British Journal of Cancer (1999)81(8), 1419-1425
`' 1999 Cancer Research Campaign
`Article no. bjoc.1999.0861
`
`Dose escalation and pharmacokinetic study of a
`humanized anti-HER2 monoclonal antibody in patients
`with HER2Ineu-overexpressing metastatic breast cancer
`
`V Tokuda 1 , T Watanabe 2, Y Omuro, M And0 2, N Katsumata2, A Okumura’, M Ohta 1 , H Fujii(cid:176), V Sasaki 3, T Niwa4 and
`T Tajima 1
`
`’Department of Surgery, Tokai University School of Medicine, Bohseidai, Isehara, Kanagswa 259-1193, Japsn; 2National Cancer Center Hospital,
`Tokyo 104-0045, Japan; ’National Cancer Center Hospital East, Kashiwa, Chiba 277-0882, Japan; 4Mitsubishi Chemical Corporation, Yokohama Research
`Center, Kanagawa 227-8502, Japan
`
`85HER2 monoclonal antibody
`Summary We conducted a phase I pharmacokirtetic dose escalation study of a recombinant humanized anti-pi
`(MKC-454) in 18 patients with metastatic breast cancer refractory to chemotherapy. Three or six patients at each dose level received 1, 2, 4
`and 8 mg kg -1 of MKC-454 as 90-min intravenous infusions. The first dose was followed in 3 weeks by nine weekly doses. Target trough
`serum concentration has been set at 10 pg ml
`-1 based on in vitro observations. The mean value of minimum trough serum concentrations at
`each dose level were 3.58 – 0.63, 6.53 – 5.26, 40.2 – 7.12 and 87.9 – 23.5 pg ml -1 respectively. At mg kg -1 , although minimum trough serum
`concentrations were lower than the target trough concentration with a wide range of variation, trough concentrations increased and exceeded
`the target concentration, as administrations were repeated weekly. Finally 2 mg kg -1 was considered to be sufficient to achieve the target
`trough concentration by the weekly dosing regimen. One patient receiving 1 mg kg -1 had grade 3 fever, one at the 1 mg kg level had severe
`fatigue defined as grade 3, and one at 8 mg kg -1 had severe bone pain of grade 3. No antibodies against MKC-454 were detected in any
`patients. Objective tumour responses were observed in two patients; one receiving 4 mg kg -1 had a partial response in lung metastases and
`the other receiving 8 mg kg had a complete response in soft tissue metastases. These results indicate that MKC-454 is well tolerated and
`effective in patients with refractory metastatic breast cancers overexpressing the HER2 proto-oncogene. Further evaluation of this agent with
`2-4 mg kg -1 weekly intravenous infusion is warranted. ' 1999 Cancer Research Campaign
`
`Keywords: HER21neu; humanized monoclonal antibody; pharmacokinetics; phase I study
`
`The c-erbB-2/HER2 proto-oncogene encodes a receptor-type
`tyrosine kinase (Yarden and Ulirich, 1988) corresponding to, but
`distinct from, the epidermal growth factor receptor (Coussens
`eta!, 1985; Yamamoto et al, 1986). The HER2 product consists of
`three domains, extracel!ular, transmembrane and intracellular
`domains which has tyrosine kinase activity making the HER2
`product autophosphory!ated. Appreciable amplification and/or
`overexpression of this gene has been demonstrated in a variety of
`adenocarcinomas including breast cancer (King et al, 1985;
`S!amon et a!, 1989). However, the expression of this gene in
`normal adult tissues is weak (Dc Potter et a!, 1989; Press et al,
`1990). Therefore, the HER2 product is thought to be a useful
`target for antibody therapy of cancers overexpressing the HER2
`gene.
`Several studies of murine monoclonal antibodies (Mabs)
`directed against the HER2 product have already been reported to
`have in vitro and in vivo anti-tumour effects (Drebin et al, 1985;
`Hudziak et al, 1989; Hancock eta!, 1991; Stancovski eta!, 1991;
`Tagliabue et al, 1991; Harwerth et al, 1992; Kasprzyk eta!, 1992).
`However, human anti-mouse antibody response during therapy
`
`Received 20 November 1998
`Revised 14 May 1999
`Accepted 7 June 1999
`
`Correspondence to: Y Tokuda
`
`would be a major limitation in the clinical application of such
`murine mabs (Schroffet al, 1985; Shawler eta!, 1985). Carter and
`his colleagues constructed a humanized antibody containing only
`the antigen-binding loops from a murine mab against the extracel-
`lular domain of the HER2 gene product and human variable region
`framework residues plus IgGi constant domains (Carteret a!,
`1992). A clinical study of the humanized antibody revealed some
`objective responses without antibodies against it (Baselga et a!,
`1996).
`We report here the results of a phase I dose escalation study of
`the humanized mab (MKC-454) against the HER2 product in
`patients with metastatic breast cancer refractory to conventional
`chemotherapeutic agents and positive for this oncogene product.
`
`PATIENTS AND METHODS
`
`Patient eligibility
`
`Patients with metastatic breast cancer refractory to conventional
`chemo or endocrine therapies and overexpressing the HER2
`product were eligible for this study. Patients were considered
`refractory to endocrine therapy if hormone receptors were
`negative or tumour growth was noted during treatment with
`tamoxifen, and were considered refractory to chemotherapy if
`disease progression was noted after treatment with doxorubicin-
`containing regimens. All patients had measurable disease,
`
`1419
`
`IMMUNOGEN 2058, pg. 1
`Phigenix v. Immunogen
`IPR2014-00676
`
`

`

`1420 YTokuda eta!
`
`Table I Patient demographics
`
`Parameter (cid:9)
`
`No. of patients (cid:9)
`Age median (years) (range) (cid:9)
`Performance score (ECOG)
`0 (cid:9)
`1 (cid:9)
`2 (cid:9)
`Receptor status
`Oestrogen receptor
`Positive
`Negative
`Unknown
`Progesterone receptor
`Positive
`Negative
`Unknown
`Histological grade
`II
`III
`Unknown
`Prior treatment
`Chemotherapy
`Adjuvant chemotherapy
`Neoadjuvant chemotherapy
`Metastatic disease (no. of regimens)
`1
`2
`>2
`Median (range)
`Hormonal therapy
`Adjuvant therapy
`Metastatic disease
`
`No.
`
`18
`51 (32-64)
`
`10
`7
`1
`
`3
`11
`4
`
`3
`10
`5
`
`3
`12
`3
`
`12
`1
`
`7
`7
`4
`2(1-4)
`
`11
`6
`
`satisfactory haematologic, hepatic, renal and pulmonary function
`with an Eastern Cooperative Oncology Group (ECOG) perfor-
`mance status grade 3 or less. Patients who had chemotherapy
`within 4 weeks (6 weeks for mitomycin or nitrosurea) or hormonal
`therapy within 2 weeks before study entry were ineligible. Written
`informed consent was mandatory before study entry.
`The expression of HER2 was determined by immunohistochem-
`ical staining of the paraffin-embedded thin sections of the primary
`or metastatic tumours using rabbit polyclonal antibodies (DAKO,
`Glostrup, Denmark and NICHIREI, Tokyo, Japan) or a murine
`monoclonal antibody (Lab Corp, North Carolina, USA) against the
`human HER2 product. Tumours were considered to overexpress
`HER2 if at least 10% of tumour cells had positive membrane
`staining.
`
`Treatment
`
`A recombinant humanized anti-HER2 mAb (trastuzumab, MKC-
`454) was constructed by molecular engineering from a marine
`mAb recognizing the extracellular domain of the HER2 product
`(Carter et at, 1992). The drug was administered intravenously at a
`constant infusion rate for 90 mm. The starting dose level of MKC-
`454 was 1 mg kg -1 , and subsequent dose escalations were to 2, 4
`and 8 mg kg-’. The first dose was followed in 3 weeks by nine
`weekly doses. A minimum of three patients assessable for toxicity
`were treated at each dose level. If one of the first three patients
`entered at any dose level experienced a dose-limiting toxicity, an
`additional three patients were entered at that dose level. Toxicities
`
`were graded according to the JCOG toxicity criteria (Tobinai
`et al, 1993). Dose-limiting toxicity was defined as any grade 3 or 4
`toxicity.
`
`Pharmacokinetics, determination of antibodies against
`the humanized antibody and circulating shed antigen
`
`Serum concentrations of MKC-454 were determined in a receptor
`binding assay that detects binding with the extracellular domain of
`the HER2 product. The recombinant extracellular domain of the
`HER2 product provided from Genentech, Inc. was coated on 96-
`well microtitre plates. MKC-454 bound to the coated antigen was
`detected by horseradish peroxidase- labelled goat anti-human IgG
`Fc. The quantitative limit for MKC-454 in serum samples was
`156 ng ml - ’. The presence of antibodies against MKC-454 was
`determined with a bridging-type titre enzyme-linked immunosor-
`bent assay (ELISA). Serum concentrations of circulating extracel-
`lular domain of the HER2 product, circulating shed antigen were
`measured using an ELISA. A pair of polyclonal antibodies against
`extracellular domain of the HER2 product were provided from
`Genentech, Inc. The quantitative limit for circulating shed antigen
`was 1.54 ng ml’. Pharmacokinetic parameters of MKC-454 after
`first administration were determined for each patient. Maximum
`serum concentration (Cax) was the observed value.
`Half-life (t 1/2), area under concentration-time curve (AUC 0 J,
`distribution volume (V) and serum clearance (CL) were estimated
`by non-compartmental model of WinNonlin Standard Japanese
`Edition Version 1.1 (Scientific Consulting Inc.). As for the trough
`serum levels during the weekly treatment period, minimum and
`maximum values were obtained for each patient.
`
`Evaluation of response
`
`All responses were reviewed centrally by an independent extra-
`mural evaluation committee. A complete response (CR) was
`defined as the complete resolution of all measurable tumours for a
`duration of at least 4 weeks. Partial response (PR) was defined as a
`>_ 50% reduction in the sum of the products of the two longest
`perpendicular diameters of all measurable tumours for a duration
`of at least 4 weeks, a minimal response (MR) as a ~! 25% but less
`two longest
`than 50% reduction in the sum of the products of the
`perpendicular diameters of all tumours, and progressive disease
`(PD) as a ~! 25% increase in any measurable lesions or the appear-
`ance of any new lesion.
`
`RESULTS
`
`Patient characteristics are listed in Table 1. All patients had
`received chemotherapy for metastatic disease and 11 patients had
`received two or more regimens. All of the metastatic diseases had
`become refractory to anthracycline-containing regimens.
`Although hormonal therapy for metastatic disease was also given
`to a third of the patients, 11 primary tumours were negative for
`oestrogen receptor. Twelve patients had pathological grade III
`primary tumours.
`Serum concentration-time profiles after first administration are
`illustrated in Figure 1 and estimated pharmacokinetic parameters
`for each patient are summarized in Table 2. Mean C,,,, increased in
`good proportion to dose. Mean distribution volume (V) ranging
`from 52.1 to 74.3 ml kg, was independent of dose, and approxi-
`mated the serum space. Half-life (t,12 ) increased from 2.7 days at
`
`British Journal of Cancer (1999) 81(8), 1419-1425 (cid:9)
`
`@ 1999 Cancer Research Campaign
`
`IMMUNOGEN 2058, pg. 2
`Phigenix v. Immunogen
`IPR2014-00676
`
`

`

`Phase land pharmacokinetic study of anti-HER2 antibody 1421
`
`Table 2 single dose pharmacokinetic parameters of MKC-454 in each patient
`
`Dose
`(mg kg-1 )
`
`Patient no.
`
`C
`(ng ml-1 )
`
`tl
`(day)
`
`AUC Q
`(pg day ml)
`
`V
`(ml kg)
`
`CL
`(ml day kg -1 )
`
`2
`
`4
`
`8
`
`1-102
`1_i 03
`1-104
`1-105
`1-106
`3-107
`Mean’
`s.d.b
`3-108
`2-109
`1-110
`Mean
`s.d.
`3-111
`3-112
`1-113
`Mean
`s.d.
`3-114
`1-115
`1-116
`2-117
`3-118
`3-119
`Mean
`s.d.
`
`17506
`14994
`21 664
`22230
`18590
`15770
`19152
`2750
`52370
`42500
`35270
`43413
`8537
`62340
`62720
`92320
`72460
`17200
`167 600
`193500
`197050
`149 850
`176700
`133250
`169 658
`24862
`
`2,6
`2.3
`2.4
`3.2
`2.8
`2.3
`2.7
`0.4
`1.6
`2.3
`5.3
`3.1
`2.0
`10.2
`7.7
`8.4
`8.8
`1.3
`6.4
`15.4
`10.3
`10.2
`11.3
`9.0
`10.4
`3.0
`
`67
`47
`70
`94
`85
`53
`74
`16
`158
`198
`190
`182
`21
`549
`611
`746
`635
`101
`928
`2101
`1954
`1551
`1810
`1111
`1576
`471
`
`56.0
`45.2
`49.6
`48.0
`45.9
`61.1
`52.1
`6.3
`33.4
`49.1
`75.4
`52.6
`21.2
`85.9
`77.0
`60.0
`74.3
`13.2
`68.8
`77.1
`56.9
`72.4
`67.5
`79.5
`70.4
`8.1
`
`15.0
`14.2
`14.2
`10.6
`11.8
`18.9
`14.1
`3.2
`12.7
`10.1
`10.5
`11.1
`1.4
`7.3
`6.5
`5.4
`6.4
`1.0
`8.6
`3.8
`4.1
`5.2
`4.4
`7.2
`5.6
`1.9
`
`0.67 mg/kg of dose was used for calculation of pharmacokinetic parameters because infusion was discontinued at 60 mm
`’Patient no. 1-103 was deleted from calculation of mean and s.d. due to different dose.
`
`F
`
`C
`0
`cc
`
`0
`
`1000000
`
`100000
`
`10000
`
`1000
`
`100
`
`lot (cid:9)
`0 (cid:9)
`
`I (cid:9)
`2 (cid:9)
`
`1 (cid:9)
`4 (cid:9)
`
`1 (cid:9)
`6 (cid:9)
`
`I
`1 (cid:9)
`1 (cid:9)
`I (cid:9)
`1 (cid:9)
`1 (cid:9)
`8 10 12 14 16 18 20 22
`
`Time (day)
`
`Figure 1 Serum concentration-time profiles of MKC-454 after first
`administration. The values of serum concentration at a dose level of
`1 mg kg-1 (open circle), 2 mg kg -1 (closed circle), 4 mg kg (open triangle),
`or 8 mg kg -1 (closed triangle) represent mean – s.d.
`
`Serum concentration of MKC-454 (ng ml)
`
`100 (cid:9)
`
`1000 (cid:9)
`
`10000 (cid:9)
`
`100000 (cid:9)
`
`1000000
`
`1-102
`Level 1 1-104
`(1 mg kg)
`
`Level2 (cid:9)
`(2mgkg)
`
`Level3 (cid:9)mg
`
`(4
` kg)
`
`Level4 (cid:9)
`(8mgkg)
`
`3107
`
`3-los
`
`L2(cid:176)9
`
`1
`3-111
` 12
`
`1-115
`1-hf
`
`3-119
`
`Figure 2 Trough serum concentrations of MKC-454. Left and right ends of
`each horizontal bar represent minimum and maximum trough serum
`concentration of MKC-454 during weekly administration
`
`the lowest dose (1 mg kg -1 ) to 10.4 days at the highest dose
`(8 mg kg -1 ). Mean serum clearance (CL) decreased dose-depen-
`dently from 14.1 to 5.6 ml day - ’ kg-1 . Trough serum concentrations
`during repeated administration of MKC-454 are individually
`summarized in Figure 2. Maximum values of trough serum
`concentrations at each dose level were 9.19 – 2.26, 19.1 – 15.1,
`102 – 47.9, and 248 – 64.4 .tg ml
`- ’ respectively. The mean value
`
`of minimum trough serum concentrations at each dose level were
`3.58 – 0.63, 6.53 – 5.26, 40.2 – 7.12 and 87.9 – 23.5 p.g ml - ’
`respectively. Figure 3 shows the serum concentrations of circu-
`lating extracellular domain of the HER2 product, shed antigen.
`One patient (Patient No. 3-108) at 2 mg kg - ’ with high values of
`circulating shed antigen showed reduced values of the trough
`serum concentrations compared with those of the other two
`
`1999 Cancer Research Campaign (cid:9)
`
`British Journal of Cancer (1999) 81(8), 1419-1425
`
`IMMUNOGEN 2058, pg. 3
`Phigenix v. Immunogen
`IPR2014-00676
`
`(cid:9)
`(cid:9)
`

`

`1422 YTokudaetal
`
`Table 3 Toxicity of MKC-454
`
`Dose
`I mg kg-1
`n=6
`Grade
`
`Dose
`2 mg kg-1
`n3
`Grade
`
`Dose
`4 mg kg-1
`n=3
`Grade
`
`Dose
`8 mg kg-1
`n=6
`Grade
`
`- (cid:9)
`
`- (cid:9)
`
`4 (cid:9)
`2 (cid:9)
`
`- (cid:9)
`
`II (cid:9)
`
`2 (cid:9)
`1 (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`III
`
`1
`
`-
`
`1
`
`-
`
`-
`
`-
`
`-
`
`I
`
`-
`
`-
`
`-
`
`-
`
`-
`
`II (cid:9)
`
`1
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`Ill
`
`-
`
`-
`
`-
`
`-
`
`-
`
`I (cid:9)
`
`1
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`II (cid:9)
`
`III (cid:9)
`
`I
`
`II (cid:9)
`
`Ill
`
`- (cid:9)
`
`- (cid:9)
`
`-
`
`- (cid:9)
`
`1 (cid:9)
`1
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`-
`
`-
`
`-
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`-
`
`
`
`-
`
`-
`
`-
`
`Fever
`Nausea/vomiting
`Gastrointestinal disorder - (cid:9)
`Liver
`ASAT
`ALAT
`Tachycardia
`Rigors
`Feeling of warmth
`Bone pain
`Tumour pain
`Cough
`Oedema
`Malaise
`
`1 (cid:9)
`1 (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`1
`1
`
`-
`
`1
`1
`
`- (cid:9)
`
`-
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`-
`
`-
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`- (cid:9)
`
`-
`
`-
`
`- (cid:9)
`
`- (cid:9)
`
`
`
`
`
`-
`
`-
`
`Serum concentration of HER2 [CD (ng ml -1 )
`
`0 (cid:9)
`
`100 (cid:9)
`
`200 (cid:9)
`
`300 (cid:9)
`
`400 (cid:9)
`
`500
`
`1.102a-
`1 -103
`1-104
`
`Level I (cid:9)
`(1 mg kg-’) (cid:9)
`
`I
`
`11 -11 21
`r 3-108 1- (cid:9)
`Level 2 (cid:9)
`(2 mg kg) [
`r
`Level 3 (cid:9)
`(4 mg kg) L 1-i13
`
`L3-1o7 (cid:9)
`
`1 10
`
`:
`
`1
`
`Level 4
`(8mgkg)
`
`3-114
`
`1 116
`
`1 1117 J.
`
`L
`
`3-119 (cid:9) (cid:149)
`mean
`
`Figure 3 Serum concentrations of circulating extracellular domain of HER2
`product (HER2 ECD). Open circles represent concentrations of HER2 ECD
`prior to the commencement of the treatment. Left and right ends of each
`horizontal bar represent minimum and maximum concentrations of circulating
`HER2 ECD during weekly administration
`
`patients at the same dose level. Antibodies against MKC-454 were
`not detected in any patient.
`From a total of 134 administrations of MKC-454, drug-related
`toxicity is shown in Table 3. A 38(cid:176)C or higher fever was observed
`in six patients. One patient at 1 mg kg - ’ experienced grade 3 fever
`up to 40.7(cid:176)C while receiving the first administration. Despite the
`temporary event, further treatment with MKC-454 was not given.
`Although one patient had no bone metastasis, the patient at the
`dose of 8 mg kg’ experienced severe generalized bone pain
`judged as grade 3. Although the pain subsided within 8 h, adminis-
`tration of MKC-454 was discontinued.
`After the clinical trial had been completed, treatment responses
`of all the 18 patients were assessed by the committee confirming
`toxicity and efficacy. Data are summarized in Table 4. Although
`no response was observed at the dose level of 1 mg kg -1 , one
`patient with cervical and mediastinal lymph node metastases had a
`MR at the dose level of 2 mg kg -1 . One patient with multiple lung
`metastases had a PR at 4 mg kg -1 . Due to her good response to
`
`a’
`
`Figure 4 (cid:9) Metastatic tu (cid:9) ours n the lung before treatment with MKC-4 4 (A)
`and 7 months later showing marked response (B)
`
`date, she has received continuous weekly administration of MKC-
`454 4 mg kg’ for 18 months (Figure 4). A patient at 8 mg kg - ’
`with skin and bilateral supraclavicular lymph node metastases had
`a CR for 3 months (Figure 5). However, skin metastasis relapsed
`
`British Journal of Cancer (1999) 81(8), 1419-1425 (cid:9)
`
`O 1999 Cancer Research Campaign
`
`IMMUNOGEN 2058, pg. 4
`Phigenix v. Immunogen
`IPR2014-00676
`
`(cid:9)
`(cid:9)
`(cid:9)
`

`

`Phase land pharmacokinetic study of anti-HER2 antibody 1423
`
`I
`
`/
`
`Figure 5 Skin metastasis before treatment with MKC 4n4 (ik) showing strong positivity for HER2 product (B) and 4 months later showing pathologically
`complete response (C). Relapsing tumour cells with positive HER2 product (D)
`
`0
`
`Table 4 Response to MKC-454
`
`Dose
`mg kg’ (cid:9)
`
`1
`2
`4
`8
`Total
`
`NE (cid:9)
`
`PD (cid:9)
`
`NC (cid:9)
`
`MR (cid:9)
`
`PR (cid:9)
`
`CR (cid:9)
`
`Total
`
`1
`
`-
`
`-
`
`1
`2
`
`4
`2
`2
`1
`9
`
`1
`
`-
`
`-
`
`1
`2
`
`-
`
`1
`
`-
`
`2
`3
`
`-
`
`-
`
`1
`
`-
`
`1
`
`-
`
`-
`
`-
`
`1
`1
`
`6
`3
`3
`6
`18
`
`NE, not evaluable; PD, progressive disease; INC, no change; MR, minimal
`response; PR, partial response; CR, complete response.
`
`during the course of the treatment. It is of some interest that the
`relapsed tumour cells were still strongly overexpressing the HER2
`product. Her circulating shed antigen had been found low through
`the entire treatment course. Therefore it was considered that the
`circulating shed antigen had not affected her MKC-454 pharmaco-
`kinetics.
`
`DISCUSSION
`The HER2 product is thought to be a unique and useful target for
`antibody therapy of cancers overexpressing the HER gene. Several
`
`series of murine mAbs directed against the extracellular domain of
`the HER2 gene product have been developed and examined to
`reveal their anti-tumour effects, mainly in vitro. However, human
`anti-mouse antibody response during the therapy would be a major
`limitation on the clinical application of such murine mAbs.
`Preclinical studies suggested that a humanized antibody would
`have the same or greater anti-tumour potency in clinical trials than
`its murine counterpart (Tokuda et al, 1996). Therefore, a human-
`ized antibody against the HER2 gene product is expected to be
`useful in the clinic.
`Baselga and his colleagues reported the first clinical evidence of
`the anti-tumour activity of a humanized antibody against the
`HER2 product (Baselga et al, 1996). They set 10 j.Lg ml as the
`target trough serum concentration based on in vitro data (Carter
`et al, 1992). Our preclinical data also indicated 10 jig ml’ as a
`minimally effective concentration for anti-proliferation effects and
`antibody-dependent cell-mediated cytotoxicity (ADCC) (Tokuda
`et al, 1996). The dosage and schedule of the antibody administra-
`tion in this clinical trial was based on unpublished phase I trials in
`the United States. in this clinical trial, non-linear phannacokinetics
`of MCK-454 was demonstrated as previously described for other
`monoclonal antibodies (Koizumi et al, 1986; Eger et al, 1987).
`According to our data, 4 mg kg -1 is sufficient to achieve the target
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`1999 Cancer Research Campaign (cid:9)
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`British Journal of Cancer (1999) 81(8), 1419-1425
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`1424 Y Tokuda eta!
`
`-1). At 2 mg kg-’, although
`trough serum concentration (10 lLg ml
`minimum trough serum concentrations were lower than the target
`concentration with a wide range of variation, trough serum
`concentrations increased and exceeded the target concentration in
`the case of patients with absent or low circulating shed antigen
`(Patient nos 2-109 and 1-110), as administrations were repeated
`weekly. The maximum trough serum concentration of patient nos
`2-109 and 1-110 were 35.4 and 16.7 p.g m1’ respectively.
`Although 16.7 tg ml- ’ was lower due to discontinuation of treat-
`ment before reaching steady state, these values corresponded to
`54 – 32 pg ml - ’ observed in the previous clinical trial (Pegram
`et al, 1998) which used 100 mg per body as weekly dose level.
`These suggested that 2 mg kg - ’ was also sufficient to achieve the
`target concentration by the weekly dosing regimen. A patient with
`high circulating shed antigen at 2 mg kg - ’ (Patient no. 3-108)
`showed reduced serum concentrations. This observation was
`consistent with previous reports suggesting that high circulating
`shed antigen decrease the half-life and the trough serum concen-
`trations of humanized mAb against HER2 product (Baselga et al,
`1996; Pegram et al, 1998). Therefore, monitoring of circulating
`shed antigen level is considered to be essential in MKC-454
`therapy and more than 2 mg kg -’ maybe necessary in patients with
`high circulating shed antigen.
`Responding cases, including MRs, were observed at the dose
`levels of 2 mg kg - ’ or more. One patient with a PR for lung
`metastases who relapsed after high-dose chemotherapy received
`4 mg kg- ’ of MKC-454. The other responding patient receiving
`8 mg kg-’ achieved a CR for skin metastases, which had been
`heavily treated with chemotherapy and radiotherapy. Despite
`continuous treatment of MKC-454, it is noteworthy that the HER2
`product was still remarkably overexpressed in tumour cells of
`relapsed skin lesions. Circulating shed antigen in this patient had
`been low. It is possible that tumour clones overexpressing trun-
`cated forms of the extracellular domain of the HER2 product
`appeared (Scott et al, 1993), but confirmation of this would require
`further analysis.
`Toxicity caused by the treatment was well tolerated compared
`with that of chemotherapeutic drugs. Two patients discontinued
`the treatment after the first administration. However, both
`toxicities were temporary and could have been prevented with
`prophylactic use of drugs such as anti-inflammatory agents, which
`was prohibited in the protocol of this study.
`In conclusion, MKC-454 showed clinical activity with
`minimum toxicity. These findings indicate that this treatment
`deserves further clinical trials at suggested weekly intravenous
`infusions of 2-4 mg kg -1 .
`
`ACKNOWLEDGEMENTS
`
`We thank Ms Rieko Matsumoto, Dr Kazuhiro Takahashi and
`Dr Jindow Itoh of the Mitsubishi Chemical Corporation for their
`helpful advice and cooperation. We also thank Dr Robert L Cohen of
`the Molecular Oncology Department and Dr Sharon A Baughman of
`the Pharmacokinetics, Genentec, Inc, both for helpful comments
`during the preparation of this manuscript. This work was supported
`in part by Grant-in-Aids from the Ministry of Education, Science and
`Culture, and from the Ministry of Health and Welfare of Japan.
`
`REFERENCES
`
`Baselga J, Tripathy D, Mendelsohn 3, Baughman S, Benz CC, Danits L, Skiarin NT
`Seidman AD, Hudis CA, Moore J, Rosen PP, Twaddell T, Henderson IC and
`
`Norton L (1996) Phase II study of weekly intravenous recombinant humanized
`anti_pl851 IEs2 monoclonal antibody in patients with HER2/neu-overexpressing
`metastatic breast cancer. J Clin Oncol 14: 737-744
`Carter P, Presta L, Gorman CM, Ridgway JBB, Henner B, Wong WLT, Rowland
`AM, Kotts C, Carver ME and Shepard HM (1992) Humanization of an anti-
`p185 11E(cid:176) antibody for human cancer therapy. Proc Nat! Acad Sc! USA 89:
`4285-4289
`Coussens L, Yang-Feng TL, Liao V-C, Chen E, Gray A, McGrath J, Seeburg PH,
`Liebermann TW, Schlessinger 3, Franke U, Levison A and Ullrich A (1985)
`Tyrosine kinase receptor with extensive homology to EGF receptor shares
`chromosomal location with neu oncogene. Science 230: 1132-1139
`Be Potter CR, Van Dade S, Van Dc Vijver MJ, Pauwels C, Maertens G, Dc Boever
`J, Vandekerckhove D and Roels H (1989) The expression of the neu oncogene
`product in breast lesions and in normal fetal and adult human tissues.
`Histopathology 15: 315-326
`Drebin JA, Link VC, Stem DF, Weinberg RA and Green MI (1985) Down
`modulation of an oncogene protein product and reversion of the transformed
`phenotype by monoclonal antibodies. Cell 41: 695-706
`Eger RR, Covell DG, Carrasquillo JA, Abrams PG, Foon KA, Reynolds JC, Schroff
`RW, Morgan AC, Larson SM and Weinstein JN (1987) Kinetic model for the
`biodistribution of an In-labeled monoclonal antibody in humans. Cancer Res
`47:3328-3336
`Hancock MC, Langton BC, Chan T, Toy P, Monahan JJ, Mischak RP and Shawver
`LK (1991) A monoclonal antibody against the c-erbB-2 protein enhances the
`cytotoxicity of cis-diamminedichloroplatinum against human breast and
`ovarian tumour cell lines. Cancer Res 51: 4575-4580
`Harwerth I-M, Wels W, Marte BM and Hynes NE (1992) Monoclonal antibodies
`against the extracellsslar domain of the erbB-2 receptor function as partial
`ligand agonists. J Biol Che,n 267: 15160-15167
`Hudziak RM, Lewis GD, Winger M, Fetidly BM, Shepard M and Ullrich A (1989)
`p185 HERI monoclonal antibody has antiproliferative effects in vitro and
`sensitized human breast tumor cells to tumor necrosis factor. Mo! Cell Biol 9:
`1165-1172
`Kasprzyk PG, Song SU, Di Fiore PP and King CR (1992) Therapy of an animal
`model of human gastric cancer using a combination of anti-erbB-2 monoclonal
`antibodies. Cancer Res 52: 2771-2776
`King CR, Kraus MH and Aronson SA (1985) Amplification of a novel v-erbB-
`related gene in a human mammary carcinoma. Science 229: 974-976
`Koizs,mi K, DeNardo GL, DeNardo SJ, Hays MT, Hines HH, Scheibe P0, Peng J,
`Macey DJ, Tonami N and Hisada K (1986) Multicompartmental analysis of
`the kinetics of radioiodinated monoclonal antibody in patients with cancer.
`JNucl Med 27: 1243-1254
`Pegram MD, Lipton A, Hayes DF, Weber BL, Baselga JM, Tripathy D, Baly B,
`Baughman SA, Twaddell T, Glaspy JA and Slamon DJ (1998) Phase II study of
`receptor-enhanced chemosensitivity using recombinant humanized
`anti-p185HER2/neu monoclonal antibody plus cisplatin in patients with
`HER2/neu-overexpressing metastatic breast cancer refractory to
`chemotherapy treatment. J Clin Oncol 16: 2659-2671
`Press MF, Cerdon-Cardo C and Slamon Di (1990) Expression of the HER-2/neu
`proto-oncogene in normal human adult and fetal tissues. Oncogene 5: 953-962
`SchroffRW, Foon KA, Beatty SM, Oldham RK and Morgan Jr AC (1985) Human
`anti-murine immunoglobulin responses in patients receiving monoclonal
`antibody therapy. Cancer Res 45: 879-885
`Scott GK, Robles R, Park 3W, Montgomery PA, Daniel J, Holmes WE, Lee 3, Keller
`GA, Li WL, Fendly BM, Wood WI, Shepard HM and Benz CC (1993) A
`truncated intracellular HER2/neu receptor produced by alternative RNA
`processing affects growth of human carcinoma cells. Mo! Cell Rio! 13:
`2247-2257
`Shawler DL, Bartholomew RM, Smith LM and Dillman RO (1985) Human immune
`response to multiple injection of murine monoclonal IgG. JJmnunol 135:
`1530-1535
`Slamon DJ, Godolphin W, Jones LA, Holt JA, Wong SG, Keith BE, Levin WJ,
`Stuart SG, Udove J, IJllrich A and Press MF (1989) Studies of the HER-2/neu
`proto-oncogene in human breast and ovarian cancer. Science 244: 707-712
`Stankovski I, Hurwitz E, Leitner 0, Ullrich A, Yarden V and Sela M (1991)
`Mechanistic aspects of the opposing effects of monoclonal antibodies to the
`ERBB-2 receptor on tumor growth. Proc Nat! Acad Sci USA 88: 8691-8695
`Tagliabue E, Centis F, Campiglio M, Mastroianni A, Martignone S, Pellegrini R,
`Casalini P, Lanzi C, Menard Sand Colnaghi MI (1991) Selection of
`monoclonal antibodies which induce internalization and phosphorylation of
`p185’ 1112 and growth inhibition of cells with HER21neu gene amplification.
`list J Cancer 47: 933-937
`Tobinai K, Kohno A, Shimada Y, Watanabe T, Tamura T, Takeyama K, Narabayashi
`M, Fuksstomi T, Kondo H, Shimoyama M and Suemasu K (1993) Toxicity
`
`British Journal of Cancer (1999) 81(8), 1419-1425 (cid:9)
`
`@ 1999 Cancer Research Campaign
`
`IMMUNOGEN 2058, pg. 6
`Phigenix v. Immunogen
`IPR2014-00676
`
`

`

`Phase land pharmacokinetic study of anti-HER2 antibody 1425
`
`grading Criteria of the Japan Clinical Oncology Group. Jpn J Clin Oncol
`23:250-257
`Tokuda Y, Ohnishi Y, Shimamura K, Iwasawa M, Yoshimura M, Ueyama Y,
`Tamaoki N, Tajima T and Mitomi T (1996) In Vitro and in vivo anti-tumour
`effects of a humanised monoclonal antibody against c-erbB-2 product.
`Br Cancer 73: 1362-1365
`
`Yamamoto T, Ikawa 5, Akiyama T, Semba K, Nomura N, Miyajima N, Saito I and
`Toyoshima K (1986) Similarity of protein encoded by human c-erbB-2 gene to
`epidermal growth factor receptor. Nature 319: 230-234
`Yarden Y and Ullrich A (1988) Growth factor receptor tyrosine kinases. Annu Rev
`Biochem 57: 443-478
`
`1999 Cancer Research Campaign (cid:9)
`
`British Journal of Cancer (1999) 81(8), 1419-1425
`
`IMMUNOGEN 2058, pg. 7
`Phigenix v. Immunogen
`IPR2014-00676
`
`