Phase I study of TP300 in patients (pts) with advanced solid tumors

2563

Background: TP300 (CH4556300) is a synthetic camptothecin analogue and potent topoisomerase I inhibitor designed to have superior efficacy, tolerability and pharmacokinetic (PK) characteristics compared to current inhibitors. Intravenous (i/v) TP300 undergoes rapid chemical conversion to the active compound CH0793076, then enzymatic conversion to an active metabolite, CH0793011. The objectives of this study were to determine the dose-limiting toxicities (DLTs), maximum-tolerated dose (MTD) and PK profiles of TP300; antitumor activity and pharmacodynamics (PD) were also evaluated. Methods: Eligible pts with refractory, advanced solid tumors who had adequate PS, hematologic, renal, and hepatic function were recruited into this open-label, modified- Fibonacci dose escalation (“3 + 3” pts/dose level, with expansion at the MTD) study. TP300 was given as a 1-hour i/v infusion 3-weekly; the starting dose was 1 mg/m2. The MTD was defined as the dose level below that where > 2 of 3–6 pts experienced DLT. PK profiles of TP300, CH0793076 and CH0793011 were analysed; DNA strand breaks in peripheral blood mononuclear cells (PBMCs) were measured with the comet assay as a PD marker. Results: 32 pts (m=20; f=12), median age 58 (range 31–72), received TP300 at doses of 1, 2, 4, 8, 12, then 10mg/m2. The MTD was 10mg/m2; DLTs seen at 12mg/m2 (2/4 pts) and 10mg/m2 (3/12 pts) included anaemia, thrombocytopenia and febrile neutropenia. Other grade 3/4 toxicities included lethargy, chills and lower back pain. Diarrhoea was uncommon. Seven pts, all previously treated with irinotecan, had disease stabilisation for 1.5–5 months. CH0793076 PK (AUC and Cmax) were linear from 1 to 10mg/m2. There was a strong PD relationship between CH0793076 AUC and fall in neutrophils, the threshold AUC for DLT neutropenia being 5 hr.umol/L. DNA strand breaks were detected consistently in PBMCs on completion of TP300 infusion . Conclusions: The Phase II starting dose will be 8mg/m2 because hematologic toxicity was seen in cycle 1 at the MTD. As the AUC of CH0793076 at MTD is substantially greater than that of SN38 in pts treated with irinotecan, and CH0793076 is almost equipotent to SN38 pre-clinically, a PK advantage for TP300 is confirmed. Further investigation is warranted.

[Table: see text]

Gemcitabine with or without cisplatin in patients (pts) with advanced or metastatic biliary tract cancer (ABC): Results of a multicenter, randomized phase III trial (the UK ABC-02 trial)

4503

Background: There is no established standard chemotherapy for pts with inoperable ABC. We previously reported an improvement in progression-free survival (PFS) in a randomised phase II trial of 86 pts (ABC-01) using gemcitabine/cisplatin (GemCis) vs. gemcitabine (Gem) (Valle ASCO-GI 2006, abstr. 98). This study was extended into ABC-02, a phase III trial, to recruit a further 314 pts with overall survival (OS) as the primary end-point. Methods: Consenting pts with histologically/cytologically-confirmed ABC, aged ≥18 years, ECOG performance status 0 - 2, and adequate haematological, hepatic and renal function were randomised to receive either Cis (25 mg/m2) followed by Gem (1000 mg/m2 D1, 8 q21d) for 8 cycles, or Gem alone (1000 mg/m2 on D1, 8, 15 q28d) for 6 cycles, stratified by extent of disease, site of primary tumour, ECOG score and centre. The trial had an 80% power to detect an OS hazard ratio of 0.73. Results: From May 2005 to October 2008, 324 pts were randomised to ABC- 02 from 34 UK centres. We report the pre-planned combined analysis of ABC-01 and ABC-02 based on 410 pts (GemCis=206/Gem=204). Patient characteristics: median age 64 yrs (range 23–85); male (47%); metastatic disease (75%), locally advanced (25%); gallbladder (36%), bile duct (59%), ampulla (5%); and ECOG 0–1 (87%), 2 (12%). With a median follow-up of 6.1 months and 263 deaths, the median OS was greater with GemCis than Gem, 11.7 vs. 8.2 months (log rank p=0.002), with hazard ratio 0.68 (95%-CI 0.53, 0.86). The median PFS was greater with GemCis than Gem, 8.5 vs. 6.5 months (log rank p=0.003), with hazard ratio 0.70 (95%-CI 0.56, 0.88).Toxicity was similar between the arms (by week 12, 57% had a grade 3/4 toxicity in each arm), though there was a slight excess of neutropenia using GemCis. Conclusions: This is the largest ever study in ABC and demonstrates a clear survival advantage for GemCis without added clinically significant toxicity, setting a new international standard of care.

No significant financial relationships to disclose.

Monitoring the treatment of carcinoid disease using blood serotonin and plasma 5-hydroxyindoleacetic acid: three case examples

The results for plasma 5-hydroxyindoleacetic acid (5-HIAA), whole blood serotonin and the chromogranins on three patients following their treatment for carcinoid disease with somatostatin analogues are presented. Two of the patients (a 56-year-old woman and a 55-year-old man) demonstrated a good clinical response following treatment, with initial high blood serotonin and plasma 5-HIAA concentrations showing a significant decline. However, blood serotonin concentrations remained above the reference range during the course of treatment, whereas plasma 5-HIAA remained borderline high or marginally elevated with respect to the clinical cut-off concentration. The third patient, a 79-year-old man, demonstrated saturation of platelets with serotonin and increasing elevation of plasma 5-HIAA, which later fell with the introduction of interferon into this patient's treatment regimen. Results for the plasma chromogranin fragments, pancreastatin (Chromogranin A) and GAWK (Chromogranin B), showed a much greater degree of variability in all three cases. This study shows promise for plasma 5-HIAA as a useful marker for monitoring carcinoid disease. The limitations of blood serotonin expressed to the platelet count are highlighted.

A phase II study of DJ-927 as second-line therapy in patients (pts) with advanced gastric cancer (GC) who have failed a 5-FU non taxane based regimen

4081

Background: Most 1st-line combination chemotherapy regimens in pts with advanced GC include 5-FU. Taxanes are also active agents in GC, either alone or in combination. However, there is no recognized 2nd-line regimen for use in pts with advanced GC. DJ-927 is a semi-synthetic novel taxane with in vitro activity against GC cells lines. It is administered orally, with hematologic dose-limiting toxicity (DLT) in Phase I studies. The primary objective of this study was to determine the objective response rate of DJ-927 as 2nd-line therapy in pts with advanced GC. Methods: Eligible pts had confirmed advanced GC with no more than 1 prior systemic 5-FU-containing regimen for advanced disease, with adequate hematologic, renal and liver function, and with measurable disease. The starting dose in the 1st cohort of 6 pts was 27 mg/m2 orally, every 3 weeks. If < 2 DLTs occurred at this dose, the next cohort of 6 pts would start at a dose of 35 mg/m2, every 3 weeks, and all subsequent pts would be treated at the optimal dose level. Measurable disease was assessed after every 2 courses. Pharmacokinetic sampling was performed during course 1 only. Sample size based on a 3-outcome 1-stage design was calculated to be 27 pts evaluable for response, with ≥ 4 responses of 27 pts indicating that DJ-927 has activity in advanced GC. Results: 36 pts (male=25; female = 11), KPS ≥ 60%, with GC (n = 23) or OG junction cancer (n = 13), received 104 courses (median = 2; range 1–9) of DJ-927. 2 DLTs (febrile neutropenia; Grade 4 neutropenia > 5 days) occurred at 35 mg/m2, and the optimal starting dose was confirmed as 27 mg/m2. 6 of 36 pts were not evaluable for response (< 1 complete treatment course) due to early disease progression (3), toxicity (2), and drug not given (1). Response data is available for 26 of 30 evaluable pts with confirmed PR (n = 5), SD (15), and PD (6). Toxicity, ≥ grade 3, in evaluable pts (n = 33) included neutropenia (17), anemia (5), thrombocytopenia (4), diarrhoea (7), fatigue (5), lethargy (4), neutropenic sepsis (5). Conclusions: DJ-927 has modest activity in pts with GC who have failed a 5-FU non-taxane based regimen. Toxicities include neutropenia ± sepsis, diarrhoea and lethargy. Further studies of DJ-927 in combination with other active agents are warranted in pts with GC.

[Table: see text]

A phase I and II study of 2-weekly irinotecan with capecitabine in advanced gastroesophageal adenocarcinoma

We investigated 2-weekly intravenous irinotecan combined with oral capecitabine in patients with advanced gastroesophageal adenocarcinoma. In phase I, doses were escalated in chemotherapy naïve or pretreated patients to establish maximum tolerated doses (MTD). In phase II, patients were treated at MTD as first-line therapy with the primary end point of RECIST response. Dose levels in phase I were as follows: Level 1: irinotecan 150 mg m-2 on day 1; capecitabine 850 mg m-2 12-hourly on days 1-9. Level 2: as level 1 but capecitabine 1000 mg m-2. Level 3: as level 2 but irinotecan 180 mg m-2. Level 4: as level 3 but capecitabine 1250 mg m-2. In phase I, 21 patients were entered. Maximum tolerated dose was level 3. Dose-limiting toxicities were lethargy, diarrhoea, vomiting and mucositis. In phase II, 31 patients were entered at level 3. During the first six cycles, 13 of these patients underwent dose reduction and three patients stopped treatment for toxicity. A further six patients stopped for progressive disease. The commonest grade 3-4 toxicities were lethargy (20%), diarrhoea (17%), nausea (10%) and anorexia (10%). There were no treatment-related deaths. The response rate was 32% (95% CI 16-52%). Median overall survival was 10 months. This regimen is active in gastroesophageal adenocarcinoma. However, using the MTD defined in phase I, fewer than 50% patients tolerated six cycles without modification in phase II; therefore, modification of these doses is recommended for further study.

Intravenous irinotecan plus oral ciclosporin

We previously reported a phase I study of intravenous irinotecan plus oral ciclosporin, in which dose-limiting diarrhoea was not observed, supporting the hypothesis that pharmacokinetic modulation of irinotecan by ciclosporin may improve its therapeutic index. We now report results of a further 34 patients treated at the recommended dose. A low rate of diarrhoea of grade 3 or above (3%) was again seen, with useful anti-tumour activity. The regimen is to be formally evaluated as part of a future phase III trial.

Weekly 5-fluorouracil and leucovorin: achieving lower toxicity with higher dose-intensity in adjuvant chemotherapy after colorectal cancer resection

BACKGROUND

Current standard therapy following resection of high-risk colon cancer is intravenous bolus 5-fluorouracil (5-FU) with leucovorin (LV), but there is no consensus on the optimum regimen of these drugs: practice ranges from the high toxicity Mayo Clinic schedule to the very low toxicity weekly QUASAR schedule. We present data for a weekly schedule that aims to provide moderately dose-intense treatment with low toxicity.

PATIENTS AND METHODS

One hundred and sixty-two patients were studied: 60% male; median age 65 years (36% over 70 years); 94% colorectal primary. Treatment was intravenous bolus (5 min) 5-FU 425 mg/m(2) plus D,L-LV 45 mg flat rate once weekly, for a planned 24 weeks. Data for toxicity, dose-reductions, delays and stoppages were collected.

RESULTS

Overall, 20% of patients experienced any grade > or = 3 toxicity, most commonly diarrhoea (14% patients). Dose reductions were made in 35% of patients (although only 21% required 20% or more reduction); toxicity contributed to a decision to stop treatment before 24 weeks in 16% of patients. Median delivered dose intensity (DI) was 96% of planned (407 mg/m(2)/week) during treatment, and 91% of planned (385 mg/m(2)/week) over the full 24 week treatment plan. Female sex and age >70 years were significantly associated with higher rates of toxicity and dose adjustment, and lower delivered DI.

CONCLUSIONS

Weekly treatment at these doses is convenient and well-tolerated for the large majority of patients, and achieves DI comparable with the 5 days a month QUASAR schedule and other more toxic standard regimens.

Bleomycin, vincristine, cisplatin/bleomycin, etoposide, cisplatin chemotherapy: an alternating, dose intense regimen producing promising results in untreated patients with intermediate or poor prognosis malignant germ-cell tumours

Patients with poor and intermediate prognosis metastatic germ-cell tumours (MGCTs) are at a significant risk of relapse after standard platinum-based chemotherapy. Novel treatment regimens are required to improve survival. Dose intense, alternating combinations of drugs with known activity in germ-cell tumours represents one approach. In all, 43 patients with IGCCCG intermediate/poor prognosis MGCT were treated with a dose intense regimen alternating bleomycin, vincristine, cisplatin (BOP) with bleomycin, etoposide, cisplatin (BEP) to a maximum of three cycles. Data were collected on the maintenance of dose intensity, toxicity, response, progression-free (PFS) and overall survival (OS). The complete response rate was 58%; a further 7% of patients being rendered disease free by resection of viable residual tumour. With a median follow-up of more than 4 years in surviving patients, 3-year OS and PFS rates of 81% (95% CI: 66–91%) and 72% (95% CI: 56–83%) are seen, respectively. Bleomycin, vincristine, cisplatin (BOP)/bleomycin, etoposide, cisplatin (BEP) was well tolerated, with 86% of patients completing all planned courses. Toxicity was predominantly haematological with common toxicity criteria grade III neutropenia in 90% of patients. Cisplatin neuropathy and bleomycin-induced pulmonary toxicity represented the most significant nonhaematological toxicity. Bleomycin, vincristine, cisplatin (BOP)/bleomycin, etoposide, cisplatin (BEP) represents a practicable, well-tolerated, dose intense chemotherapy regimen with significant activity in intermediate and poor prognosis MGCT.

DNA: still a target worth aiming at? A review of new DNA-interactive agents

DNA acts as the final target for most clinically effective cytotoxic agents, but the lack of selectivity for tumor cells has raised questions about the value of developing new DNA-interactive agents. Three new classes of cytotoxic agents are reviewed; each interacts directly with DNA but cytotoxicity appears to be mediated through novel mechanisms, including the interaction with specific proteins by DNA-bound drug molecules. Irofulven is the lead compound of the illudin family of molecules. It causes a novel type of DNA damage whose repair is dependent on functioning DNA helicases. Pre-clinical and clinical synergy between irofulven and agents which inhibit topoisomerases has been observed. Clinical trials with irofulven have shown significant activity and phase II studies in pancreatic, ovarian and prostatic cancer are ongoing. Toxicity in the form of myelosuppression and fatigue have been shown to be schedule dependent, with intermittent administration appearing to significantly reduce toxicity. DNA-interacting agents which alkylate bases exposed in the minor groove have been derived from a number of natural sources. The minor groove alkylation appears to be sequence specific; although the significance of this specificity for cytotoxicity is unclear, one proposed mechanism is through inhibition of expression of particular genes. Three cyclopropylpyrroloinole analogues which cause sequence specific minor groove alkylation are currently under clinical assessment. Myelosuppression is the dose limiting toxicity and is biphasic in its time course. Moderate activity in phase I trials has been observed. Ecteinascidins represent one of the increasing number of groups of drugs isolated from marine organisms. Ecteinascidin-743 (ET-743) is the most advanced in its clinical development. Binding to the minor groove of DNA occurs, although with a different base specificity from other compounds. The cytotoxic effects of ET-743 may occur by inhibition of the inducible transcription of a number of genes by sequestration of specific transcription factors. Clinical trials of ET-743 have shown significant activity, and phase II trials are underway in soft tissue sarcoma and breast cancer. Hepatic toxicity and myelosuppression are predictable and appear associated with peak plasma concentrations, whereas efficacy seems to be improved with prolonged infusion.

A phase II trial of the vitamin D analogue Seocalcitol (EB1089) in patients with inoperable pancreatic cancer

Inoperable cancer of the exocrine pancreas responds poorly to most conventional anti-cancer agents, and new agents are required to palliate this disease. Seocalcitol (EB1089), a vitamin D analogue, can inhibit growth, induce differentiation and induce apoptosis of cancer cell lines in vitro and can also inhibit growth of pancreatic cancer xenografts in vivo. Thirty-six patients with advanced pancreatic cancer received once daily oral treatment with seocalcitol with dose escalation every 2 weeks until hypercalcaemia occurred, following which patients continued with maintenance therapy. The most frequent toxicity was the anticipated dose-dependent hypercalcaemia, with most patients tolerating a dose of 10-15 microg per day in chronic administration. Fourteen patients completed at least 8 weeks of treatment and were evaluable for efficacy, whereas 22 patients were withdrawn prior to completing 8 weeks' treatment and in 20 of these patients withdrawal was due to clinical deterioration as a result of disease progression. No objective responses were observed, with five of 14 patients having stable disease in whom the duration of stable disease was 82-532 days (median=168 days). The time to treatment failure (n=36) ranged from 22 to 847 days, and with a median survival of approximately 100 days. Seocalcitol is well tolerated in pancreatic cancer but has no objective anti-tumour activity in advanced disease. Further studies are necessary to determine if this agent has any cytostatic activity in this malignancy in minimal disease states.

Inflammatory demyelinating polyneuropathy: a complication of immunotherapy in malignant melanoma

Paraneoplastic syndromes (PNS) involving the central nervous system are a rare manifestation of malignant disease. As they commonly precede the diagnosis of malignancy their acute manifestations do not often present themselves to oncologists in the first instance. It is currently believed that most, if not all, neurological PNS are autoimmune in nature. Proteins expressed ectopically on the surface of tumour cells generate an immune response which cross-reacts with the same, or similar, proteins in the nervous system resulting in damage. This can involve a single cell type of the nervous system whilst in other cases the impairment is more widespread. The following report is of a case of chronic inflammatory demyelinating polyneuropathy (CIDP) occurring in metastatic malignant melanoma, following treatment with interferon-alpha. We review the current literature on this rare association and speculate on its pathogenesis, and the implications for future therapeutic strategies in melanoma targeting tumour antigens.

hMLH1 expression and cellular responses of ovarian tumour cells to treatment with cytotoxic anticancer agents

Loss of expression of the hMLH1 and hPMS2 subunits of the MutL alpha-mismatch repair complex is a frequent event (9/10) in independent cisplatin resistant derivatives of a human ovarian carcinoma cell line. However, only hMLH1 mRNA is decreased in these MutL alpha-deficient lines. No alterations in the levels of the hMSH2 and hMSH6 (GTBP) subunits of the MutS alpha-complex are observed. An increase in the proportion of ovarian tumours negative for the hMLH1 subunit is observed in samples taken at second look laparotomy after chemotherapy (36%: 4/11), compared to untreated tumours (10%: 4/39). No significant difference is observed for hMSH2, hMSH6 or hPMS2. Furthermore, cisplatin and doxorubicin-resistant ovarian lines deficient in hMLH1 expression are cross-resistant to 6-thioguanine and the methylating agent N-methyl-N-nitrosourea (MNU). Depletion of O6-alkylguanine-DNA-alkyltransferase (ATase) activity confers only limited increased sensitivity to MNU. Thus the mismatch repair deficient lines retain DNA damage tolerance even after ATase depletion. The hMLH1 deficient lines also lose ability to engage G1 and G2 cell cycle arrest after cisplatin damage. Together these data suggest that loss of hMLH1 expression may be a high frequency event following exposure of ovarian tumour cells to cisplatin and may be critically involved in the development of drug resistance. Thus, the hMLH1 status of these cells appears to be highly correlated with the ability to engage cell death and cell cycle arrest after DNA damage induced by cisplatin.

Microsatellite instability, apoptosis, and loss of p53 function in drug-resistant tumor cells

We have examined microsatellite instability and loss of p53 function in human tumor cell line models of acquired anticancer drug resistance. We observe acquisition of an RER(+) phenotype in cell lines selected for resistance to cisplatin or doxorubicin. The majority of independent cisplatin-resistant sublines are RER(+), whereas the parental line shows no evidence of microsatellite instability. Microsatellite mutations in random, nonselected subclones of a cislatin-resistant line are observed in the absence of further drug exposure, suggesting that the RER(+) phenotype is a stable phenotype rather than being transiently induced by DNA damage. Furthermore, a cisplatin-resistant derivative shows reduction in a G:T mismatch recognition activity compared to the parental line. Independent lines selected by multiple exposure to cisplatin show resistance factors of up to a 5-fold by clonogenic assay and have reduced cisplatin-induced apoptosis. The resistant lines that are RER(+) show evidence of loss of p53-dependent functions, as measured by a loss of radiation-induced G(1) arrest and reduced CIP1 mRNA. Induced loss of p53 function by transfection of mutant TP53 does not cause a detectable RER(+) phenotype. We speculate that tolerance of DNA damage and expansion of cells with an RER(+) phenotype may select for reduced ability to engage apoptosis and loss of p53 function.

Colonic adenocarcinoma associated ectopic ACTH secretion: a case history

A 57-year-old woman developed features of Cushing's syndrome after resection of a Duke's C adenocarcinoma of the sigmoid colon. Biochemical and endocrine investigation indicated ectopic production of adrenocorticotrophic hormone (ACTH) as the cause for her condition. Hepatic metastases were detected by computed tomography (CT) scan. Histology of the original tumour displayed neuroendocrine characteristics but no definite evidence of ACTH synthesis. Treatment was instituted to control her hypercortisolism, and chemotherapy initiated to reduce the production of ectopic hormone. A clinical, biochemical and radiological response was obtained with complete resolution of her Cushing's syndrome. The tumour relapsed after several months with distant metastases, but no further endocrine abnormality was noted. A review of ectopic ACTH producing adenocarcinoma is given along with a discussion of the major pathological and therapeutic features of the case.