Phase II Study of Receptor-Enhanced Chemosensitivity
`Using Recombinant Humanized Anti-pl85HER2/neu Monoclonal
`Antibody Plus Cisplatin in Patients With
`H ER2/neu-Overexpressing Metastatic Breast Cancer
`Refractory to Chemotherapy Treatment
`
`By Mark D. Pegram, Allen Lipton, Daniel F. Hayes, Barbara L. Weber, Jose M. Baselga, Debu Tri pathy, Debbie Baly,
`Sharon A. Baughman, Tom Twaddell, John A. Glaspy, and Dennis J. Slamon
`
`Purpose: To detennine the toxicity, phannacokinetics,
`response rate, and response d~ration of intravenous (IV)
`administration of recombinant, humanized anti-p 18SHER2
`monoclonal antibody (rhuMAb HER2) plus cisplatin (CDDP)
`in a phase II, open-label, multicenter clinical trial for po(cid:173)
`tients with HER2/ neu-overexpressinsf metastatic breast
`cancer.
`Patients and Methods: The study population consisted
`of ex tensively pretreated advanced breast cancer potients
`with HER2/ neu overexpression and disease progression
`during standard chemotherapy. Patients received a load(cid:173)
`ing dose of rhuMAb HER2 (250 mg IV) on day 0, followed
`by weekly doses of 100 mg IV for 9 weeks. Patients
`received CDDP (75 mg/m2) on days 1, 29, and 57.
`Results: Of 37 potients assessable for response, nine
`(24.3%) achieved a PR, nine (24.3%) had a minor response
`or stable disease, and disease progression occurred in 19
`(51 .3%). The median response duration was 5.3 months
`
`THE HER2/neu GENE encodes a 185-kd transmem(cid:173)
`
`brane protein that is a member of the type I family of
`growth factor receptors. Amplification of this gene is found
`in approximately 25% of human breast cancers and results in
`overexpression of the 185-kd encoded receptor tyrosine
`kinase, which is homologous to the epidermal growth factor
`receptor (EGFR). Overexpression of p 185HER2/neu is an
`independent predictor of both relapse-free and overall
`survival in patients with breast cancer. 1-4 In addition,
`overe} pression of this gene has prognostic significance in
`patients with ovarian,2 gastric,5 endometrial,6 and salivary
`gland malignancies.7 In breast cancer, overexpression of
`HER2/neu is also associated with a number of other adverse
`prognostic factors that include advanced pathologic stage,4
`number of metastatic axillary lymph nodes,2 absence of
`estrogen and progesterone receptors,8 increased S-phase
`fraction, 9 DNA ploidy, 10 and high nuclear grade. 11 A role for
`the HER2/neu alteration in metastasis has also been sug(cid:173)
`gested given the increased occurrence of visceral metasta(cid:173)
`sis12 and micrometastatic bone marrow disease in patients
`with HER2/neu overexpression. 13 Like many other cell(cid:173)
`surface receptors, a soluble form of the extracellular domain
`(ECD) of pl 85HER2111' 11 can be shed from the surface of tumor
`cells and is detectable in the sera of experimental animals
`that bear HER2/neu-overexpressing xenografts, as well as in
`
`(range, 1.6-18). Grade Ill or IV toxicity was observed in 22
`of 39 potients (56%). The toxicity profile reflected that
`expected from CDDP alone with the most common toxici(cid:173)
`ties being cytopenias (n = 10), nausea/vomiting (n = 9),
`and asthenia (n = 5). Mean phannacokinetic parameters
`of rhuMAb HER2 were unaltered by coadministration of
`CDDP.
`Conclusion: The use of rhuMAb HER2 in combination
`with CDDP in patients with HER2/ neu-overexpressing meta(cid:173)
`static breast cancer results in objective clinical response
`rates higher than those reported previously for CDDP alone,
`or rhuMAb HER2 alone. In addition, the combination results
`in no apparent increase in toxicity. Finally, the phannacol(cid:173)
`ogy of rhuMAb HER2 was unaffected by coadministration
`withCDDP.
`J Clin Oncol 16:2659-2671 . © 1998 by American Society
`of Clinical Oncology.
`
`the sera of approximately 20% to 25% of patients with
`locally advanced or metastatic breast cancer.14- 16 Patients
`with elevated serum levels of shed HER2/neu ECD have a
`decreased response to hormonal therapy and shortened
`overall survival compared with patients without shed HER2/
`16
`neu ECD.14
`•
`A murine monoclonal anti-HER2 antibody, 4D5, known
`to have antiproliferative activity against HER2/neu-overex-
`
`From the Department of Medical Oncology, The University of
`California at Los Angeles, Los Angeles, CA; the Department of Medical
`Oncology, Hershey Medical Center, Hershey, PA; the Department of
`Medical Oncology, Dana-Farber Cancer Institute, Boston, MA ; the
`Department of Medical Oncology, University of Pennsylvania, Philadel(cid:173)
`phia, PA; the Department of Medical Oncology, Memorial Sloan
`Kettering Cancer Center, New York, NY; the Department of Medical
`Oncology, University of California at San Francisco; and Genentech,
`Inc, San Francisco, CA.
`Submitted February 11, 1998; accepted May 29, 1998.
`Supported in part by grant no. I KJ2CA01714 (M.D.P.); and by the
`Revlon/University of California at Los Angeles Womens Cancer
`Research Fund, Los Angeles, CA.
`Address reprint requests to Mark D. Pegram, MD, 11-934 Factor
`Building, UCLA Center for the Health Sciences, 10833 Le Conte Ave,
`Los Angeles, CA 90095, Campus Mail Code I67817; Email
`mpegram@ ucla.edu.
`© 1998 by American Society of Clinical Oncology.
`0732-/83X/98/1608-0037$3.00/0
`
`Journal of Clinical Oncology, Vol 16, No 8 (August), 1998: pp 2659-2671
`
`2659
`
`Celltrion v. Genentech
`IPR2017-01374
`Genentech Exhibit 2061
`
`

`

`2660
`
`pressing human breast carcinoma cells in vitro and against
`breast cancer xenografts with HER2/neu overexpression in
`vivo, was humanized, which resulted in a human immuno(cid:173)
`globulin (IgG I ) molecule with retained murine sequences
`only in the complementarity determining regions. The
`resultant molecule has improved binding affinity to the
`extracellular domain of HER2/neu (kd = 0.1 nM v 0.3 nM
`for murine 405) and similar growth inhibitory activity
`against HER2/neu-overexpressing cell
`lines and xeno(cid:173)
`grafts.17
`Previous work has shown that treatment with monoclonal
`antibodies directed against EGFR in combination with the
`in a marked
`cytotoxic drug cisplatin (CDDP) resulted
`reduction in both size and number of human epidermoid
`carcinoma xenografts that overexpressed EGFR. 18 Using a
`similar experimental approach, we have shown a synergistic,
`cytocidal effect against cell lines and xenografts with
`HER2/neu overexpression by using monoclonal anti-HER2/
`neu antibodies plus CDDP.19 The mechanism of this effect
`appears to involve. a decreased capacity of HER2/neu(cid:173)
`overexpressing cells to repair COOP-induced DNA adducts
`after pretreatment with anti-HER2/neu antibodies. 19-21 This
`acti vity, which we have termed receptor-enhanced chemosen(cid:173)
`siti vity (REC), has potential clinical application based on the
`. fact that ( I) the dose-effect relationship of the anti-HER2/
`neu antibody plus CDDP is synergistic, (2) thi s synergistic
`effect is specific for cells that overexpress the HER2/neu
`receptor, (3) the combination of CDDP plus anti-HER2/neu
`antibody results in a two-log increase in cell killing, and (4)
`the combination yields pathologic complete remissions
`against HER2/neu-overexpressi ng human breast carcinoma
`xenografts in athymic mice. 19
`Pursuant to these preclinical observations, a series of
`phase I clinical trials were initiated and conducted at the
`University of California at Los Angeles to determine the
`safety and pharmacology of the murine monoclonal anti(cid:173)
`body 405, as well as the recombinant, humanized anti(cid:173)
`p l 85HERZ antibody monoclonal (rhuMAb HER2), both alone
`and in combination with CDDP. These studies showed that
`the pharmacokinetics of rhuMAb HER2 were predictable,
`and that the doses delivered achieved a target trough serum
`concentration of 10 to 20 µg/mL, which is associated with
`antitumor activity in preclinical models. In addition, admin(cid:173)
`istration of this anti-HER2/neu antibody was safe; the on ly
`toxicity was low-grade fever that occurred with the first
`infusion and/or pain at the site of known tumor deposits in a
`minority of patients. Moreover, these studies showed that
`rhuMAb HER2 was not immunogenic in contrast to murine
`monoclonal antibody 405 . Finally, the phase I studies
`showed that the combination of rhuMAb HER2 and CDDP
`
`PEGRAM ET AL
`
`showed significant antitumor efficacy, with four of 15
`patients who achieved objective responses, which included
`three partial responses and one sustained complete remission
`that lasted in excess of 5.5 years without subsequent
`treatment. Based on these findings, we designed the current
`phase II trial with the following objectives: (I) to determine
`the overall response rate and response duration of intrave(cid:173)
`nous (IV) rhuMAb HER2 plus CDDP in an open-label,
`multicenter clinical trial for patients with HER2/neu(cid:173)
`overexpressing metastatic breast cancer who have shown
`di sease progress ion while undergoing standard chemother(cid:173)
`apy treatment; (2) to document the tolerance and toxicity of
`rhuMAb HER2 plus CDDP; and (3) to determine the
`pharmacokinetics of rhuMAb HER2 when administered in
`combination with CDDP.
`
`PATIENTS AND METHODS
`Eligibility Criteria
`
`'
`
`Women aged from 18 to 75 years with a primary histologic diagnosis
`of invasive breast cancer, with radiographically or visuall y measurable
`and assessable metastatic disease documented by physical examination
`or radiographic find ings, were considered for enrollment. Patients were
`required to have evidence of overexpression (2 + to 3 +) of the
`HER2/neu proto-oncogene in their malignant cells as determined by
`immunohistochemical analysis (Roche Biomedical Laboratories, Re(cid:173)
`search Triangle Park, NC), and were required to have documentation of
`objecti ve tumor progression while receivi ng active chemotherapy for
`breast cancer. No therapy of any kind (cytotox.jc, cytokine, or hormonal)
`was a.llowed within the 3 weeks before study entry. In addition, no
`therapy wi th mitomyci n or nitrosoureas was allowed within 6 weeks of
`study entry. A Karnofsky performance status (KPS) greater than 60%;
`life expectancy of 3 months or greater; normal serum calcium level
`( :5 10.5 mg/d.L); and preserved cardiac, renal (serum creatin ine
`level :5 1.5 mg/dL, creatini ne clearance 2: 60 mL/min, :5 2 + protein(cid:173)
`uria), hepatic (bilirubin level :5 1.5 mg/dL), pulmonary (forced expira(cid:173)
`tory volume in 1 second 2: 70% of predicted value), hematologic (WBC
`count 2: 3,000/µL, granulocyte count 2: 1,500/µL, platelet count 2:
`125,000/µL) , and coagul ation (prothrombi n time < 14 seconds, partial
`thromoplastin time < 35 seconds) function were all required. All
`patients signed a wri tten, internal review board-approved, informed
`consent document. Patients were excluded for active infection, preg(cid:173)
`nancy or lactation, significant cardiac disease (New York Heart
`Association class II or IV), known hemorrhagic di athesis, hepatic
`metastases that involved greater than 50% of the li ver parenchyma,
`lymphangitic pulmonary metastasis, CNS metastasis, bone-only metas(cid:173)
`tasis, prior treatment wi th COOP or other cisplatin analogues, previous
`therapy with a monoclonal or polyclonal antibody, or concomitant use
`of any investigational agent.
`
`Study Design
`Eligible patients received a 250-mg loading dose of rhuMAb HER2
`IV day 0, fo llowed by 100 mg IV weekly for a total of eight doses.
`Patients also received COOP 75 mg/m 2 day I of treatment, with repeat
`doses on days 29 and 57. Clinical response was assessed on day 70.
`Responsive patients or patients with stable disease were eligible for
`entry onto a maintenance phase program after day 70. The maintenance
`
`

`

`rhuMAb HER2 PLUS CISPLATIN IN BREAST CANCER
`
`phase protocol consisted of rhuMAb HER2 100 mg IV weekly plus
`CDDP 75 mg/m2 IV every 4 weeks until disease progression or
`prohibitive toxicity ensued.
`
`Treatment Plan
`A baseline pretreatment evaluation that included a complete history
`and physical examination, 12-lead ECG, chest radiograph, serum
`pregnancy test, complete blood count, urinalysis, creatinine clearance,
`serum chemistries (which included hepatic function tests), coagulation
`studies, hepatitis serologies, audiologic testing, pulmonary function
`tests, and baseline tumor measurements was performed within 2 weeks
`before study entry. Study patients were monitored weekly by physical
`examination, complete blood counts, serum chemistries, and coagula(cid:173)
`tion studies. All rhuMAb HER2 doses were administered in 250 mL of
`0.9% sodium chloride solution infused IV over 90 minutes. Vital signs
`were recorded before each dose, at the end of tbe infusion, and 1 hour
`postinfusion. Serum samples were collected just before and 1 hour after
`each rhuMAb HER2 dose for pharmacokinetic analysis of rhuMAb
`HER2, presence of shed pl85HER2 ECD, and detection of anti-rhuMAb
`HER2 antibodies. All CDDP doses were administered 1 day after
`scheduled rhuMAb HER2 doses, consisted of CDDP 75 mg/m2 diluted
`in 500 mL of 0.9% sodium chloride solution, and were administered IV
`over 60 minutes after hydration with a minimum of 500 mL of 5%
`dextrose/0.9% sodium chloride solution. After CDDP administration,
`patients received an additional 500 mL of 5% dextrose/0.9% sodium
`chloride solution. Additional hydration, mannitol, furosemide, and
`electrolyte solutions were administered as medically indicated. Anti(cid:173)
`emetic therapy consisted of dexamethasone 20 mg IV before CDDP
`administration and ondansetron 0.15 mg/kg IV before CDDP adminis(cid:173)
`tration and 1.5 and 3.5 hours after the CDDP infusion. A graded toxicity
`scale based on the modified National Cancer Institute criteria was used
`to assess toxicity. Dose modification of CDDP to 50% of the original
`dose was performed for grades I to II nephrotoxicity or grades III to IV
`gastrointestinal toxicity. For any other grades III to IV toxicity,
`treatment was reinstituted at doses of CDDP of 50 mg/m2 and rhuMAb
`HER2 of 50 mg IV after resolution of toxicity. Response criteria were
`defined as follows: complete response, disappearance of all radio graphi(cid:173)
`cally and/or visually apparent tumor; partial response, reduction of at
`least 50% in the sum of the products of the perpendicular diameters of
`all measurable lesions with no new lesions detected; minor response, a
`reduction of 25% to 49% in the sum of the products of the perpendicular
`diameters of all measurable lesions with no new lesions detected; stable
`disease,,not meeting the criteria for response or progression; and
`progressive disease, objective evidence of an increase of 25% in any
`measurable lesion or the appearance of any new lesion. All objective
`responses were assessed by an independent response evaluation commit(cid:173)
`tee comprised of a medical oncologist and radiologist who were
`otherwise not involved in the conduct of this study.
`
`Detection of HER2/neu Oncogene Overexpression
`in Clinical Tissue Specimens
`Patterns ofHER2/neu expression were evaluated by a modification of
`published immunohistochemical techniques that used a murine mono(cid:173)
`clonal antibody (4D5) directed against HER2/neu. 2·22 Four-micron
`sections from formalin-fixed, paraffin-embedded tissues were cut and
`mounted on positively charged slides. Tissue sections were deparaf(cid:173)
`fini zed and endogenous peroxidase activity was quenched with 1 %
`hydrogen peroxide in methanol. Sections were digested with 1 mg/mL
`of protease in phosphate buffered saline (PBS) and allowed to incubate
`
`2661
`
`with horse serum to block nonspecific antibody binding. Primary
`antibody (405 ; Genentech, Inc, South San Francisco, CA) was applied
`(I 0 µg/mL) and sections were allowed to incubate at 4 °C for 18 hours.
`Sections were washed with PBS and treated with a biotinylated
`antimouse secondary antibody (Vector Laboratories, Inc, Burlingame,
`CA). After rinsing with PBS, sections were incubated with avidin(cid:173)
`biotinylated enzyme complex (Vector Laboratories, Inc). Sections were
`then rinsed in PBS, and antibody binding was detected by staining with
`a diaminobenzidine/hydrogen peroxide chromogen solution. Sections
`were rinsed in deionized water, counterstained in Harris hematoxylin,
`dehydrated through graded alcohols, cleared in xylene, and cover(cid:173)
`slipped. The scoring system for interpretation ofHER2/neu immunostain(cid:173)
`ing is as follows: 0, 10% or less of tumor cells show any level of
`positive staining; 1 +,barely perceptible light membranous rimming
`that may not totally encircle the cell membrane; 2 +, light to moderate
`membranous rimming that totally encircles the membrane; and 3 +,
`moderate to strong membrane rimming that totally encircles the
`membrane.
`
`Pharmacokinetics of rhuMAb HER2
`The concentration of rhuMAb HER2 in serum was measured by
`means of an enzyme-linked immunosorbent assay (ELISA) with the
`ECD of pl85HERZ as the coat antigen. In this ELISA format, 100 µL of
`pl85HER2 (Genentech, Inc) was added to MaxiSorp 96-well microtiter
`plates (Nunc, Roskilde, Denmark) at 1 mg/mL in 0.05 mol/L of sodium
`carbonate, pH 9.6. After overnight incubation at 2° to 8°C, the plates
`were washed three times with ELISA wash buffer (PBS that contained
`0.05% Tween-20) using a Biotek EL304 platewasher (Bio-tek Instru(cid:173)
`ments, Inc, Winooski, VT). The plates were then blocked with 200 µL
`per well of ELISA diluent (PBS that contained 0.5% bovine serum
`albumin [BSA] ; 0.05% Tween-20; and 0.05% Proclin300, pH 7.2) for 1
`to 2 hours at ambient temperature with agitation. After blocking, plates
`were washed again three times with ELISA wash buffer. Subsequently,
`100 µL of standards, samples, or controls were added to duplicate wells
`and allowed to incubate for 1 hour at ambient temperature. The standard
`curve range for the assay is 1.56 to 100 µg/mL. After the sample/
`standard incubation, the plates were washed six times with ELISA wash
`buffer and 100 µI of goat antihuman IgG Fc-hotseradish peroxidase
`(HRP), freshly di luted to its optimal concentration in ELISA diluent,
`was added to the plates. After a I-hour incubation, the plates were
`washed six times in ELISA wash buffer and 100 µL of PBS, pH 7.2, that
`contained 2.2 mmol/L of orthophenylene diamine (Sigma Chemical Co,
`St Louis, MO) and 0.012% (vol/vol) hydrogen peroxide (Sigma
`Chemical Co) were added to each well. When color had fully
`developed, the reaction was stopped with 100 µL per well of 4.5 mol/L
`of sulfuric acid. The absorbencies of the well contents were read at 492
`nm minus 405 nm reference absorbance using an automatic plate reader
`(Molecular Devices, Palo Alto, CA). A four-parameter curve fit program
`was used to generate the standard curve, from which sample and control
`concentrations were interpolated.
`
`Detection of Anti-rhuMAb HER2 Antibodies in Serum
`An antibody titer ELISA was developed to measure the presence and
`titer of antibodies against rhuMAb HER2 in human sera. The positive
`control in the ELISA was an antiserum prepared against rhuMAb HER2
`in cynomologous monkeys. The negative control was a human serum
`pool prepared from a panel of healthy donors. Briefly, I 00 µL of
`rhuMAb HER2 was added to 96-well microtiter plates at I µg/mL in
`0.05 mol/L of sodium carbonate buffer, pH 9.6. After overnight
`
`

`

`2662
`
`incubation at 4°C, plates were washed with ELJSA wash buffer (PBS
`that contained 0.05 % Tween-20 and 0.0 l % thimerosal) and blocked for
`I hour with ELISA diluent (PBS that contained 0.05% Tween-20, 0.5%
`BSA, and 0.01 % thimerosal). Subsequently, 50 µL of sample, positive
`control, or negative control and 50 µL of biotin-rhuMAb HER2 were
`added to appropriate wells and all owed to incubate for I hour at room
`temperature (RT). The titer of the positive control was determined by an
`initial I: l 00 dilution of the sample followed by serial l :2 dilutions. The
`plates were washed in ELISA wash buffer, then 100 µL of PBS that
`contained 2.2 mmol/L of orthophenylene diamine (OPO) and 0 .0 12%
`hydrogen peroxide was added to each well. The colorimetric reaction
`was quenched with I 00 µL of 4.5 mol/L of sulfuric acid and absorbance
`was measured at 492-nm wavelength in an automated plate reader.
`Intra-assay and
`interassay variab ility averaged 2.6% and 12. I%,
`respectively.
`
`Detection of pl 85HER2l neu ECD in Serum
`
`The method for detection of shed HER2 ECO levels in serum is an
`ELISA-based assay and has been described in detai l elsewhere.23
`Briefly, the ELISA uses pairs of anti- HER2 monoclonal antibodies
`(Genentech, Inc) that recognize mutually exclusive determinants of the
`ECO of pl85HER2/neu. We lls were coated overnight at 4°C with MAb
`7F3, which does not compete wi th rhuMAb HER2 for shed HER2 ECO
`binding. Assay standards (recombi nant, p 135HER2/neu ECO) and pati ent
`samples were added to appropriate wells and allowed to incubate for 2
`hours. After a wash step, secondary antibody was added (MAb 405 to
`detect free shed HE R2 ECO and MAb 2C4 to detect total shed HER2
`ECO) for 2 hours. T he bound conj ugate was detected with OPO
`substrate and the resulting absorbance was measured at a 490-nm
`wavelength. The range of the assay is 2.75 to 1,800 ng/mL in serum or
`plasma.
`
`Patient Characteristics
`
`RESULTS
`
`Thirty-nine patients were enrolled onto the study, and
`their characteristics are listed in Table l. Patients ranged in
`age from 29 to 75 years. Eighty-six percent of the patients
`had a KPS of 90% or greater. High levels of HER2/neu
`overexpression (3 +) were observed in 82% of the patients.
`Twenty-four of 37 patients (65%) who had measurements of
`serum shed HER2/neu ECD performed before treatment had
`levels greater than 2.75 ng/mL (the lower limit of detection
`in the ELISA assay). Only one third of the patients for whom
`hormone receptor data were available were either estrogen
`receptor- or progesterone receptor-positive, consistent with
`previous studies that showed an inverse correlation between
`HER2/neu overexpression and hormone receptor expres(cid:173)
`sion.24 Twenty-seven of the 39 patients (69%) were post(cid:173)
`menopausal at diagnosis, and a majority of the patients had a
`high di sease burden, with 18 of 39 patients (46%) who had
`three or more sites of metastatic disease. This patient
`population had been heavily pretreated before study entry,
`with 35 of 39 patients (90%) in whom two or more prior
`chemotherapeutic regimens had failed for metastatic dis-
`
`PEGRAM ET AL
`
`Table 1. Patient Characteristics
`
`Characteristic
`
`No.
`
`%
`
`Age, years
`Mean
`Range
`Karnalsky performance status,% In = 37)
`100
`90
`80
`70
`Level al HER2/ neu averexpression
`2 +
`3 +
`Detection of shed HER2 ECD In = 37)
`Receptor status
`Estrogen receptor-pasitive In = 37)
`Progesterone receptor-pasitive {n = 36)
`Menopausal status
`Premenopausal
`Postmenopausal
`Peri menopausal
`No. of metastatic sites
`
`2
`2: 3
`Sites of metastasis
`Lung
`Lymph nade
`Bone
`Chest wall/ skin
`Liver
`Breast
`Ovary
`Eye
`No. of prior chemotherapy regimens for metastatic disease
`1
`2
`2: 3
`Prior hormanal therapy
`Prior radiotherapy
`
`NOTE. N = 39.
`
`50
`29-75
`
`22
`10
`4
`
`7
`32
`
`59
`27
`11
`3
`
`18
`82
`
`13
`
`35
`
`10
`27
`2
`
`7
`14
`18
`
`19
`19
`18
`17
`14
`4
`
`4
`18
`17
`21
`27
`
`, 26
`69
`5
`
`18
`36
`46
`
`49
`49
`46
`44
`36
`10
`2.5
`2.5
`
`10
`46
`44
`54
`69
`
`ease. In addition, all patients had to show resistance to
`standard chemotherapy as evidenced by tumor progression
`while receiving che"motherapy treatment to be eligible for
`this trial.
`
`Toxicity
`
`Toxicity data are listed in Table 2. During the main study,
`105 cycles of CDDP were administered in combination with
`314 weekly IV doses of rhuMAb HER2. During the
`maintenance phase, an additional 81 cycles of CDDP and
`434 doses of rhuMAb HER2 were administered. Thirty(cid:173)
`seven patients had KPS assessed at baseline and at least once
`during the course of the study. The KPS remained un(cid:173)
`changed in 19 patients (the majority of whom had
`
`

`

`rhuMAb HER2 PLUS CISPLATIN IN BREAST CANCER
`
`Table 2. Grade 3 ar 4 Clinical Adverse Events, Irrespective of Causality
`
`Event
`Main study (n = 39)
`Accidental injury
`Back pain
`Infection
`Dyspnea
`Anorexia
`Nausea and/ or vomiting
`Increased AST
`Increased alkaline phosphatase
`Hyperbilirubinemia
`Nephrotoxicity
`Asthenia
`Hypertonia
`Leukopenia
`Anemia
`Thrombocytopenia
`Maintenance phase (n = 19)
`Hyperglycemia
`Sepsis
`Cardiomyopathy
`Nausea and/ or vomiting
`Hyperbilirubinemia
`Peripheral neuropathy
`Leukopenia
`Anemia
`Thrombacytopenia
`
`Grade 3
`
`Grade4
`
`No.
`
`%
`
`No.
`
`%
`
`1
`2
`2
`
`7
`1
`1
`3
`0
`5
`
`2
`3
`4
`
`0
`
`2
`1
`2
`
`4
`
`3
`3
`5
`5
`3
`lB
`3
`3
`8
`0
`13
`3
`5
`8
`10
`
`5
`0
`5
`10
`5
`10
`5
`5
`21
`
`0
`0
`0
`0
`0
`0
`0
`0
`
`0
`0
`0
`0
`0
`
`0
`1
`0
`1
`0
`0
`0
`0
`0
`
`0
`0
`0
`0
`0
`0
`0
`0
`3
`3
`0
`0
`0
`0
`0
`
`0
`5
`0
`5
`0
`0
`0
`0
`0
`
`KPS > 80% ), improved in two patients, and decreased in 16
`patients. Four patients experienced weight loss in excess of
`10% of their baseline body weight during the study. Four
`patients experienced fever greater than 38°C during rhuMAb
`HER2 infusion or at the postinfusion measurement. There
`was no significant difference in blood pressure between
`pretreatment and posttreatment measurements across all
`treatment days. During the main study, 22 of 39 patients
`(56%) experienced at least one episode of grade III or IV
`toxicity. The most frequent grade III toxicities observed
`were nausea and/or vomiting in seven patients (18%),
`asthenia in five patients (13 %), thrombocytopenia in four
`patients (10%), anemia in three patients (8%), and leukope(cid:173)
`nia in two patients (5 %). One episode of reversible grade IV
`nephrotoxicity was registered during the main study, and this
`patient's renal function recovered after 9 days. One patient
`developed grade IV hyperbilirubinernia during the main
`study. Th.is event was believed to be disease-related rather
`than treatment-related. During the maintenance phase, 10 of
`19 patients (53 %) experienced grade III or IV toxicity. The
`most frequent grade III toxicities were thrombocytopenia,
`four patients (21 %); nausea and/or vomiting, two patients
`(10%); and peripheral neuropathy, two patients (19%). Two
`patients experienced grade IV toxicity during the mainte-
`
`2663
`
`nance phase, one patient with sepsis and another with
`gastrointestinal toxicity. Grade III/IV toxicity reported as
`possibly related to rhuMAb HER2 was infrequent and was
`reported in six of 39 patients (15 %). These events consisted
`of grade III cytopenia in three patients, grade III nausea or
`anorexia in two patients, grade III asthenia in one patient,
`and grade III hyperbilirubinernia in one patient. In most of
`these cases, we were not able to dissociate toxicity possibly
`related to rhuMAb HER2 from toxicity likely caused by
`CDDP or the patient's underlying disease. There was no
`report of grade IV toxicity attributable to rhuMAb HER2
`administration. We observed no evidence of increased
`toxicity in those tissues that are known to express pl85HER2,
`ie, lung, gastrointestinal tract, CNS, or skin, nor was there
`any toxicity at the IV injection site. Three patients discontin(cid:173)
`ued the main study treatment because of toxicity or intercur(cid:173)
`rent medical illness (two with nephrotoxicity and one with
`hepatic failure), and one patient discontinued the mainte(cid:173)
`nance phase as a result of cardiomyopathy. The latter patient
`had a cumulative anthracycline dose of 420 mg/m2 and had
`also received prior chest-wall irradiation. This patient also
`had a history of concurrent hypertension and diabetes. Four
`patients died before day 70; however, in each case, patients
`had been removed from the study because of disease
`progression before death. In summary, the toxicities ob(cid:173)
`served were consistent with those previously reported for
`CDDP alone in a heavily pretreated population of breast
`cancer patients (Table 3).
`
`Response and Response Duration
`
`Tumor response was evaluated on day 70 during the main
`study and every 10 weeks during the maintenance phase
`protocol. Patients with symptoms or suspected progressive
`disease could have tumor assessment at any time during the
`course of the study. Thirty-seven of the 39 patients enrolled
`(95 %) were assessable for tumor response (Table 4 ). Assess(cid:173)
`able patients were defined as those who met all eljgibility
`criteria, received at least one dose of therapy, and underwent
`response evaluation other than at baseline. Patient deaths
`before tumor evaluation were considered assessable (progres(cid:173)
`sive disease). Two patients were not assessable for tumor
`response because of adverse events before tumor assess(cid:173)
`ment. During the main study, the median number of doses of
`rhuMAb HER2 per patient was nine (range, one to nine
`doses). The median number of doses of CDDP per patient
`was three, and the average administered dose was 74 mg/m2.
`Three patients missed one dose of CDDP or received dose
`reduction as dictated by the study guidelines. Nineteen
`patients (49%) entered the maintenance phase protocol, in
`
`

`

`2664
`
`Table 3. Studies of Single-Agent Cisplatin in Patients With Previously Treated Metastatic Breast Ca ncer
`
`Investigator
`
`Dosage
`
`No. CR PR
`
`Response
`Duration
`
`Nephro·
`toxicity• (%)
`
`Neuroloxicityt
`
`Gastrointestinal
`Toxicity
`
`Leukopeniot
`(%)
`
`16 0
`
`2 21-85 days
`
`23 0
`
`0 NA
`
`8
`
`0
`
`36% Hearing loss
`
`97% Severe nausea
`
`44
`
`9% Tinnitus
`4% Ataxia/lethargy
`
`70% Nausea and
`vomiting
`
`29-50
`
`PEGRAM ET AL
`
`Thrombocytopenia
`
`47% < 50,CXXJ/
`µL x 7 days
`50%-57% <
`100,CXXJ/µL
`
`Yap et al35 ( 1978)
`
`26 0
`
`0 NA
`
`21 -33
`
`8% Tinnitus
`4% Hearing loss
`
`Bull et al38 ( 1978)
`
`Somol et al39 ( 1978)
`
`70 mg/m2 every 3
`weeks
`15 mg/m2/d X 5
`every 4 weeks ar
`120 mg/m2 every
`4weeks
`100 mg/ m2 every
`3-4 weeks or 20
`mg/m2 X 5 every
`4weeks
`Ostrow et ol36 ( 1980) 100 mg/ m2 every
`3-4weeks
`
`Forastiere et a l37
`(1982)§
`
`60 mg/m2 every 3
`weeks or 120
`mg/m2 every 3-4
`weeks
`
`17 1 0 3 months
`
`35
`
`37 0 5 1-6 months
`
`13 .5
`
`17%-57% Moderate
`to severe nausea
`and vomiting
`
`100% Nausea and
`vomiting, Ire-
`quen~y severe
`
`NR
`
`NR
`
`33
`
`6% < 20,CXXJ/µL
`
`100% Nausea nd
`vomiting
`
`3-7
`
`1%-2% <
`50,ooq,fµL
`
`17%-97% Nausea
`and vomiting Ire-
`quen~y severe
`
`3-50
`
`1%-47% <
`50,CXXJ/µL
`
`29% Hearing loss
`6% Optic neuritis
`6% Peripheral neu-
`ropothy
`66% Tinnitus
`33% Hearing loss
`(5% tinnitus/
`hearing loss with
`60mg/m2)
`5%-66% Tinnitus/
`hearing loss
`0%-6% Peripheral
`neuropothy
`
`Total
`
`119 1 7 21 days-
`6 months
`
`0 -35
`
`Overall response rate 7% (95%CI, 2to 11)
`
`Abbreviations: CR, complete response; PR, partial response; NA, not available; NR, not reported .
`'Creatinine level > 2 mg/dl.
`tHigh-lrequency hearing loss > 20 dB.
`fWBC count < 3 ,CXXJ/µl.
`§All 5 responses in this study occurred in the 120-mg/m2 arm .
`
`which the median number of rhuMAb HER2 doses per
`patient was 17 (range, three to 75 doses), and the median
`number of COOP doses per patient was four (range, one to
`10 doses), with an average COOP dose of 65 mg/m2. Ten
`patients required dose reductions of COOP during the
`maintenance phase. The maximum number of rhuMAb
`HER2 doses received by any patient was 84.
`Of the 37 patients assessable for tumor response, eight
`patients had a partial response documented during the main
`study, and one additional patient had a partial response that
`occurred during the maintenance phase. There were no
`complete responses in this study. Three patients met the
`
`Table 4. Response Data for Main Study Plus Maintenance Phase
`Among 37 Assessable Patients
`
`Response
`
`No. of Patients
`
`Complete response
`Partial response
`Overall response
`Minor response
`Stobie disease
`Disease progression
`
`0
`9
`9
`3
`6
`19
`
`%
`
`0
`24.3
`24.3
`8
`16
`51.3
`
`criteria for minor response and six patients had stable
`di sease during the main study. Disease progression was
`observed in 19 patients. The overall objective response rate
`among assessable patients (main study plus maintenance
`phase) was 24% (nine of 37 patients), all of whom had
`partial responses (95% confidence interval [CI], 12.4 to
`41.6). The overall response rate for all patients (intent-to(cid:173)
`treat population) was 23% (nine of 39 patients; 95% CI, 11 .7
`to 39.7). The sites of response were lung (n = 5), lymph
`node (n = 2), chest.wall/skin (n = 6), and liver (n = l). The
`median response duration was 5.3 months (range, 1.6 to 18
`months). The characteristics of the responders are listed in
`Table 5. Pretreatment clinical