The Drug Rediscovery protocol facilitates the expanded use of existing anticancer drugs.

The large-scale genetic profiling of tumours can identify potentially actionable molecular variants for which approved anticancer drugs are available1-3. However, when patients with such variants are treated with drugs outside of their approved label, successes and failures of targeted therapy are not systematically collected or shared. We therefore initiated the Drug Rediscovery protocol, an adaptive, precision-oncology trial that aims to identify signals of activity in cohorts of patients, with defined tumour types and molecular variants, who are being treated with anticancer drugs outside of their approved label. To be eligible for the trial, patients have to have exhausted or declined standard therapies, and have malignancies with potentially actionable variants for which no approved anticancer drugs are available. Here we show an overall rate of clinical benefit-defined as complete or partial response, or as stable disease beyond 16 weeks-of 34% in 215 treated patients, comprising 136 patients who received targeted therapies and 79 patients who received immunotherapy. The overall median duration of clinical benefit was 9 months (95% confidence interval of 8-11 months), including 26 patients who were experiencing ongoing clinical benefit at data cut-off. The potential of the Drug Rediscovery protocol is illustrated by the identification of a successful cohort of patients with microsatellite instable tumours who received nivolumab (clinical benefit rate of 63%), and a cohort of patients with colorectal cancer with relatively low mutational load who experienced only limited clinical benefit from immunotherapy. The Drug Rediscovery protocol facilitates the defined use of approved drugs beyond their labels in rare subgroups of cancer, identifies early signals of activity in these subgroups, accelerates the clinical translation of new insights into the use of anticancer drugs outside of their approved label, and creates a publicly available repository of knowledge for future decision-making.

Safe Stop IPI-NIVO trial: early discontinuation of nivolumab upon achieving a complete or partial response in patients with irresectable stage III or metastatic melanoma treated with first-line ipilimumab-nivolumab - study protocol.

BACKGROUND: Patients with irresectable stage III or metastatic melanoma presenting with poor prognostic factors are usually treated with a combination of immune checkpoint inhibitors (ICIs), consisting of ipilimumab and nivolumab. This combination therapy is associated with severe immune related adverse events (irAEs) in about 60% of patients. In current clinical practice, patients are usually treated with ICIs for up to two years or until disease progression or the occurrence of unacceptable AEs. The incidence of irAEs gradually increases with duration of treatment. While durable tumour responses have been observed after early discontinuation of treatment, no consensus has been reached on optimal treatment duration. The objective of the Safe Stop IPI-NIVO trial is to evaluate whether early discontinuation of ICIs is safe in patients with irresectable stage III or metastatic melanoma who are treated with combination therapy. METHODS: The Safe Stop IPI-NIVO trial is a nationwide, multicentre, prospective, single-arm, interventional study in the Netherlands. A total of 80 patients with irresectable stage III or metastatic melanoma who are treated with combination therapy of ipilimumab-nivolumab and have a complete or partial response (CR/PR) according to RECIST v1.1 will be included to early discontinue maintenance therapy with anti-PD-1. The primary endpoint is the rate of ongoing response at 12 months after start of ICI. Secondary endpoints include ongoing response at 24 months, disease control at different time points, melanoma specific and overall survival, the incidence of irAEs and health-related quality of life. DISCUSSION: From a medical, healthcare and economic perspective, overtreatment should be prevented and shorter treatment duration of ICIs is preferred. If early discontinuation of ICIs is safe for patients who are treated with the combination of ipilimumab-nivolumab, the treatment duration of nivolumab could be shortened in patients with a favourable tumour response. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT05652673, registration date: 08-12-2022.

Efficacy and safety of biweekly i.v. administrations of the Aurora kinase inhibitor danusertib hydrochloride in independent cohorts of patients with advanced or metastatic breast, ovarian, colorectal, pancreatic, small-cell and non-small-cell lung cancer: a multi-tumour, multi-institutional phase II study.

BACKGROUND: This multi-centre phase II trial assessed the activity, safety (CTCAE 3.0) and pharmacokinetics (PK) of the pan-Aurora kinase inhibitor danusertib hydrochloride (PHA-739358) in breast (BC), ovarian (OC), pancreatic (PC), colorectal (CRC), small-cell (SCLC) and non-small-cell lung (NSCLC) cancers. METHODS: Consenting adult patients with good performance and organ function with advanced/metastatic tumours who had failed systemic therapy were treated in independent, disease-specific cohorts with danusertib 500 mg/m(2) given as 24-h i.v. infusion every 14 days with until progression or unacceptable toxicity. A two-stage design was applied. Primary end point was the progression-free rate (PFR) at 4 months (RECIST1.1). RESULTS: A total of 223 patients were enrolled with 219 actively treated. The median relative dose intensity of danusertib was similar for all tumour types (84.6%-99.6%). The median number of biweekly treatment cycles ranged from 3 to 4/patient (maximum 5-40 cycles/entity) and the median treatment duration varied between 7.6 and 10.0 weeks per histotype. Danusertib did not meet pre-specified protocol criteria for clinically relevant activity in any of the treated cancers. The PFR at 4 months was 18.4% in BC, 12.1% in OC, 10.0% in PC, 10.4% in NSCLC (all histotypes), 16.1% in squamous NSCLC and 0% in SCLC and CRC. Some radiological and/or biochemical indication of antitumor activity was seen in BC, OC, PC and NSCLC, including two confirmed partial responses. The most frequent drug-related non-laboratory adverse events (AEs) were fatigue/asthenia, nausea, diarrhoea, anorexia, vomiting, alopecia, constipation and pyrexia. Common laboratory AEs included haematological toxicity, hypalbuminaemia and increases in liver enzymes. Treatment was discontinued due to AEs in only 5.5% of patients. Plasma concentrations of danusertib were in line with results from earlier studies. CONCLUSION: Single-agent danusertib did show only marginal anti-tumour activity in common solid tumours after failure of prior systemic therapies. The safety and PK profile was consistent with previous experience. CLINICAL TRIAL NUMBER: 2006-003772-35.

Pharmacokinetically guided sunitinib dosing: a feasibility study in patients with advanced solid tumours.

BACKGROUND: Plasma exposure of sunitinib shows large inter-individual variation. Therefore, a pharmacokinetic (PK) study was performed to determine safety and feasibility of sunitinib dosing based on PK levels. METHODS: Patients were treated with sunitinib 37.5 mg once daily. At days 15 and 29 of treatment, plasma trough levels of sunitinib and N-desethyl sunitinib were measured. If the total trough level (TTL) was <50 ng ml(-1) and the patient did not show any grade ⩾3 toxicity, the daily sunitinib dose was increased by 12.5 mg. If the patient suffered from grade ⩾3 toxicity, the sunitinib dose was lowered by 12.5 mg. RESULTS: Twenty-nine out of 43 patients were evaluable for PK assessments. Grade ⩾3 adverse events were experienced in seven patients (24%) at the starting dose and in nine patients (31%) after dose escalation. TTLs were below target in 15 patients (52%) at the starting dose. Of these, five patients (17%) reached target TTL after dose escalation without additional toxicity. CONCLUSIONS: In a third of the patients that were below target TTL at standard dose, the sunitinib dose could be increased without additional toxicities. This could be the basis for future studies and the implementation of a PK-guided dosing strategy in clinical practice.

The meaning of screening: detection of brain metastasis in the adjuvant setting for stage III melanoma.

BACKGROUND: The incidence of melanoma is increasing and 37% of patients with metastatic melanoma eventually have brain metastasis (BM). Currently, there is no consensus on screening for BM in patients with resected stage III melanoma. However, given the high incidence of BM, routine screening magnetic resonance imaging (MRI) of the brain is considered in patients with completely resected stage III melanoma before the start of adjuvant treatment. The aim of this study was to assess the yield of screening for BM in these patients. MATERIALS AND METHODS: A single-center cohort study was carried out in the Erasmus MC, Rotterdam, The Netherlands, a large tertiary referral center for patients with melanoma. Eligible patients with complete resection of stage III melanoma and a screening MRI of the brain, made within 12 weeks after resection and before adjuvant treatment (programmed cell death protein 1 inhibitors, dabrafenib-trametinib), available between 1 August 2018 and 1 January 2021, were included. RESULTS: A total of 202 patients were included. Eighteen (8.9%) of 202 patients had extracranial metastasis at screening. Two (1.1%) of the remaining 184 patients had BM at screening, resulting in a switch from adjuvant treatment to ipilimumab-nivolumab. At a median follow-up of 21.2 months, BM was detected in another 4 (2.4%) of 166 patients who started with adjuvant treatment. CONCLUSIONS: The yield of screening MRI of the brain is low after complete resection of stage III melanoma, before the start of adjuvant treatment. Therefore, routine screening MRI is not recommended in this setting.

Erlotinib 'dosing-to-rash': a phase II intrapatient dose escalation and pharmacologic study of erlotinib in previously treated advanced non-small cell lung cancer.

BACKGROUND: To evaluate the anticancer activity of erlotinib in patients with previously treated, advanced non-small cell lung cancer (NSCLC) whose dose is increased to that associated with a maximal level of tolerable skin toxicity (i.e., target rash (TR)); to characterise the pharmacokinetics (PK) and pharmacodynamics (PD) of higher doses of erlotinib. METHODS: Patients initially received erlotinib 150 mg per day. The dose was successively increased in each patient to that associated with a TR. Anticancer activity was evaluated. Plasma, skin, and hair were sampled for PK and PD studies. RESULTS: Erlotinib dose escalation to 200-475 mg per day was feasible in 38 (90%) of 42 patients. Twenty-four (57%) patients developed a TR, but 19 (79%) did so at 150 mg per day. Five (12%) patients, all of whom developed a TR, had a partial response. Median progression-free survival (PFS) was 2.3 months (95% CI: 1.61, 4.14); median PFS was 3.5 months and 1.9 months, respectively, for patients who did and did not experience a TR (hazard ratio, 0.51; P=0.051). Neither rash severity nor response correlated with erlotinib exposure. CONCLUSION: Intrapatient dose escalation of erlotinib does not appreciably increase the propensity to experience a maximal level of tolerable skin toxicity, or appear to increase the anticancer activity of erlotinib in NSCLC.

Phase I and pharmacological study of the broad-spectrum tyrosine kinase inhibitor JNJ-26483327 in patients with advanced solid tumours.

BACKGROUND: JNJ-26483327 is an oral, potent, multi-targeted tyrosine kinase inhibitor, inhibiting kinases of epidermal growth factor receptor (EGFR)-1, -2 and -4, rearranged during transfection (RET) receptor, vascular endothelial growth factor receptor (VEGFR)-3 and Src family (Lyn, Fyn, Yes) at low nanomolar concentrations. This phase I, accelerated titration study assessed maximum tolerated dose, safety, pharmacokinetics and pharmacodynamic effects of JNJ-26483327. METHODS: Nineteen patients with advanced cancers received JNJ-26483327 continuous twice daily (BID) in escalating dose cohorts ranging from 100 to 2100 mg. Pharmacodynamic effects were assessed in paired skin biopsies and blood. RESULTS: JNJ-26483327 was well tolerated in doses up to 1500 mg BID, with target-inhibition-related toxicity such as diarrhoea and skin rash, and other common reported toxicities being nausea, vomiting, anorexia and fatigue. At 2100 mg, two episodes of dose-limiting toxicity were observed, consisting of grade 3 anorexia and a combination of grade 3 anorexia and fatigue, respectively. Pharmacokinetics were dose proportional up to 1500 mg in which plasma levels were obtained showing anti-tumour activity in xenograft mouse models. Pharmacodynamic analysis did not show a substantial effect on expression of Ki-67, p27(kip1), phosphorylated mitogen-activated protein kinase, phosphorylated Akt and EGFR, and serum levels of sVEGFR-2, VEGF-C and VEGF-D remained unchanged. Stable disease was noted in six patients (32%). CONCLUSION: JNJ-26483327 is well tolerated and shows a predictable pharmacokinetic profile; the recommended dose for further studies is 1500 mg BID.

Irinotecan and cisplatin with concurrent thoracic radiotherapy in a once-every-three-weeks schedule in patients with limited-disease small-cell lung cancer: a phase I study.

BACKGROUND: Irinotecan and cisplatin with concurrent radiotherapy is a powerful treatment combination for patients with limited-disease small-cell lung cancer (LD-SCLC). The objective was to determine the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD) of irinotecan and cisplatin with concurrent thoracic radiotherapy (TRT) as a once-every-three-weeks schedule. PATIENTS AND METHODS: Patients with LD-SCLC received a fixed-dose of irinotecan (340 mg) and cisplatin (135mg) at day 1 in cycles 1 and 4. During cycles 2 and 3, irinotecan and cisplatin were given in a dose-escalation schedule with concurrent TRT (once daily, total dose 45Gray). RESULTS: No DLT was observed at first two levels (irinotecan 100mg or 120 mg and cisplatin 100mg at day 1 of cycles 2 and 3). In the first five patients, four episodes of grade III diarrhoea/dehydration were observed at cycles 1 and 4. Therefore, from the sixth patient on, fixed-dose irinotecan at cycles 1 and 4 was reduced to 250 mg. At the subsequent level of irinotecan 140 mg and cisplatin 100mg in cycles 2 and 3, two DLTs (severe oesophagitis and late vertebral radiation toxicity) were observed in one patient. CONCLUSION: Irinotecan 140 mg and cisplatin 100mg with concurrent TRT was considered the MTD. Irinotecan and cisplatin in a once-every-three-weeks schedule is not recommended due to severe toxicity. Irinotecan may be more suited for intermittent weekly administration.

Multiple targeted tyrosine kinase inhibition in the clinic: all for one or one for all?

Recent insight into the role of receptor tyrosine kinase function in cancer cells culminated in the design of highly selective tyrosine kinase inhibitors. After proof of concept for the clinical efficacy and tolerability of selective tyrosine kinase inhibitors, it was conceived that most tumours will depend on more than one signalling pathway for their growth and survival. As a consequence, different strategies were pursued to inhibit multiple signalling pathways or multiple steps in the same pathway either by the development of multi-targeted agents or the combination of single targeted drugs. The use of a combination of different compounds will be less convenient to the patient, may result in dosing mistakes and drug-drug interaction should be anticipated. However, this approach will enable the titration of the dose of either agent to optimize target inhibition. The use of multi-targeted agents will circumvent several of the problems of combination therapy. Clinical activity resulting in FDA approval for both BAY 43-9006 and SU11248 has been noted. However, optimal inhibition of several targets might not be feasible at a dose with acceptable toxicity.

Phase I and pharmacokinetic study of halofuginone, an oral quinazolinone derivative in patients with advanced solid tumours.

PURPOSE: Halofuginone (tempostatin) is a synthetic derivative of a quinazolinone alkaloid showing anti-angiogenic, anti-metastatic and anti-proliferative effects in preclinical studies. The objectives of this phase I study were to assess the dose-limiting toxicities (DLTs), to determine the maximum tolerated dose (MTD) and to study the pharmacokinetics (PKs) of halofuginone when administered once or twice daily orally to patients with advanced solid tumours. METHODS: Patients were treated with escalating doses of halofuginone at doses ranging from 0.5 to 3.5 mg/day. For pharmacokinetic analysis plasma sampling was performed during the first and second course and assayed using a validated high-performance liquid chromatographic assay with mass spectrometric detection. RESULTS: Twenty-four patients received a total of 106 courses. The 'acute' MTD was reached at 3.5 mg/day, with nausea, vomiting, and fatigue as DLT. The recommended dose for chronic administration was defined as 0.5mg/day with the requirement of 5HT3 antagonists to control nausea and vomiting considered as DLT. Several patients experienced bleeding complications on treatment with halofuginone in which a causal relationship could not be excluded. The PKs of halofuginone were linear over the dose range studied with a large interpatient variability. CONCLUSIONS: In this study the DLT of halofuginone was nausea, vomiting, and fatigue. The recommended dose for phase II studies of halofuginone is 0.5mg administered orally, once daily.

A pharmacokinetic interaction study of docetaxel and cisplatin plus or minus 5-fluorouracil in the treatment of patients with recurrent or metastatic solid tumors.

BACKGROUND: The purpose of this study was to look at the pharmacokinetics of docetaxel, cisplatin-derived platinum and 5-fluorouracil (5-FU), when used in combination, to exclude potential clinically relevant pharmacokinetic interactions. METHODS: Fifteen patients with recurrent or metastatic solid tumors were randomized to receive docetaxel 75 mg/m2 and cisplatin 75 mg/m2 in the first treatment course on day 1 and the same combination plus 5-FU 750 mg/m2/day on days 1-5 in the second course, or the two treatment courses in reversed order. Cycles were repeated every 3 weeks. A pharmacokinetic analysis was performed during the first two cycles. RESULTS: Full pharmacokinetic data was available for 12 of the 15 patients. Treatment was tolerated well, with frequency of toxicity consistent with the safety profile known for docetaxel, cisplatin and 5-FU. Mean clearance values for docetaxel and cisplatin showed no statistically significant difference across the "triple" and the "double" combination treatments, and the mean pharmacokinetic parameters of all agents were within the ranges for previously reported single agent treatment. CONCLUSION: No clinically relevant pharmacokinetic interactions between docetaxel, cisplatin and 5-FU used in combination were noticed in this study.

Impact of pazopanib on docetaxel exposure: results of a phase I combination study with two different docetaxel schedules.

PURPOSE: There are several reasons why combining an inhibitor of the vascular endothelial and the platelet-derived growth factor receptor with a taxane might induce synergistic antitumor activity. This phase I study aimed to determine the maximal tolerated dose (MTD) of the combination of pazopanib with two different schedules of docetaxel. METHODS: In a 3 + 3 + 3 design, patients with advanced solid tumors received escalating doses of oral pazopanib combined with docetaxel given either every 3 weeks (D3w) or weekly at days 1, 8, and 15 every 28 days (D1w). Pharmacokinetic data of docetaxel and pazopanib were obtained through extensive sampling and WinNonlin modeling. RESULTS: Forty-six patients were enrolled to six dose levels. Both schedules of docetaxel could be combined with 400 mg/day pazopanib. The MTD of D3w docetaxel was 50 mg/m(2), while for D1w MTD, it was 20 mg/m(2). In the D3w schedule, the administration of pazopanib led to a 33% lower docetaxel clearance (mean 31.5 vs 21.1 L/h/m(2); P = 0.019) and >50% increase in AUC(0-∞) (mean 1,602 vs 2,414 ng*h/mL; P = 0.029) compared with docetaxel single-agent data. Data for the D1w schedule were comparable. CONCLUSIONS: Both treatment schedules of docetaxel combined with pazopanib are feasible but at doses for both drugs that are considerably lower than the recommended single-agent doses. This is largely due to a clinically relevant pharmacokinetic interaction with pazopanib, substantially increasing docetaxel exposure. This interaction is most likely due to CYP3A4 and OATP1B1 inhibition.

The use of oral cytotoxic and cytostatic drugs in cancer treatment.

Although with a few exceptions, most new anticancer agents are initially developed for intravenous use, oral treatment with anticancer agents is, if feasible, to be preferred, as this route of administration is convenient to patients, reduces administration costs and facilitates the use of more chronic treatment regimens. Recent studies have identified various physiological barriers limiting the oral absorption of anticancer drugs. Presently, several strategies are explored to alter the low and variable oral bioavailability of several important anticancer agents by taking advantage of an intentional interaction between anticancer agents and drugs that modulate active intestinal drug transporters or (intestinal) enzymes.

Predicting the maximum-tolerated dose of PNU-159548 (4-demethoxy-3'-deamino-3'-aziridinyl-4'-methylsulphonyl-daunorubicin) in humans using CFU-GM clonogenic assays and prospective validation.

A haematotoxicity model was proposed by Parchment in 1998 to predict the maximum-tolerated dose (MTD) in humans of myelosuppressive antitumour agents by combining data from in vitro clonogenic assays on haematopoietic progenitors and in vivo systemic exposure data in animals. A prospective validation of this model in humans was performed with PNU-159548, a novel agent showing selective dose-limiting myelosuppression in animals. PNU-159548 and its main metabolite, PNU-169884, were tested in vitro on murine, canine and human colony forming units-granulocyte macrophages (CFU-GM) and in vivo on mice and dogs. The IC(90x) ratios (IC(x)=concentration inhibiting x% of colony growth) for CFU-GM and drug plasma protein binding were used to adjust the target plasma concentrations versus time curve (AUC) and predict the human MTD. The predicted MTD was compared with values achieved in phase I studies. Canine CFU-GM were 6-fold more sensitive (P<0.01) and murine CFU-GM 1.7-fold less sensitive (P<0.05) to PNU-159548 treatment than the human progenitors. PNU-169884 behaved similarly to PNU-159548. The predicted MTDs in humans calculated from data in mice and dogs were 15 and 38 mg/m(2), respectively. Overall, 61 patients were treated in two phase I studies, at doses ranging from 1.0 to 16 mg/m(2). Thrombocytopenia was dose-limiting with a MTD of 14 and 16 mg/m(2) in heavily and minimally pretreated/non-pretreated patients, respectively. Adjusting animal MTD data by means of the CFU-GM ratio between species can predict the human MTD with a good quantitative accuracy. Inhibition of common haemopoietic progenitors by PNU-159548 induced neutropenia/thrombocytopenia in animals and thrombocytopenia in patients, probably due to the higher sensitivity to the compound observed in human colony forming units-megakaryocyte (CFU-MK).

RFS2000 (9-nitrocamptothecin) in advanced small cell lung cancer, a phase II study of the EORTC New Drug Development Group.

Camptothecins have shown efficacy in terms of response rate in patients with small cell lung cancer (SCLC). RFS2000 is a new camptothecin derivative, which has shown objective responses in various tumour types. The aim of this phase II study was to determine the objective response rate of RFS2000 in patients with sensitive and refractory SCLC. RFS2000 was given orally at 1.5 mg/m(2) per day for five consecutive days (five days on - two days off) on a continuous basis. Patients were evaluated weekly for toxicity and every six weeks for response. Thirty seven patients were included, 36 patients (14 with sensitive and 22 with refractory SCLC) were evaluable for toxicity, and 35 patients were evaluable for response. No objective responses were observed. Toxicity was acceptable, with myelosuppression, nausea/vomiting, and diarrhoea as the main toxicities. RFS2000 therefore has an acceptable toxicity profile but is not active as a single agent in SCLC.

Influence of the cisplatin hydration schedule on topotecan pharmacokinetics.

The study described here was designed to investigate the influence of the hydration schedule of cisplatin on the pharmacokinetics of topotecan. To test this hypothesis, 13 adult cancer patients were treated with intravenous (i.v.) cisplatin followed by i.v. topotecan for 5 days every 3 weeks using a short hydration schedule (SHS) for cisplatin in the first course and a hyper-hydration schedule (HHS) in the second course or vice versa. Topotecan pharmacokinetic analysis was performed in plasma, whole blood and red blood cells in both courses on days 1, 2 and 5. 11 patients received both courses and were pharmacokinetically evaluable. No significant differences between the two studied schedules were noted in the clearances of topotecan on day 1 in the different matrices. However, in both hydration schedules, on average, slightly lower topotecan clearances were observed on both days 2 and 5 compared with day 1 in all of the matrices, while no differences were noted between days 2 and 5. This alteration was independent of the schedule used and was less pronounced than that which has been initially reported for SHS and, overall, will not have clinical consequences.

Real-time pharmacokinetics guiding clinical decisions; phase I study of a weekly schedule of liposome encapsulated paclitaxel in patients with solid tumours.

The purpose of this weekly schedule phase I study of liposome encapsulated paclitaxel (LEP) was to define the maximum-tolerated dose (MTD), the recommended dose (RD), the dose-limiting toxicities (DLTs), the pharmacokinetic profiles, and to evaluate preliminarily antitumour effects in patients with refractory solid malignancies. LEP was administered as an intravenous (i.v.) infusion over 45 min once every week for 6 out of 8 weeks. Fourteen patients were treated at doses ranging from 90 to 150 mg/m(2)/week. In one patient, DLT was observed at the dose level of 150 mg/m(2)/week, who received less than 70% of the intended cumulative dose. No cumulative toxicities were observed. Stabilisation of disease for 8 weeks was documented in two patients. The whole blood clearance of total paclitaxel was similar for LEP (15.3+/-8.98 l/h/m(2)) and Taxol (17.5+/-3.43 l/h/m(2)), and the extraliposomal to total drug ratio increased rapidly to unity at later sampling time points. The trial was discontinued upon completion of enrolment of the 150 mg/m(2)/week cohort because an assessment of the pharmacokinetics and clinical data suggested that LEP was unlikely to have any advantages over Taxol. It is concluded that this formulation of LEP is unlikely to provide improvements over the taxanes currently in clinical use.

Modulation of cisplatin pharmacodynamics by Cremophor EL: experimental and clinical studies.

The paclitaxel vehicle Cremophor EL (CrEL) has been shown to selectively inhibit the accumulation of cisplatin in peripheral blood leucocytes, but not in tumour cells in vitro, and we hypothesised that this phenomenon is responsible for the improvement of the therapeutic index of cisplatin observed in combination studies with paclitaxel. Here, we report on studies assessing the interaction between CrEL and cisplatin in a murine model, and involving the potential clinical applicability of CrEL as a protector for cisplatin-associated haematological side-effects. In mice, CrEL (0.17 ml/kg, intravenous (i.v.)) given in combination with cisplatin (10 mg/kg, intraperitoneal (i.p.)) did not change the pharmacokinetics of cisplatin. Cisplatin-induced haematological toxicity, expressed as white blood cells (WBC) at nadir, was significantly reduced by CrEL from 5.05+/-0.95 to 6.50+/-1.31 x 10(9)/l (P=0.0009). Data obtained from cancer patients treated with cisplatin (70 mg/m(2), 3-h i.v.) and topotecan (0.45 or 0.60 mg/m(2)/day x 2) preceded by CrEL (12 ml, 3-h i.v.) (n=6) or without CrEL (n=10) similarly indicated significant differences in the percent decrease in WBC between the groups (46.5+/-18.7 versus 67.2+/-15.0%; P=0.029). Likewise, the percent decrease in platelet count was significantly greater in the absence of CrEL (23.9+/-5.38 versus 73.3+/-15.5%; P=0.0003). Pharmacokinetic parameters of unbound and total cisplatin and of topotecan lactone and total drug were not significantly different from historic control values (P>or=0.245). Overall, this study provides further evidence on the important role of CrEL in the pharmacological and toxicological profile of cisplatin, and implies that reformulation of cisplatin with CrEL for systemic treatment might achieve an improvement of its therapeutic index, particularly in the setting of a weekly dose-dense concept.

Phase I and pharmacokinetic studies of PNU-159548, a novel alkycycline, administered intravenously to patients with advanced solid tumours.

PNU-159548 (4-demethoxy-3'-deamino-3'-aziridinyl-4'-methylsulphonyl-daunorubicin) is the lead compound of a novel class of cytotoxic agents (alkycyclines) with a unique mechanism of action combining DNA intercalation with alkylation of guanines in the DNA major groove. The objectives of two phase I studies were to assess the dose-limiting toxicities (DLTs), to determine the maximum tolerated dose (MTD) and to study the pharmacokinetics (PKs) of PNU-159548 and its active metabolite PNU-169884 when administered intravenously (i.v.) over 10 or 60 min to patients with advanced solid tumours. Patients were treated with escalating doses of PNU-159548, courses repeated every 21 days at doses ranging from 1.0 to 16 mg/m(2). For pharmacokinetic analysis, plasma sampling was performed during the first course and assayed using a validated high-performance liquid chromatographic assay with mass spectrometric detection. 69 patients received a total of 161 courses. The MTD was reached at 14 and 16 mg/m(2) in heavily (HP) and minimally pretreated/non-pretreated (MP) patients, respectively, with thrombocytopenia as the DLT. A hypersensitivity reaction was observed in 8 patients across all dose levels, characterised by fever with chills, erythema, facial oedema and dyspnoea. The PKs of PNU-159548 and PNU-169884 were linear over the dose range studied. A significant correlation was observed between the percentage decrease in platelet count and the AUC of PNU-159548. In these studies, the DLT of PNU-159548 was thrombocytopenia. The recommended dose for phase II studies of PNU-159548 is 12 and 14 mg/m(2) administered i.v. over 10 min, once every 21 days, in HP and MP patients, respectively.

Phase I safety and pharmacokinetic study of SU-014813 in combination with docetaxel in patients with advanced solid tumours.

BACKGROUND: In pre-clinical models enhanced anti-tumour activity was observed when SU-014813, an oral multi-targeted tyrosine kinase inhibitor was combined with docetaxel. This synergy might be explained by improvement of the penetration of cytotoxic agents into tumours as a result of both VEGFR and PDGFR inhibition. We assessed the maximal tolerated dose (MTD), evaluated the pharmacokinetics and preliminary anti-tumour efficacy of oral SU-014813 administered continuously in combination with docetaxel to patients with advanced solid tumours. METHODS: In this phase I study successive patient cohorts received docetaxel 60 or 75mg/m(2) every 3weeks in combination with chronic daily dosing of SU-014813. Dose limiting toxicity was assessed both in the first and second treatment cycle. RESULTS: Twenty-five patients were entered on study of which 24 started treatment. Dose limiting toxicities were prolonged neutropenia, neutropenic fever, fatigue and diarrhoea. Other toxicities included fatigue, alopecia, nausea, vomiting, anorexia, rash, hypertension and hair discolouration. The recommended phase II dose was determined to be docetaxel 75mg/m(2) in combination with SU-014813 50mg/day. There was no clinically relevant pharmacokinetic drug-drug interaction. Two patients (8%) achieved a partial response (PR) and 7 patients (29%) had stabilisation of their disease (SD) >6months, for a clinical benefit rate of 37.5%. The activity observed in patients with melanoma and sunitinib refractory gastrointestinal stromal tumours (GIST) was particularly noteworthy. CONCLUSIONS: Oral SU-014813 50mg/day with docetaxel 75mg/m(2) is a clinically feasible regimen with a manageable safety profile and anti-tumour activity. Further development is warranted in patients with melanoma and GIST.