Epratuzumab, a Humanized Anti-CD22 Antibody, in Aggressive Non-Hodgkin's Lymphoma: Phase I/II Clinical Trial Results

Vol. 10, 5327–5334, August 15, 2004 Clinical Cancer Research 5327

Featured Article Epratuzumab, a Humanized Anti-CD22 Antibody, in Aggressive Non-Hodgkin’s Lymphoma: Phase I/II Clinical Trial Results

John P. Leonard,1 Morton Coleman,1 within 1 h. The mean serum half-life was 23.9 days. Across Jamie C. Ketas,1 Amy Chadburn,2 all dose levels and histologies, objective responses (ORs) Richard Furman,1 Michael W. Schuster,1 were observed in five patients (10%; 95% confidence inter- 1 1 val, 3–21%), including three complete responses. In patients Eric J. Feldman, Michelle Ashe, with diffuse large B-cell lymphoma, 15% had ORs. Overall, 3 4 Stephen J. Schuster, William A. Wegener, 11 (20%) patients experienced some tumor mass reduction. Hans J. Hansen,4 Heather Ziccardi,4 Median duration of OR was 26.3 weeks, and median time to Michael Eschenberg,5 Urte Gayko,5 progression for responders was 35 weeks. Two responses are > Scott Z. Fields,6 Alessandra Cesano,5 and ongoing at 34 months, including one rituximab-refractory 4,7 patient. David M. Goldenberg Conclusions: These data demonstrate that epratu- 1 2 Division of Hematology and Oncology and Department of zumab has a good safety profile and exerts antitumor activ- Pathology, Center for Lymphoma and Myeloma, Weill Medical > College of Cornell University and New York Presbyterian Hospital, ity in aggressive non-Hodgkin’s lymphoma at doses of 240 2 New York, New York; 3University of Pennsylvania Cancer Center, mg/m , thus warranting further evaluation in this clinical Philadelphia, Pennsylvania; 4Immunomedics, Inc., Morris Plains, New setting. Jersey; 5Amgen Inc., Thousand Oaks, California; 6Eisai Medical Research, Teaneck, New Jersey; and 7Center for Molecular Medicine and Immunology, Garden State Cancer Center, Belleville, New Jersey INTRODUCTION Non-Hodgkin’s lymphomas (NHLs), a heterogeneous group of cancers principally arising from B lymphocytes, rep- ABSTRACT resent approximately 4% of all newly diagnosed cancers (1). Purpose: We conducted a single-center, dose-escalation Aggressive NHL comprises approximately 30–40% of adult study evaluating the safety, pharmacokinetics, and efficacy NHL (2) and includes diffuse large B-cell lymphoma (DLBCL), of epratuzumab, an anti-CD22 humanized monoclonal an- mantle cell lymphoma (MCL), peripheral T-cell lymphoma, and tibody, in patients with aggressive non-Hodgkin’s lym- anaplastic large cell lymphoma. Frontline combination chemo- phoma. therapy cures less than half of the patients with aggressive NHL, Experimental Design: Epratuzumab was administered 2 and most patients eventually succumb to their disease (3). once weekly for 4 weeks at 120-1000-mg/m doses to 56 For nearly three decades, the combination chemotherapy ؍ patients [most (n 35) with diffuse large B-cell lymphoma]. regimen of cyclophosphamide, doxorubicin, vincristine, and Results: Patients were heavily pretreated (median, 4 prednisone (CHOP) has been the standard initial therapy for prior therapies), 25% received prior high-dose chemother- aggressive NHL. Clinical trials comparing CHOP with more apy with stem cell transplant, and 84% had bulky disease toxic second- and third-generation chemotherapy regimens > ( 5 cm). Epratuzumab was well tolerated, with no dose- showed no advantage of the newer regimens over CHOP (4, 5). limiting toxicity. Most (95%) infusions were completed For patients with relapsed chemotherapy-sensitive aggressive NHL, the standard of care in most settings is high-dose chemotherapy and autologous stem cell transplantation [ASCT (6)]. However, most patients who die of aggressive NHL either are Received 2/16/04; revised 4/14/04; accepted 4/19/04. not candidates for ASCT (3) or relapse after ASCT. After Grant support: Immunomedics, Inc. (Morris Plains, NJ) and Amgen decades of very little progress in the outcomes for patients with Inc. (Thousand Oaks, CA). J. Leonard is supported in part by a K23 aggressive NHL, a number of promising therapies have recently award from the National Institutes of Health (RR16814-02) and a pilot grant from the Cornell Center for Aging Research and Clinical Care. J. emerged. These include the use of colony-stimulating factors to Leonard has served as a consultant to Amgen. M. Coleman, W. Wege- allow dose escalation of active but myelosuppressive agents (as ner, H. Hansen, H. Ziccardi, and D. Goldenberg are officers and/or in the CHOP-14 regimen) and monoclonal antibodies (7, 8). employees of Immunomedics, Inc. M. Eschenberg, U. Gayko, S. Fields, Rituximab [Rituxan; Genentech, Inc. (South San Fran- and A. Cesano are or were employees of Amgen Inc. cisco, CA) and IDEC Pharmaceutical Corp. (San Diego, CA)], The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked a chimeric (mouse/human) anti-CD20 monoclonal antibody, advertisement in accordance with 18 U.S.C. Section 1734 solely to was the first therapeutic antibody approved by the United States indicate this fact. Food and Drug Administration for treatment of relapsed or Requests for reprints: John P. Leonard, Center for Lymphoma and refractory low-grade or follicular NHL. Approval was based on Myeloma and Division of Hematology and Oncology, Weill Medical College of Cornell University and New York Presbyterian Hospital, 520 a total of 166 patients with indolent NHL who had an overall East 70th Street, New York, NY 10021. Phone: (212) 746-2932; Fax: response rate of 48% and a complete remission rate of 6% (9). (212) 746-3844; E-mail: [email protected]. Rituximab single-agent activity as second-line treatment in pa-

tients with aggressive NHL (DLBCL or MCL) has been some- results demonstrate that single-agent epratuzumab has an excel- what lower. In a Phase II study, Coiffier et al. (10) reported a lent safety profile, exhibits antitumor activity, and offers prom- response rate of 37% in patients with DLBCL (n ϭ 30) and 33% ise as a new agent with potential utility in the treatment of in patients with MCL (n ϭ 12). A retrospective review of a aggressive NHL. clinical pharmacology database identified 17 patients who were refractory to or relapsed after ASCT and had a higher objective PATIENTS AND METHODS response (OR) rate to rituximab as a single agent (54% in Study Population DLBCL and 50% in MCL; Ref. 11). Clinical trials have shown Fifty-six patients with relapsed or refractory aggressive that rituximab in combination with CHOP as first-line therapy in NHL (with at least one prior chemotherapy regimen) were older patients with DLBCL provides a statistically significant enrolled in this Phase I/II study between April 1998 and No- survival benefit over CHOP (12). Consequently, this combina- vember 2000. Patients were required to have CD22ϩ NHL, as tion therapy has recently been approved in Europe as a first-line shown by either immunohistochemistry or flow cytometry of therapy in DLBCL patients ages 60 years or older, whereas a malignant tissue obtained at any time point before enrollment. United States intergroup study of CHOP with rituximab is International Working Formulation classification of lymphoma currently undergoing evaluation. Rituximab continues to be subtype was used at the time of study design and was converted evaluated in a variety of other settings and indications, both as to the World Health Organization classification for this report. a single agent and in combination with other therapies. At least 4 weeks had elapsed after chemotherapy, radiotherapy, Other B-cell antigens, such as CD19, CD22, and CD52, or biological therapy, and 2 weeks had elapsed after corticoste- represent targets of therapeutic potential for treatment of lym- roid use. Additional study eligibility criteria included Eastern phoma (13). CD22 is a 135-kDa B-cell-restricted sialoglyco- Cooperative Oncology Group (ECOG) performance status of protein expressed on the B-cell surface only at the mature stages 0–2; serum creatinine of Ͻ1.5 ϫ the upper limits of normal; of differentiation (14). In B-cell NHL, CD22 expression ranges serum bilirubin of Ͻ1.5 ϫ upper limits of normal; and absence from 91% to 99% in the aggressive and indolent populations, of hepatitis B and C positivity. The protocol was approved by respectively (15). Using immunohistochemistry staining of for- the Weill Medical College of Cornell University and New York malin-fixed paraffin-embedded samples, CD22 positivity has Presbyterian Hospital Institutional Review Board, and all pa- shown to be highly variable between samples and within the tients provided informed consent. same samples in terms of the percentage of positive cells, intensity of staining, and localization (i.e., membrane versus cytoplasm). The function of CD22 is uncertain, although studies Study Drug Administration have implicated roles for the antigen both as a component of the Epratuzumab [humanized IgG1 anti-CD22 monoclonal an- B-cell activation complex (16) and as an adhesion molecule tibody (hLL2)] was produced and quality-controlled at Immu- (17). The B cells of CD22-deficient mice have a shorter life span nomedics, Inc. (Morris Plains, NJ) and administered by intra- and enhanced apoptosis, which suggests a key role of this venous infusion at doses of 120, 240, 360, 480, 600, or 1000 2 antigen in B-cell survival (18). After binding with its natural mg/m /week for 4 consecutive weeks. ligand(s) or antibodies, CD22 is rapidly internalized, providing Dose escalation was sequential, with each dose cohort a potent costimulatory signal in primary B cells and proapo- initiated in the absence of any dose-limiting toxicity (DLT) in ptotic signals in neoplastic B cells (19). the previous group. Because clinical activity was observed at 2 The LL2 antibody (formerly called HPB-2) is an IgG2a doses of Ն240 mg/m without DLT, dose escalation was 2 mouse monoclonal antibody directed against the CD22 antigen stopped at 1000 mg/m , and additional patients were treated at 2 (20). In vitro immunohistological evaluations demonstrated re- dose levels of Ն240 mg/m to further assess efficacy. Before activity of the LL2 antibody with 50 of 51 B-cell NHL speci- each infusion, patients were premedicated with acetaminophen mens tested, but not with other malignancies or normal nonlym- and diphenhydramine to minimize any potential infusion reac- phoid tissues (20, 21). Whereas rituximab has been postulated to tions. act through antibody-dependent cellular cytotoxicity (22), com- plement-mediated cytotoxicity (22), direct induction of apopto- Study Design sis (23), or other pathways, the mechanism of action of LL2 is The study was an open-label, Phase I/II trial designed to still under active investigation (24). Epratuzumab, the human- evaluate the safety, pharmacokinetics, and efficacy of epratu- ized (CDR-grafted) IgG1 version of LL2, was developed to zumab therapy. Infusions were administered once weekly for 4 reduce the potential for immunogenicity, to prolong half-life, consecutive weeks, with restaging for treatment response per- and to increase effector function (25). Preliminary clinical eval- formed 4 weeks after the last infusion. Patients were evaluated uations of this humanized antibody labeled with 131I and with every 3–4 months for the first 2 years and every 6 months 111In/90Y have shown evidence of tumor localization and accu- thereafter until disease progression. Adverse events were re- mulation, as well as evidence of therapeutic activity for the corded throughout the study and graded according to the Na- radioimmunoconjugate (26–28). tional Cancer Institute (NCI) Common Toxicity Criteria (29). Herein we report Phase I/II clinical trial results of epratu- Laboratory assessments (including serum chemistry, complete zumab in patients with recurrent aggressive NHL, including blood count, immunophenotyping of blood mononuclear cells, information on safety, pharmacokinetics, and antilymphoma urinalysis, and quantitative serum immunoglobulin) were per- activity. In this study, epratuzumab was administered by weekly formed at screening, 24 h after the last infusion, and at restaging. infusion for 4 consecutive weeks at different dose levels. These Vital signs were monitored every 15 min during the infusions.

Blood samples were tested for the presence of human antihuman (all enrolled patients who received Ն1 dose of epratuzumab, had antibodies (HAHAs) using an enzyme-linked immunosorbent a diagnosis of recurrent aggressive NHL, and had Ն1 posttreat- assay developed by Immunomedics, Inc., which had a lower ment evaluation for response or had withdrawn from study level of detection of 25 ng/m. Samples were obtained within 4 before the first posttreatment evaluation of response due to weeks before study entry, 24 h after the last infusion, at restag- disease progression). Duration of response was analyzed for the ing, and 3–4 months after restaging. patients who responded within the evaluable subset. The pro- Blood samples to determine serum concentrations of portion of patients with OR is provided with its 95% confidence epratuzumab were collected before each weekly infusion, 30 interval (CI). Median duration of response and TTP were esti- min after the end of each infusion, and periodically thereafter for mated using the Kaplan-Meier method. Karnofsky performance the next 8 weeks, when possible. More extensive sampling after scores were converted to ECOG performance scores for the the fourth infusion sufficient for half-life determination was analysis. performed on a subset of patients (n ϭ 10). Study design used ECOG definitions for complete response RESULTS (CR), partial response (PR), stable disease, and progressive Patients disease (30). Bidimensional computed tomography data for the Fifty-six patients with aggressive NHL received at least 1 neck/chest and abdomen/pelvis were collected at screening, dose of epratuzumab and were included in the evaluation of restaging, and follow-up for evaluation of disease response. safety. Fifty-two of these patients were included in the evalua- Bone marrow aspirate and biopsy were performed at study entry tion of efficacy; 4 patients withdrew from the study and were and to confirm CR after treatment in patients who had no not included in the evaluation of efficacy because of inadequate radiographic or other evidence of disease but had bone marrow posttreatment evaluation. Dose escalation was conducted with involvement at baseline. A range of dose levels was evaluated to three patients receiving 120 mg/m2 in the initial cohort. Subse- identify safe and potentially active doses for use in Phase II quently, three patients per group were treated at each of the 240, clinical trials. 360, 480, and 600 mg/m2/week dose levels, and one patient was treated at the 1000 mg/m2 level. Because biological agents do Study End Points not necessarily have optimal activity at the maximally tolerated Safety. Safety end points included the incidence of ad- dose, additional patients were treated at dose levels (Ն240 verse events (including those occurring during or within 7 days mg/m2) where clinical activity was observed to assess efficacy. of the epratuzumab infusion and all later events deemed possi- Overall, of the 52 patients assessable for response in the study, bly or probably treatment-related) and change in HAHA status, 3 patients received 120 mg/m2, 7 received the 240-mg/m2 dose, laboratory values, and infusion-day vital signs. DLT was de- 23 subjects received epratuzumab at a weekly dose of 360 fined as any grade 3 or 4 (according to the NCI Common mg/m2, 11 received 480 mg/m2, 7 patients received the 600- Toxicity Criteria) treatment-related adverse event. Maximum mg/m2 dose, and 1 received 1000 mg/m2. Thirty-three of the 52 tolerated dose was defined as the dose level with an observed patients who were evaluable for both safety and efficacy had incidence of DLT in no more than 1 of 6 patients, such that for DLBCL. a given cohort, if 2 of 3 patients or Ն2 of 6 patients experienced DLTs, the maximum tolerated dose was determined as the dose Patient Characteristics given in the preceding cohort. Demographic characteristics for patients included in the Pharmacokinetics. Serum concentration of epratuzumab analysis of safety are shown in Table 1. More men (63%) than was measured at various time intervals using an anti-idiotype- women were enrolled; age ranged from 19 to 88 years, with a based competitive enzyme-linked immunosorbent assay devel- median age of 61.0 years. Of the patients with available data oped by Immunomedics, Inc. The mean serum half-life of (n ϭ 50), most (84%) had bulky disease of Ն5 cm, and 63.3% epratuzumab was calculated based on measurements after the had elevated (Ͼ234 units/liter) lactate dehydrogenase levels. last infusion for those subjects having data available from a Patients had received multiple prior therapies (median, 4 prior sufficient number of time points. therapies; range, 1–11 prior therapies): 58.9% had previously Efficacy. Efficacy was evaluated by calculating the OR received rituximab; and 25% had received high-dose chemo- rate overall and at each dose level (the proportion of patients therapy and stem cell transplant as prior therapy. Thirty-five whose best response at any time during the study was either a patients (62.5%) had DLBCL, 9 (16.1%) had MCL, and 12 had CR or PR before disease progression); duration of response was other aggressive histologies (such as follicle center cell lym- defined as the time from the date a response is determined to the phoma, grade 3 and diffuse follicle center lymphoma, grade 1). date of first evidence of progression or death regardless of cause; and time to progression (TTP) was defined as the time Study End Points from study day 1 to the date of first evidence of progression or Safety. Ninety-six percent of patients experienced one or death, if determined to be due to disease progression. more adverse events, with 42% of patients experiencing at least one treatment-related adverse event. All treatment-related Statistical Analysis events were mild to moderate in severity (Fig. 1). These events All patients who received Ն1 dose of epratuzumab were occurred principally with the first infusion and were less com- included in the safety analyses. The analyses of OR rate for a mon thereafter. The most frequent toxicity for all adverse events given dose and TTP were based on the evaluable patient subset was fatigue (23%). Other toxicities (whether or not they were

Table 1 Baseline demographic characteristics for patients receiving included as a nonresponder in the analyses; however, this patient at least 1 dose of epratuzumab had a PR (decrease in SPD ϭ 73%) on study day 172 and a CR Patients receiving at on study day 659 without interim therapy. The duration of least 1 dose of response for this patient was 21 months. Baseline characteristic epratuzumab (N ϭ 56) Overall, 15% of DLBCL patients had ORs: 2 of 6 (33%), Median age (range) (yrs) 61.0 (19-88) 2 of 13 (15%), and 1 of 5 (20%) patients responded at the 240-, No. of females (%) 21 (38) 360-, and 600-mg/m2 dose levels, respectively (Fig. 2). No Median no. prior therapies (range) 4 (1-11) responses were observed at the 480- and 1000-mg/m2 dose No. with prior rituximab treatment (%) 33 (58.9) No. with prior high-dose chemotherapy 14 (25) levels (n ϭ 8 and n ϭ 1, respectively). Three of the five and stem cell transplant (%) responses were complete, and by ECOG response criteria, they Median time from initial diagnosis 39.5 (3–169) were confirmed at Ն4 weeks after the first determination of (range) (mo) response (30). No patient who was classified as having a CR had WHO classification [n (%)] Ն 2 Follicle center cell, follicular grade III 4 (7.1) residual nodal lesions of 1cm in bidimensional measure- Diffuse follicle center lymphoma, grade I 2 (3.6) ments. Overall, 11 (20%) patients (all histologies) experienced Diffuse follicle center lymphoma, grade II 2 (3.6) some tumor mass reduction (Fig. 3). By Kaplan-Meier estimate, DLBCLl 35 (62.5) the median duration of OR is 26.3 weeks (range, 11.1–219.9ϩ MCL 9 16.1) weeks), and the median TTP for responding patients is 35.0 Other (marginal zone) 4 (7.1) No. with ECOG performance scale ϭ 0 (%) 22 (39.3) weeks (range, 20.9–225.7ϩ weeks). Biopsies were not routinely No. with bulky disease at least 5 cm (%) 42 (84)* performed at progression after epratuzumab because this proce- Median SPD (range) (cm2) 32.1 (1.04–202.61) dure was not prospectively included in the protocol. Interest- Ͼ No. with LDH 234 units/liter (%) 31 (55.4) ingly, however, one responder (with multiple prior biopsies Median peripheral blood B-cell counts, CD20, 16.6 (0–282,605)† cells/␮l (range) demonstrating DLBCL) was found to have progression with marginal zone lymphoma after epratuzumab. Two responses are Abbreviations: WHO, World Health Organization; LDH, lactate Ն dehydrogenase. ongoing at 34 months, including one patient with rituximab- * n ϭ 50. refractory disease. † n ϭ 46. Characteristics of those patients who responded are shown in Table 3. All ORs occurred in the DLBCL subset of patients. Increased amounts of serum lactate dehydrogenase were noted at baseline in 80% of responders; otherwise, this group tended to infusion/treatment-related) included vomiting, dyspnea, nausea, have more favorable prognostic indicators (lower SPD; no le- back pain, upper respiratory infection, diarrhea, and cough (Ta- sions of Ն10 cm; four of five patients with ECOG performance ble 2). No clinical correlation between the frequency of adverse status of 0). Although only 38% of all subjects enrolled were events and administered dose level was observed, and no DLT women, three of the five responders (60%) were women. Sim- occurred. No clinically significant changes in laboratory meas- ilar proportions (60%) of responders and nonresponders had ures (including hematology values and immunoglobulin levels) prior rituximab treatment. or vital signs were noted, and no serious treatment-related adverse events occurred. Epratuzumab treatment did not affect DISCUSSION ϩ T-cell levels as measured by CD3 cell count. B-cell levels, as Unlabeled monoclonal antibody therapy of lymphomas has ϩ measured by CD19 cell counts, were generally low at study been under evaluation for more than two decades, focusing ϭ ␮ entry (median 16.1 cells/ l at baseline), likely due to prior mostly on antibodies that target the CD19, CD20, and CD52 therapy; therefore, the effects of epratuzumab on circulating B-cell levels could not be assessed in this study. One patient developed transient HAHAs; of note, this patient had an objective CR. Seven patients died within 30 days of their last infusion; six of seven deaths were related to disease progression. Pharmacokinetics. Based on measurements after the last infusion, epratuzumab had a mean serum half-life of 23.9 days (SD, 13.1 days; n ϭ 10), which is comparable to the half-life of a human IgG1 (21 days; Ref. 31). Efficacy. When all dosing groups and histologies are considered, 5 of the 52 evaluable patients (10%; 95% CI, 3–21%) achieved an OR. Three patients (6%; 95% CI, 1–16%) had a CR, one each at the 240-, 360-, and 600-mg/m2 dose levels. Two patients (4%; 95% CI, 0–13%) had a PR, one at 240 mg/m2 and one at 360 mg/m2. Twelve patients (23%; 95% CI, Fig. 1 Treatment-related adverse events by infusion and NCI toxicity 13–37%) had stable disease as best response, and 35 (67%; 95% grade for patients with aggressive disease (n ϭ 56). Each patient is counted once for each infusion at the highest reported NCI toxicity CI, 53–80%) progressed. An additional DLBCL patient given 2 grade for that infusion. Treatment-related adverse events are defined as 480 mg/m progressed [increase in the sum of products of those that are possibly or probably related to treatment. Ⅺ, grade 1 greatest diameter (SPD) ϭ 35%] on study day 55 and was (mild); f, grade 2 (moderate).

Table 2 All adverse events with at least 10% incidence over all treatment groups combined Weekly dose group (mg/m2) 120 240 360 480 600 1000 Total* Preferred term (n ϭ 3) (n ϭ9) (n ϭ 24) (n ϭ 12) (n ϭ 7) (n ϭ 1) (N ϭ 56) No. of patients with adverse events 3 (100) 8 (89) 24 (100) 12 (100) 7 (100) 1 (100) 55 (98) Fatigue 1 (33) 2 (22) 7 (29) 2 (17) 1 (14) 0 (0) 13 (23) Vomiting 0 (0) 1 (11) 6 (25) 1 (8) 0 (0) 0 (0) 8 (14) Dyspnea 0 (0) 0 (0) 2 (8) 3 (25) 1 (14) 0 (0) 6 (11) Nausea 0 (0) 0 (0) 5 (21) 1 (8) 0 (0) 0 (0) 6 (11) Back pain 0 (0) 2 (22) 2 (8) 1 (8) 1 (14) 0 (0) 6 (11) Upper respiratory infection 0 (0) 2 (22) 2 (8) 1 (8) 1 (14) 0 (0) 6 (11) Diarrhea 0 (0) 0 (0) 4 (17) 1 (8) 0 (0) 1 (100) 6 (11) Cough 1 (33) 0 (0) 3 (13) 1 (8) 0 (0) 1 (100) 6 (11) NOTE. All values expressed as n (%). * Intention to treat subset includes all subjects receiving at least one dose of study drug.

antigens associated with B-cell malignancies (32–36). In 1980, agents are needed. One strategy is the development of non- Nadler et al. (37, 38) showed that a murine monoclonal antibody cross-reactive antibodies targeting other B-cell antigens, which could target human lymphoma cells and induce tumor cell death. may have different and nonoverlapping mechanism(s) of anti- Lymphoma regressions were observed by Hsu et al. (39) after tumor activity. Treatment with a combination of a non-cross- treatment with tumor-specific anti-idiotype antibodies. Subse- reactive antibody and rituximab (and/or chemotherapy) might quent therapeutic approaches evaluated antibodies directed result in higher antitumor activity than either of the drugs alone. against B-cell lineage antigens widely associated with B-cell Antibodies targeting the CD19 or CD52 antigens have been malignancies, with Press et al. (40) demonstrating evidence of tested in B-cell malignancies in general, but clinical benefit with activity with a murine antibody targeting CD20. The most these approaches has not been well established to date in ag- significant recent advance in the clinical care of lymphoma gressive NHL (32, 41). patients, however, has been the development of the chimeric The wide expression of CD22 in B-cell malignancies (15), anti-CD20 monoclonal antibody rituximab, an antibody ap- including aggressive lymphoma, and its role in B-cell biology proved by the United States Food and Drug Administration for make it a potentially useful target for immunotherapy of aggres- the treatment of indolent NHL. sive NHL. Previous studies have evaluated murine and human- Although the single-agent activity of rituximab is most ized forms of an anti-CD22 antibody both preclinically and prominent in low-grade lymphomas, its predominant use in clinically, as a carrier of radionuclides for NHL imaging and aggressive NHL subtypes is in combination with chemotherapy, therapy (42–44), as well as a conjugate with toxins [ricin particularly CHOP (12). Despite the demonstrated benefits of (45–47), pseudomonas exotoxin (48), or RNase (49)] for ther- rituximab in this patient population, approximately half of pa- apy. Results of these trials with one radioimmunoconjugate tients with DLBCL die of their disease, indicating that new form of the antibody (42, 43) suggested that the unlabeled

Fig. 2 OR rates by dose for evaluable patients with DLBCL. n ϭ number of evaluable patients. Ⅺ, PR; f, CR.

Fig. 3 Maximum percentage change from baseline in SPD for each treated patient with baseline and post-baseline SPD meas- -patients with ab ,ء .(urements (n ϭ 56 solute value of maximum percentage change Յ 1. Œ, SPD value Ͼ 100%. E, patients with progressive disease as best response; no post-baseline SPD measure- ment available.

murine antibody had some antilymphoma activity and prompted effects on hematological parameters, immunoglobulin levels, or the development of the humanized form (25) of the naked serum chemistries were observed. Because of relatively low antibody and its clinical evaluation. Results in patients with baseline levels (likely related to previous therapy), direct effects indolent NHL showed evidence of both safety and activity in of epratuzumab on circulating B-cell levels could not be clearly patients with NHL who had progressive disease after numerous determined in this study. Of note, evaluation of epratuzumab in prior therapies, including rituximab (50). In aggressive NHL, a different population of patients (indolent NHL) indicates that development of an unlabeled antibody (rather than radiolabeled epratuzumab administration can result in decreases in number of agents) may be of particular importance because naked antibod- circulating B cells (50), and treatment of normal nonhuman ies are generally easier to combine with the chemotherapy primates has yielded similar findings (51). agents usually required for disease control, as opposed to indo- It is interesting that across all doses and histologies, 20% of lent NHL, where single agents are commonly used to minimize patients demonstrated evidence of some level of antilymphoma toxicity. activity as measured by reduction in tumor mass. This occurred This trial is the first clinical evaluation of the safety and despite the extensive previous therapy in this group (group efficacy of this anti-CD22 humanized monoclonal antibody, members had a median of four previous regimens, reflecting a epratuzumab, in the treatment of patients with aggressive NHL. poor prognosis group). Fifteen percent of subjects with DLBCL It was designed to assess the safety, pharmacokinetics, and demonstrated ORs (three of five were complete), and an addi- efficacy of weekly administration of epratuzumab for 4 weeks tional patient (classified as a nonresponder) had initial disease and to define dosing regimens for further clinical development. progression followed by a delayed CR without intervening Our findings indicate that epratuzumab has an excellent safety treatment. This individual had an increase in SPD of 35% at profile, with mostly grade 1 toxicities that were principally approximately 2 months on study, had a PR (decrease in SPD ϭ associated with the first infusion. Side effects were not related to 73%) at approximately 6 months, and a CR at nearly 2 years. protein dose amount, which is particularly notable given that the The time course of this patient’s response, unusual in this vast majority of infusions were completed in 60 min or less. No disease setting even with cytotoxic drugs, leads us to speculate

Table 3 Baseline characteristics by response for evaluable patients (N ϭ 52) Baseline characteristic Responders (n ϭ 5) Nonresponders (n ϭ 47) Median age (range) (yrs) 59.0 (45–81) 62.0 (19–88) No. of females (%) 3 (60.0) 17 (36.2) Median no. of prior chemotherapies (range) 3 (2, 5) 3 (1, 9) Median no. of prior radiotherapies (range) 1 (0, 2) 1 (0, 4) No. with prior rituximab treatment (%) 3 (60.0) 29 (61.7) No. with prior high-dose chemotherapy and stem cell transplant (%) 3 (60.0) 11 (23.4) Median time from initial diagnosis (range) (mo) 46.7 (21–78) 40.9 (3–169) WHO classification [n (%)] Follicle center cell, follicular grade III 0 (0.0) 3 (6.4) Diffuse follicle center lymphoma, grade I 0 (0.0) 2 (4.3) Diffuse follicle center lymphoma, grade II 0 (0.0) 2 (4.3) DLBCL 5 (100.0) 28 (59.6) MCL 0 (0.0) 9 (19.1) Other (marginal zone) 0 (0.0) 3 (6.4) No. with ECOG performance scale ϭ 0 (%) 4 (80.0) 17 (36.2) No. with bulky disease at least 5 cm (%) 2 (40.0) 36 (76.6) Median SPD (range) (cm2) 13.39 (1.80–30.19) 34.86 (1.04–202.61) No. with LDH Ͼ 234 units/liter (%) 4 (80.0) 23 (48.9) Median peripheral blood B-cell counts, CD20, cells/␮l (range) 12.2 (3–54) 16.6 (0–282,605)* Abbreviation: WHO, World Health Organization; LDH, lactate dehydrogenase. * n ϭ 38.

that immune mechanisms may play a role in the antilymphoma responsible for antibody production. Dr. Ellen Laber and Christine Dale effects of epratuzumab, as with other monoclonal antibodies. (both from Amgen, Inc.) assisted in manuscript preparation. StatProbe, Of note in multiply relapsed DLBCL, two CRs are ongoing Inc. assisted with statistical analyses. at Ն34 months after therapy. Most responding patients had either progressed after high-dose chemotherapy and ASCT REFERENCES (three of five patients) or were ineligible for ASCT (1 patient who was Ͼ80 years old). Although this group represents pa- 1. Jemal A, Thomas A, Murray T, Thun M. Cancer statistics, 2002. CA-Cancer J Clin 2002;52:23–47. tients with limited therapeutic alternatives, they have been re- 2. Harris NL, Jaffe ES, Diebold J, et al. The World Health Organization ported to respond well to single-agent rituximab therapy with an classification of neoplasms of the hematopoietic and lymphoid tissues: OR rate of 53% and a median progression-free survival of 13 report of the Clinical Advisory Committee meeting–Airlie House, Vir- months (range, 6–18 months; Ref. 11). The clinical activity of ginia, November, 1997. Hematol J 2001;1:53–66. epratuzumab in aggressive NHL was limited to the DLBCL 3. Fisher RI. Current therapeutic paradigm for the treatment of non- subtype in this study; however, this group represented most Hodgkin’s lymphoma. Semin Oncol 2000;27(Suppl 12):2–8. patients enrolled, and insufficient numbers of patients with other 4. Fisher RI, Gaynor ER, Dahlberg S, et al. Comparison of a standard histologies were evaluated to fully assess activity in other NHL regimen (CHOP) with three intensive chemotherapy regimens for ad- subtypes. Responses were seen at doses ranging from 240 to 600 vanced non-Hodgkin’s lymphoma N Engl J Med 1993;328:1002–6. mg/m2, but no clear dose-response relationship was observed. 5. Gordon LI, Harrington D, Andersen J, et al. Comparison of a second- generation combination chemotherapeutic regimen (m-BACOD) with This result reflects the relatively small number of patients standard regimen (CHOP) for advanced diffuse non-Hodgkin’s lym- treated at each dose level and is consistent with findings in phoma. N Engl J Med 1992;327:1342–9. patients with indolent NHL, in which clinical responses appear 6. Vose JM, Sharp G, Chan WC, et al. Autologous transplantation for to be higher at the 360-mg/m2/week ϫ 4 dose level (50). Further aggressive non-Hodgkin’s lymphoma: results of a randomized trial clinical evaluation of epratuzumab administered at doses rang- evaluating graft source and minimal residual disease. J Clin Oncol ing from 240 to 600 mg/m2 in a Phase II setting is warranted. 2002;20:2344–52. The precise mechanism of action of epratuzumab has not 7. Itoh K, Ohtsu T, Wakita H, et al. Dose-escalation study of CHOP with or without prophylactic G-CSF in aggressive non-Hodgkin’s lym- been defined but may relate to effects on B-cell signaling phoma. Ann Oncol 2000;11:1241–7. (through induction of CD22 phosphorylation). Ligation of hu- 8. Glennie MJ, Johnson PWM. Clinical trials of antibody therapy. man CD22 with monoclonal antibodies (or natural ligands) Immunol Today 2000;8:403–10. triggers internalization of the complex, tyrosine phosphorylation 9. McLaughlin P, Grillo-Lopez AJ, Link BK, et al. Rituximab chimeric of the cytoplasmic tail of CD22, and binding of the tyrosine anti-CD20 monoclonal antibody therapy for relapsed indolent lym- phosphatase SHP-1, a negative regulator of signaling from the phoma: half of patients respond to a four-dose treatment program. J Clin B-cell receptor. As a consequence in resting B cells, CD22 Oncol 1998;16:2825–33. engagement negatively regulates BCR signaling. Of note, en- 10. Coiffier B, Haioun C, Ketterer N, et al. Rituximab (anti-CD20 gagement of CD22 in activated B cells results (paradoxically) in monoclonal antibody) for the treatment of patients with relapsing or refractory aggressive lymphoma: a multicenter phase II study. Blood up-regulation of BCR signaling (16). With respect to the mech- 1998;92:1927–32. anism of action of epratuzumab, it is possible that inappropriate 11. Pan D, Moskowitz CH, Zelenetz AD, et al. Rituximab for aggres- signaling and interference with CD22 signaling due to antibody sive non-Hodgkin’s lymphomas relapsing after or refractory to autolo- binding may render cells more prone to apoptosis (24). Addi- gous stem cell transplantation. Cancer J 2002;8:371–6. tionally, a recent report suggested that antibody-dependent cel- 12. Coiffier B. Rituximab in combination with CHOP improves sur- lular cytotoxicity activity was involved in the antitumor activity vival in elderly patients with aggressive non-Hodgkin’s lymphoma. of epratuzumab in preclinical models, and it was also shown Semin Oncol 2002;29(Suppl 6):18–22. that, in these models, epratuzumab can enhance the efficacy of 13. Grillo-Lopez AJ, Dallarie BK, McClure A, et al. Monoclonal antibodies: a new era in the treatment of non-Hodgkin’s lymphoma. Curr rituximab when the two antibodies are combined (52–54). This Pharm Biotechnol 2001;2:301–11. appears in support of preliminary clinical observations that in 14. Dorken B, Moldenhauer G, Pezzutto A, et al. 39 (B3), a B lineage- low-grade follicular and DLBCL histologies (55), the combina- restricted antigen whose cell surface expression is limited to resting and tion of epratuzumab with rituximab could potentially offer activated human B lymphocytes. J Immunol 1986;136:4470–9. greater therapeutic effects than either agent given alone, re- 15. Cesano A, Gayko U, Brannan C, et al. Differential expression of flected by an apparent improvement in the CR rate. The dem- CD22 by indolent and aggressive NHLs: implications for targeted onstration of CRs in DLBCL in this Phase I/II study with immunotherapy. Blood 2002;100:350a. single-agent epratuzumab supports further evaluation of this 16. Sato S, Tuscano JM, Inaoki M, Tedder TF. CD.22 negatively and positively regulates signal transduction through the B lymphocyte anti- antibody combination. Ongoing studies include evaluation of gen receptor. Semin Immunol 1998;10:287–97. epratuzumab in combination with CHOP-rituximab in first-line 17. Engel P, Nojima Y, Rothstein D, et al. The same epitope on CD22 treatment of DLBCL. of B lymphocytes mediates the adhesion of erythrocytes, T and B lymphocytes, neutrophils, and monocytes. J Immunol 1993;150:4719– 32. ACKNOWLEDGMENTS 18. Otipoby KL, Andersson KB, Draves KE, et al. CD22 regulates We thank the patients who agreed to participate in this clinical trial. thymus-independent responses and the lifespan of B cells. Nature Jennifer Fiore, Alan Dosik, Darlene Dreher, and Manuel Vargas assisted (Lond) 1996;384:634–7. in the treatment and monitoring of patients. Dr. Ding Shieh and Yan 19. Sato S, Miller AS, Inaoki M, et al. CD22 is both a positive and Xing (both from Immunomedics, Inc.) performed specialized assays of negative regulator of B lymphocyte antigen receptor signal transduction: clinical samples, and Rohini Mitra and her team at Immunomedics were altered signaling in CD22-deficient mice. Immunity 1996;5:551–62.

20. Pawlak-Byczkowska EJ, Hansen HJ, Dion AS, Goldenberg DM. 38. Nadler LM, Stashenko P, Hardy R, Schlossman SF. A monoclonal Two new monoclonal antibodies, EPB-1 and EPB-2, reactive with antibody defining a lymphoma-associated antigen in man. J Immunol human lymphoma. Cancer Res 1989;49:4568–77. 1980;125:570–7. 21. Stein R, Belisle E, Hansen HJ, Goldenberg DM. Epitope specificity 39. Hsu FJ, Kwak L, Campbell M, et al. Clinical trials of idiotype- of the anti-(B cell lymphoma) monoclonal antibody, LL2. Cancer Im- specific vaccine in B-cell lymphomas. Ann N Y Acad Sci 1993;690: munol Immunother 1993;37:293–8. 385–7. 22. Reff M, Carner K, Chambers K, et al. Depletion of B cells in vivo 40. Press OW, Appelbaum F, Ledbetter JA, et al. Monoclonal antibody by a chimeric mouse human monoclonal antibody to CD20. Blood 1F5 (anti-CD20) serotherapy of human B cell lymphomas. Blood 1987; 69:584–91. 1994;83:435–45. 41. Lundin J, Osterborg A, Brittinger G, et al. CAMPATH.-1H mono- 23. Shan D, Ledbette JA, Press OW. Apoptosis of malignant human B clonal antibody in therapy for previously treated low-grade non- cells by ligation of CD20 with monoclonal antibodies. Blood 1998;91: Hodgkin’s lymphomas: a phase II multicenter study. J Clin Oncol 1644–52. 1998;16:3257–63. 24. Carnahan J, Wang P, Kendal lR. Epratuzumab, a humanized mono- 42. Vose JM, Colcher D, Gobar L, et al. Phase I/II trial of multiple dose clonal antibody targeting CD22: characterization of in vitro properties. 131iodine-Mab LL2 (CD22) in patients with recurrent non-Hodgkin’s Clin Cancer Res 2003;9:3982S–90S. lymphoma. Leuk Lymphoma 2000;38:91–101. 25. Leung SO, Goldenberg DM, Dion AS, et al. Construction and 43. Goldenberg DM, Horowitz JA, Sharkey RM, et al. Targeting, characterization of a humanized, internalizing, B-cell (CD22)-specific, dosimetry, and radioimmunotherapy of B-cell lymphomas with iodine- leukemia/lymphoma antibody, LL2. Mol Immunol 1995;32:1413–27. 131-labeled LL2 monoclonal antibody. J Clin Oncol 1991;9:548–64. 26. Juweid ME, Stadtmauer E, Hajjar G, et al. Pharmacokinetics, do- 44. Juweid M, Sharkey RM, Markowitz A, et al. Treatment of non- simetry, and initial therapeutic results with 131I- and 111In-/90Y-labeled Hodgkin’s lymphoma with radiolabeled murine, chimeric, or humanized humanized LL2 anti-CD22 monoclonal antibody in patients with re- LL2, an anti-CD22 monoclonal antibody. Cancer Res 1995;55(Suppl lapsed, refractory non-Hodgkin’s lymphoma. Clin Cancer Res 1999; 1):5899s–907s. 5(Suppl 10):3292s–303s. 45. Vitetta ES, Stone M, Amlot P, et al. Phase I immunotoxin trial in 27. Griffiths GL, Govindan SV, Sharkey RM, Fisher DR, Goldenberg patients with B-cell lymphoma. Cancer Res 1991;51:4052–8. 90 DM. Y-DOTA-hLL2: an agent for radioimmunotherapy of non- 46. Sausville EA, Headlee D, Stetler-Stevenson M, et al. Continuous Hodgkin’s lymphoma. J Nucl Med 2003;44:77–84. infusion of the anti-CD22 immunotoxin IgG-RFB4-SMPT-dgA in pa- 28. Linden O, Tennevall J, Hindorf C, et al. Radioimmunotherapy using tients with B-cell lymphoma: a phase I study. Blood 1995;85:3457–65. 131I-labelled anti-CD22 monoclonal antibody (LL2) in patients with 47. Amlot PL, Stone MJ, Cunningham D, et al. A phase I study of an previously-treated B-cell lymphomas. Clin Cancer Res 1999;5(Suppl anti-CD22-deglycosylated ricin A chain immunotoxin in the treatment 10):3287s–91s. of B-cell lymphomas resistant to conventional therapy. Blood 1993;82: 29. National Cancer Institute Common Toxicity Criteria. Version 2.0. 2624–33. http://home.earthlink.net/ϳjohnres/ncitox/ncitox.html (accessed 12 48. Kreitman RJ, Hansen HJ, Jones AL, et al. Pseudomonas exotoxin- September 2003). based immunotoxins containing the antibody LL2 or LL2-FabЈ induce 30. Oken MM, Creech RH, Tormey DC, et al. Toxicity and response regression of subcutaneous human B-cell lymphoma in mice. Cancer criteria of the Eastern Cooperative Oncology Group. Am J Clin Oncol Res 1993;53:819–25. 1982;5:649–55. 49. Newton DL, Hansen HJ, Liu H, et al. Specifically targeting the 31. Turner, A. Antibodies. In: Roitt I, Brostoff J, Male D, editors. CD22 receptor of human B-cell lymphomas with RNA damaging Immunology. New York: Mosby; 2001. p. 65–86. agents. Crit Rev Oncol Hematol 2001;39:78–86. 32. Brown KS, Levitt DJ, Shannon M, Link BK. Phase II trial of 50. Leonard JP, Coleman M, Matthews JC, et al. Phase I/II trial of Remitogen (humanized 1D10) monoclonal antibody targeting class II epratuzumab (humanized anti-CD22 antibody) in indolent non- patients with relapsed low-grade or follicular lymphoma. Clin Lym- Hodgkin’s lymphoma. J Clin Oncol 2003;21:3051–9. phoma 2001;2:188–90. 51. Briddell R, Kern B, Stoney G, et al. The effect of epratuzumab on peripheral blood B-cell levels in normal, male cynomolgus monkeys. 33. Witzig TE, Gordon LI, Cabanillas F, et al. Randomized controlled Blood 2002;100:576a. trial of yttrium-90-labeled ibritumomab tiuxetan radioimmunotherapy versus rituximab immunotherapy for patients with relapsed or refractory 52. Czuczman MS, Reising S, Repasky EA, et al. Concurrent admin- low-grade, follicular, or transformed B-cell non-Hodgkin’s lymphoma. istration of granulocyte colony-stimulating factor (G-CSF) or granulo- J Clin Oncol 2002;20:2453–63. cyte-monocyte colony-stimulating factor (GM-CSF) enhance rituximab’s biological activity and upregulate CD11b in a severe combined 34. Vose JM, Wahl RL, Saleh M, et al. Multicenter phase II study of immunodeficiency (SCID) mouse lymphoma model. Blood 2002;100: iodine-131 tositumomab for chemotherapy-relapsed/refractory low- 157a. grade and transformed low-grade B-cell non-Hodgkin’s lymphomas. 53. Hernandez-Ilizaliturri FJ, Gada P, Repasky EA, Czuczman MS. J Clin Oncol 2000;18:1316–23. Enhancement in anti-tumor activity of rituximab when combined with 35. Kaminski MS, Zelenetz AD, Press OW, et al. Pivotal study of epratuzumab or apolizumab (Hu1d10) in a B-cell lymphoma severe iodine-131 tositumomab for chemotherapy-refractory low-grade or combined immunodeficiency mouse model. Blood 2002;100:158a. transformed low-grade B-cell non-Hodgkin’s lymphomas. J Clin Oncol 54. Gada P, Hernandez-Ilizaliturri FJ, Repasky EA, Czuczman MS. 2001;19:3918–28. Epratuzumab’s predominant antitumor activity in vitro/in vivo against 36. Hekman A, Honselaar A, Vuist WMJ, et al. Initial experience with non-Hodgkin’s lymphoma (NHL) is via antibody-dependent cellular treatment of human B-cell lymphoma with anti-CD19 monoclonal an- cytotoxicity (ADCC). Blood 2002;100:353a. tibody. Cancer Immunol Immunother 1991;32:364–72. 55. Leonard JP, Coleman M, Matthews JC, et al. Epratuzumab (anti- 37. Nadler LM, Stashenko P, Hardy R, et al. Serotherapy of a patient CD22) and rituximab (anti-CD20) combination immunotherapy for non- with a monoclonal antibody directed against a human lymphoma-asso- Hodgkin’s lymphoma: preliminary response data. Proc Am Soc Clin ciated antigen. Cancer Res 1980;40:3147–54. Oncol 2002;21:266a.

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