,.1:l;~r: ~t ~ ~\~.~~~,. (, ~ · 1 ! .. ~ ~_-rs {:~r~,·· .. ~
`:: ._._ .. ;,.. ... .;N , ~J15~-~ .. ~.
`~ !./ .. l 1.1:: -~
`,
`
`INTELGENX 1037
`
`

`
`JOURNAL OF CLINICAL ONCOLOGY
`The Official Journal of the American Society of Clinical Oncology
`
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`1995, W.B. Saunders Company
`
`Philadelphia, P A
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`A Division of Harcourt Brace & Company
`
`INTELGENX 1037
`
`

`
`I
`I
`I
`
`I
`
`Initial Phase I Evaluation of the Novel Thymidylate
`Synthase Inhibitor, L Y231514, Using the Modified
`Continual Reassessment Method for Dose Escalation
`
`By D.A. Rinaldi, H.A. Burris, F.A . Dorr, J.R. Woodworth, J.G. Kuhn, J.R. Eckardt, G. Rodriguez, S.W. Corso,
`S.M. Fields, C. Langley, G. Clark, D. Faries, P. Lu, and D.D. Von Hoff
`
`Purpose: To determine the toxicities, maximal-toler(cid:173)
`ated dose (MTD}, pharmacokinetic profile, and potential
`antitumor activity of L Y231514, a novel thymidylate syn(cid:173)
`thase (TS} inhibitor.
`Patients anc/ Methods: Patients with advanced solid
`tumors were administered L Y231514 intravenously over
`1 0 minutes, weekly for 4 weeks, every 42 days. Dose
`escalation was based on the modified continual reassess(cid:173)
`ment method (MCRM}, with one patient treated at each
`minimally toxic dose level. Pharmacokinetic studies were
`performed in all patients.
`Results: Twenty-five patients were administered 58
`courses of L Y231514 at doses that ranged from 1 0 to 40
`mg/m2/wk. Reversible neutropenia was the dose-lim(cid:173)
`iting toxicity. Inability to maintain the weekly treatment
`schedule due to neutropenia limited dose escalation on
`
`this schedule. Nonhematologic toxicities observed in(cid:173)
`cluded mild fatigue, anorexia, and nausea. At the 40-
`mg/m2/wk dose level, the mean harmonic half-life,
`maximum plasma concentration, clearance, and a ppar(cid:173)
`ent volume of distribution at steady-state were 2.02
`hours, 11.20 ~tg/ml, 52.3 ml/min/m2, and 6.64 L/ m2,
`respectively. No major antitumor responses were ob(cid:173)
`served; however, minor responses were achieved in two
`patients with advanced colorectal cancer.
`Conclusion: The dose-limiting toxicity, MTD, and rec(cid:173)
`ommended phase II dose of L Y231514 when adminis(cid:173)
`tered weekly for 4 weeks every 42 days are neutropenia,
`40 mg/m2, and 30 mg/m2, respectively.
`J Clin Oncol 13:2842-2850. © 1995 by American So(cid:173)
`ciety of Clinical Oncology.
`
`L Y231514 (N-[4-[2-(2-amino-4,7-dihydro-4-oxo-1H(cid:173)
`
`pyrrolo, 3-d]pyrimidin-5-yl) ethyl]benzoyl]-L-glu(cid:173)
`tamic acid disodium salt) is a novel compound representa(cid:173)
`tive of a new class of folate antimetabolites. It has a
`pyrrole ring that replaces the pyrazine ring in the pterine
`portion of folic acid, and a methylene group that replaces
`the benzylic nitrogen in the bridge portion (Fig 1). The
`primary mechanism of antitumor effect of L Y231514 is
`via inhibition of the enzyme thymidylate synthase (TS),
`which is the only de novo source of thymidylate for the
`3 This enzyme catalyzes the reductive methylation
`cell. 1
`-
`of deoxyuridine monophosphate (dUMP), in the presence
`of a reduced folate cofactor, 5,1 0-methylene tetrahydrofo(cid:173)
`late, to deoxythymidine monophosphate (dTMP) and di(cid:173)
`hydrofolate. Deoxythymidine monophosphate is the pre-
`
`From the Institute for Drug Development, Cancer Therapy and
`Research Center; Brooke Army Medical Center, Fort Sam Houston;
`The University of Texas Health Science Center at San Antonio, San
`Antonio, TX; and Eli Lilly and Co, Indianapolis, IN.
`Submitted January 3, I995; accepted June 6, 1995.
`Supported by a grant from Eli Lilly and Co, Indianapolis, IN.
`The opinions or assertions herein are the private views of the
`authors and are not to be construed as reflecting the views of the
`Department of the Army or the Department of Defense.
`Address reprint requests to David A. Rinaldi, MD, Cancer Ther(cid:173)
`apy and Research Center, 8122 Datapoint Dr, Suite 1000, San Anto(cid:173)
`nio, TX 78229.
`© 1995 by American Society of Clinical Oncology.
`0732-183X/95/1311-0024$3.00/0
`
`cursor of deoxythymidine triphosphate ( dTTP), one of
`5
`the deoxyribonucleotides necessary for DNA synthesis.4
`•
`L Y231514 undergoes extensive intracellular polygluta(cid:173)
`mation, 1
`3 which with other chemotherapeutic agents, con(cid:173)
`-
`verts the drug from a form that readily effluxes from the
`cell, to a form that is retained intracellularly for a pro(cid:173)
`longed period. This produces a more sustained drug ef(cid:173)
`fect.5
`In preclinical models, L Y231514 has demonstrated ac(cid:173)
`tivity against a wide spectrum of tumor types. In vitro, it
`is highly cytotoxic against CCRF-CEM human leukemia
`cells in culture, with a 50% inhibitory concentration
`(IC50) of 0.007 f.tg/mL. This activity was reversed by the
`addition of thymidine to the medium. 1
`3 L Y231514 has
`-
`also demonstrated substantial in vitro activity against hu(cid:173)
`man tumor colony-forming units obtained from patients
`with colon cancer, renal cancer, hepatoma, carcinoid tu(cid:173)
`mor, and both non-small-cell and small-cell lung cancer
`(Von Hoff DD, personal communication, August 1995). 6
`In animal studies, L Y231514 was able to suppress tumor
`growth completely at doses :2:: 10 mg/kg in mice with
`two types of transplanted human colon xenografts (VRC5
`and GC3) resistant to methotrexate (MTX). 1
`Toxicology studies of L Y231514 in mice (CD-1
`strain), using daily intraperitoneal doses of up to 150 mg/
`kg for 2 weeks, were associated with minimal toxicity.
`There was a dose-related decrease in body weight, reach(cid:173)
`ing a maximum of 20% at the 150-mg/kg level. Moderate
`decreases in WBC and platelet counts, as well as mild
`decreases in RBC counts, were also observed. WeeklY
`
`2842
`
`Journal of Clinical Oncology, Vol 13, No 11 (November), 1995: pp 2842-2850
`
`INTELGENX 1037
`
`

`
`pHASE I STUDY OF LY231 514
`
`2 843
`
`0
`
`COOH
`
`N~COOH
`
`H
`
`0
`
`COOH
`
`N~COOH
`
`H
`
`fig 1. Structure of l Y231514
`and methotrexate.
`
`L Y 2 31 514
`
`N)
`~ L3
`
`~ N
`
`N
`
`Methotrexate
`
`doses of 315 mg/kg (944 mg/m2
`) for 6 weeks was also
`minimally toxic in mice. The 50% lethal dose (LD50) of
`LY231514 given as a single intravenous dose was more
`than 1,574 mg/kg.'
`Beagle dogs were treated on various intravenous dosing
`schedules to determine toxicity. The weekly schedule be(cid:173)
`gan at 105 mg/kg, but the two dogs died after two doses.
`The dosing was then reduced to 105 mglkg for one dose,
`followed by 26.24 mg/kg/wk for five doses. The major
`toxicities observed were anorexia, emesis, diarrhea, oral
`mucositis, and weight loss. Neutropenia, lymphopenia,
`and mild anemia were also observed. By 6 weeks, two
`of t ,e four dogs died of sepsis, secondary to mucositis
`in one case and pneumonia in the other. Plasma concen(cid:173)
`trations of L Y231514 increased in a linear fashion with
`increasing doses. The terminal half-life was approxi-
`• mately 2.3 hours. When comparing the toxicity of the
`varivus schedules, modest toxicity was observed in dogs
`treated with 100 mg/kg as a single dose, 5 mg/kg, twice
`weekly, and 0.5 mg/kg/d. 1
`In vitro and in vivo, folinic acid has been shown to
`anta~onize the antitumor effect of other TS inhibitors
`currently undergoing clinical evaluation. This effect ap(cid:173)
`pears to be mediated via a competitive inhibition for
`
`transport of the agent into the cell and/or intracellular
`8 Folinic acid was evaluated as a rescue
`polyglutamation. 7
`•
`agent for L Y231514. Four beagle dogs were administered
`potentially lethal intravenous doses (50 mg/kg for two
`doses, 3 days apart) of LY231514. All dogs developed
`signs of toxicity characterized by oral mucositis, anorexia,
`diarrhea, and a decrease in the leukocyte count by 50%
`to 80% beginning the day after the second dose of
`L Y231514. Folinic acid was administered parenterally for
`7 days with total daily doses of 150 mg initially, then
`tapering to 20 mg/d. The clinical signs resolved within 4
`days and the hematologic abnormalities resolved within
`6 days of the initiation of folinic acid rescue. At the
`termination of the study, one dog had a residual healed
`oral ulcer. The other animals had no gross pathologic
`evidence of residual tissue damage following folinic acid
`rescue.'
`The starting dose of a phase I investigational drug trial
`is generally one third the toxic-dose-low in the most sen(cid:173)
`sitive large animal species tested, or one tenth the 10%
`lethal dose (LD 10) in mice. LY231514 was only mini(cid:173)
`mally toxic in mice. In dogs, deaths occurred in those
`that received 26.24 mg/kg (525 mg/m2
`) per week, so one
`third of this, 175 mg/m2/wk, was not felt to be a safe
`
`INTELGENX 1037
`
`

`
`2844
`
`starting dose. An initial dose of 10 mg/m2/wk was used
`to enhance safety. The dose escalation format was based
`on the modified continual reassessment method (MCRM)
`proposed by Faries. 9 Using this scheme, a single patient
`is treated at each minimally toxic dose level and more
`patients are added to a level when significant toxicity is
`observed. This dose-escalation format reduces the number
`of patients treated with lower, possibly less effective
`doses, while increasing the proportion treated at dose
`levels closer to the maximal-tolerated dose (MTD). The
`objectives of this study were to determine the qualitative
`and quantitative toxicities, the MTD, pharmacokinetic
`profile, and antitumor effect of LY231514 when dosed
`weekly for 4 weeks. This schedule will be repeated every
`42 days to allow for resolution of toxic effects.
`
`PATIENTS AND METHODS
`
`Patient Selection
`All patients underwent a complete history, physical examination,
`chest x-ray, and laboratory evaluation. Eligibility criteria included
`the following: (1) histologic evidence of solid tumor refractory to
`conventional therapy and other investigational agents of higher prior(cid:173)
`ity; (2) at least 18 years of age; (3) World Health Organization
`(WHO) performance status :::.;; 2; (4) life expectancy ;;:=:: 12 weeks;
`(5) off previous anticancer therapy for at least 3 weeks (at least 6
`weeks for nitrosoureas or mitomycin); (6) adequate bone marrow
`function (WBC count ;;:=:: 3,000/p,L or granulocyte count ;;:=:: 1,500/
`p,L, platelet count ;;:=:: 100,000/p,L, hemoglobin level ;;:=:: 9 g/dL),
`hepatic function (bilirubin level :::.;; 1.5 mg/dL, AST :::.;; two times
`the upper limit of normal, albumin level ;;:=:: 2.5 g/dL, normal pro(cid:173)
`thrombin/partial thromboplastin time), renal function (creatinine
`concentration :::.;; 1.5 mg/dL or creatinine clearance ;;:=:: 60 mL/min),
`cardiac function (no dysrhythmias requiring therapy and no myocar(cid:173)
`dial infarction in the previous 6 months), and metabolic function
`(electrolytes within normal limits unless due to cancer, blood glucose
`< 200 mg/dL); and (7) written, informed consent. Exclusion criteria
`included the following: (1) clinical evidence of brain metastases,
`(2) serious preexisting medical conditions that would prevent full
`compliance with the study, (3) pregnancy, (4) concomitant anticancer
`therapy, (5) use of aspirin, or (6) presence of pleural or peritoneal
`effusions. Patients who required chronic aspirin therapy and those
`with effusions were excluded due. to the structural similarities of
`LY231514 and MTX (Fig 1). MTX may be displaced from albumin
`and its renal secretion may be impaired by the concurrent use of
`aspirin, thereby increasing its cytotoxic effect. 10 MTX also is retained
`in effusions and released slowly into plasma, causing potentially
`substantial toxicity.
`
`Pharmacokinetics
`Plasma samples for pharmacokinetics were planned for all patients
`during their first treatment course. A reverse-phase high-performance
`liquid chromatography (HPLC) assay was developed to determine
`the concentration of LY231514 in plasma. A quantity of 0.5 to 1
`mL of plasma was subjected to a preconditioned solid-phase extrac(cid:173)
`tion (SPE) cartridge (Bond Elut Certity II, part no. 1210-2080; Var(cid:173)
`ian, Harbor City, CA). The SPE cartridges were preconditioned with
`
`RINALDI ET AL
`
`2 mL of HPLC grade methanol, followed by 2 mL of a pH 7.0
`phosphate buffer. Immediately following the addition of the sample,
`the column was washed with 2 mL of the pH 7.0 phosphate buffer,
`and then with 2 mL of methanol. The absorbed LY2315 14 was
`eluted with 2 mL of 40% acetonitti le and 60% buffer solution. The
`eluate was evaporated to dryness under nitrogen. The residues were
`reconstituted with 200 p,L of distilled, deionized water, and then
`filtered with 0.1-p,m Ultrafree-MC centrifuge filters (Millipore Inc,
`Bedford, MA). The extraction efficiency of LY231514 from plasma
`was 60%. The chromatographic procedure consisted of injecting 150
`p,L of the filtrate onto an octadecyl column (YMCbasic, 25 em
`X 4.6 mm; YMC Inc, Wilmington NC) preceded by a YMCbasic
`precolumn (23 em X 4 mm). The mobile phase consisted of 14%
`acetonitrile and 86% pH 3.0 phosphate buffer solution, pumped at
`a flow rate of 0.8 mL/min, and monitored by UV detection at 250
`nm. The internal standard used was dideazatetrahydrofolate (Lome(cid:173)
`trexol; Eli Lilly, Indianapolis, IN), with a retention time of approxi(cid:173)
`mately 13 minutes, The retention time for LY231514 was approxi(cid:173)
`mately 17 minutes. Two calibration curves were used in the assay
`of the plasma samples. A low concentration range (1 0 to 400 ng/
`mL) was used for the 1-mL plasma sample, and a high concentration
`range (400 to 20,000 ng/mL) for the 0.5-mL plasma sample. Both
`concentration curves were linear over their respective ranges, with
`a correlation coefficient more than 0.96. The lower limit of quantita(cid:173)
`tion of L Y231514 was 10 ng/mL.
`
`Drug Administration
`L Y231514 disodium was supplied as a lyophilized powder in 100-
`mg vials and reconstituted in 10 mL of normal saline. The ar,::pro(cid:173)
`priate dose was then withdrawn and diluted in normal saline to a
`total volume of 50 mL. This was administered intravenously over
`10 minutes. weekly for 4 weeks, repeated every 42 days. To be
`eligible to receive subsequent weekly doses, all toxicity must have
`been :::.;; grade I at the time of treatment. Toxicity was assessed
`according to the WHO toxicity criteria. Patients were evaluated by
`a physician weekly during therapy for signs and symptoms of toxic(cid:173)
`ity. The initial patient treated at each dose level was observed for a
`minimum of 4 weeks before decisions regarding dose escalation were
`made. Folinic acid would be considered, based on animal rescue data,
`for grade IV myelosuppression that persisted for 7 days or for grade
`III/IV nonhematologic side effects. The planned dosing of folinic
`acid was 50 mg/m2 intravenously every 6 hours for 2 days, then 40
`mg/m2 intravenously every 6 hours for 6 additional days. All serious
`adve~se events were reported to the institutional review board and
`the study sponsor, Eli Lilly and Co, Indianapolis, IN.
`
`Dose Escalation
`Dose levels to be studied were 10, 20, 40, 75, 150, 225, 375,
`. to 1,000 mg/m2/wk. Dose escalation was planned based on the
`.
`.
`MCRM, with one patient treated at each minimally toxic dose level.
`Before each new patient was treated, an estimated MTD was ca cu(cid:173)
`lated based on the toxicity experienced by all previously treated
`patients. The dose level selected for a new patient was based on the
`following criteria: at least three patients would be treated at the
`initial dose level of 10 mg/m2
`; the dose level for a new patient could
`not be more than one level above the level assigned to the previous
`patient; the dose level could not be greater than the estimated MTD;
`a minimum of three patients would be treated at a level before dose
`escalation when moderate reversible toxicity (grade III hematologic
`or grade II nonhematologic toxicity, excluding nausea, vomiting,
`
`INTELGENX 1037
`
`

`
`pHASE 1 STUDY OF LY231 514
`
`and alopecia) occurred; and a mi~imum of six patients would. be
`treated at a dose level before ~scalat10n when unacceptable. rever.si~le
`toxicity (grade IV hematologic or grade III nonhematologic toxicity,
`excluding nausea, vomiting, and alopecia) occurred:
`The MTD was defined as that dose level at which 30% of the
`atient population developed unacceptable reversible toxicity. The
`~ecornmended dose for phase II clinical trials on this schedule would
`be the dose that caused moderate reversible toxicity in most patients,
`with at I~" ast 10 patients treated at this dose level. Intrapatient dose
`escalation was allowed if the next dose level was completed without
`unaccept;1.ble toxicity.
`
`Ejficac~ · Criteria
`Disease assessment was performed every one to two cycles. Stan(cid:173)
`dard response criteria were used. A complete response required dis(cid:173)
`appearance of all evidence of disease for at least 4 weeks. A partial
`response required a 2:: 50% decrease in the sum of the products of
`the dian eters of all measured lesions for at least 4 weeks. There
`also could be no new lesions or increases in the size of any assessable
`lesions. -\. minor response was defined as a 2:: 25% reduction in
`measurable or assessable disease that did not meet criteria for a
`response. Progressive disease was defined as a greater than 25%
`increase in the sum of the products of the diameters of the measured
`lesions ur the appearance of any new lesions. Stable disease was
`defined as not meeting criteria for a response or progressive disease.
`
`RESULTS
`
`Twenty-five patients were enrolled onto the study. One
`patient was not assessable due to the development of a
`small bowel obstruction, secondary to his malignancy,
`after a single dose of L Y231514. He subsequently de(cid:173)
`clined further treatment. The characteristics of the 24
`assessable patients are listed in Table 1. A majority of
`
`Table 1. Patient Characteristics
`
`!\lo. entered
`No. assessable
`,'v\ale/female
`Age, years
`Median
`Range
`W HO performance status
`0
`
`2
`N o. of prior chemotherapy regimens
`1
`2
`3
`4
`Prior radiation therapy
`Tumor type
`Colorectal
`Gastric
`Head and neck
`Hepatoma
`Renal
`Sarcoma
`
`25
`24
`11/13
`
`59
`20-82
`
`12
`11
`1
`
`3
`12
`7
`2
`8
`
`17
`2
`2
`
`2845
`
`the patients who participated in the trial had refractory
`metastatic colon cancer and had received prior chemo(cid:173)
`therapy; eight had also been treated with radiation ther(cid:173)
`apy. A total of 58 courses of LY231514 were adminis(cid:173)
`tered, with a range of one to seven courses per patient.
`Two patients were not fully assessable for toxicity during
`their first courses of treatment. One was hospitalized dur(cid:173)
`ing his first two courses with gastrointestinal hemor(cid:173)
`rhages, due to tumor infiltration of the small bowel. His
`first fully assessable course was the third cycle. A second
`patient was diagnosed with brain metastases during the
`first course, and L Y231514 was withheld during radiation
`therapy. Her first fully assessable course was the second
`cycle.
`
`Toxicities
`
`The dose-limiting toxicity of LY231514 on this sched(cid:173)
`ule was neutropenia. Overall, of 24 assessable patients,
`four developed grade IV and five grade III neutropenia
`as their maximal toxicity. Nonhematologic toxicity was
`relatively mild, with no instances of grade III or IV side
`effects (Table 2). There was no evidence of cumulative
`toxicity.
`At the 10-mg/m2 dose level, the second patient devel(cid:173)
`oped grade III neutropenia and grade IV thrombocyto(cid:173)
`penia. Three other patients were treated at this dose level
`with no side effects. Since three of four patients at this
`dose level had no toxicity, dose escalation proceeded per
`protocol to the 20-mg/m2 level. The patient tolerated the
`20-mg/m2 dosing without side effects. The next patient
`was treated at the 40-mg/m2 dose level and developed
`grade IV neutropenia after the second dose. Five addi(cid:173)
`tional patients were subsequently treated at this dose
`level, with both grade IV and grade III neutropenia oc(cid:173)
`curring in two of six patients (Table 3). As a result of
`the grade IV toxicity at the 40-mg/m2 level, three patients
`were added at the 20-mg/m2 level to insure tolerability.
`There were no instances of grade III or IV side effects
`
`Table 2. Toxicity (course 1)
`
`WHO Grade (no. of patients)
`
`Toxicity
`
`Neutropenia
`Thrombocytopenia
`Anemia
`Nausea/ emesis
`Fatigue
`T ransaminasemia
`Anorexia
`Mucositis
`Dermatitis
`
`0
`
`6
`20
`9
`13
`13
`20
`13
`20
`23
`
`1
`0
`8
`9
`10
`3
`11
`4
`
`7
`2
`7
`2
`
`0
`0
`0
`
`Ill
`
`5
`1
`0
`0
`0
`0
`0
`0
`0
`
`IV
`
`5
`1
`0
`0
`0
`0
`0
`0
`0
`
`INTELGENX 1037
`
`

`
`2846
`
`Table 3. Neutropenia (course 1)
`
`Dose Level
`(mg/ m2
`
`)
`
`No . of
`Patients
`
`Doses Gi ven / Planned
`
`10
`20
`30
`40
`
`4
`4
`10
`6
`
`14/16
`15/16
`30/40
`18/24
`
`WHO Toxicity Grode
`(no . of patie nts)
`
`0
`
`3
`3
`0
`0
`
`2
`
`0
`
`4
`2
`
`3
`
`0
`0
`3
`2
`
`4
`
`0
`2
`2
`
`0
`0
`1
`0
`
`observed. Since toxicity was minimal at the 20-mg/m2
`level, but significant at the 40-mg/m2 dose level, an inter(cid:173)
`mediate dose level of 30 mg/m2 was added, based on the
`estimated MTD determined by the MCRM. Ten patients
`were treated at this dose level, with grade IV neutropenia
`occurring in two of 10 patients. Folinic acid rescue was
`not required in any patients.
`Inability to deliver scheduled doses due to ::.:::: grade II
`myelosuppression at the time of treatment limited dose
`escalation on this schedule (Table 3). At the 10- and 20-
`mg/m2levels, 29 of 32 planned doses were delivered, and
`six of eight patients received all doses. At the 40-mg/m2
`level, 18 of the planned 24 doses were delivered, and at
`the 30-mg/m2 dose level, 30 of the 40 doses were given.
`Only one patient at each of these dose levels received all
`four of the scheduled doses during the first course.
`Patients with clinically significant pleural or peritoneal
`
`RINALDI ET AL
`
`effusions were excluded from the study, but fi ve patients
`had evidence of small effusions by computed tomo(cid:173)
`graphic (CT) scan. All were treated at the 30-mg/m2 or
`40-mg/m2 dose levels. There was no apparent difference
`in toxicity between those with and without these small
`effusions. Grade III or IV neutropenia occurred in three
`of five patients with effusions and in six of 11 patients
`without effusions. The patient who experienced severe
`myelosuppression at the 10-mg/m2 dose level had no evi(cid:173)
`dence of pleural or peritoneal effusions.
`Although mild weight loss was evident in animal stud(cid:173)
`ies, this was not a significant clinical problem. Five of 24
`patients exhibited weight loss greater than 5% (maximum,
`8.4% ), while three patients gained greater than 5%. There
`did not appear to be a relationship between dose level and
`weight loss. Three of 16 patients treated at the 30- or 40-
`mg/m2levels had weight loss of greater than 5%, compared
`with two of eight patients treated at the lower levels.
`
`Pharmacokinetics
`
`During the first course of therapy, plasma samples were
`obtained at 5, 15, 30, and 45 minutes, 1, 2, 4, 5, 9, 18,
`24, and 48 hours, and weekly before drug dosing. Figure
`2 shows the mean concentrations from 10, 20, 30, and 40
`mg/m2, and Table 4lists the pharmacokinetic calculations
`from these data. LY23 1514 exhibits a relative small vol-
`
`E
`..........
`0>
`:I.
`:
`u
`c
`0
`()
`
`~
`yo-
`L{)
`yo-
`(Y)
`N
`>-
`
`_.J
`
`20
`
`10
`
`0 .1
`
`0.01
`
`• 10 mg/m2
`(n = 4)
`~~<2_ m[.l~~~~~
`~- ~ ~ -~ 9~~~ _(!'~] 9)
`~-. ~q .. ~.9/.~~- . _(_~-~-~).
`
`2 . LY23 1514: mea n
`Fig
`(± SD) pla sma conce ntrati ons.
`
`\. \.
`\.
`
`.. .. .. .. .
`. .
`
`0
`
`4
`
`8
`
`12
`
`16
`
`20
`
`24
`
`Time, hr
`
`' .. ' . ..
`'
`..
`'
`. .
`'
`'
`
`\.
`
`.
`.. . . .. .
`
`·,._ i
`'i
`
`INTELGENX 1037
`
`

`
`pHASE 1 STUDY OF LY231 514
`
`Table 4. L Y231514: Mean ± SD Pharmacokinetic Parameters
`
`AUC
`('"g/ h/ml)
`
`2.57 ± 1.27
`5 .91 ± 1.58
`13.61 ± 4.82
`14.38 ± 6.00
`
`Half-Life•
`(hours)
`
`1.27
`1.53
`2.11
`2.02
`
`Cl
`(ml/min/ m2)
`
`79 .2 ± 38.7
`9.6 ± 15.9
`39.6 ± 9.4
`52.3 ± 17.9
`
`2847
`
`Vss
`(L/m2)
`
`6 .31 ± 1.01
`5.70 ± 0.49
`5.63 ± 1.29
`6.64 ± 1.05
`
`N
`
`4
`4
`10
`6
`
`Age
`(years)
`
`48 ± 21
`50 ± 17
`66 ± 9
`51 ± 13
`
`Cmax
`('"g/ ml)
`
`2.01 ± 0 .40
`4.32 ± 0 .60
`7 .48 ± 1.28
`11.2 ± 4 .45
`
`I max
`(hours)
`
`0 .13 ± 0.08
`0 .21 ± 0 .08
`0 .20 ± 0.08
`0 .19 ± 0.09
`
`Dose
`rng/ m2
`..:..--
`10
`20
`30
`.40
`Abbreviations : Cl , total systemic clearance; tmax , time to achieve maximum plasma concentration ; Yss, steady-state volume of distribution .
`•Harmonic mean ; range of all values, 0 .89 to 3.87 hours .
`
`ume of distribution, which reflects the polar nature of the
`compound. These data also suggest the compound has a
`moderate clearance and a relatively short half-life. The
`clearance varies, with what initially appears to be an in(cid:173)
`verse relationship to dose. As the dose increases from 10
`to 30 mg/m2, clearance is almost halved. However, the
`clearance is higher when the dose increases to 40 mg/m2.
`Figure 3 shows the regressions between dose and both
`area under the curve (AUC) and maximum plasma con(cid:173)
`centration (Cmax) values. The AUC values from the 30-
`mg/m2 dose are nearly identical to those from the 40-mg/
`m2 dose. The regression of AUC values with dose is
`highly variable; the regression between Cmax values and
`dose shows less variability and appears linear. Although
`the regression between AUC values and dose may suggest
`saturable elimination, the high variability of this regres(cid:173)
`sion and the consideration of both regressions together
`do not fully support saturable behavior. Further inspection
`of these data suggest that there may be an inverse relation(cid:173)
`ship of drug clearance to patient age, with clearance de(cid:173)
`creasing as age increases (Fig 4). Although this is not a
`strong correlation (R2 = .43), it may provide at least a
`
`partial explanation of the low clearance values from those
`patients given the 30-mg/m2 dose, as these patients were,
`on average, older than patients enrolled at the 40-mg/m2
`dose level (Table 3).
`Like other folate derivatives, renal excretion was sus(cid:173)
`pected to be the primary route of excretion for L Y231514;
`however, no urine samples for drug levels were collected
`in this study. The estimated creatinine clearances (Cock(cid:173)
`roft and Gault estimation) for each patient appear to corre(cid:173)
`late with the patient's L Y231514 clearance values (Fig
`5). The correlation of LY231514 clearance with age may
`also be influenced by renal function, since there is a
`known reduction in renal clearance with increasing age.
`These data suggest that, like other folates, L Y231514 is
`primarily eliminated renally.
`Correlations were attempted between pharmacokinetic
`values and the degree of neutropenia attained after the
`first cycle. The AUC and Cmax values were plotted against
`the neutrophil nadir measured after the first cycle (Figs
`6 and 7, respectively). Linear correlations were found,
`with a reduction in the neutrophil nadir occurring with
`an increase in AUC or Cmax .
`
`30 A
`
`25
`
`y = 0.407(x) - 0.422
`r2 = 0.57
`
`E 20
`.........
`.....
`7
`Ol
`::J.. 15
`u
`~ 10
`~
`
`5
`
`0
`
`•
`
`•
`
`•
`
`•
`•
`
`I
`
`20 B
`
`y = 0.309(x) - 1.51
`r2 = 0.66
`
`(.)
`
`E
`0
`E
`)c
`cG
`E
`u
`
`16
`
`12
`
`8
`
`4
`
`0
`
`•
`
`•
`•
`•
`•
`•
`
`I
`I •
`•
`
`0
`
`10
`
`20
`
`30
`
`40
`
`50
`
`0
`
`LY231514 Dose, mg/m2
`
`10
`30
`20
`LY231514 Dose, mg/m2
`
`40
`
`50
`
`Fig 3. Regression of (A) AUC and (B) Cmax v Dose.
`
`INTELGENX 1037
`
`

`
`2848
`
`'RINALDI ET AL
`
`N
`E
`........
`c
`E 100
`........
`E ..
`
`Q)
`0
`c
`m
`.....
`m
`Q)
`()
`.....
`.....
`M
`N
`>-