Trofosfamide metabolism in different species--ifosfamide is the predominant metabolite

Maintenance treatment with trofosfamide in patients with advanced soft tissue sarcoma - a retrospective single-centre analysis

BACKGROUND

The prognosis of patients with advanced soft tissue sarcoma (STS) remains dismal. Trofosfamide (TRO) has been proposed as a well-tolerated oral maintenance therapy. This retrospective analysis aims to determine the value of this therapy.

METHODS

Fifty-nine patients with advanced STS who received TRO maintenance therapy between 2016 and 2022 were reviewed and analysed regarding clinical parameters and outcomes.

RESULTS

The median age was 48 years; the most common histological subtype was synovial sarcoma (n = 22, 37%), and 71% of patients (n = 42) presented with metastatic disease. No radiological evidence of disease (NED) before the start of maintenance was reported in 36% of patients (n = 21). The median follow-up was 38.2 months with a median maintenance duration of 9.0 months. The median event-free survival (EFS) and overall survival (OS) were 9.5 and 33.2 months, respectively. In metastatic patients achieving NED before the initiation of TRO, the median EFS was 29.4 months, while the median OS was not reached. In metastatic patients with anthracycline + ifosfamide (AI) as first-line induction therapy without prior metastasis-directed local therapy, the median EFS and OS from the start of AI were 13.9 and 26.8 months, respectively. Multivariate analysis of the overall cohort demonstrated that NED before the start of maintenance was significantly associated with a prolonged EFS (p = 0.024, hazard ratio [HR] = 0.26), and G2 histology correlated with longer OS (p = 0.030, HR = 0.16, reference: G3).

INTERPRETATION

Oral maintenance therapy with TRO appears to improve outcomes in patients with advanced STS. Metastatic patients who achieve NED through prior metastasectomy may particularly benefit from TRO maintenance.

Developmental Toxicity and Biotransformation of Two Anti-Epileptics in Zebrafish Embryos and Early Larvae

The zebrafish (Danio rerio) embryo is gaining interest as a bridging tool between in-vitro and in-vivo developmental toxicity studies. However, cytochrome P450 (CYP)-mediated drug metabolism in this model is still under debate. Therefore, we investigated the potential of zebrafish embryos and larvae to bioactivate two known anti-epileptics, carbamazepine (CBZ) and phenytoin (PHE), to carbamazepine-10,11-epoxide (E-CBZ) and 5-(4-hydroxyphenyl)-5-phenylhydantoin (HPPH), respectively. First, zebrafish were exposed to CBZ, PHE, E-CBZ and HPPH from 5¼- to 120-h post fertilization (hpf) and morphologically evaluated. Second, the formations of E-CBZ and HPPH were assessed in culture medium and in whole-embryo extracts at different time points by targeted LC-MS. Finally, E-CBZ and HPPH formation was also assessed in adult zebrafish liver microsomes and compared with those of human, rat, and rabbit. The present study showed teratogenic effects for CBZ and PHE, but not for E-CBZ and HPPH. No HPPH was detected during organogenesis and E-CBZ was only formed at the end of organogenesis. E-CBZ and HPPH formation was also very low-to-negligible in adult zebrafish compared with the mammalian species. As such, other metabolic pathways than those of mammals are involved in the bioactivation of CBZ and PHE, or, these anti-epileptics are teratogens and do not require bioactivation in the zebrafish.

Nitrogen Mustards as Anticancer Chemotherapies: Historic Perspective, Current Developments and Future Trends

Nitrogen mustards, a family of DNA alkylating agents, marked the start of cancer pharmacotherapy. While traditionally characterized by their dose-limiting toxic effects, nitrogen mustards have been the subject of intense research efforts, which have led to safer and more effective agents. Even though the alkylating prodrug mustards were first developed decades ago, active research on ways to improve their selectivity and cytotoxic efficacy is a currently active topic of research. This review addresses the historical development of the nitrogen mustards, outlining their mechanism of action, and discussing the improvements on their therapeutic profile made through rational structure modifications. A special emphasis is made on discussing the nitrogen mustard prodrug category, with Cyclophosphamide (CPA) serving as the main highlight. Selected insights on the latest developments on nitrogen mustards are then provided, limiting such information to agents that preserve the original nitrogen mustard mechanism as their primary mode of action. Additionally, future trends that might follow in the quest to optimize these invaluable chemotherapeutic medications are succinctly suggested.

Trofosfamide in the treatment of elderly or frail patients with diffuse large B-cell lymphoma

PURPOSE

The introduction of immunochemotherapy has led to a significant improvement in treatment results and prognosis of diffuse large B-cell non-Hodgkins lymphoma (DLBCL) both at initial diagnosis and in relapse. Trofosfamide, an oxazaphosphorine derivative, has been utilized as alternative treatment option for patients with lymphoproliferative diseases unsuitable for conventional chemotherapy agents and protocols because of age, comorbidity, or poor performance score. While data on the activity and safety of single-agent trofosfamide have been published, the potential value of this agent in immunochemotherapy in combination with anti-CD20 antibodies such as rituximab has not been investigated to our knowledge.

METHODS

Safety and therapeutic effectiveness of trofosfamide given orally at a dose of 50 mg twice daily alone, or in combination with standard-dose rituximab, was investigated in a cohort of elderly and/or highly comorbid patients with histologically confirmed primary or secondary DLBCL.

RESULTS

Treatment with trofosfamide in this combination setting was generally well tolerated with no treatment-related deaths and manageable side effects, most of which were WHO class I-II; the most clinically relevant toxicity was cytopenia. 19 of 21 examined patients responded to therapy with 11 of 21 (52.4%) achieving a complete remission (CR). Median overall and progression-free survival (OS and PFS) in the CR-group was 14 and 9 months, respectively. In the subgroup with trofosfamide-based first-line therapy, 7 of 10 (70%) achieved CR and median PFS was not reached.

CONCLUSIONS

Immunochemotherapy with rituximab and trofosfamide (RT) is safe and effective in elderly and poor-performance patients with DLBCL. Response rates are comparable to most commonly used primary and salvage treatment protocols. The potential value of TR regimen in both first-line and relapsed/refractory DLCBL merits further investigation and is probably underestimated.

TiO2 photocatalytic degradation and transformation of oxazaphosphorine drugs in an aqueous environment

This study investigated the TiO2 photocatalytic degradation and transformation of the oxazaphosphorines ifosfamide (IFO), cyclophosphamide (CP) and trofosfamide (TRO). Under the optimum conditions of TiO2=100mg/L, IFO=100μg/L and solution pH=5.5, IFO was completely removed within 10min (k=0.433min(-1)). The results indicated that OHfree radicals generated by valence holes in the bulk solution were the predominant species for the degradation of IFO. At higher initial concentrations of oxazaphosphorines (20mg/L), >50% of TOC remained after 6h of reaction time, indicating that parent compounds were transformed to byproducts, which exhibit higher Microtox acute toxicities; chlorinated byproducts were likely the source of toxicity. Photocatalytic degradation pathways of the three oxazaphosphorines were proposed. IFO, CP and TRO follow very similar pathways and bond-breaking processes: ketonization and breaking of the CCl bond, the PN bond and the CN bond (N-dechloroethylation). Chloride (Cl(-)) release is likely the first and primary step in the decomposition process. Several of the identified byproducts were also metabolites, which implies that photocatalytic oxidation proceeds through pathways that are similar to metabolic pathways.

Liquid-liquid extraction combined with high performance liquid chromatography-diode array-ultra-violet for simultaneous determination of antineoplastic drugs in plasma

A liquid-liquid extraction (LLE) combined with high-performance liquid chromatography-diode array detection method for simultaneous analysis of four chemically and structurally different antineoplastic drugs (cyclophosphamide, doxorubicin, 5-fluorouracil and ifosfamide) was developed. The assay was performed by isocratic elution, with a C18 column (5 µm, 250 x 4.6 mm) and mobile phase constituted by water pH 4.0- acetonitrile-methanol (68:19:13, v/v/v), which allowed satisfactory separation of the compounds of interest. LLE, with ethyl acetate, was used for sample clean-up with recoveries ranging from 60 to 98%. The linear ranges were from 0.5 to 100 µg mL-1, for doxorubicin and 1 to 100 µg mL-1, for the other compounds. The relative standard deviations ranged from 5.5 to 17.7%. This method is a fast and simple alternative that can be used, simultaneously, for the determination of the four drugs in plasma, with a range enabling quantification of the drugs in pharmacokinetics, bioequivalence and therapeutic drug-monitoring studies.

Metronomic trofosfamide inhibits progression of human lung cancer xenografts by exerting anti-angiogenic effects

BACKGROUND

Recent studies of conventional chemotherapeutic drugs administered in metronomic therapy schedules showed remarkable inhibitory effects on tumor angiogenesis. Subsequent and prolonged tumor regression was achieved moreover by circumventing acquired drug resistance. In this study, metronomic and conventional trofosfamide were compared on human NSCLC xenograft "LX-1."

MATERIALS AND METHODS

In vitro cytotoxicity of trofosfamide on tumor and human umbilical cord endothelial cells was determined under normoxic and hypoxic conditions. Additionally fractions and duration of cell cycles were analyzed by flow cytometry. In vivo LX-1 xenotransplanted nude mice were treated with trofosfamide in conventional and metronomic schedules (i.p./p.o.). Tumor sections were evaluated for microvessel density (MVD), relative growth fraction and apoptosis.

RESULTS

In contrast to the rapid growth of conventionally treated lung cancer, long lasting tumor growth retardation over the total treatment period was achieved with metronomic treatment. While growth fraction and apoptotic rate of LX-1 cells remained unchanged, the MVD was significantly reduced (50%).

CONCLUSION

Our results show advantages of a metronomic trofosfamide schedule compared to a conventional bolus therapy mainly due to inhibition of angiogenesis. In vitro data show that this mechanism works under normoxic and hypoxic conditions and suggest that this is in part a direct cytotoxic effect on endothelial cells.

Metabolism and transport of oxazaphosphorines and the clinical implications

The oxazaphosphorines including cyclophosphamide (CPA), ifosfamide (IFO), and trofosfamide represent an important group of therapeutic agents due to their substantial antitumor and immuno-modulating activity. CPA is widely used as an anticancer drug, an immunosuppressant, and for the mobilization of hematopoetic progenitor cells from the bone marrow into peripheral blood prior to bone marrow transplantation for aplastic anemia, leukemia, and other malignancies. New oxazaphosphorines derivatives have been developed in an attempt to improve selectivity and response with reduced toxicity. These derivatives include mafosfamide (NSC 345842), glufosfamide (D19575, beta-D-glucosylisophosphoramide mustard), NSC 612567 (aldophosphamide perhydrothiazine), and NSC 613060 (aldophosphamide thiazolidine). This review highlights the metabolism and transport of these oxazaphosphorines (mainly CPA and IFO, as these two oxazaphosphorine drugs are the most widely used alkylating agents) and the clinical implications. Both CPA and IFO are prodrugs that require activation by hepatic cytochrome P450 (CYP)-catalyzed 4-hydroxylation, yielding cytotoxic nitrogen mustards capable of reacting with DNA molecules to form crosslinks and lead to cell apoptosis and/or necrosis. Such prodrug activation can be enhanced within tumor cells by the CYP-based gene directed-enzyme prodrug therapy (GDEPT) approach. However, those newly synthesized oxazaphosphorine derivatives such as glufosfamide, NSC 612567 and NSC 613060, do not need hepatic activation. They are activated through other enzymatic and/or non-enzymatic pathways. For example, both NSC 612567 and NSC 613060 can be activated by plain phosphodiesterase (PDEs) in plasma and other tissues or by the high-affinity nuclear 3'-5' exonucleases associated with DNA polymerases, such as DNA polymerases and epsilon. The alternative CYP-catalyzed inactivation pathway by N-dechloroethylation generates the neurotoxic and nephrotoxic byproduct chloroacetaldehyde (CAA). Various aldehyde dehydrogenases (ALDHs) and glutathione S-transferases (GSTs) are involved in the detoxification of oxazaphosphorine metabolites. The metabolism of oxazaphosphorines is auto-inducible, with the activation of the orphan nuclear receptor pregnane X receptor (PXR) being the major mechanism. Oxazaphosphorine metabolism is affected by a number of factors associated with the drugs (e.g., dosage, route of administration, chirality, and drug combination) and patients (e.g., age, gender, renal and hepatic function). Several drug transporters, such as breast cancer resistance protein (BCRP), multidrug resistance associated proteins (MRP1, MRP2, and MRP4) are involved in the active uptake and efflux of parental oxazaphosphorines, their cytotoxic mustards and conjugates in hepatocytes and tumor cells. Oxazaphosphorine metabolism and transport have a major impact on pharmacokinetic variability, pharmacokinetic-pharmacodynamic relationship, toxicity, resistance, and drug interactions since the drug-metabolizing enzymes and drug transporters involved are key determinants of the pharmacokinetics and pharmacodynamics of oxazaphosphorines. A better understanding of the factors that affect the metabolism and transport of oxazaphosphorines is important for their optional use in cancer chemotherapy.

Dose escalation study for defining the maximum tolerated dose of continuous oral trofosfamide in pretreated patients with metastatic lung cancer

BACKGROUND

Trofosfamide is increasingly used in the treatment of patients with several types of malignancies. However, the optimal dose of trofosfamide for patients with advanced cancer has not been systematically investigated yet. The aim of this study was to define the maximum tolerated dose (MTD) of continuous oral trofosfamide.

PATIENTS AND METHODS

16 patients with advanced lung cancer (14 nonsmall cell lung cancer, 2 small cell lung cancer; 10 male, 6 female; median age 64 years (range 46-82); median Karnofsky status 70%; median number of organs involved 3 (range 1-6)) were enrolled. All patients were previously treated with chemotherapy (median 2x, range 1-6) and 8/16 (50%) with radiotherapy. Patients received trofosfamide p.o. administered in 3 doses per day for 3 weeks (1 cycle) using a 3-patient-cohort dose-escalation strategy. Toxicities were graded according to the WHO Criteria.

RESULTS

Patients received a median of 2 cycles of trofosfamide (range 1-4) at 3 dose levels (90, 125, and 175 mg/m2). Grade 3 and 4 neutropenia, anemia, and thrombocytopenia were observed in 20, 13.3, and 6.6%, respectively. Dose-limiting toxicities during the first cycle were grade 3 muscle weakness and anorexia observed in 1/6 patients in cohort 1 (trofosfamide 90 mg/m2), grade 3 neutropenia in 1/6, and encephalopathy in 1/6 patients in cohort 3 (trofosfamide 175 mg/m2). Therefore, the dose level of 125 mg/m2 was defined as the MTD.

CONCLUSION

Trofosfamide at 125 mg/m2 administered in 3 doses per day was well tolerated. This dose level is recommended for further clinical studies.

Trofosfamide in the Palliative Treatment of Cancer: A Review of the Literature

Trofosfamide is an alkylating agent that is derived from the oxazaphoshorines. It has found application in a broad spectrum of malignancies in the last three decades. The main indications for application were in the palliative situation and as maintenance therapy. Good results were reported from the treatment of non-Hodgkin's lymphomas and soft tissue sarcomas. A lot of small studies and casuistic contributions are available giving treatment results of several solid carcinomas (malignant gliomas, ovarian, lung and prostate cancer, and others). Due to its oral formulation and good tolerability trofosfamide is an attractive candidate for the palliative situation because treatment on an outpatient basis is possible. However, there is still a lack of randomized clinical studies with trofosfamide. Thus, evidence-based conclusions on the therapeutic value of the drug cannot be drawn. In the future, phase III trials should be undertaken.

Trofosfamide as salvage therapy for anaplastic large cell lymphoma relapsing after high-dose chemotherapy

Patients with relapsed aggressive lymphoma after high dose chemotherapy have a very poor prognosis and long-term survival is rare. Most patients are not eligible for allogeneic stem cell transplantation in this setting and treatment, therefore, becomes palliative. A few studies have shown that trofosfamide, an oral alkylating agent, may be effective as palliative treatment in non-Hodgkin's lymphoma. Trofosfamide therapy is considered rather non-toxic with an overall response rate from 50 to 80%. Most responses are, however, partial and their duration is short. We report a patient with a very aggressive ALK + anaplastic large cell lymphoma (ALCL), relapsing shortly after high dose chemotherapy. Unrelated allogeneic transplantation was hot possible. After several radio/chemotherapy regimens trofosfamide was started as palliative treatment. This therapy resulted in a complete remission, still ongoing, 27 months after termination of intravenous cytotoxic therapy and 16 months after withdrawal of trofosfamide. Thus, in this particular case, trofosfamide turned out to be an unexpectedly effective salvage therapy for an otherwise very aggressive relapsing ALCL.

Treatment of paediatric pontine glioma with oral trophosphamide and etoposide

To evaluate the overall survival of paediatric patients with pontine gliomas treated with oral trophosphamide and etoposide. Patients between 3 and 17 years of age with either typical diffuse pontine glioma on MRI or histologically proven anaplastic astrocytoma/glioblastoma multiforme located in the pons, were eligible. Treatment consisted of oral trophosphamide 100 mg x m(-2) x day(-1) combined with oral etoposide at 25 mg x m(-2) x day(-1) starting simultaneously with conventional radiation. Twenty patients were enrolled (median age 6 years, male : female=9 : 11). Surgical procedures included: no surgery: five, open biopsy: three, stereotactic biopsy: six, partial resection: three, and sub-total resection: three. Histological diagnoses included pilocytic astrocytoma: one, astrocytoma with no other specification: three, anaplastic astrocytoma: three, glioblastoma multiforme: eight, no histology: five. The most frequent side effects were haematologic and gastrointestinal. There was no toxic death. The response to combined treatment in 12 evaluable patients was: complete response: 0, partial response: three, stable disease: four, and progressive disease: five. All tumours progressed locally and all patients died. The overall median survival was 8 months. The overall survival rates at 1 and 4 years were: 0.4 and 0.05 respectively. This was not different from a control group of patients documented in the same population. Oral trophosphamide in combination with etoposide did not improve survival of pontine glioma patients. The treatment was well tolerated and should be evaluated for more chemoresponsive paediatric malignancies.

Palliative chemotherapy in pretreated patients with advanced cancer: oral trofosfamide is effective in ovarian carcinoma

Thirty-four patients with advanced cancer of various origins and documented disease progression were treated with continuous daily doses of 50-150 mg of oral trofosfamide (TRO). Of 31 evaluable patients, 5 responded to this treatment (1 complete remission and 4 partial remissions) and 12 patients had stable disease. Four of 9 patients with advanced ovarian cancer resistant to platinum-containing regimens and paclitaxel responded to oral TRO. The median treatment duration was 26 weeks for responders and 6 weeks for nonresponders, with cumulative doses of up to 46.000 mg TRO. Response duration was 11-47 weeks. No significant side effects were observed. Oral TRO given in the outpatient setting seems to be an attractive therapeutic option for heavily pretreated cancer patients, and it has remarkable antitumor effects in patients with ovarian cancer.

Cyclophosphamide and related anticancer drugs

This article presents an overview of the methods of bioanalysis of oxazaphosphorines, in particular, cyclophosphamide, ifosfamide, and trofosfamide as well as their metabolites. The metabolism of oxazaphosphorines is complex and leads to a large variety of metabolites and therefore the spectrum of methods used is relatively broad. The various methods used are shown in a table and the particularly important assays are described.

Oral trofosfamide and etoposide in pediatric patients with glioblastoma multiforme

BACKGROUND

Glioblastoma multiforme in childhood is rare, and the prognosis for patients with the disease is poor. The Pediatric Oncology Society of the Germanic language group (GPOH) enrolls patients in a series of pilot trials, the first of which is reported here (HIT-GBM-A).

METHODS

Twenty-two patients with glioblastoma multiforme, World Health Organization Grade 4, between the ages of 3-15 years (45% male) were enrolled during the period 1995-1997. There were 13 supratentorial tumors, 8 brainstem tumors, and 1 cerebellar tumor. The patients underwent the following procedures: stereotactic biopsy (n = 3 patients), open biopsy (n = 1 patient), partial resection (n = 6 patients), subtotal resection (n = 4 patients), and macroscopic total resection (n = 8 patients). Adjuvant treatment consisted of oral chemotherapy with trofosfamide, 100 mg/m(2), and etoposide, 25 mg/m(2), daily or for 21-day cycles interrupted by 1-week rests. Standard fractionated radiation (54 grays) was started concurrently with the first cycle.

RESULTS

The chemotherapy was well tolerated, with no treatment-related deaths and only minor side effects. The responses in 12 evaluable patients after two cycles were as follows: 1 complete response, 1 partial response, 3 patients with stable disease, and 7 patients with progressive disease. The median overall survival was 12 months. The 1-year, 2-year, and 4-year overall survival rates were 52%, 26%, and 22%, respectively, and the event free survival rates were 26%, 22%, and 4%, respectively. None of the four surviving patients (3.2 years, 3.4 years, 4.0 years, and 4.2 years after diagnosis) is event free. Two patients are alive after tumor progression: One patient was diagnosed with a medulloblastoma, and one patient was diagnosed with an osteosarcoma as second malignancies. A control group extracted from the Surveillance, Epidemiology, and End Results data had lower survival rates: the difference between the groups was not statistically significant (P = 0.26).

CONCLUSIONS

This chemotherapy will not be used in a randomized trial of patients with glioblastoma; however, it may be evaluated for patients with tumors that have more chemoresponsive histologies.

Pharmacokinetics of anticancer drugs in vitro

It is generally assumed that drug concentration does not change significantly under cell culture conditions. Nevertheless, most of the therapeutic trials in acute leukemia that were based on in vitro drug sensitivity assays of patient samples have been disappointing. In order to show possible pitfalls of unphysiological alterations in vitro we investigated concentration versus time curves, metabolism and effects on the culture media for some antineoplastic drugs. Oxazaphosphorines and cytarabine were incubated in RPMI and in established cell lines and measured by HPLC. HPLC also served to measure enzyme activity and levels of related amino acids at various concentrations of asparaginase, ammonia release was photometrically determined. Etoposide was monitored by HPLC relative to different contents of FCS in RPMI. All oxazaphosphorines showed a rapid decrease of in vitro activity down to about 10% within 4-6 h, and 2% within 72 h. The level of cytarabine, when incubated in RPMI, was stable over 24h, and no change was seen with K562, while a rapid decrease to below 50% occurred within 6h in the presence of HL 60 and BLIN. 2 U/L of asparaginase led to asparagine depletion of the medium within 4h, while 200 U/L were associated with a preferential increase of glutamic acid and ammonia. Further, there was evidence of instability by rapid adsorption to plastic surfaces (paclitaxel) or isomerisation (etoposide) in RPMI with low FCS content. The instability of drugs in vitro is attributed to a variety of different factors: i.e. physico-chemical instability results in inactivation of oxazaphosphorines, cytarabine disappears by cellular metabolism without saturation depending on the cell-line. Epiphenomena like adsorption and isomerisation in vitro are unphysiological. Results of drug sensitivity assays should be interpreted with great caution.

Trofosfamide as a salvage treatment with low toxicity in malignant lymphoma. A phase II study

37 patients with disease progression after prior treatment for malignant lymphoma (27 low grade, 7 high grade and 3 Hodgkin's) were treated with oral trofosfamide daily. Most of these patients were heavily pretreated, with a median number of two regimens. Their median performance status was 1 (22 patients with 0-1 and 14 with 2-3). The overall response rate was 49% (18/37; 3/37 CRs and 15/37 (41%) PRs). Median time to progression (TTP) from start of therapy was 4 months for patients with low-grade lymphoma and 2 months for high-grade lymphoma. For responding patients (CR + PR), TTP was approximately 10 and 7 months, respectively, for the two groups of lymphomas. Median survival from the start of treatment was 11 months (range 1.3-46.6) for low-grade lymphoma and 3.8 months (range 2.2-17.6) for high-grade lymphoma. Haematological and other toxicities were low and did not cause any major treatment interruptions. Trofosfamide is an interesting and a non-toxic palliative treatment for relapsing malignant lymphomas especially in elderly patients.

In vivo effects of chlorophyllin on the antitumour agent cyclophosphamide

Cyclophosphamide (CP) is a potent antitumour agent used against many forms of cancer and against certain other diseases. Chlorophyllin (CHL), which is obtained by hydrolysis of chlorophyll to remove phytyl alcohol, is an efficient antimutagenic agent and has been used as a dietary supplement or to diminish the intensity of the discomforting side effects of CP therapy. We undertook to determine the antimutagenic effectiveness of CHL against CP in a mouse model and to determine whether the antitumour efficacy of CP was compromised in vivo by CHL treatment. Experiments utilised CHL administered either in drinking water (1%) for 2 days before treatment, or by gavage (200 mg/kg) 2 hr before treatment with CP (220 mg/kg). Urinary mutagenicity following CP treatment, as determined by the Salmonella/microsome assay, was decreased by both regimes of CHL co-treatment. Similarly, the increase in micronuclei in bone marrow polychromatic erythrocytes in response to CP was reduced by concomitant CHL treatment. In contrast, antitumour efficacy, as determined by growth delay of Colon 38 adenocarcinomas, was not diminished by CHL treatment. We conclude that CHL may have beneficial effects when used in combination with CP therapy.

Oral trofosfamide: an active drug in the treatment of soft-tissue sarcoma

A total of 23 patients with metastatic sarcomas were treated with continuous oral trofosfamide, an alkylating agent structurally related to cyclophosphamide and ifosfamide. In all, 12 of the patients were chemotherapy-naive. Doses were escalated every 3rd week until the development of leukopenia of WHO grade 2. The treatment was well tolerated and produced little subjective toxicity. Leukopenia was the dose-limiting toxicity. The daily dose that produced grade 2 leukopenia was 200-250 mg in 65% of the patients. Three patients responded, all of whom had been treated with trofosfamide as first-line treatment.