ALBERT

Description: Abstract 285 Background: KW-0761 is a defucosylated, humanized, monoclonal antibody with enhanced antibody-dependent cellular cytotoxicity (ADCC; Potelligent®) that binds to CC chemokine receptor 4 (CCR4). CCR4 is expressed on the surfaces of cells comprising several T-cell malignancies such as ATL, peripheral T-cell lymphoma (PTCL) and cutaneous T-cell lymphoma (CTCL). A phase I study of KW-0761 in patients with CCR4-positive ATL and PTCL demonstrated that 4 weekly intravenous infusions of KW-0761 were well tolerated up to 1.0 mg/kg and it showed encouraging clinical activity with an overall response rate (ORR) of 31.3% (4 of 13 ATL and 1 of 3 PTCL) in 16 patients (J Clin Oncol 2010;28:1591-8). Methods: A multicenter phase II study of KW-0761 has been conducted for relapsed patients with CCR4-positive ATL to evaluate its efficacy, pharmacokinetics (PK), safety and immunogenicity. Patients were planned to receive 8 weekly intravenous infusions of KW-0761 at 1.0 mg/kg. The primary endpoint was ORR. Objective responses were assessed after the 4th and 8th infusions of KW-0761 according to the response criteria for ATL (J Clin Oncol 2009;27:453-9) by each investigator and the independent efficacy assessment committee. The number of patients required was estimated to be 25, for 90% power to detect a lower limit of the 95% confidence interval (CI) exceeding the 5% threshold of ORR, based on the assumptions that the minimum required response ORR to a new drug for relapsed ATL is 5% and the expected ORR to KW-0761 is 30%. Results: Twenty-seven patients (12 males and 15 females) were enrolled and received KW-0761. The median age was 64 years (range: 49–83). The disease subtypes of ATL consisted of 14 acute-, 6 lymphoma-, and 7 chronic-types with unfavorable prognostic factors. Among the 27 patients enrolled, 14 patients (52%) completed the protocol treatment of 8 infusions. Eleven patients (41%) discontinued the protocol treatment because of progressive disease, and the remaining 2 discontinued because of skin rash or the concurrent colon tumor. The treatment-related grade (G) 2 or greater adverse events (AEs) were lymphopenia (96%), leukopenia (56%), skin rash (52%), neutropenia (33%), thrombocytopenia (26%), AST increase (26%), ALT increase (22%), hypoxemia (19%), anemia (15%), pruritus (15%), g-GTP increase (15%) and hypophosphatemia (15%). G2 or greater Infusion-related toxicities were observed in 22 of 27 patients (81%) including 1 G3, but immediately recovered after treatment with systemic steroids. Treatment-related severe AEs (SAEs) were observed in 5 patients, including a Stevens-Johnson syndrome (G3) and 4 skin rashes (each G3). All these AEs also improved by steroids. PK analysis demonstrated that Cmax and trough (C168h) after the 8th infusion was 38,853 ± 11,267 and 25,934 ± 10,193 ng/mL, respectively, and T1/2 after the 8th infusion were 457 ± 144 h. No anti-KW-0761 antibody has been detected. Among the 26 patients evaluable for efficacy, KW-0761 exhibited an ORR of 54% (14/26; 95% CI, 33 to 73) (acute: 6/14 patients, lymphoma: 3/6 patients, chronic: 5/6 patients) including 7 complete responses (CRs) (27%; 95% CI, 12 to 48) and 7 partial responses (PRs). These are remarkable results, considering that the ORR of relapsed or refractory patients with ATL to a single-agent chemotherapy has been reported to be low (7 to 39%). Response rates according to the affected disease lesion were 100% (13 patients, all CR), 71% (5 of 7 patients), and 38% (5 of 13 patients), respectively, for peripheral blood, skin, and lymph node disease. Conclusions: KW-0761 is a highly effective agent with acceptable toxicity profiles in relapsed patients with CCR4-positive ATL who have no standard therapies. A multicenter, randomized study for untreated ATL patients to compare mLSG15 (a dose-intensified multi-agent regimen, J Clin Oncol 2007;25:5458-64) + KW-0761 with mLSG15 alone has been initiated. Disclosures: Ogura: Kyowa Hakko Kirin Co Ltd: Consultancy. Akinaga:Kyowa Hakko Kirin Co Ltd: Employment.

Description: The long-term prognosis of indolent adult T-cell leukemia-lymphoma (ATL) is not clearly elucidated. From 1974 to 2003, newly diagnosed indolent ATL in 90 patients (65 chronic type and 25 smoldering type) was analyzed. The median survival time was 4.1 years; 12 patients remained alive for more than 10 years, 44 progressed to acute ATL, and 63 patients died. The estimated 5-, 10-, and 15-year survival rates were 47.2%, 25.4%, and 14.1%, respectively, with no plateau in the survival curve. Although most patients were treated with watchful waiting, 12 patients were treated with chemotherapy. Kaplan-Meier analyses showed that advanced performance status (PS), neutrophilia, high concentration of lactate dehydrogenase, more than 3 extranodal lesions, more than 4 total involved lesions, and receiving chemotherapy were unfavorable prognostic factors for survival. Multivariate Cox analysis showed that advanced PS was a borderline significant independent factor in poor survival (hazard ratio, 2.1, 95% confidence interval, 1.0-4.6; P = .06), but it was not a factor when analysis was limited to patients who had not received chemotherapy. The prognosis of indolent ATL in this study was poorer than expected. These findings suggest that even patients with indolent ATL should be carefully observed in clinical practice. Further studies are required to develop treatments for indolent ATL.

Description: We examined the expression of messenger RNA (mRNA) of the human inducible nitric oxide synthase (hiNOS) gene in a panel of human T-cell lines. Reverse transcriptase-polymerase chain reaction showed that human T-cell leukemia virus type-I (HTLV-I)–infected T-cell lines (MT-1, SLB-1, and C5/MJ) expressed mRNA for the hiNOS, but TL-Om1 or uninfected Jurkat, H9, and CCRF-CEM did not. The MT-1, SLB-1, and C5/MJ cell lines are infected with HTLV-I and express the viral transactivator Tax, whereas TL-Om1 cells, although derived from adult T-cell leukemia (ATL) leukemic cells, do not express Tax. There was, thus, a correlation between Tax and hiNOS mRNA expression. The transcriptional regulatory region of the hiNOS gene was activated by Tax in Jurkat, in which endogenous hiNOS is induced by Tax. Deletion analysis showed that the region of hiNOS encompassing nucleotides −159 to −111 contained the minimum Tax-responsive elements. Mutations in the NF-κB element at position −115 and −106 bp in the hiNOS promoter were still activated by Tax, and a Tax mutant defective for activation of the NF-κB pathway retained the ability to activate the hiNOS promoter. In addition, overexpression of the dominant-negative mutants of IκB and I κBβ failed to reduce Tax-induced activation of hiNOS gene. Furthermore, hiNOS mRNA was detected in leukemic cells from ATL patients. Our results show that the hiNOS promoter contains a minimum Tax-responsive element located between nucleotides −159 and −111, and imply that the expression of the hiNOS gene is involved in the pathogenesis of HTLV-I–associated diseases.

Description: Prognosis of patients with AML varies widely reflecting the heterogeneity of AML and the background of each patient. It is important for both physicians and patients to predict the response to chemotherapy to correctly select the therapeutic options. In the JALSG-AML97 study, patients were stratified using JALSG scoring system, and those who were categorized into the intermediate or adverse prognosis group were assigned to allo-HSCT during CR1 if they had an HLA-matched sibling. JALSG scoring contains several factors that have 1 or 2 points: 2 points, age 〈 50 years, WBC 50%; 1 point, PS

Description: Interleukin-15 receptor (IL-15R) and IL-2R have the same β and γ chains, but IL-15R has a specific α chain distinct from that of IL-2Rα, which is indispensable for the high affinity binding of IL-15. In the present study, we examined four IL-2-dependent adult T-cell leukemia (ATL) cell lines for their IL-15R expression. All cell lines bound IL-15, which was not inhibited by a 100-fold excess amount of IL-2, proliferated in response to IL-15 to the same degree as to the stimulation with IL-2, and were maintained without IL-2. The responses to 1L-15 were inhibited by the antibodies against IL-2R β or γ chains but was not by the IL-2R α chain antibody. [125I]–IL-15 exhibited a single high-affinity binding with an apparent kd of 0.17 nmol/L. Reverse transcription–coupled polymerase chain reaction (RT-PCR) showed that the cell lines had the mRNA of IL-15R α. The cell lines also had IL-15 mRNA. Despite the presence of IL-15 mRNA, the cell lines did not secrete IL-15, and the culture supernatants of fresh ATL cells and plasma from the patients did not contain a detectable amount of IL-15 with a few exceptional cases, although fresh ATL cells also responded to IL-15. These results suggest that ATL cells have the complete form of IL-15R and respond to IL-15. Such an IL-15–dependent cell proliferation mechanism might be used in the development of ATL and for the invasion and proliferation of ATL cells in the visceral organs.

Description: To examine whether donor-derived cells could exist in nonhematopoietic tissues of recipients after allogeneic hematopoietic stem-cell transplantation, we examined the patterns of the short tandem repeat (STR) of DNA extracted from fingernail clippings of recipients so that the contamination of blood cells was excluded. All 21 patients reached donor-derived hematopoiesis after transplantation and 20 of them were in remission of the primary diseases at the time of sampling. Compared with the STRs of donor cells, among 9 of 21 patients, DNA extracted from fingernail samples showed coexistence of the donor pattern of the STRs, sharing from 8.9% to 72.9% of total STR areas. Time from transplantation to sampling was from 305 to 2399 days among positive cases. These results demonstrate for the first time the existence of stable contribution of donor cells in fingernails among recipients of allogeneic hematopoietic stem cells.

Description: Sixty-four patients with adult T-cell leukemia/lymphoma (ATL; 18 patients with indolent subtype and 46 with aggressive subtype) associated with human T-lymphotropic virus type 1 (HTLV-1) were analyzed using comparative genomic hybridization (CGH). The most frequent observations were gains at chromosomes 14q, 7q, and 3p and losses at chromosomes 6q and 13q. Chromosome imbalances, losses, and gains were more frequently observed in aggressive ATL than in indolent ATL, with significant differences between the 2 ATL subtypes at gains of 1q and 4q. An increased number of chromosomal imbalances was associated with a significantly shorter survival in all patients. A high number of chromosomal losses was associated with a poor prognosis in indolent ATL, whereas the presence of 7q+ was marginally associated with a good prognosis in aggressive ATL. Paired samples (ie, samples obtained at different sites from 4 patients) and sequential samples from 13 patients (from 6 during both chronic disease and acute crisis and from 7 during both acute onset and relapse) were examined by CGH and Southern blotting for HTLV-1. All but 2 paired samples showed differences on CGH assessment. Two chronic/crisis samples showed distinct results regarding both CGH and HTLV-1 integration sites, indicating clonal changes in ATL at crisis. In 11 patients, the finding of identical HTLV-1 sites and clonally related CGH results suggested a common origin of sequential samples. In contrast to chronic/crisis samples, CGH results with all acute/relapse sample pairs showed the presence of clonally related but not evolutional subclones at relapse, thereby suggesting marked chromosomal instability. In summary, clonal diversity is common during progression of ATL, and CGH alterations are associated with clinical course.

Description: Background: KW-0761 produced by POTELLIGENT ® technology is a defucosylated humanized IgG1 monoclonal antibody against CC chemokine receptor 4 (CCR4). Fucose is demonstrated to be the most critical IgG1 oligosaccharide component for antibody-dependent cellular cytotoxicity (ADCC) activity and KW-0761 composed of defucosylated IgG1 exhibits an enhanced ADCC activity. Previous studies revealed that CCR4 was overexpressed on tumor cells from 88% of pts with ATL and 38% of pts with PTCL unspecified (PTCL-U), and its expression was associated with poor prognosis. CCR4 was also expressed in cutaneous T-cell lymphoma (CTCL) such as mycosis fungoides (MF) and Sezary syndrome, especially its large cell transformant. These results suggest that CCR4 could be a realistic therapeutic target for ATL, CTCL and PTCL-U. Methods: A multicenter phase I study of KW-0761 has been conducted for relapsed pts with CCR4-positive ATL or PTCL to evaluate its safety, pharmacokinetics (PK), immunogenicity and efficacy. Pts were planned to receive 4 weekly intravenous infusions of KW-0761 at 0.01, 0.1, 0.5, and 1.0 mg/kg. A dose-limiting toxicity (DLT) was defined as any of the following adverse events: ≥ grade (G) 4 hematologic toxicities except for lymphopenia, ≥ G4 acute infusion reaction/cytokine release syndrome or tumor lysis syndrome, or ≥ G3 other non-hematologic toxicities. Plasma KW-0761 levels were assessed in all pts enrolled. Response was assessed by standard response criteria for NHL by each investigator. Results: As of August 18, 2008, 13 pts including 6 males and 7 females (11 ATL, 1 PTCL-U, 1 MF) were treated with KW-0761 at 0.01 (N=3), 0.1 (N=4), 0.5 (N=3) and 1.0 mg/kg (N=3). Median age was 62 years (range 46 – 69). KW-0761 was well tolerated without any DLT. ≥ G2 toxicities included: hematologic: lymphopenia (G4: N=2, G3: N=6, G2: N=3), neutropenia (G3: N=2, G2: N=3), eosinophilia and thrombocytopenia (G2: N=1, each); and non-hematologic: herpes zoster (3 months after the 4th dosing, G3: N=1), acute infusion reaction/cytokine release syndrome (G3: N=1, G2: N=4), constipation, rash, prolonged QTc, ALT increase, CRP increase, and pain of lymph node (G2: N=1, each). One pt enrolled at 0.1 mg/kg was withdrawn due to early disease progression. PK analysis showed that Cmax at 0.01 and 1.0 mg/kg after the 4th dosing were 324 ± 57 and 43469 ± 3819 ng/mL, respectively, and C168h at 0.01 and 1.0 mg/kg after the 4th dosing were 152 ± 12 and 21900 ± 3880 ng/mL, respectively. T1/2 at 0.01 and 1.0 mg/kg after the 4th dosing were 244 ± 117 and 554 ± 125 h, respectively. No anti-KW-0761 antibody has been detected. Complete response (CR) was observed in one ATL pt (0.1 mg/kg) with the disappearance of abnormal blood cells and skin disease, and in one PTCL-U pt (1.0 mg/kg) with the disappearance of abnormal blood cells, skin disease and enlarged lymph node. Overall, investigator-assessed responses for 13 enrolled pts were 31% including 2 CRs, 2 PRs (ATL at 0.01, and 0.1 mg/kg) and 4 SDs (ATL at 0.01, 0.1 and 1.0 mg/kg). Conclusions: KW-0761 was tolerable across a wide range (0.01 – 1.0 mg/kg) and had clinical activity in relapsed CCR4-positive ATL or PTCL. KW-0761 is a promising new antibody therapy for ATL and PTCL. Patient accrual is ongoing and the updated results will be presented.

Description: Introduction: KW-0761 is a defucosylated humanized IgG1 monoclonal antibody against CC chemokine receptor 4 (CCR4). Previous studies revealed that CCR4 was over-expressed on tumor cells from 88% of pts with ATLL and 38% of pts with PTCL. CCR4 expression was associated with unfavorable prognosis in both diseases. These evidences suggest that CCR4 could be a reasonable molecular target for treatment of CCR4-positive ATLL and PTCL. KW-0761 exerted very potent ADCC but not CDC against cultured ATLL cell lines using normal effecter cells. KW-0761 also exhibited potent ADCC against freshly isolated ATLL cells using the auto-effecter cells. Methods: KW-0761 is being investigated in a Phase I, single-agent, dose-escalation, multicenter study for relapsed or refractory pts with ATLL or PTCL after undergoing the initial chemotherapy. Eligible pts were required to express CCR4 on their tumor cells by FCM and/or IHC. This phase I trial was designed to evaluate toxicity, pharmacokinetics (PK), immunogenicity and anti-tumor activity. Toxicity was evaluated by NCI CTCAE (v3.0). Pts were planned to receive four weekly intravenous injections of KW-0761 at the doses of 0.01, 0.1, 0.5 and 1.0 mg/kg. Results: As of August 10, 2007, 6 pts (1 PTCL and 5 ATLL) have been treated with KW-0761 at the dose of 0.01 (N=3) and 0.1 mg/kg (N=3). Three pts were evaluable for toxicity, PK, immunogenicity and 4 pts were evaluable for anti-tumor activity. KW-0761 was well tolerated with no dose-limiting toxicities. Reversible grade (G) 3 toxicities were lymphocytopenia and herpes zoster. G1-2 adverse events were; rash, constipation, nausea, EF decrease, neutropenia, thrombocytopenia, eosinophilia, lymphocytopenia, ALP increase and QT prolongation. In one leukemic ATLL pt with swollen lymph nodes (LNs) treated at 0.01 mg/kg, peripheral ATLL cells disappeared and the LNs were decreased in size, attaining PR. In another leukemic ATLL pt with skin involvement treated at 0.1 mg/kg, peripheral ATLL cells disappeared and the skin achieved PR by Physicians Global Assessment of Clinical Conditions (PGA). One ATLL pt with skin and bone involvement at 0.01 mg/kg showed SD. Preliminary PK analysis at 0.01 mg/kg showed that Cmax and T1/2 after the 4th dosing was 323.7 56.7 ng/ml and 244 117 hrs, respectively. KW-0761 did not exhibit immunogenicity at 0.01 mg/kg. Conclusions: Preliminary phase I data warrant further investigations of KW-0761, a first-in-class humanized anti-CCR4 antibody, against CCR4-positive peripheral T-cell malignancies including ATLL. Patient accrual is ongoing and the updated results will be presented at the meeting.