Pharmacokinetic study of solid-lipid-nanoparticles of altretamine complexed epichlorohydrin-ß-cyclodextrin for enhanced solubility and oral bioavailability.

Altretamine is a synthetic drug approved for treatment of ovarian cancer. The only drawback with its formulation is poor aqueous solubility and low oral bioavailability. In the present work an attempt has been made to prepare inclusion complex of altretamine with epichlorohydrin beta cyclodextrin. The complexes were prepared by kneading, co-evaporation and freeze-drying method and were confirmed by FTIR, XRD, DSC, drug content and dissolution study. Kneaded complex possess maximum solubilizing efficiency of 82.63 in 25mM Epi-ß-CD solution. SLNs of pure altretamine and ALT complexed with Epi-ß-CD were prepared by modified emulsification-ultrasonication method. The particle size and zeta potential was found to be 151.5nm and -21.3mV. The drug release pattern of SLNs was bi-phasic in nature; with an initial burst release followed by sustained drug release. Pharmacokinetic study showed that the average Cmax was found to be 0.94µg/ml, which was 2.47 times higher as compared to the pure drug. The AUCt for SLNs was 150minµgh/ml and 54minµgh/ml for pure ALT suspension which proved that the SLNs exhibited greater absorption compared to the pure drug. Thus, smaller particle size, higher entrapment efficiency and enhanced aqueous solubility led to improvement in oral bioavailability of ALT.

Importance of multiagent chemotherapy regimens in ovarian carcinoma: dose intensity analysis.

BACKGROUND: In the previous meta-analysis of dose intensity (dosage) of chemotherapy in advanced ovarian cancer, we analyzed data on cyclophosphamide, altretamine (hexamethylmelamine), doxorubicin, and cisplatin. Only cisplatin showed statistically significant association of complete and partial clinical response with dose intensity. PURPOSE: This analysis updates the previous results and further characterizes response to cisplatin alone or in multiagent regimens. METHODS: We analyzed data from 18 regimens containing platinum (cisplatin or carboplatin) that were used in nine new randomized trials, in addition to data from the 60 groups of patients in our previous study in which responses were reported. Relative dose intensity was calculated as a fraction of the dosage of a drug in the standard regimen of cyclophosphamide, altretamine, doxorubicin, and platinum (CHAP). We performed single and multiple regression analyses to determine the relationship between disease outcome and relative dose intensity for cyclophosphamide, platinum, and doxorubicin alone or in combination. RESULTS: The association between outcome and dose intensity for platinum alone or in multiagent regimens was statistically significant. This association was of borderline significance for cyclophosphamide alone but was not significant for this drug in multiagent regimens. There were insufficient data to test the relationship for doxorubicin as a single agent, but in multiagent regimens, the relationship was borderline (P = .05). Multiagent regimens containing platinum produced greater response rates than platinum alone for any fixed, planned relative dose intensity for platinum. CONCLUSIONS: Our results support other published findings that use of cyclophosphamide and doxorubicin increases the efficacy of single-agent platinum. Relative dose intensity values for cyclophosphamide used alone were larger than those used in multiagent regimens, which might explain why the relationship between relative dose intensity and outcome for cyclophosphamide was not significant for use in multiagent regimens. Similarly, none of the multiagent regimens incorporated doxorubicin at a relative dose intensity for which the drug is found to be effective as a single agent. IMPLICATIONS: Prospective clinical trials are required to test the effect of higher relative dose intensity for doxorubicin and cyclophosphamide added to platinum in advanced ovarian cancer. An important element in the design of prospective trials will be to test for the relative importance of dose intensity versus total dose. This testing is best achieved in a three-arm study design such as that reported in adjuvant treatment of stage II breast cancer conducted by the Cancer and Leukemia Group B.

Selecting drug combinations based on total equivalent dose (dose intensity)

We describe a mathematical model for selecting cytotoxic drugs and dosages for a combination regimen based on the antitumor activities of the drugs given as single agents and their organ-specific maximum tolerated doses. The regimen defined maximizes an approximate measure of antitumor effect subject to constraints on combined toxicity. This approach does not assume that the underlying dose-response curve is steep; nor does it assume that maximally dose-intense regimens are clinically appropriate in all situations. Whether the identified regimen is superior to standard treatments should be determined by prospective, randomized clinical trials. Determining which drugs to combine and in what proportions to combine them offers combinatorially huge numbers of possibilities. The method described here offers one approach to identifying combinations worthy of evaluation in prospective trials.

Pharmacokinetics of hexamethylmelamine in intralipid following hepatic regional administration in rabbits.

Hexamethylmelamine (HMM) is a cytotoxic agent demonstrated to have broad antitumor activity. Poor solubility in aqueous media has precluded significant evaluation of parenteral administration of this drug. A formulation of HMM dissolved in Intralipid has demonstrated excellent tolerance following parenteral administration. The goal of this study was to evaluate the pharmacology of HMM in Intralipid following hepatic regional administration. The routes of administration were intraarterial via the hepatic artery with and without arterial occlusion, i.v. via the portal and jugular veins, and i.p. All animals received a total dose of 10 mg HMM/kg of body weight. Hepatic extraction of HMM was most evident via the portal vein (PV) route [AUC(PV)/AUC(i.v.) = 0.5; P less than 0.05]. Lower plasma levels and areas under the curve (AUCs) were observed for the hepatic artery and hepatic artery-stop flow groups when compared to i.v., but the difference was not significant. Administration i.p. yielded low plasma levels but a very long half-life (88 min). Hepatic tissue levels were highest in the group receiving HMM by the hepatic artery-stop flow route. We conclude that the HMM-Intralipid mixture is well tolerated, that HMM is extracted to a significant degree by the liver following PV administration, and that an i.p. installation of HMM-Intralipid results in prolonged plasma drug levels. This preclinical study supports further efforts at evaluation of parenteral administration of the HMM-intralipid mixture.

Disposition and metabolism of pentamethylmelamine and hexamethylmelamine in rabbits and humans.

The disposition and metabolism of pentamethylmelamine (PMM) and hexamethylmelamine (HMM) were studied in the rabbit, and the disposition of PMM was studied in humans. Parent compound and metabolites were identified by thin-layer chromatography, gas chromatography, and gas chromatography/mass spectrometry analyses. Plasma elimination in both species following i.v. administration of each drug was best described by a two-compartment open model. Both compounds were extensively demethylated with less than 1% of the total dose administered recovered in the urine over 24 hr. The areas under the plasma time-concentration curves of PMM and HMM following p.o. administration to rabbits were 5 and 25% of the areas following i.v. administration. Gastrointestinal absorption was rapid and efficient with 75 to 89% of drug equivalents recoverable in the urine after p.o. administration of [ring-14C]PMM or [ring-14C]HMM to rabbits. Reduced bioavailability of PMM and HMM p.o. appears to be a consequence of rapid metabolism presumably in the liver.

Phase I and clinical pharmacological evaluation of a parenteral hexamethylmelamine formulation.

Hexamethylmelamine has been evaluated in single agent and combination regimen studies for many years, but only following p.o. administration. Pharmacological studies in animals and humans have shown that systematic availability of parent drug following p.o. administration is relatively low and variable due to extensive first-pass metabolism rather than due to poor absorption. Two Phase I clinical trials, with accompanying pharmacokinetic studies, have been conducted by using a parenteral formulation in which hexamethylmelamine was prepared by Intralipid 10%. The parenteral formulation was well tolerated by all patients receiving hexamethylmelamine by 1-day and by daily for 5-days schedules. Nausea and vomiting were the dose-limiting toxicities. Maximally tolerated doses on the 1-day and daily for 5-days schedules were approximately 850 mg/m2 and 630 mg/m2/day, respectively. No responses were observed in either study. Following i.v. administration of 540 mg/m2 hexamethylmelamine, plasma elimination was best described by a three-compartment open model with terminal half-life, total body clearance, and steady-state volume of distribution values of 10.4 h, 0.75 liter/min/m2 and 460 liters/m2, respectively. Twenty-four h urinary recoveries of parent drug were less than 1% for all patients. Accumulation of hexamethylmelamine during the 5-day treatment at 945 mg/m2 suggested possible saturation of parent drug elimination at that dose. Phase II studies are currently under way with the parenteral formulation of hexamethylmelamine.

Low oral bioavailability of hexamethylmelamine in the rat due to simultaneous hepatic and intestinal metabolism.

The disposition of both hexamethylmelamine (HMM) after intraarterial, i.v., portal vein, and intraduodenal administration and of pentamethylmelamine following its i.v. administration was studied in male Wistar rats. HMM (5 and 10 mg/kg) and pentamethylmelamine (5 mg/kg) were infused via implanted cannulas into conscious animals (n greater than or equal to 4). Plasma levels of parent compound and of metabolites were determined by gas chromatography. The areas under the plasma concentration-time curves of HMM following its intraarterial and i.v. administration were not significantly different, indicating that HMM was not appreciably metabolized in the lung. Areas under plasma-concentration-time curves of HMM following portal vein and intraduodenal administration were 27 and 8% of the area under the plasma concentration-time curve after i.v. administration, respectively. Absorption of HMM was complete as judged from metabolite data. The reduced bioavailability of HMM intraduodenally was thus a consequence of presystemic elimination in the liver and the gut wall. Extraction ratios (or first-pass effects) of the liver and the gut wall were 73 and 71%, respectively. Linear kinetic behavior of HMM i.v. was observed in the 5- to 10-mg/kg dose range. Extensive gut wall metabolism may have important implications for the antitumor activity mechanism of HMM.

Phase I and pharmacological studies of pentamethylmelamine administered by 24-hour intravenous infusion.

A Phase I study of pentamethylmelamine (PMM) was conducted, administering the drug as a 24-hr i.v. infusion once weekly for 3 weeks. Doses ranged from 80 to 3000 mg/sq m/week. Twenty-six evaluable patients received a total of 30 courses of PMM. The median performance status of the patients was 60% (range, 40 to 90%), and the median age was 58 years (range, 43 to 72 years). The highest tolerated dose was 2000 mb/sq m/week. Nausea and vomiting were the dose-limiting toxicities; myelosuppression was neither consistent nor severe. One objective response lasting 10 months was noted in a patient with renal cancer. Pharmacokinetic studies using [ring-14C]PMM demonstrated a postinfusion half-life of 14C of approximately 12 hr, with the majority of the radiolabel excreted in the urine. PMM was introduced as a parenteral form of hexamethylmelamine. The present schedule does not permit administration of PMM in a dose greater than the tolerated dose of hexamethylmelamine and does not appear to offer an advantage over the p.o. use of the parent compound.

Phase II trial of oral altretamine for relapsed ovarian carcinoma: evaluation of defining response by serum CA125.

PURPOSE: A phase II study was performed of oral altretamine in 71 patients with ovarian carcinoma who entered clinical complete remission with CA125 levels less than 35 U/mL after initial or second-line chemotherapy, and relapsed more than 6 months later. Response was compared between standard and CA125-based criteria. PATIENTS AND METHODS: Altretamine 260 mg/m2 was given in divided doses daily for 14 days per month. Response was evaluated according to European Organization for Research and Treatment of Cancer (EORTC) criteria in 45 of 66 eligible patients. Response was assessed according to precise CA125 criteria in 51 patients based on either a confirmed > or = 50% or > or = 75% decrease in CA125 levels. RESULTS: A combination of domperidone, dexamethasona, and chlorpromazine at night controlled toxicity in most patients, which was mainly nausea (National Cancer Institute criteria grade 2 or 3 in 27), vomiting (grade 2 or 3 in 19, grade 4 in one), and tiredness (grade 2 or 3 in 15). Responses (complete plus partial) were seen in 18 (40%; 95% confidence interval [CI], 25.4% to 54.6%) of those evaluated according to EORTC criteria and in 20 (39%; 95% CI, 25.5% to 52.9%) of those evaluated according to CA125 level. The overall response rate was 26 of 57 (45.6%) and was related to treatment-free interval: 6 to 12 months, 35%; 12 to 24 months, 52%; and greater than 24 months, 67%. The medium duration of response was 8 months. CONCLUSION: Oral altretamine is a useful agent in patients-who relapse after previously responsive ovarian cancer. Response evaluation by a strict CA125 definition gave a similar estimate of the efficacy of altretamine as EORTC criteria.

Long-term results of a cisplatin-containing combination chemotherapy regimen for the treatment of advanced ovarian carcinoma.

Sixty-two patients with advanced ovarian adenocarcinoma (stages III and IV) and without prior chemotherapy or radiotherapy were treated with a four-drug combination consisting of cyclophosphamide, hexamethylmelamine, 5-fluorouracil (5-FU), and cisplatin (Chex-UP). All patients were evaluable for toxicity and response, and survivors have been observed for a minimum of 48 months. The overall response rate to Chex-UP chemotherapy was 69%, with 12 patients (19%) achieving a pathologically confirmed complete remission (CR) as documented by a negative second-look laparotomy. Seven of the twelve patients (58%) who achieved a surgically confirmed CR were randomized to six cycles of intraperitoneal (IP) 5-FU. There have been seven relapses in patients who had a negative second-look laparotomy, but only four of the patients died from recurrent ovarian cancer. The median duration of remission following a negative second-look laparotomy was 53 months, while the median duration of survival has not been reached and will exceed 7.5 years. Seventeen patients (27%) achieved a clinical CR with chemotherapy but were found to have residual disease at second-look laparotomy. The median survival for these patients was 29 months, which was statistically inferior to that achieved for those patients with a negative second-look laparotomy (P less than .002), and only one patient is alive after 4 years. All patients who either achieved a partial response (PR) to therapy (14 of 62; 23%) or did not respond to therapy (19 of 62; 31%) died of ovarian cancer by 24 months. Thus, prolonged survival is associated with a surgically confirmed CR to induction therapy with Chex-UP. However, only a minority of advanced-stage ovarian cancer patients (15%) are alive 4 years after initiation of treatment with this regimen.

Randomized trial comparing two combination chemotherapy regimens (CHAP-5 v CP) in advanced ovarian carcinoma.

One hundred ninety-one patients with advanced epithelial ovarian carcinoma were treated with either a combination of doxorubicin and a five-day course of cisplatin alternating with cyclophosphamide and hexamethylmelamine orally for 14 days (CHAP-5) or cyclophosphamide and cisplatin both administered intravenously (IV) on a single day at 3-week intervals (CP). At a median follow-up time of 45 months, treatment with each of these combinations resulted in the same remission rates (80% and 74%, respectively) and exactly the same progression-free survival and overall survival (median, 26 months). Despite adequate hydration, more renal toxicity was encountered in the CP-treated patients than in those who received CHAP-5. Disabling neurotoxicity and severe myelosuppression were encountered more frequently in the patients treated with CHAP-5. Because the toxicity was lower and CP treatment required shorter hospitalization, the single-day regimen was considered preferable for future use. The Karnofsky index was the only independent predictor for response, whereas both this index and the size of residual tumor before chemotherapy were predictive of survival. After correcting for other prognostic factors, it was determined that tumor size associated with improved survival was less than 1 cm. The site of metastases in International Federation of Gynecology and Obstetrics (FIGO) stage IV patients did not influence survival within this category. The results of this study confirm our previous findings that patients with microscopic remnants at second-look have a survival similar to that of patients who are histopathologically free of disease. This makes the significance of so-called pathologically confirmed complete remission questionable. The survival benefit of debulking surgery performed during chemotherapy seems only minimal for patients in whom debulking has already been attempted before treatment. Like others, we have found the CP regimen to have a good therapeutic index.

A randomized comparison of standard chemotherapy versus alternating chemotherapy and maintenance versus no maintenance therapy for extensive-stage small-cell lung cancer: a phase III study of the Eastern Cooperative Oncology Group.

The present randomized, prospective study was designed to assess whether alternating induction cyclophosphamide, doxorubicin, vincristine-altretamine (hexamethylmelamine), etoposide, and methotrexate (CAV-HEM) chemotherapy is better than standard chemotherapy (CAV) in improving response, survival, and remission time in 577 evaluable patients having extensive-disease small-cell lung cancer (SCLC). In addition, the study was designed to assess the impact of maintenance chemotherapy following a complete response (CR) on the time to progression and survival. The response rates (CR plus partial response [PR]) for CAV-HEM and CAV were 64% and 61%, respectively, but 23% of the patients on CAV-HEM achieved a CR compared with 16% for CAV alone (P = .03). Among complete responders, the continuation of therapy significantly increased the remission time for patients on CAV, while maintenance therapy for patients on CAV-HEM had no significant impact on remission time. However, the increased remission had little effect on survival. Patients on CAV maintenance therapy survived marginally longer than those patients on no maintenance therapy, whereas patients who received CAV-HEM and no maintenance therapy survived longer than those on maintenance therapy. CAV-HEM was associated with significantly higher severity of complications (ie, mainly myelosuppression) than CAV (P = .01). Maintenance chemotherapy was associated with significantly more complications than no maintenance therapy. Patients on CAV-HEM lived significantly longer than those on CAV alone (45.9 weeks v 42.7 weeks; P = .002). Ten percent of patients treated on CAV-HEM survived at least 2 years, compared with 4% on CAV alone. In our study involving patients with extensive-disease SCLC, the alternating induction chemotherapy significantly increased the CR rates and had a small impact on long-term survival compared with the results achieved with standard induction chemotherapy. Moreover, when the alternating induction chemotherapy was used, long-term maintenance chemotherapy was not needed.

A randomized trial of anticoagulation with warfarin and of alternating chemotherapy in extensive small-cell lung cancer by the Cancer and Leukemia Group B.

The Cancer and Leukemia Group B (CALGB) conducted a prospective randomized trial to evaluate the role of warfarin and alternating chemotherapy in extensive small-cell lung cancer (SCCL). After stratification for sex and performance status, patients were randomly assigned to receive chemotherapy with methotrexate, doxorubicin (Adriamycin; Adria Laboratories, Columbus, OH), cyclophosphamide, and lomustine (CCNU) (MACC), or MACC plus warfarin (MACC + W), or mitomycin, etoposide, cisplatin, and hexamethylmelamine alternating with MACC (MEPH/MACC). Warfarin was given continuously to maintain a prothrombin time of one and one half to twice the control values. A total of 328 patients were enrolled, and 294 were evaluable. There was a statistically significant advantage in objective response rates (complete [CR] and partial responses [PR], respectively) for MACC + W (17% and 50%) as compared with MACC alone (8% and 43%) or MEPH/MACC (10% and 38%) (P = .012). Both failure-free survival (P = .054 Wilcoxon test) and overall survival (P = .098 Wilcoxon test) were higher on MACC + W (median, 6.6 months and 9.3 months, respectively), as compared with MACC (5.0 months and 7.9 months) and MEPH/MACC (5.0 months and 7.9 months). Toxicity was comparable among the three arms, except for increased hemorrhagic events on MACC + W, which were life-threatening in four patients (4%), and lethal in two others (2%). These data support the role of warfarin in the treatment of SCCL, but do not establish its mechanism of action. Warfarin deserves further studies in SCCL, particularly in patients with limited disease.

Four-drug combination chemotherapy (methotrexate, cyclophosphamide, hexamethylmelamine, and CCNU) for non-small cell bronchogenic carcinoma: a Cancer and Leukemia Group B study.

Ninety-eight evaluable patients with nonresectable regional or metastatic non-small cell bronchogenic carcinoma were treated with a four-drug combination chemotherapy program of methotrexate, cyclophosphamide, hexamethylmelamine, and CCNU (MCHC). Fifteen partial or complete responses (15%) were obtained, all but one of which occurred in good performance status (0-1) patients. While "responders lived longer than non-responders", this was due more to initial performance status among responding patients than to achievement of partial (greater than 50%) or complete disease regression. Evaluation of those patients with good performance status (PS 0-1), indicated no statistically significant differences in median survival time for complete response and partial response patients compared to patients with "improved" or "stable" disease status in this group. This combination of modestly active single agents produced disappointing results in our lung cancer population. A search for more active single agents in lung cancer is necessary.

Chemotherapy of drug-resistant ovarian cancer: a Southwest Oncology Group Study.

We present a final analysis, including pathology review, of a cooperative group study of drug-resistant ovarian cancer. Of 200 patients registered, 112 were eligible and evaluable, with a response rate of 26% and median survival of 7 months. Because these results are poorer than those reported in the preliminary and interim analyses of this study, we scrutinized the 88 excluded patients, most of whom failed to meet our strict pathologic criteria for a diagnosis of ovarian cancer of epithelial type, and who, as a heterogeneous group, fared better than patients who did meet the eligibility criteria. We believe this analysis provides insight into the spectrum of diseases that are frequently called ovarian cancer, but might be more properly labeled abdominal carcinomatosis.

Long-term follow-up and prognostic factor analysis in advanced ovarian carcinoma: the Gynecologic Oncology Group experience.

Long-term follow-up was obtained on 726 women with advanced ovarian carcinoma (suboptimal stage III and stage IV) who had received primary chemotherapy on two Gynecologic Oncology Group (GOG) protocols between 1976 and 1982. The first study compared melphalan alone versus melphalan plus hexamethylmelamine versus cyclophosphamide plus doxorubicin (CA). The second study evaluated the same CA regimen with or without cisplatin. Eligibility for the two studies was the same. At last contact, 76 patients were alive. In a multivariate analysis, cell type other than clear cell or mucinous, cisplatin-based treatment, good performance status, younger age, lower stage, clinically nonmeasurable disease, smaller residual tumor volume, and absence of ascites were favorable characteristics for overall survival (P less than .05). Second-look laparotomy was negative significantly more often among those with endometrioid tumors; there were no negative second-look laparotomies among those with mucinous or clear cell tumors. There were 30 patients with suboptimal stage III disease who had a negative second-look laparotomy; 18 (60%) have experienced recurrence, and 13 (43%) have died. Although cisplatin treatment was beneficial, new treatments are clearly needed.

Recurrent ovarian cancer: how important is it to treat to disease progression?

Ovarian cancer is increasingly recognized as a chronic disease whose treatment is often characterized by administration of multiple, sequential active agents, each of which may or may not be accompanied by a tumor response. Despite the large proportion of patients who relapse and undergo longer-term treatment, the question of optimal treatment duration has not been fully addressed to date. For patients who progress on therapy, the answer is straightforward: they are switched to another active agent, presumably having a different mechanism of action from previous therapies with, ideally, limited overlapping toxicities. However, for patients who remain in partial response or who have stable disease, the answer is less apparent and less clear. The majority of oncologists believe that treatment beyond 6 cycles of a given therapy does not provide any additional benefit to patients. There are some data to support that treatment strategy. However, with the advent of new, less toxic agents, treatment to progression should be further explored. Agents that are potentially well suited for extended treatment intervals may include such properties as absence of cumulative toxicity, non-cross-resistance, positive benefit on quality of life, and convenient schedule. A number of active agents in ovarian cancer (platinum, paclitaxel, topotecan, liposomal doxorubicin, docetaxel, gemcitabine, and etoposide) will be reviewed in the context of what is known about cumulative toxicity, potential adverse effects on patients' quality of life, and evidence addressing the potential benefits of longer-term treatment.

Hexamethylmelamine for the treatment of ovarian cancer--the Mount Sinai experience.

Two regimens were tested, CHAP I and CHAP II, the latter, a hexamethylmelamine dosage-intensive regimen, first as second line (salvage) therapy and then as primary therapy. Both produced the most successful results achieved in the Mount Sinai series up to the time of their introduction, when compared to their predecessor regimens: CAP, AP and P. In an overall interim comparison, CHAP II was significantly superior to historical AP and CAP as primary therapy, as was CHAP I vs. AP in several important subgroups compared as part of a randomized trial. CHAP II overall progression-free survival was improved in spite of added new sensitive test methods. Salvage therapy also improved markedly with the addition of intensive hexamethylmelamine. Several biological and treatment characteristics strongly influenced outcome, especially young age and adding hexamethylmelamine. Other possible factors included: poor tumor grade, poor performance status, and extent of surgical debulking, even to intermediate residual, 2-6 cm size [CHAP II only]; extensive (optimum) surgery [CHAP I only]. The hexamethylmelamine-containing regimens interact favorably with some of these factors, better than did the preceding regimens. Five-year follow-up analyses weakened slightly for extensive surgery, intermediate size and poorly differentiated tumors. It confirmed and strengthened several findings favoring CHAP I & II, the hexamethylmelamine-containing regimens.

The role of hexamethylmelamine in the management of ovarian cancer.

Hexamethylmelamine has been recognized as having useful single-agent activity for the treatment of ovarian cancer for the past 25 years, with some patients surviving disease-free for periods in excess of 12 years. Data from recently analysed and mature trials demonstrate that the addition of hexamethylmelamine to first-line combination chemotherapy results in significant improvements in survival compared to what is achieved with regimens of cisplatin and cyclophosphamide with or without doxorubicin.

Hexamethylmelamine: activity in lymphoma and other tumors.

Hexamethylmelamine, an orally administered substituted melamine, has single agent activity in lymphoma (39% PR + CR), cervical cancer (28% PR), transitional carcinoma of the bladder (27% PR + CR), and Bilharzial bladder cancer (38% PR). Toxicity is mild and reversible and is manifested by myelosuppression, neurotoxicity and gastrointestinal toxicity. The potential role of hexamethylmelamine in combination chemotherapy in the diseases in which it has single agent activity is largely unexplored and should be investigated in clinical trials.