Search PubMed⌕ Search

Biomedical subjects

T S Ganesan

Publications and source records attributed to T S Ganesan.

At least 19 recordsLinked to original sources

Phase I and pharmacokinetic study of PKC412, an inhibitor of protein kinase C.

PURPOSE: N-Benzoyl staurosporine (PKC412) is a protein kinase C inhibitor with antitumor activity in laboratory models. We determined the toxicity of oral PKC412 administered daily for repeat cycles of 28 days. PATIENTS AND METHODS: Thirty-two patients with advanced solid cancers were treated at seven dose levels (12.5 to 300 mg daily) for a total of 68 cycles. RESULTS: The most frequent treatment-related toxicities were nausea, vomiting, fatigue, and diarrhea. At the two top dose levels (225 and 300 mg/d), 15 of 16 patients experienced nausea/vomiting (common toxicity criteria [CTC], version 1), grade 2 in nine of 16 and grade 3 in three of 16 patients; and six of 16 patients developed CTC grade 2 diarrhea. After 1 month of treatment, there were significant reductions in circulating lymphocyte (P <.02) and monocyte (P <.01) counts in patients receiving doses > or = 100 mg/d. Nevertheless, only two patients developed myelosuppression (both grade 2). Of two patients with progressive cholangiocarcinoma, one attained stable disease lasting 4.5 months and one a partial response lasting 4 months. There was a linear relationship between PKC412 dose and area under the curve (0-24 hours) and maximum plasma concentration with marked interpatient variability. The estimated median elimination half-life was 1.6 days (range, 0.9 to 4.0 days), and a metabolite with a median half-life of 36 days was detected. Steady-state PKC412 plasma levels at the top three dose cohorts (150 to 300 mg) were five to 10 times the cellular 50% inhibitory concentration for PKC412 of 0.2 to 0.7 micromol/L. CONCLUSION: PKC412 can be safely administered by chronic oral therapy, and 150 mg/d is suitable for phase II studies. The pharmacokinetics and lack of conventional toxicity indicate that pharmacodynamic measures may be additionally needed to optimize the drug dose and schedule.

Administration, Oral↗

Evaluation of the possible protective role of adeno-associated virus type 2 infection in HPV-associated premalignant disease of the cervix.

OBJECTIVE: Our objective was to examine the prevalence of adeno-associated virus (AAV) infection in women with normal cervical smears and those with HPV-associated cervical intraepithelial neoplasia (CIN). METHODS: HPV typing was performed on DNA from cervical smears of 211 women with CIN (CIN 1 = 83, CIN 3 = 128) and 433 healthy women who had a normal cervical smear. HPV typing was performed on all cases and controls using type-specific oligonucleotide primers (HPV 16, 18, 31, 33). AAV DNA was amplified by nested PCR from the same samples. The amplified DNA were separated on 2% agarose gels, blotted, and hybridized to AAV-2 DNA labeled by random priming with [alpha-(32)P]dCTP to confirm specificity of amplification. RESULTS: A total of 131 cases of CIN were positive for one of the HPV types either alone or in combination. HPV 16 was present in 120 (57%) cases, HPV 18 in 15 (7%), HPV 31 in 27 (13%), and HPV 33 in 15 (7%) and there were multiple HPV types detected in 34 (16%) cases. All of the controls were selected to be negative for HPV. A total of 6/433 (1.4%) control cervical smears and 4/211 (1.9%) of CIN (CIN1 = 2; CIN3 = 2) contained AAV DNA. No correlation between AAV and any clinical feature was observed. CONCLUSIONS: These results are different from some that have been previously published and suggest that AAV DNA is not frequently present in either normal control cervical samples or cervical intraepithelial neoplasia. This does not support the hypothesis that AAV may be protective against cervical cancer. Further research is necessary to understand the natural history of AAV infection and its role in human disease.

Adenovirus Infections, Human↗

Evaluation of toremifene for reversal of multidrug resistance in renal cell cancer patients treated with vinblastine.

PURPOSE: Expression of P-glycoprotein (Pgp), which confers the multidrug resistance (MDR) phenotype, is thought to contribute to the insensitivity of renal cell cancer (RCC) to chemotherapy. The development of Pgp inhibitors for clinical application has been hampered by unacceptable toxicity at doses required to achieve adequate cellular concentration. Toremifene is able to reverse MDR and sensitise RCC to vinblastine in vitro. However, in vivo toremifene is tightly bound to serum proteins, in particular the acute phase protein alpha1-acid glycoprotein (AAG), which may limit tissue availability. In this phase I-II study we assessed the tolerability of short courses of high dose toremifene in combination with vinblastine and evaluated the key determinants of MDR reversal in vivo. METHODS: Twenty-seven patients with metastatic RCC received escalating doses of oral toremifene for 3 days every 2 weeks in combination with vinblastine 6 mg/m2 i.v. on day 3 of each cycle. The serum concentration of toremifene, its metabolites and AAG were measured and the effect of patients' serum on inhibition of Pgp in vitro was determined. RESULTS: Twenty-six patients were evaluable for response. Eight patients (31%) had stable disease and 18 patients (69%) progressive disease. The mean serum concentration of toremifene at 780 mg daily for 3 days was 7.82 microM [standard deviation (SD) 2.48, range 2.50 to 14.70], which exceeds that known to reverse MDR in vitro. The serum concentration of the major metabolite of toremifene, N-demethyltoremifene, which also reverses MDR, was 5.13 microM (SD 1.78, range 1.80 to 9.00). In 60% of patients the pre-treatment AAG concentration was above that known to block the effects of toremifene in vitro. However, addition of serum from patients on toremifene to MCF-7 adr cells in vitro inhibited Pgp-mediated efflux of rhodamine 123. CONCLUSIONS: We have shown that short course, high-dose toremifene in combination with vinblastine is generally well tolerated and that the concentration of toremifene required to reverse MDR in vitro is achievable in vivo.

Administration, Oral↗

Phase II study of the oxygen saturation curve left shifting agent BW12C in combination with the hypoxia activated drug mitomycin C in advanced colorectal cancer.

BW12C (5-[2-formyl-3-hydroxypenoxyl] pentanoic acid) stabilizes oxyhaemoglobin, causing a reversible left-shift of the oxygen saturation curve (OSC) and tissue hypoxia. The activity of mitomycin C (MMC) is enhanced by hypoxia. In this phase II study, 17 patients with metastatic colorectal cancer resistant to 5-fluorouracil (5-FU) received BW12C and MMC. BW12C was given as a bolus loading dose of 45 mg kg(-1) over 1 h, followed by a maintenance infusion of 4 mg kg(-1) h(-1) for 5 h. MMC 6 mg m(-2) was administered over 15 min immediately after the BW12C bolus. The 15 evaluable patients had progressive disease after a median of 2 (range 1-4) cycles of chemotherapy. Haemoglobin electrophoresis 3 and 5 h after the BW12C bolus dose showed a fast moving band consistent with the BW12C-oxyhaemoglobin complex, accounting for approximately 50% of total haemoglobin. The predominant toxicities--nausea/vomiting and vein pain--were mild and did not exceed CTC grade 2. Liver 31P magnetic resonance spectroscopy of patients with hepatic metastases showed no changes consistent with tissue hypoxia. The principle of combining a hypoxically activated drug with an agent that increases tissue hypoxia is clinically feasible, producing an effect equivalent to reducing tumour oxygen delivery by at least 50%. However, BW12C in combination with MMC for 5-FU-resistant colorectal cancer is not an effective regimen. This could be related to drug resistance rather than a failure to enhance cytotoxicity.

Adult↗

Phase II study of second-line therapy with DTIC, BCNU, cisplatin and tamoxifen (Dartmouth regimen) chemotherapy in patients with malignant melanoma previously treated with dacarbazine.

This study assessed response rates to combination dacarbazine (DTIC), BCNU (carmustine), cisplatin and tamoxifen (DBPT) chemotherapy in patients with progressive metastatic melanoma previously treated with DTIC, as an evaluation of DBPT as a second-line regimen, and as an indirect comparison of DBPT with DTIC. Thirty-five consecutive patients received DBPT. The patients were divided into two groups. Group 1 comprised 17 patients with progressive disease (PD) on DTIC + tamoxifen therapy who were switched directly to DBPT. Group 2 comprised 18 patients not immediately switched to DBPT and included patients who had either a partial response (PR; one patient) or developed stable disease (SD; four patients) with DTIC, or received adjuvant DTIC (nine patients). All except four patients had received tamoxifen at the time of initial DTIC treatment. Median times since stopping DTIC were 22 days (range 20-41) and 285 days (range 50-1,240) in Groups 1 and 2 respectively. In Group 1, one patient developed SD for 5 months and the remainder had PD. In Group 2, there were two PRs, four patients with SD (4, 5, 6, and 6 months), and 11 with PD. These results indicate that the DBPT regimen is not of value in melanoma primarily refractory to DTIC. There were responses in patients not directly switched from DTIC to DBPT, suggesting combination therapy may be of value in a small subgroup of melanoma patients.

Adult↗

Induction of thymidine phosphorylase as a pharmacodynamic end-point in patients with advanced carcinoma treated with 5-fluorouracil, folinic acid and interferon alpha.

Thymidine phosphorylase (TP) is an essential enzyme for the biochemical activation of 5-fluorouracil (5-FU). Interferon upregulates TP in vivo, although the dose and schedule of interferon for optimal biomodulation of 5-FU is not known. In this study, TP activity was measured in peripheral blood lymphocytes (PBLs) from patients with advanced carcinoma receiving treatment with 5-FU and folinic acid. Cohorts of patients were treated with interferon alpha (IFNalpha), immediately prior to 5-FU/folinic acid, at doses of 3 MIU m(-2), 9 MIU m(-2) and 18 MIUm(-2). IFNalpha was administered on day 0 cycle two, day-1 and day 0 cycle three and day-2, day-1 and day 0 cycle four. A fourth cohort was treated with IFNalpha 9 MIU m(-2) three times per week from cycle 2 onwards. Twenty-one patients were entered into the study with 19 evaluable for response. Six patients (32%) had stable disease and 13 (68%) progressive disease. There were no grade-IV toxicities. TP activity was detected in PBLs from all patients with wide interpatient variability in constitutive TP activity prior to chemotherapy, and in response to IFNalpha. 5-FU/folinic acid alone did not induce TP activity but a single dose of IFNalpha led to upregulation of TP within 2 h of administration with a further increase by 24 h (signed rank test, P = 0.006). TP activity remained elevated for at least 13 days (signed rank test, P= 0.02). There were no significant differences in TP activity between schedules or with additional doses of IFNalpha. A single dose of IFNalpha as low as 3 MIU m(-2) can cause sustained elevation of PBL TP activity in vivo indicating that biochemical markers are important pharmacodynamic endpoints for developing optimal schedules of IFNalpha for biomodulation of 5-FU.

Aged↗

Overexpression of H-Ryk in epithelial ovarian cancer: prognostic significance of receptor expression.

H-Ryk is an atypical receptor tyrosine kinase that is expressed in a differentiation-specific manner in epithelial tissues. We have previously shown by in situ hybridization and immunohistochemistry that H-Ryk is overexpressed in malignant ovarian tumors. In addition, we have demonstrated that overexpression of H-Ryk is transforming in vitro and in vivo. To evaluate whether expression of H-Ryk is a prognostic factor in epithelial ovarian cancer, we carried out a retrospective study of 88 primary malignant ovarian tumors (28 serous tumors, 11 mucinous tumors, 29 endometrioid tumors, 13 clear cell tumors, 3 malignant mixed Mullerian tumors, 1 mixed epithelial tumor, 1 primary peritoneal tumor, 1 undifferentiated tumor, and 1 transitional carcinoma) diagnosed between 1990 and 1993 using immunohistochemistry. On univariate analysis, overall survival decreased significantly with age (P = 0.01); in patients with International Federation of Gynecology and Obstetrics (FIGO) stage II (P = 0.008), FIGO stage III (P < 0.001), and FIGO stage IV (P < 0.001) disease; and in patients with residual disease (residual disease < or = 2 cm, P = 0.007; residual disease > 2 cm, P < 0.001) after surgery. In addition, overexpression of the H-Ryk receptor in malignant epithelium (P = 0.04) and blood vessel (P = 0.01) was associated with a significantly decreased overall survival. H-Ryk blood vessel overexpression (P = 0.03), residual disease > 2 cm (P = 0.006), and residual disease < or = 2 cm (P = 0.01) conferred a significantly shorter progression-free survival. No correlation was found between H-Ryk overexpression and age, histological subtype, degree of differentiation, FIGO stage, or residual disease. Overall, after adjustment for all of the prognostic factors by multivariate analysis (Cox proportional hazards model), residual disease was the most powerful prognostic indicator for overall survival (P < 0.001) and progression-free survival (P = 0.01) in this patient subset. This implies that H-Ryk acts cooperatively with other biological factors in the pathogenesis of ovarian cancer.

Adult↗

A phase II study of razoxane, an antiangiogenic topoisomerase II inhibitor, in renal cell cancer with assessment of potential surrogate markers of angiogenesis.

Renal cell carcinoma (RCC) is an angiogenic tumor resistant to standard cytotoxic chemotherapeutic agents. Although often responsive to immunomodulatory agents including interleukin 2 and IFN-alpha, the overall results in randomized Phase III studies are disappointing with only modest improvements in overall survival. This Phase II study evaluated the efficacy and tolerability of razoxane, an antiangiogenic topoisomerase II inhibitor, in 40 patients (32 men, 8 women; age: range, 31-76 years; median, 58 years) with inoperable RCC. Twenty patients received razoxane 125 mg p.o., twice a day for 5 days each week for 8 weeks (one cycle). This was repeated in patients with stable disease (StD), but was discontinued after 16 weeks if there was no evidence of an objective response. Because minimal toxicity was seen, subsequent patients (n = 20) were treated until progressive disease (PD) was documented. Of 38 evaluable patients, 11 (29%) had StD for a minimum of 4 months, and the remainder had PD. Median overall survival was 7.3 months. Duration of survival was significantly better in patients with StD compared with those with PD (P = 0.003). The effect of treatment on six potential surrogate serum/plasma (vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), urokinase plasminogen activator soluble receptor (uPAsr), E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and von Willebrand's factor (vWF) and two urinary (VEGF and bFGF) markers of angiogenesis was evaluated before and after 1 cycle of treatment. Pretreatment serum VEGF and E-selectin levels above the median value were associated with a poor prognosis. Serum VCAM-1 levels and urinary VEGF levels rose significantly after one cycle in patients with PD but not in those with StD. Serum VEGF, bFGF, VCAM-1 and vWF, plasma uPAsr and urinary bFGF levels were significantly higher in PD patients compared with StD patients before and/or after 1 cycle of treatment. In conclusion, razoxane is an antiangiogenic agent that has minimal toxicity and that requires further evaluation in combination with other active agents in the treatment of RCC. Surrogate serum and urinary markers of angiogenesis may have a role to play in predicting disease response and overall survival in RCC.

Adult↗

Overexpression of H-Ryk in mouse fibroblasts confers transforming ability in vitro and in vivo: correlation with up-regulation in epithelial ovarian cancer.

Abnormalities in the function of receptor tyrosine kinases (RTKs) have been demonstrated to be important in the pathogenesis of cancer. H-Ryk, a new member of the RTK family, is an unusual RTK in that it is catalytically inactive because of amino acid substitutions of conserved residues in the catalytic domain. We show by immunohistochemistry that it is expressed in the epithelium, stroma, and blood vessels of normal tissues. Evaluation of a panel of 33 primary ovarian tumors (2 benign, 8 borderline, and 23 malignant) was performed. H-Ryk was overexpressed in borderline and malignant ovarian tumors. In serous and clear cell subtypes, there was increased expression in the epithelium, stroma, and blood vessels. Consistent with this observation, overexpression of H-Ryk in the mouse fibroblast cell line NIH3T3 induces anchorage-independent growth and tumorigenicity in nude mice. This implies that overexpression of the receptor can be transforming and may therefore be significant in the pathogenesis of ovarian cancer.

3T3 Cells↗

A phase II study of the modulation of 5-fluorouracil and folinic acid with high-dose infusional hydroxyurea in metastatic colorectal carcinoma.

BACKGROUND: Hydroxyurea (HU), an inhibitor of ribonucleotide reductase, may potentiate the activity of 5-fluorouracil (5-FU) and folinic acid (FA) by reducing the deoxyribonucleotide pool available for DNA synthesis and repair. However as HU may inhibit the formation of 5-fluoro-2-deoxyuridine-5-monophosphate (FdUMP), one of the principal active metabolites of 5-FU, the scheduling of HU may be critical. In vitro experiments suggest that administration of HU following 5-FU, maintaining the concentration in the region of 1 mM for six or more hours, significantly enhances the efficacy of 5-FU. PATIENTS AND METHODS: 5-FU/FA was given as follows: days 1 and 2-FA 250 mg/m2 (max. 350 mg) over two hours followed by 5-FU 400 mg/m2 by intravenous bolus (i.v.b.) over 15 minutes and subsequently 5-FU 400 mg/m2 infusion (ivi) over 22 hours. HU was administered on day 3 immediately after the 5-FU with 3 g i.v.b. over 15 minutes followed by 12 g ivi over 12 hours. RESULTS: Thirty patients were entered into the study. Median survival was nine months (range 1-51+ months). There were eight partial responses (28%, 95% CI: 13%-47%). The median duration of response was 6.5 (range 4-9 months). Grade 3-4 toxicities included neutropenia (grade 3 in eight patients and grade 4 in five), anaemia (grade 3 in one patient) and diarrhoea (grade 3 in two patients). Neutropenia was associated with pyrexia in two patients. Phlebitis at the infusion site occurred in five patients. The treatment was complicated by pulmonary embolism in one patient and deep venous thrombosis in another. CONCLUSION: HU administered in this schedule is well tolerated. Based on these results and those of other phase II studies, a randomised phase III study of 5-FU, FA and HU versus 5-FU and FA using the standard de Gramont schedule is recommended.

Adenocarcinoma↗

Phase I trial of the selective mitochondrial toxin MKT077 in chemo-resistant solid tumours.

BACKGROUND: MKT077 is a rhodacyanine dye analogue which preferentially accumulates in tumour cell mitochondria. It is cytotoxic to a range of tumours. In this phase I study, MKT077 was administered as a five-day infusion once every three weeks. PATIENTS AND METHODS: Ten patients, median age 59 (38-70) years, with advanced solid cancers were treated at three dose levels: 30, 40 and 50 mg/m2/day for a total of 18 cycles. 31Phosphorus magnetic resonance spectroscopy (MRS) was used to evaluate the effect of MKT077 on skeletal muscle mitochondrial function. RESULTS: The predominant toxicity was recurrent reversible functional renal impairment (grade 2, two patients). One patient with renal cancer attained stable disease and the remainder progressive disease. There were no MRS changes in the first or second treatment cycles but one patient received 11 treatment cycles and developed changes consistent with a mitochondrial myopathy. Mean values for all pharmacokinetic parameters were at sub micromolar levels and did not exceed IC50 values (> or = 1 microM). CONCLUSIONS: Because of the renal toxicity, and animal studies showing MKT077 causes eventual irreversible renal toxicity, further recruitment was halted. The study shows, however, that it is feasible to target mitochondria with rhodacyanine analogues, if drugs with higher therapeutic indices could be developed.

Adult↗

Functional analysis of H-Ryk, an atypical member of the receptor tyrosine kinase family.

H-Ryk is an atypical receptor tyrosine kinase which differs from other members of this family at a number of conserved residues in the activation and nucleotide binding domains. Using a chimeric receptor approach, we demonstrate that H-Ryk has impaired catalytic activity. Despite the receptor's inability to undergo autophosphorylation or phosphorylate substrates, we demonstrate that ligand stimulation of the chimeric receptor results in activation of the mitogen-activated protein kinase pathway. The ability to transduce signals is abolished by mutation of the invariant lysine (K334A) in subdomain II of H-Ryk. Further, by in vitro mutagenesis, we show that the amino acid substitutions in the activation domain of H-Ryk account for the loss of catalytic activity. In addition to the essential aspartate residue, either phenylalanine or glycine is required in the activation domain to maintain proper conformation of the catalytic domain and thus ensure receptor autophosphorylation. Homology modelling of the catalytic domain of H-Ryk provides a rationale for these findings. Thus, the signalling properties of H-Ryk are divergent from those of other classical receptor tyrosine kinases.

Amino Acid Sequence↗

Phase I study of the novel cyclic AMP (cAMP) analogue 8-chloro-cAMP in patients with cancer: toxicity, hormonal, and immunological effects.

The cyclic AMP (cAMP)-dependent protein kinase regulatory subunit RI is overexpressed in cancer cells. 8-Chloro-cAMP (8-Cl-cAMP) is an RII site-specific analogue that down-regulates RI and inhibits the growth of a wide range of cancer cells in vitro and in vivo. We performed a Phase I trial of 8-Cl-cAMP in 32 patients with malignancies that were refractory to standard treatments. 8-Cl-cAMP was initially given in a 1-month cycle by constant infusion at 0.005 mg/kg/h for 21 days, followed by 1 week of rest. The dose was escalated to 0.045 mg/kg/h, but hypercalcemia became the dose-limiting toxicity. The length of drug administration was, therefore, reduced to 5 days per week for the first 3 weeks of the cycle, but it was not possible to increase the drug dose without producing hypercalcemia. Hence, the length of drug administration was reduced to 3 days per week for the first 3 weeks of the cycle. The maximum tolerated dose for this regimen was 0.15 mg/kg/h, and the dose-limiting toxicities were reversible hypercalcemia and hepatotoxicity. Stable disease for > or =4 months was observed in two patients treated at > or =0.045 mg/kg. cAMP-dependent protein kinase is involved in hormone- and cytokine-mediated signaling, and so representative hormone, cytokine, and peripheral lymphocyte subsets were measured. The drug had a parathyroid hormone-like effect on calcium homeostasis and significantly increased circulating luteinizing hormone and 17-hydoxyprogesterone levels (P < 0.02 and P < 0.0006, respectively). We conclude that 8-Cl-cAMP is well tolerated without attendant myelotoxicity, and in this study, it was associated with biological effects. In Phase II studies, a dose of 0.11 mg/kg/h for 3 days per week would be appropriate.

8-Bromo Cyclic Adenosine Monophosphate↗

Cyclophosphamide, methotrexate and infusional 5-fluorouracil (infusional CMF) in metastatic breast cancer.

Bolus 5-fluorouracil (5-FU) is a phase-specific drug with a short plasma half-life that is used in combination with bolus cyclophosphamide and methotrexate in the treatment of breast cancer. The efficacy of 5-FU can be improved by continuous intravenous infusion using portable infusion pumps (infusional 5-FU). Infusional 5-FU, 200 mg m(-2) day(-1), in combination with standard doses of bolus cyclophosphamide and methotrexate, was evaluated in a phase I/II dose-finding study. The cyclophosphamide and methotrexate were administered in 28-day cycles as follows: cohort 1, cyclophosphamide 600 mg m(-2), days 1 and 8, and methotrexate 40 mg m(-2), day 1; cohort 2, cyclophosphamide 400 mg m(-2), days 1 and 8, and methotrexate 40 mg m(-2), day 1; cohort 3, cyclophosphamide 480 mg (m-2), days 1 and 8, and methotrexate 40 mg m(-2), day 1; cohort 4, cyclophosphamide 480 mg m(-2), days 1 and 8, and methotrexate 40 mg m(-2), days 1 and 8. Median overall survival was 10 months (range 3-21 months). Objective tumour responses were seen in 9 of 25 patients (36%, 95% CI 18-58%), including 3 of 13 patients (23%) previously treated for metastatic disease. Cohorts 1 and 4 proved to be too toxic, with five of six patients in cohort 1 and three of four in cohort 4 developing grade III/IV neutropenia. The dose intensity of cyclophosphamide achieved was as follows: cohort 1, 82%; cohort 2, 86%; cohort 3, 97%; cohort 4, 90%. Infusional 5-FU can be administered safely and is effective in combination with cyclophosphamide 480 mg m(-2), days 1 and 8, and methotrexate 40 mg m(-2), day 1, in the treatment of metastatic breast cancer.

Adult↗

Phase I study of the mitomycin C analogue BMS-181174.

BMS-181174 is an aminodisulphide derivative of Mitomycin C (MMC) with activity against a range of tumour cell lines and xenografts, including MMC-resistant tumours. In a phase I study of 82 patients with confirmed malignancy, we administered BMS-181174 at doses of 0.8-75 mg m(-2) by intravenous injection every 28 days. At least three patients were evaluated at each dose level, and 174 courses were administered. The pharmacokinetics were dose linear at BMS-181174 doses of 11.5-75 mg m(-2) and the drug appeared to undergo wide distribution. The maximum-tolerated dose was 65 mg m(-2) in previously treated patients and 75 mg m(-2) in chemotherapy-naive cases. The dose-limiting toxicity was myelosuppression, particularly thrombocytopenia, which was prolonged and cumulative. Three patients treated at 65-75 mg m(-2) died suddenly with evidence of pneumonia/pneumonitis, thought to be drug-related. Other toxicities included thrombophlebitis, possible cardiotoxicity (asymptomatic, reversible decline in left ventricular function) and renal impairment. The partial response rate was 5% (4 out of 82) overall, and 9% (3 out of 32) in patients treated at 65-75 mg m(-2). Responses occurred in treated and previously-untreated patients, including cases of colorectal cancer, non-small-cell lung cancer, ovarian cancer and adenocarcinoma of unknown primary site. BMS-181174 has anti-cancer activity but, because of its toxicity, particularly pneumonitis and thrombophlebitis, no phase II studies are planned.

Adult↗

A phase II study of bryostatin 1 in metastatic malignant melanoma.

Bryostatin 1 is a protein kinase C partial agonist which has both antineoplastic and immune-stimulatory properties, including the induction of cytokine release and expansion of tumour-specific lymphocyte populations. In phase I studies, tumour responses have been observed in patients with malignant melanoma, lymphoma and ovarian carcinoma. The dose-limiting toxicity is myalgia. Sixteen patients (age 35-76 years, median 57 years) with malignant melanoma were treated. All had received prior chemotherapy. In each cycle of treatment, patients received bryostatin 25 degrees g m(-2) weekly for three courses followed by a rest week. The drug was given in PET diluent (10 microg bryostatin ml(-1) of 60% polyethylene glycol, 30% ethanol, 10% Tween 80) and infused in normal saline over 1 h. The principal toxicities were myalgia (grade 2, eight patients and grade 3, six patients) and grade 2 phlebitis (four patients), fatigue (three patients) and vomiting (one patient). Of 15 patients evaluable for tumour response, 14 developed progressive disease. One patient developed stable disease for 9 months after bryostatin treatment. In conclusion, single-agent bryostatin appears ineffective in the treatment of metastatic melanoma in patients previously treated with chemotherapy. It should, however, be investigated further in previously untreated patients.

Adult↗

Immunohistochemical expression of inhibin/activin subunits in epithelial and granulosa cell tumours of the ovary.

Dimeric inhibin-A has been shown recently by a sensitive two-site ELISA assay to be a useful tumour marker in granulosa cell tumours of the ovary. It is also elevated in some patients with malignant epithelial ovarian tumours. To identify the precise subunits of inhibin expressed in ovarian tumours, three monoclonal antibodies, R1, E4, and INPRO (against the alpha C-, beta A-, and pro-alpha-subunits, respectively), were evaluated by immunohistochemistry on a panel of six granulosa cell and nine epithelial tumours. All granulosa cell tumours stained positively with E4 and R1, suggesting expression of dimeric inhibin-A; in two patients where serum levels were measured pre-operatively, they were elevated. The tumours also reacted weakly with INPRO, suggesting the presence of precursor forms of the alpha-subunit. Eight malignant epithelial ovarian tumours expressed the beta A-subunit only, as recognized by E4, while one tumour expressed both alpha- and beta A-subunits, which correlated with an elevated serum inhibin-A level. Thus, while granulosa cell tumours express inhibin, the majority of epithelial tumours probably express activin, a result which needs to be confirmed by serum measurements.

Activins↗