
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Cancer Therapy: Clinical |
Authors' Affiliations: 1 Division of Hematology/Oncology, Department of Medicine and 2 Department of Pharmacology, University of Pittsburgh School of Medicine; 3 Molecular Therapeutics/Drug Discovery Program and 4 Biostatistics Department, University of Pittsburgh Graduate School of Public Health and Biostatistics Facility, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania; and 5 Investigational Drug Branch, Cancer Therapy Evaluation Program, Division of Cancer Treatment and Centers, National Cancer Institute, Bethesda, Maryland
Requests for reprints: Ramesh K. Ramanathan, University of Pittsburgh Medical Center Cancer Pavilion, #562, 5150 Centre Avenue, Pittsburgh, PA 15232. Phone: 412-648-6507; Fax: 412-648-6579; E-mail: ramanathanrk{at}upmc.edu.
| Abstract |
|---|
|
|
|---|
Experimental Design: Escalating doses of 17AAG were given i.v. to cohorts of three to six patients. Dose levels for schedule A (twice weekly x 3 weeks, every 4 weeks) were 100, 125, 150, 175, and 200 mg/m2 and for schedule B (twice weekly x 2 weeks, every 3 weeks) were 150, 200, and 250 mg/m2. Peripheral blood mononuclear cells (PBMC) were collected for assessment of heat shock protein (HSP) 90 and HSP90 client proteins.
Results: Forty-four patients were enrolled, 32 on schedule A and 12 on schedule B. On schedule A at 200 mg/m2, DLTs were seen in two of six patients (one grade 3 thrombocytopenia and one grade 3 abdominal pain). On schedule B, both patients treated at 250 mg/m2 developed DLT (grade 3 headache with nausea/vomiting). Grade 3/4 toxicities seen in >5% of patients were reversible elevations of liver enzymes (47%), nausea (9%), vomiting (9%), and headache (5%). No objective tumor responses were observed. The only consistent change in PBMC proteins monitored was a 0.8- to 30-fold increase in HSP70 concentrations, but these were not dose dependent. The increase in PBMC HSP70 persisted throughout the entire cycle of treatment but returned to baseline between last 17AAG dose of cycle 1 and first 17AAG dose of cycle 2.
Conclusions: The recommended phase II doses of 17AAG are 175 to 200 mg/m2 when given twice a week and consistently cause elevations in PBMC HSP70.
|
Biomarkers that may be affected by 17AAG therapy have been evaluated in clinical trials (610). HSP90 has not shown a consistent increase or decrease in response to 17AAG therapy. However, several animal and human studies have shown HSP70 increases resulting from 17AAG-HSP90 interaction. (613).
Inhibition of HSP90 function seems to last only 1 to 5 days after a single dose of 17AAG (6). In addition, frequent administration of 17AAG is more effective in inhibiting tumor growth than is weekly 17AAG dosing (11). Based on these observations, we did a phase I study, in which 17AAG was administered on a twice-a-week schedule. The principal objectives of the study were to define the DLT and maximal tolerated dose (MTD) of 17AAG, recommend a dose for future phase II studies, and characterize the pharmacodynamics of 17AAG as reflected by changes in peripheral blood mononuclear cell (PBMC) content of HSP90 and client proteins.
| Patients and Methods |
|---|
|
|
|---|
The following were grounds for exclusion from the trial: pregnancy or lactation, untreated brain metastasis, active infections, or serious concomitant conditions. Because 17AAG is formulated in a diluent containing egg phospholipids, patients with a history of serious allergic reactions to eggs were excluded. Before entering the study, all patients gave written consent according to institutional and Federal guidelines.
Drug administration. 17AAG (NSC 330507) and EPL diluent (NSC 704057) were supplied by the Pharmaceutical Resources Branch of the National Cancer Institute (Rockville, MD). 17AAG was supplied in sterile vials that contained 50 mg 17AAG in 2.0 mL DMSO. EPL diluent was supplied in sterile, 50-mL flint glass vials that contained 48 mL of 2% egg phospholipids in 5% dextrose in water for injection. 17AAG was prepared for infusion by adding 2 mL 17AAG to 48 mL EPL diluent, thereby producing a 17AAG concentration of 1 mg/mL. The final 17AAG dosing solution was transferred to a glass bottle and administered within 6 h of preparation. Most 17AAG infusions were given over 1 h; however, if the volume of the infusion exceeded 500 mL, the infusion could be given over 2 h.
Patients were entered onto schedule A (Table 2 ) or B (Table 3 ) independently. The dose levels planned for schedule A (twice weekly x 3 weeks, repeated every 4 weeks) were 100, 125, 150, 175, and 200 mg/m2 and for schedule B (twice weekly x 2 weeks, repeated every 3 weeks) were 150, 200, and 250 mg/m2. A modified Fibonacci schema, with three to six patients per cohort, was used. No intrapatient dose escalation was allowed. At least three patients were to be enrolled at each dose level, assuming DLT did not occur in the first two patients enrolled at that level. The first three patients enrolled at a given dose level were observed for 4 weeks on schedule A and 3 weeks on schedule B. If none of the first three patients treated at a given dose level had a DLT, as defined below, patients were enrolled at the next dose level. If one of three patients experienced a DLT, up to three additional patients were accrued at the same dose level, and only if none of those additional three patients had a DLT was the next cohort of three patients accrued to the next higher dose. If two or more patients treated at any dose level experienced DLT, that level was considered the excessively toxic dose, and accrual to that dose level ceased. If only three patients had been treated at the dose level immediately below the excessively toxic dose, that dose level was expanded to six patients, assuming fewer than two of those six patients experienced a DLT. The highest dose level at which zero or one of six patients experienced a DLT was considered the MTD or the dose recommended for future phase II studies. At the MTD, cohorts could be expanded up to 12 patients.
|
|
grade 3 despite maximal antiemetic therapy, persistent decrease of creatinine clearance to <50% of baseline, or increase of serum creatinine to more than two times baseline were also considered a DLT. Hematologic criteria for a DLT were thrombocytopenia <25,000/µL or leucopenia <500/µL. Dose modifications. If any grade 3 or greater nonhematologic toxicity occurred, 17AAG administration was withheld until resolution to grade <1 or baseline, at which time 17AAG dosing could be resumed at a dose one level below that which produced the toxicity. Weekly laboratory tests were done, and drug dosing was withheld, if serum creatinine was elevated to more than two times baseline. On recovery of the creatinine to <1.5 times baseline, reinitiation of treatment was allowed at a dose one level below that associated with the elevated creatinine. If grade 2 neuropathy developed, treatment was withheld until normalization of signs and symptoms. If the absolute neutrophil count nadir was <500/µL or platelet nadir was <100,000/µL, subsequent 17AAG treatment could be resumed after hematologic recovery to an absolute neutrophil count >1500/µL or platelet count >100,000/µL but at a 17AAG dose one level below that which produced the hematologic toxicity. A dose delay of up to 4 weeks was permitted before treatment discontinuation was required.
Study requirements and assessments. A history and physical examination were done prestudy and before every cycle. A complete blood count, serum electrolytes, and chemistries were evaluated prestudy and once weekly. Radiographs to follow response were done prestudy and after every two cycles. The WHO response criteria were used (16).
We reported previously on the pharmacokinetic characteristics of 17AAG given on a weekly schedule (7, 15), as the 17AAG doses were similar in this study, pharmacokinetic sampling was omitted.
Assessment of HSP90 and client proteins in PBMCs. During cycle 1, 8-mL blood samples were collected in heparinized Vacutainer tubes or Vacutainer CPT cell preparation tubes before the start of 17AAG treatment, 4 h after the day 1 dose, and before dosing on days 4, 8, and 11. Patients treated on schedule A also had samples obtained before dosing on days 15 and 18. When possible, samples were also obtained at the same times during cycle 2. PBMCs were isolated from heparinized blood by centrifugation over Histopaque (density 1.077, Sigma-Aldrich, St. Louis, MO). PBMCs were isolated from blood collected in Vacutainer CPT cell preparation tubes by centrifugation at 1,500 x g for 25 min. All PBMC isolations were done at room temperature. Isolated PBMCs were washed twice with PBS at 4°C and stored at 80°C.
Before analysis by Western blot, PBMC pellets were thawed and lysed, on ice, by incubation for 40 min in 100 µL lysis buffer [50 mmol/L Tris-HCl (pH 7.9), 2 mmol/L EDTA, 100 mmol/L NaCl, 1% NP40, 10 mmol/L NaF, 10 mmol/L sodium vanadate] that contained the following freshly prepared protease inhibitors: 1 µg/mL pepstatin, 10 µg/mL aprotin, 5 µg/mL leupeptin, 5 mmol/L phenylmethylsulfonyl fluoride, 0.1 µmol/L microcystin, and 5 mmol/L sodium pyrophosphate. The cell lysates were centrifuged at 13,000 x g for 10 min, and protein concentrations in the resulting supernatants were determined using the Bio-Rad protein assay (Hercules, CA) and bovine albumin standards for calibration curves. Equal amounts of protein from each lysed supernatant (40 µg) were denatured in 3x modified Laemmli sample buffer (Bio-Rad), loaded onto 4% to 15% gradient gels (Bio-Rad), and electrophoresed at 100 V. The separated proteins were transferred onto polyvinylidene difluoride membranes that were blotted with 5% nonfat dry milk in TBS (Bio-Rad) for 1 h and then incubated overnight at 4°C with antibodies against HSP70 (Stressgen Biotechnologies, Victoria, British Columbia, Canada), HSP90 (Stressgen Biotechnologies), Akt (Cell Signaling Technology, Danvers, MA), phosphorylated Akt (Ser473, 587F11, Cell Signaling Technology), Raf-1 (C-12, Santa Cruz Biotechnology, Inc., Santa Cruz, CA), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH; Chemicon International, Inc., Temecula, CA). The immunoreactive signals were detected with ELC detection reagents (Perkin-Elmer Life Sciences, Boston, MA) following the manufacturer's instructions. The density of each signal was quantitated using UN-Scan-It software (Silk Scientific, Inc., Orem, UT). Densities of the same-sized areas from each band, as well as selected background, were digitized. The ratio between each band of interest and the loading control band (GAPDH) were calculated. These ratios were then further normalized by comparing the ratio from each time point after 17AAG treatment with the corresponding density ratio for that specific patient's pretreatment sample. Other PBMC samples had their HSP70 content determined by ELISA (StressXpress HSP70 ELISA kit, Stressgen Biotechnologies) using reagents and instructions provided by the manufacturer.
| Results |
|---|
|
|
|---|
|
The most common drug-related toxicities reported were grades 1 or 2 fatigue, anorexia, weight loss, diarrhea, nausea, constipation, and vomiting (Table 5
). Reversible elevations of liver enzymes (mainly alkaline phosphatase, AST, and
-glutamyl transpeptidase) were the most common grade 3/4 toxicities seen, occurring in 20 (47%) patients. Hematologic toxicity was minimal, with the exception of one episode of grade 3 thrombocytopenia. (Table 5). As in our previous phase I study of weekly 17AAG administration, a mildly unpleasant odor that usually lasted for a few days after each dose of 17AAG was consistently noticed by family members and nursing staff (7).
|
Assessment of HSP90 and client proteins in PBMCs. Concentrations of HSP90, HSP70, Akt, phosphorylated Akt, Raf-1, and GAPDH were assessed by Western blot analysis in PBMCs isolated from 11 patients on schedule A. Six of the patients had been treated with 100 mg/m2 17AAG, three had been treated with 125 mg/m2 17AAG, and two had been treated with 150 mg/m2 17AAG during both cycles 1 and 2. There was great interpatient variability in the cycle 1 predose values for these proteins. Even with equivalent protein loading on the gels, the predose ratios for HSP70 to GAPDH varied from 0.25 to 1.38. Similarly, the values for HSP90, phosphorylated Akt, Akt, and Raf-1 ratios to GAPDH in predose PBMC samples ranged from 0.26 to 0.96, 0.37 to 1.51, 0.34 to 0.76, and 0.32 to 0.92, respectively. Representative Western blots from PBMCs of a patient treated with 100 mg/m2 17AAG are shown in Fig. 1 .
|
|
| Discussion |
|---|
|
|
|---|
The DLT of headache and abdominal pain has not been reported in other trials of 17AAG (610). The etiology of the severe headache seen in two patients remains unclear. It is notable that much higher doses of 17AAG have been administered in other studies and have not caused headaches. The etiology for abdominal pain is also unclear. Pancreatitis following 17AAG therapy has been reported previously (7), but laboratory and radiological evaluations of the patients in the current study were not consistent with that diagnosis. Some of these side effects may be due to DMSO, which is needed for formulation of 17AAG. Although reversible elevations of liver enzymes were often seen, they were not dose limiting.
A twice-a-week schedule of 17AAG was associated with a persistent increase of HSP70, which may be a useful biomarker. However, a correlation between increase in HSP70 levels and clinical variables of activity, such as response, time-to-progression, or survival, has not been shown to date. Consequently, other biomarkers of 17AAG treatment are being investigated. Plasma concentrations of insulin-like growth factor binding protein-2 and the extracellular domain of erb-B2 are decreased in human tumor xenograft-bearing mice after treatment with17AAG (18), but this pharmacodynamic response does not occur in the plasma of patients treated with 17AAG (19).
In summary, administration of 17AAG by a twice-a-week schedule is well tolerated. Because in vitro and in vivo preclinical studies have shown an additive or synergistic effect when 17AAG is combined with several traditional and targeted antitumor agents (11), phase I studies of 17AAG combined with agents, such as taxanes, imatinib, trastuzumab, and bortezomib, have been initiated (2, 2022). The results of the current single-agent phase I study should allow greater flexibility in expanding these combination strategies.
| Acknowledgments |
|---|
| Footnotes |
|---|
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Note: Presented in part at the 41st Annual Meeting of the American Society of Clinical Oncology, Orlando, FL, May 2005.
Received 9/ 6/06; revised 11/10/06; accepted 12/ 5/06.
| References |
|---|
|
|
|---|
Commentary
This article has been cited by other articles:
![]() |
Fang Yi, Pingjun Zhu, N. Southall, J. Inglese, C. P. Austin, Wei Zheng, and L. Regan An AlphaScreenTM-Based High-Throughput Screen to Identify Inhibitors of Hsp90-Cochaperone Interaction J Biomol Screen, March 1, 2009; 14(3): 273 - 281. [Abstract] [PDF] |
||||
![]() |
F. KOGA, K. KIHARA, and L. NECKERS Inhibition of Cancer Invasion and Metastasis by Targeting the Molecular Chaperone Heat-shock Protein 90 Anticancer Res, March 1, 2009; 29(3): 797 - 807. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. Banerji Heat Shock Protein 90 as a Drug Target: Some Like It Hot Clin. Cancer Res., January 1, 2009; 15(1): 9 - 14. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. B. Solit, I. Osman, D. Polsky, K. S. Panageas, A. Daud, J. S. Goydos, J. Teitcher, J. D. Wolchok, F. J. Germino, S. E. Krown, et al. Phase II Trial of 17-Allylamino-17-Demethoxygeldanamycin in Patients with Metastatic Melanoma Clin. Cancer Res., December 15, 2008; 14(24): 8302 - 8307. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. S. Ramalingam, M. J. Egorin, R. K. Ramanathan, S. C. Remick, R. P. Sikorski, T. F. Lagattuta, G. S. Chatta, D. M. Friedland, R. G. Stoller, D. M. Potter, et al. A Phase I Study of 17-Allylamino-17-Demethoxygeldanamycin Combined with Paclitaxel in Patients with Advanced Solid Malignancies Clin. Cancer Res., June 1, 2008; 14(11): 3456 - 3461. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Xu and L. Neckers Targeting the Molecular Chaperone Heat Shock Protein 90 Provides a Multifaceted Effect on Diverse Cell Signaling Pathways of Cancer Cells Clin. Cancer Res., March 15, 2007; 13(6): 1625 - 1629. [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Cancer Research | Clinical Cancer Research |
| Cancer Epidemiology Biomarkers & Prevention | Molecular Cancer Therapeutics |
| Molecular Cancer Research | Cancer Prevention Research |
| Cancer Prevention Journals Portal | Cancer Reviews Online |
| Annual Meeting Education Book | Meeting Abstracts Online |