibitor of the epoxyketone class that is selective and structurally distinct from bortezomib. Proteasome inhibition by carfilzomib is mechanistically irreversible. Consequently, proteasome inhibition is more sustained with carfilzomib than with bortezomib.

EXPERIMENTAL DESIGN

In a phase 1 trial evaluating the safety and efficacy of carfilzomib in relapsed or refractory hematologic malignancies, eight dose groups of three to six patients received 5 consecutive days of carfilzomib i.v. push at doses of 1.2, 2.4, 4, 6, 8.4, 11, 15, and 20 mg/m2 within 14-day cycles.

RESULTS

Twenty-nine patients enrolled that were relapsed or refractory after at least two prior therapies. Nonhematologic toxicities included fatigue, nausea, and diarrhea in more than one third of patients-mostly grade 1 or 2 in severity. At 20 mg/m2, grade 3 febrile neutropenia and grade 4 thrombocytopenia were reported, establishing 15 mg/m2 as the maximum tolerated dose. No grade 3 or 4 peripheral neuropathies were reported. Antitumor activity was observed at doses > or =11 mg/m2: one unconfirmed complete response (mantle cell), one partial response (multiple myeloma), and two minimal responses (multiple myeloma and Waldenström's macroglobulinemia).

CONCLUSION

This is the first clinical use of carfilzomib that shows tolerability and clinical activity in multiple hematologic malignancies using consecutive-day dosing.