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Biomedical subjects

G R Blackledge

Publications and source records attributed to G R Blackledge.

At least 19 recordsLinked to original sources
PubMed2005

Developing an oncology portfolio of anticancer drugs: the experience of one pharmaceutical company.

For a company or institute that wishes to develop new anti-cancer agents, it is necessary to establish a portfolio of agents to reduce the risk of failure. Success rates for developing new agents are low and therefore different biological effect areas should be explored to ensure that at least one agent targeting cancer or a specific histological sub-type of cancer is effectively developed. This paper describes how one pharmaceutical company has developed a range of different agents with the ultimate aim of developing as many of these as is technically feasible into useful new medicines for the treatment of cancer.

Angiogenesis Inhibitors↗
PubMed1998

Bicalutamide (Casodex) in the treatment of prostate cancer: history of clinical development.

BACKGROUND: Bicalutamide (Casodex) is a new nonsteroidal antiandrogen developed for use in patients with prostate cancer. The efficacy and tolerability of bicalutamide as monotherapy and as combination therapy for patients with advanced prostate cancer have been evaluated in randomized clinical trials. Clinical trials are currently in progress to further evaluate bicalutamide as monotherapy in patients with advanced stages of disease and as adjuvant or first-line therapy in patients with early-stage disease. METHODS: A review of published trials of bicalutamide focusing on dose-ranging investigations, phase II and phase III monotherapy trials, a phase III trial of combined androgen blockade, and a safety overview. RESULTS: In dose-ranging trials, bicalutamide doses of 10-200 elicited biochemical, objective, and subjective responses; higher bicalutamide doses (up to 600 mg) have also been evaluated. A 50-mg daily dose of bicalutamide was initially evaluated as monotherapy in phase II and phase III trials; in subsequent trials, a 150-mg daily dose was investigated. A 150-mg daily dose is considered to provide equivalent survival outcome compared with castration in patients with locally advanced prostate cancer, whereas the benefits of a better quality of life and better palliation with the 150-mg daily bicalutamide dose relative to castration in patients with metastatic disease needs to be balanced against the small shortfall (median difference, 42 days) in survival. In combination with a luteinizing hormone-releasing hormone agonist analogue (LHRH-A), a 50-mg daily dose of bicalutamide has equivalent efficacy to a corresponding flutamide (250 mg three times daily) combination regimen. Treatment with the bicalutamide combination regimen resulted in a longer median survival than with the flutamide combination regimen. Bicalutamide is well tolerated when used as monotherapy or in combination with a LHRH-A. The benefits of bicalutamide as monotherapy include retention of libido and sexual potency and as combination therapy a lower incidence of diarrhea relative to flutamide. CONCLUSIONS: A 50-mg daily dose of bicalutamide is sufficient when given in combination with an agent, such as a LHRH-A, that lowers serum testosterone, but higher doses of bicalutamide may be needed when the drug is given as monotherapy. Bicalutamide, 50-mg daily, is a logical first choice for antiandrogen therapy when used in combination with an LHRH-A for the treatment of patients with advanced prostate cancer. Bicalutamide 150-mg daily is considered an effective monotherapy for use in patients with locally advanced disease. Additional clinical trials are currently in progress to further evaluate bicalutamide as a monotherapy for advanced prostate cancer and to assess its value as adjuvant or first-line therapy for early-stage prostate cancer.

Anilides↗
PubMed1998

Casodex (bicalutamide) 150-mg monotherapy compared with castration in patients with previously untreated nonmetastatic prostate cancer: results from two multicenter randomized trials at a median follow-up of 4 years.

OBJECTIVES: To compare the efficacy, tolerability, and quality of life benefits of bicalutamide (Casodex) 150-mg/day monotherapy and castration in previously untreated nonmetastatic (M0) advanced prostate cancer. METHODS: A total of 480 patients with Stage T3/T4 nonmetastatic disease randomly received oral bicalutamide 150 mg/day or castration (either bilateral orchiectomy or goserelin acetate [Zoladex] 3.6 mg every 28 days) in a 2:1 ratio in two open multicenter studies (studies 306 and 307). The design of these studies was similar to allow a pooled analysis. RESULTS: In the combined survival analysis, at median follow-up of 202 and 205 weeks in studies 306 and 307, respectively, with 31% of the cases resulting in death, bicalutamide 150-mg monotherapy was statistically equivalent to castration; the risk of death from any cause was 7% less with bicalutamide than with castration (hazard ratio [HR] = 0.93). Data on time to treatment failure and objective progression could not be pooled, as results for these end points differed between the trials. In study 306, bicalutamide 150-mg monotherapy increased time to objective progression (HR = 0.58; P = 0.033) and treatment failure (HR = 0.66; P = 0.074), whereas in study 307, time to progression (HR = 1.35; P = 0.0471) and treatment failure (HR = 1.24; P = 0.097) favored castration. Bicalutamide therapy showed significant advantages over castration for both sexual interest (P = 0.029) and physical capacity (P = 0.046). Bicalutamide 150-mg monotherapy was well tolerated. CONCLUSIONS: Bicalutamide 150-mg monotherapy provides a similar survival outcome to castration in previously untreated patients with nonmetastatic advanced prostate cancer and confers statistically significant benefits over castration with respect to sexual interest and physical capacity.

Aged↗
PubMed1997

Casodex (bicalutamide): overview of a new antiandrogen developed for the treatment of prostate cancer.

Casodex (bicalutamide, Zeneca Ltd), has been developed for prostate cancer therapy. Its preclinical, pharmacokinetic, pharmacodynamic, clinical efficacy and tolerability data are described. Casodex is a potent and specific non-steroidal antiandrogen. Clinical studies indicated that Casodex is orally bioavailable and well absorbed, with a plasma half-life of around 1 week. A Casodex dose of 50 mg daily decreased prostatic acid phosphatase comparable with castration. This dose was, therefore, evaluated initially as monotherapy and later as a component of maximal androgen blockade. Using prostate specific antigen as an end point, Casodex 150 mg daily was well-tolerated with demonstrable evidence of activity. Casodex 150 mg monotherapy was less effective than castration in terms of efficacy in patients with metastatic disease at entry. However, in patients non-metastatic at entry, Casodex 150 mg monotherapy appeared to be equivalent to castration in terms of time to death (data immature). Casodex was well-tolerated. In combination treatment, Casodex at 50 mg daily was at least as effective as 750 mg flutamide (Eulexin, Schering-Plough International) with respect to time to treatment failure, equivalent in terms of survival, and better tolerated with respect to diarrhoea. In conclusion, Casodex is a good option for the antiandrogen component of maximal androgen blockade.

Androgen Antagonists↗
PubMed1996

A randomised phase III cross-over study of tamoxifen versus megestrol acetate in advanced and recurrent breast cancer.

139 peri- and postmenopausal women with advanced or recurrent breast cancer who had not received prior hormonal therapy were randomised in an open, cross-over study comparing the synthetic progestogen megestrol acetate with tamoxifen. The response rate (CR/PR) to megestrol acetate (25%; 95% confidence interval (CI) 15-35%) was not significantly different from that produced by tamoxifen (33%, CI 22-44%). Time-to-treatment failure was also similar in the two groups. Cross-over treatment was given on progression in 76 cases. Cross-over response (CR/PR) was seen in 3 of 35 patients (9%) receiving megestrol acetate as second-line therapy and in 6 of 41 patients (15%) receiving tamoxifen second-line. There was no significant difference in survival between the groups (P = 0.17) with median survival times of 24 and 32 months for the megestrol acetate and tamoxifen groups, respectively. The toxicity profile of the two drugs was different, although significant toxicity was rare with either agent. Megestrol acetate is an effective treatment for advanced breast cancer in older women when used either as first- or second-line treatment. Cross-over response is seen following both treatments. Given that most patients now receive tamoxifen as adjuvant treatment, megestrol acetate would appear to be one of the logical choices for patients who find the side-effects of tamoxifen unacceptable and for those who relapse on tamoxifen with further hormone therapy being clinically indicated.

Adult↗
PubMed1996

High-dose bicalutamide monotherapy for the treatment of prostate cancer.

OBJECTIVES: Bicalutamide is a nonsteroidal competitive inhibitor of androgens at the androgen receptor. The level of blockade that can be achieved is dependent on the relative numbers of molecules of the agonist and the competitive antagonist around the receptor. Increasing the dose of a competitive inhibitor, therefore, should potentially increase the level of blockade. Bicalutamide has been investigated extensively at daily doses up to 150 mg, and there is evidence of increasing blockade at doses up to this point, as evidenced by increasing suppression of prostate-specific antigen (PSA) and also improvement in response rate, both subjective and objective. At doses of up to 150 mg, increases in plasma concentration of bicalutamide were approximately linear, and all doses were equally well tolerated. It was thought, therefore, that there was a case for investigating higher doses of bicalutamide to determine whether increased androgen blockade could be achieved with the use of bicalutamide as monotherapy. METHODS: A number of studies have now been carried out evaluating bicalutamide in daily doses of 200 mg, 300 mg, and 450 mg. The 200-mg dose has been evaluated as a primary treatment for advanced prostate cancer and also as a second-line treatment option for patients who have demonstrated a flutamide withdrawal response. RESULTS: In noncomparative trials, the decline in PSA value associated with daily doses of 200 mg bicalutamide was greater than that observed with daily doses of 150 mg, and there was also a slightly higher response rate. When 200 mg daily doses were used as therapy following failure of flutamide in combination with castration, and also following evidence of a flutamide withdrawal response, further responses were seen, perhaps suggesting the theory that in some prostate cancer cell mutations, bicalutamide acts as a pure antagonist rather than as a partial agonist. More recently, bicalutamide has been evaluated at higher doses: 20 patients have been exposed for periods up to 6 months at daily doses of 300 mg. This dose was well tolerated, and evidence of PSA suppression and responses were seen that were at least equivalent to those observed at lower doses. Pharmacokinetics evaluation has been carried out at this dose, and there is now evidence of nonlinearity of plasma concentrations, suggesting that further dose escalation is unlikely to confer major additional benefit over the 150- and 200-mg doses. To confirm the evidence of nonlinearity of plasma concentrations at doses > 200 mg, a randomization between 450 mg bicalutamide and medical castration is currently being carried out. Patients are still being recruited into this trial, but there has been no evidence of any change in the tolerability profile of bicalutamide at any dose > 150 mg. CONCLUSIONS: In summary, bicalutamide has shown increasing evidence of activity as a competitive blocker of the androgen receptor at daily doses of up to 200 mg. At daily doses > 200 mg, there is evidence of nonlinearity of plasma concentrations, and therefore further benefit is unlikely to be seen as a result of further escalating the dose of bicalutamide.

Androgen Antagonists↗
PubMed1996

Worldwide activity and safety of bicalutamide: a summary review.

OBJECTIVES: To evaluate bicalutamide as a therapy in nearly 3000 patients with advanced prostate cancer and to determine the dose-ranging, pharmacodynamic, and pharmacokinetic properties of bicalutamide. To evaluate bicalutamide as a monotherapy or in combination with luteinizing hormone-releasing hormone analogue (LHRH-A) therapy. RESULTS: Bicalutamide is a potent, nonsteroidal antiandrogen with a plasma half-life consistent with a once-daily schedule. Monotherapy trials with 50 mg of bicalutamide established its intrinsic activity, as demonstrated by subjective and objective responses and decreases in PSA concentrations. In comparison with castration, 50 mg of bicalutamide monotherapy was inferior with respect to survival. In a randomized, double-blind (for antiandrogen therapy) trial, with a median follow-up of 49 weeks, 50 mg of bicalutamide plus an LHRH-A was superior (P = 0.005) to flutamide plus an LHRH-A in delaying time-to-treatment failure and was better tolerated, as was evident from a significantly (P < 0.001) lower incidence of diarrhea and fewer withdrawals for adverse events among bicalutamide-treated patients. With longer follow-up and a 34% mortality, survival was equivalent between groups. Dose-related effects of bicalutamide on serum PSA concentrations were clearly demonstrated in the clinical trial program. With a total exposure of > 2800 patient-years, bicalutamide has been shown to be a well-tolerated therapy with a low incidence of treatment-related withdrawals. CONCLUSIONS: Bicalutamide is a new antiandrogen that offers the convenience of once-daily administration, demonstrated activity in prostate cancer, and an excellent safety profile. Because it is effective and offers better tolerability than flutamide, bicalutamide represents a valid first choice for antiandrogen therapy in combination with castration for the treatment of patients with advanced prostate cancer.

Androgen Antagonists↗
PubMed1996

Clinical progress with a new antiandrogen, Casodex (bicalutamide).

Casodex (bicalutamide, Zeneca Limited) is a nonsteroidal competitive inhibitor of androgens at the androgen receptor. The drug was developed to fulfil a number of needs for the treatment of prostate cancer. The specific aim was to demonstrate pharmacological activity, which would translate into clinical efficacy, good tolerability in the context of its use, oral availability, a convenient and forgiving dosing regimen, and clinical acceptability. Casodex has been shown to be orally bioavailable and well absorbed, with a plasma half-life of around 1 week. Although steady-state levels are not reached for 1 month, there is evidence that the androgen receptor blockade achieved with Casodex is equivalent to that of flutamide by the end of the first day. The dose of Casodex was established in a series of dose-ranging studies using the surrogate endpoints of prostatic acid phosphatase (PAP) and prostate-specific antigen (PSA). Initial studies suggested that a dose of 50 mg daily gave a fall in PAP equivalent to that seen with castration. This dose was, therefore, evaluated as monotherapy and subsequently as a component of combined androgen blockade. Higher doses were evaluated using PSA as a surrogate endpoint and, although doses up to 450 mg have been given to man, 150 mg daily is well tolerated with demonstrable evidence of activity. Although trials of the drug at 150 mg in monotherapy have, to date, not shown survival equivalence with castration, Casodex has been well tolerated with evidence of good symptomatic response and quality-of-life benefits including the potential of retaining libido. In combination treatment, Casodex is associated with significantly less gastrointestinal effects (diarrhoea) than the nonsteroidal antiandrogen flutamide (Eulexin, Schering-Plough International). Casodex is not associated with alcohol intolerance, pneumonitis and ocular defects which have been seen with the antiandrogen nilutamide (Anandron, Roussel). Moreover, since Casodex is a nonsteroidal antiandrogen, no steroidal effects have been seen.

Absorption↗
PubMed1995

A prospective randomized trial to evaluate different oral dose regimens of medroxyprogesterone acetate in women with advanced breast cancer.

A prospective randomized study was conducted to try to answer two questions: is a loading dose of medroxyprogesterone acetate (1000 mg p.o. q.d.s. for 48 h) superior to conventional dosing; and does an oral maintenance dose of 1000 mg daily offer any advantage over 500 mg daily in women with advanced breast cancer who have failed to respond to, or have relapsed after, tamoxifen? Of 211 patients randomized, 207 were evaluable. There was no improvement in response rates, time to response, response duration or overall survival as a result of the loading dose. When comparing high and low maintenance doses, there was a significant difference in response rates (48% versus 32%; chi 2 = 10.09, df = 2, P = 0.006) and survival (66% versus 41% alive at 12 months; chi 2 = 9.06, df = 1, P = 0.003) in favour of the higher dose regimen, although there was no significant difference in the duration of response. There was no additional toxicity attributable to the loading dose regimen, but side effects were more frequent with the high dose maintenance schedule (141 of 201 adverse effects occurring in these two groups) although the incidence of severe toxicity was similar with both high dose and low dose treatments.

Administration, Oral↗
PubMed1995

Multicentre cross-over study of aminoglutethimide and trilostane in advanced postmenopausal breast cancer.

Trilostane and aminoglutethimide, both given with a physiological replacement dose of hydrocortisone, were randomly allocated to 112 eligible patients with postmenopausal advanced breast cancer. Following treatment failure on either drug the patient continued with the other, if they were in a suitable clinical condition. Sixty-three patients initially received trilostane, of whom 33 subsequently received aminoglutethimide; 49 patients initially had aminoglutethimide and 14 of these then received trilostane. Both groups of patients were comparable in all respects. There was no difference in the response rate to either drug or in the average time to disease progression for the two drugs. Of the 47 patients who received both drugs, nine (19%) showed a response to both, indicating no cross-resistance. Side effects were seen to both drugs in approximately half the patients; these were mainly gastrointestinal symptoms with trilostane and rashes and drowsiness with aminoglutethimide. There was no evidence of cross-over patient susceptibility to side effects.

Administration, Oral↗
PubMed1994

Role of prostate-specific antigen as a predictor of outcome in prostate cancer.

Prostate-specific antigen (PSA) has been shown over the past few years to be a useful and sensitive marker for prostate cancer. During Phase III studies of the nonsteroidal antiandrogen, Casodex, in which different doses were compared with castration (either surgical or medical), serum PSA was measured on a regular basis. Attention was focused on the change in serum PSA from baseline after 3 months Casodex treatment and also on the number of patients receiving Casodex whose PSA returned to the normal range. Data from trials comparing Casodex, 50 mg/day, with castration showed a clear shortfall for Casodex compared with castration, in terms of percentage fall in PSA at 3 months, and also in the number of patients whose PSA fell into the normal range after 3 months. Subsequent analysis showed, however, that the PSA level was related to outcome in terms of time to progression. These data allowed the use of PSA to determine dose selection in a subsequent trial comparing Casodex, 100 mg/day or 150 mg/day, with castration. At the time of dose selection, changes in PSA showed a statistically significant difference between Casodex, 100 mg/day, and castration, but no significant difference between Casodex, 150 mg/day, and castration, either for the change in PSA at 3 months or for the proportion of patients whose PSA had fallen into the normal range. The idea that serum PSA levels can predict outcome in prostate cancer and that they are correlated with other measures of outcome, such as time to progression, is supported by these data. A decrease in PSA is not a true surrogate endpoint in that it cannot predict the outcome for an individual patient with complete accuracy, but it does correlate well with other measures of outcome, such as time to progression, for patient populations.

Analysis of Variance↗
PubMed1994

A phase I/II trial of recombinant human granulocyte-macrophage colony-stimulating factor in the intensification of cisplatin and cyclophosphamide chemotherapy for advanced ovarian cancer.

A pilot study was undertaken in eight patients to assess the feasibility of recombinant human granulocyte-macrophage colony-stimulating factor (rH GM-CSF) support to intensify standard chemotherapy for advanced ovarian cancer using a shortened 15 day treatment interval. Only four patients completed the course of six cycles of cisplatin 75 mg m-2 and cyclophosphamide 750 mg m-2 with rH GM-CSF, 3-5 micrograms kg-1 day-1, days 3-14, but one of these suffered a toxic death on study. Another died of disease progression. There were two episodes of life-threatening infection (WHO grade 4), and three patients were withdrawn because of various rH GM-CSF-related problems. Although potentially affording some patients the hypothetical benefits of dose intensification, as well as the possible attraction of a shorter duration of chemotherapy, this regimen is not without problems.

Adenocarcinoma↗
PubMed1994

Intervention debulking surgery in advanced epithelial ovarian cancer.

OBJECTIVE: To study whether intervention debulking surgery improves survival in patients with advanced ovarian cancer who have bulky (> 2 cm) residual disease after primary surgery. DESIGN: A prospective multicentre randomised study. SETTING: Hospitals in the West Midlands. SUBJECTS: Ovarian cancer patients with bulky residual disease after primary surgery who are considered well enough to receive cis-platinum based chemotherapy and further surgery. METHODS: Eligible patients were randomised to receive combination chemotherapy alone or combined with intervention debulking surgery. MAIN OUTCOME MEASURE: Survival was assessed using product limit method and log-rank test. RESULTS: Seventy-nine patients were entered into the study. Thirty-seven patients were randomised to intervention debulking surgery, 25 (67%) of whom underwent intervention debulking surgery, which was performed a median of 13 weeks after primary surgery. The median survival for the intervention debulking surgery group was 15 months (95% CI 10-20 mo) and that of those randomised to chemotherapy alone, which was 12 months (95% CI 8-16 mo), were not significantly different (hazard ratio = 0.71; 95% CI 0.44-1.13). CONCLUSION: Intervention debulking surgery may not improve survival in patients with advanced ovarian cancer.

Adult↗
PubMed1994

ChlVPP/PABlOE and radiotherapy in advanced Hodgkin's disease. The Central Lymphoma Group.

PURPOSE: The United Kingdom Central Lymphoma Group (CLG) has modified mechlorethamine, vincristine, procarbazine, and prednisone/doxorubicin, bleomycin, vinblastine, and dacarbazine (MOPP/ABVD) by substituting mechlorethamine with chlorambucil and dacarbazine with etoposide in the treatment of patients with advanced Hodgkin's disease (HD). Prednisolone is included in the bleomycin-containing combination, and the vinca alkaloids have been switched to balance the myelotoxicity of the two component regimens. PATIENTS AND METHODS: The resulting ChlVPP/PABlOE regimen is as follows: on days 1 to 14, chlorambucil 6 mg/m2 orally, procarbazine 100 mg/m2 orally, and prednisolone 30 mg/m2 orally; on days 1 and 8, vinblastine 6 mg/m2 intravenously (i.v.); on day 29, doxorubicin 40 mg/m2 i.v.; on days 29 and 36, vincristine 1.4 mg/m2 (maximum, 2 mg) i.v., and bleomycin 10 mg/m2 i.v.; on days 30, 31, and 32, etoposide 200 mg/m2/d orally; on days 29 to 43, inclusive, prednisolone, 30 mg/m2 orally. The second full cycle restarts on day 50. Treatment continues to maximum response plus two full cycles, but with a minimum of three full cycles. Radiotherapy is administered, after chemotherapy, to sites of previously bulky disease. Since 1983, 216 patients with previously untreated, advanced Hodgkin's disease (HD) have entered this study. RESULTS: The complete remission (CR) rate after chemotherapy was 73% (95% confidence interval [CI], 67% to 79%), and after additional radiotherapy was 85% (95% CI, 80% to 90%). The failure-free survival (FFS) rate at 5 years was 68% (95% CI, 61% to 74%), and the overall actuarial survival at 5 years was 78% (95% CI, 72% to 84%). The CR rate in patients in the poorer prognostic categories was high: 81% in patients with albumin levels less than 37 g/L, 79% in patients older than 40 years of age, 84% in stages IIIB plus i.v. disease, and 79% in patients presenting with B symptoms. As expected, nausea and vomiting were not major problems, although infection, often in the context of myelosuppression, complicated almost half the cases, and 29% of patients required admission at some stage for treatment of infection. CONCLUSION: In this multicenter study, ChlVPP/PABlOE produced results comparable to those reported for MOPP/ABVD, but with less nausea and vomiting. Treatment duration was shorter than in the original MOPP/ABVD regimen, and than that used in the Cancer and Leukemia Group B (CALGB) trial. It will now be compared with PABlOE alone.

Adult↗
PubMed1993

The West Midlands epithelial ovarian cancer adjuvant therapy trial.

In a multicentre prospective randomized controlled trial, single agent cisplatinum was compared with whole abdomino-pelvic moving strip radiotherapy in the management of Stage IC-III epithelial ovarian cancer patients who had no macroscopic residual disease after primary surgery. Over a 6-year period 40 eligible patients were recruited, 15 of whom had Stage III disease. The overall 5-year survival was 60% with no significant survival difference between the treatment groups. Acute toxicity was common in both arms and six (11%) patients experienced significant long term disability.

Chemotherapy, Adjuvant↗
PubMed1993

Multicentre cross over study of aminoglutethimide and trilostane in advanced postmenopausal breast cancer.

Trilostane and Aminoglutethimide, each given with a physiological replacement dose of hydrocortisone, were randomly allocated to 72 eligible postmenopausal advanced breast cancer patients; following treatment failure on either drug the patient continued with the other drug, if in a suitable clinical condition. Thirty-eight patients initially received Trilostane of whom 19 subsequently received Aminoglutethimide; 34 patients initially had Aminoglutethimide and seven of these then received Trilostane. Both groups of patients were comparable in all respects. There was no difference in the objective response rate to either drug, Trilostane 11/38 = 29%, Aminoglutethimide 12/34 = 35%, nor in the average time to disease progression for the two drugs, Trilostane 64 weeks, Aminoglutethimide 68 weeks. Of the 26 patients who received both drugs, four showed a response to both suggesting no cross resistance. Side effects were seen to both drugs in approximately half of the patients, but were mainly gastro-intestinal with Trilostane and rash and drowsiness with Aminoglutethimide. There was no evidence of cross over patient susceptibility to side effects.

3-Hydroxysteroid Dehydrogenases↗
PubMed1992

Phase I trial of temozolomide (CCRG 81045: M&B 39831: NSC 362856).

Temozolomide (CCRG 81045: M&B 39831: NSC 362856) is an analogue of mitozolomide displaying similar broad spectrum activity in mouse tumours, but showing considerably less myelosuppression in the toxicology screen. Temozolomide was initially studied intravenously at doses between 50-200 mg m-2 and subsequently was given orally up to 1,200 mg m-2. A total of 51 patients were entered on the single dose schedule. Temozolomide exhibits linear pharmacokinetics with increasing dose. Myelotoxicity was dose limiting. Experimentally, temozolomide activity was schedule dependent and therefore oral administration was studied as a daily x 5 schedule between total doses of 750 and 1,200 mg m-2 in 42 patients. Myelosuppression was again dose limiting. The recommended dose for Phase II trials is 150 mg m-2 po for 5 days (total dose 750 mg m-2) for the first course, and if no major myelosuppression is detected on day 22 of the 4 week cycle, the subsequent courses can be given at 200 mg m-2 for 5 days (total dose 1 g m-2) on a 4 week cycle. Mild to moderate nausea and vomiting was dose related but readily controlled with antiemetics. Clinical activity was detected using the 5 day schedule in four (2CR, 2PR; 17%) out of 23 patients with melanoma and in one patient with mycosis fungoides (CR lasting 7 months). Two patients with recurrent high grade gliomas have also had partial responses. Temozolomide is easy to use clinically and generally well tolerated. In the extended Phase I trial temozolomide only occasionally exhibited the unpredictable myelosuppression seen with mitozolomide.

Adult↗