Abstract P3-12-13: First analysis of ASTER study AT for 3 cycles followed by CMF for 3 cycles as neo or adjuvant chemotherapy in early stage breast cancer. A single institution experience

Background: The ECTO study demonstrated the efficacy of concurrent doxorubicin and paclitaxel (AT) for 4 cycles followed by cyclophosphamyde/ methotrexate/fluorouracil (CMF) for 4 cycles in the neoadjuvant and adjuvant treatment of operable breast cancer (Gianni L. et al. JCO 2009). With the purpose of ameliorating the tolerability of the regimen, we designed the ASTER study to reduce both the duration and the total dose of treatment with AT followed by CMF. Herein we report on the first data of efficacy of the study and the toxicity.

Methods: A total of 345 patients with operable breast cancer were enrolled between September 2008 and November 2011. Median age was 50 years (range 23-74); 74.5% of patients presented with hormonal receptor positive (HR +) and 23,5% of patients with both hormonal receptor negative (HR-PgR-); 19% of patients presented HER2 over expression/amplification; half patients had Ki67 >14%, almost of patients had pT1 (66%) or pT2 (30%) with 27,5% of pN0. Patients were treated with Adriamycin (60 mg/mq) + Paclitaxel (200 mg/mq) q21 for 3 cycles followed by CMF i.v. 1, 8q28 for 3 cycles (73 as neo-adjuvant and 272 as adjuvant regimen). After chemotherapy in patients with HER2+ trastuzumab was delivered for 1 yr and in patients with HR+ tumors hormonal treatment was recommended for 5 yr. Breast irradiation was mandatory after conserving surgery (64% of cases).

Results: At a median follow-up of 36 months, the relapse free survival (RFS) and overall survival (OS) were 92% and 96% respectively. As expected in patients HR+/HER2- RFS were 95% and OS 99%, in patients HER2+ RFS were 90% and OS 97% and in those HR-/HER2- 83% and 79% respectively.

In the neoadjuvant subset tnpCR, defined as the absence of invasive cells in the primary tumor and in nodes, was obtained in 10% of cases. A tnpCR was achieved in 27% of patients with triple negative cancer and only in 5% of HR positive cancer.

Peripheral neuropathy toxicity was reported in 37% of cases and was essentially mild to moderate. Only 8,7% of patients experienced neutropenia G 3, 4,3% GI toxicity G3 and 2,3% mucositis G3. No cardiotoxicity was documented even in the 65 patients who received postoperative trastuzumab to date.

Conclusions: This results of Aster study AT for 3 cycles followed by CMF for 3 cycles showed similar efficacy and very favorable toxicity compared whit our previous experience of eighth cycle of sequential and non cross resistant chemotherapy in early stage breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-12-13.

An open-label expanded access study of lapatinib and capecitabine in patients with HER2-overexpressing locally advanced or metastatic breast cancer

BACKGROUND

The Lapatinib Expanded Access Program (LEAP) was designed to provide access to lapatinib plus capecitabine for HER2-positive metastatic breast cancer patients who previously received an anthracycline, a taxane, and a trastuzumab and had no other treatment options.

PATIENTS AND METHODS

LEAP opened globally and enrollment continued until lapatinib received regulatory approval in each participating country. Patients were assessed for progression-free survival (PFS) and overall survival (OS) and monitored for serious adverse events (SAEs).

RESULTS

As of 30 September 2008, 4283 patients from 45 countries enrolled in LEAP. The median treatment duration was 24.7 weeks. The most common drug-related SAEs were diarrhea (9.7%), vomiting (4.3%), and nausea (2.4%) and were mainly grade 3 or higher. The incidences of special interest SAEs were decreased left ventricle ejection fraction (0.5%), interstitial lung disease/pneumonitis (0.2%), and serious hepatobiliary events (0.4%). This safety profile is consistent with the overall lapatinib program. The median PFS and OS were 21.1 [95% confidence interval (CI) = 20.1-22.3] and 39.6 (95% CI = 37.7-40.7) weeks, respectively (n = 4006). Subgroup analysis showed longer PFS and OS in patients who had not received prior capecitabine.

CONCLUSIONS

These results demonstrate the safety and efficacy of lapatinib in a broader patient population compared with a clinical trial.

Clinical and pharmacological phase I evaluation of Exherin (ADH-1), a selective anti-N-cadherin peptide in patients with N-cadherin-expressing solid tumours

BACKGROUND

Upregulation of N-cadherin promotes dysregulated cell growth, motility, invasiveness, plus maintenance of vascular stability and is associated with cancer progression in several human tumour types. N-cadherin is expressed also on tumour cells and the anti-N-cadherin cyclic pentapeptide ADH-1, tested in the present study, can exert a direct antitumour effect.

PATIENTS AND METHODS

Adult patients with advanced solid malignancies expressing N-cadherin on tumour biopsies carried out in the previous 12 months received escalating i.v. doses of ADH-1 given weekly (initially for 3 of 4 weeks, then every week). Plasma pharmacokinetics (PK) was studied at cycle 1. Blood flow changes were assessed after first dosing in all patients treated in the initial regimen.

RESULTS

In all, 129 patients were screened, 65 (50%) were N-cadherin positive, and 30 were enrolled. The doses ranged from 150 to 2400 mg/m(2); no maximum tolerated dose was reached. Treatment was well tolerated with asthenia as the most frequent adverse event. Two patients with ovarian cancer showed prolonged disease stabilisation while one patient with fallopian tube carcinoma achieved a mixed response. PK was linear in the range of doses tested.

CONCLUSION

ADH-1 is the first anti-N-cadherin compound tested in humans. In N-cadherin-positive patients, ADH-1 showed an acceptable toxicity profile, linear PK and hints of antitumour activity in gynaecological cancers.

Phase I clinical study of the novel epothilone B analogue BMS-310705 given on a weekly schedule

BACKGROUND

BMS-310705, a water-soluble semi-synthetic analogue of epothilone B, was selected for clinical development because of its in vivo anti-tumour activity and toxicity profile similar to that of ixabepilone, currently the most extensively evaluated and promising epothilone B analogue. The improved solubility of BMS-310705 allowed a cremophore-free formulation that avoided the need for pre-medication.

PATIENTS AND METHODS

Two schedules were tested, one with drug administrations on days (D) 1, 8 and 15 followed by 1-week's rest, the other with administrations on D1 and 8 (D1&8 schedule) followed by 1-week's rest. Treatment was given as a 15-min infusion without pre-medication against hypersensitivity. The plasma pharmacokinetics of BMS-310705 was studied in 30 patients. An accelerated titration design 2B was applied for dose escalations. Twenty-seven patients were accrued in the D1, 8, 15 and 32 in the D1&8 schedule.

RESULTS

The dose was escalated from 5-30 mg/m(2)/week with diarrhoea as dose-limiting toxicity; 15 and 20 mg/m(2) were the recommended doses in the D1, 8, 15 and D1&8 schedule, respectively. Other frequent non-haematological toxicities were neurotoxicity, mainly paraesthesia, asthenia and myalgia. Preliminary results showed linear pharmacokinetics along the range of doses tested with a short half-life. Five objective responses were reported.

CONCLUSIONS

Further clinical development of BMS-310705 might be worthwhile in solid tumours where ixabepilone or other epothilones are not indicated.

Concerted escalation of dose and dosing duration in a phase I study of the oral camptothecin gimatecan (ST1481) in patients with advanced solid tumors

BACKGROUND

Gimatecan is an orally bioavailable camptothecin analogue with preclinical findings of promising antitumor activity. A phase I design of concerted dose escalation and dosing duration was implemented to assess the potential schedule dependency of tolerability that emerged from animal studies.

PATIENTS AND METHODS

Gimatecan was given daily for five consecutive days per week for 1, 2 or 3 weeks every 28 days. Plasma levels of total gimatecan were measured on the first and the last day of treatment in each schedule.

RESULTS

Overall, 108 patients were treated with 0.8-7.2 mg/m(2) of gimatecan per cycle. The main toxicity was myelosuppression with dose-limiting thrombocytopenia. In the 1-, 2- and 3-week schedule, the maximum tolerated doses were 4.5, 5.6 and 6.4 mg/m(2). Diarrhea and asthenia were of low grade and of minor clinical relevance, while the higher incidence of nausea and vomiting in the 1-week schedule required the use of antiemetic prophylaxis. Due to the prolonged half-life (approximately 77 h), the plasma concentration of gimatecan increased from the first to the last day of dosing. Six partial responses were observed.

CONCLUSIONS

Tolerability of gimatecan was schedule dependent. Further testing with schedules taking into account its long persistence in human plasma is worthwhile.

Pharmacokinetic study of paclitaxel and gefitinib in combination

13123

Background: Both gefitinib and paclitaxel are metabolized by CYP3A4, thus co-administration may result in a pharmacokinetic interaction (Miller V.A. et al. JCO 2003, 21:2094–2100). Paclitaxel is formulated in Cremophor EL (crEL), which also has the potential for pharmacokinetic interactions by either altering protein binding or inhibition of P-glycoprotein transporter systems (Gelderblom H. et al. EJC 2001, 37:1590–1598). Gefitinib is a high extraction ratio drug so changes in protein binding are not a concern, but inhibition of P-glycoprotein transporter systems could change gefitinib’s absorption profile. Methods: In a Phase II study, 17 patients (pts) with metastatic breast cancer received paclitaxel (100 mg/m2 on days 8, 15 q21) with gefitinib (250 mg daily, from day 1 to day 15). Blood samples were collected to measure plasma concentrations of gefitinib on days 7, 8, and 15 from six pts at pre-dose and at 3, 7 and 25 hours after gefitinib administration. The AUC at steady-state (AUCss) was calculated by the linear trapezoidal rule using WinNonlin and the minimum concentration at steady-state (Css, min) was taken directly from the data. Results: The effect of paclitaxel or crEL on the exposure to gefitinib was assessed by comparing the AUCss and Css,min on days 8 and 15 in the presence of paclitaxel to those on day 7 when gefitinib was alone. The geometric mean AUCss increased by 30 to 42% and Css,min by 28 to 58% in the presence of paclitaxel. Individual ratios of days 8 and 15 to day 7 also showed a trend to be greater than 1.0, further indicating an increase in exposure to gefitinib in the presence of paclitaxel. Conclusions: Steady state exposure to gefitinib increased by about 30 to 40% in the presence of paclitaxel. As the increase on day 15 was similar to that on day 8, the effect of paclitaxel appears to be transient, and would be unlikely to affect the safety profile of 250 mg gefitinib when in combination with paclitaxel compared to gefitinib monotherapy.

[Table: see text]

Combination of paclitaxel and two schedules of gefitinib in patients with metastatic breast cancer

10599

Background: The epidermal growth factor receptor (EGFR) may be overexpressed in breast cancer. Inhibition of EGFR signaling by gefitinib (Iressa) enhances the in vitro antitumor activity of many cytotoxic drugs including paclitaxel. Methods: In this phase II study patients (pts) with measurable metastatic breast cancer and maximum prior exposure to two chemotherapies were randomized to paclitaxel (100 mg/m2 on days 1, 8 q21) and continuous gefitinib, 250 mg daily for 21 days (arm A); or paclitaxel (100 mg/m2 on days 8, 15 q21) with gefitinib 250 mg daily from day 1 to 15 (arm B). Therapy continued for at least 4 cycles after best response. After 6 cycles, responding pts continued with gefitinib monotherapy until progression or unacceptable toxicity. Results: 16 pts in arm A and 17 in arm B were enrolled; 25 had visceral disease (12 in arm A and 13 in arm B). Median age was 53 years (range 29–70). All but one pt received prior anthracyclines and 9 also prior taxanes. Overall 17 pts responded to therapy (intent to treat analysis; arm A: 62.5%, 95% CI: 35.4–84.8%; arm B: 41.2%, 95% CI: 18.4–67.1%). Disease control (CR+PR+SD) was achieved in 81.3% of pts in arm A and 76.5% in arm B, with 10 and 6 pts who continued with gefitinib monotherapy after completing the combination schedule. Median time to progression was 250 (arm A) and 204 days (arm B), while median response duration was 212 (arm A) and 285 days (arm B). Tolerability was good with either schedule of gefitinib. Diarrhea was frequent (68.8% and 64.7%) and of grade 3–4 severity in 6% of pts in arm A and in arm B. Grade 3–4 neutropenia affected 6% and 12% of pts respectively, and 6% of pts in both arms had a grade 3–4 increase of AST and ALT. Other grade 1–2 adverse events included acneiform rash (100% in arm A and 58.8% in arm B), sensory neuropathy (68.8% and 58.8%), anemia (50.0% and 52.9%), neutropenia (25.0% and 17.6%) and myalgia (37.5% and 41.2%). Conclusions: The combination of paclitaxel with gefitinib given continuously or for 2 out of every 3 weeks is feasible and well tolerated. The discontinuous schedule caused less skin toxicity. The good antitumor activity deserves further studies to identify sensitive subgroups and mechanisms of sensitivity. IRESSA is a trademark of the AstraZeneca group of companies.

[Table: see text]

A phase I-II and pharmacodynamic (PD) study of the combination of the proteasome inhibitor bortezomib (B) and paclitaxel (P) in patients with taxane-sensitive solid tumors

13029

Background: Proteasome inhibition blocks the chemotherapy-induced activation of NF-кB increasing chemosensitivity to anticancer agents due to increased apoptosis. NF-кB is frequently aberrantly activated in primary human carcinomas and over-expressed in aggressive breast cancer lines1 supporting the rationale for combining B with P. We designed a phase I-II and PD trial to determine the recommended dose (RD) of the B&P combination, to screen for antitumor activity in patients with potentially taxane-sensitive tumors, to search for drug-induced changes and to identify potential surrogate markers of drug activity and toxicity in peripheral blood mononuclear cells (PBMC). Methods: Eligibility included ECOG performance status < 2, neurotoxicity < 2 and adequate organ functions. Treatment was given Q21 days: B on days 1,4, 8 and 11 and P on days 1 and 8. PBMC for gene expression profiling have been collected on day 1 and 4 before and after therapy. RECIST for response was applied. Results: Twenty-nine patients (20 female, median age 60 yrs) were accrued and 25 are evaluable (breast cancer: 13, ovarian cancer: 7, prostate cancer 1, other 4) ; 16 pts were treated in 4 escalation levels and the RD defined respectively at 1.3 mg/m2/dose & 100 mg/m2/dose for B&P. Neurotoxicity was the main toxicity (G1 36%, G2 20% and 1 case G3) requiring treatment discontinuation in 2 pts at cy 6 & 7. Other toxicities (all grades) were nausea and vomiting (68%), diarrhea (56%, G3 12%), alopecia (52%), asthenia (36%, G2 4%), and myalgia (32%, G2 8%). Antitumor activity consisted of 3 PR in pts with ovarian cancer lasting respectively 14, 8+ and 16 wks; 2 PRs in pts with breast cancer (12+ wks,14+ wks) and 1 PR in a pt with prostate cancer. Conclusions: Thus far the regimen has acceptable toxicity with evidence of antitumor activity. The trial will continue until accrual of four additional patients as planned. Footnotes 1 Adams J Current Opin Oncol 2002, 14:628–634.

[Table: see text]

Electrophysiological evaluation of visual pathways in paclitaxel-treated patients

As paclitaxel may induce positive spontaneous visual symptoms or persistent visual loss, we carried out this electrophysiological study in an attempt to clarify the underlying pathophysiological mechanisms of visual pathway involvement. The study involved 30 breast cancer patients: 14 were treated with paclitaxel alone (group A) and 16 with paclitaxel and adriamycin (group B). Pattern visual evoked potentials (VEPs), and transient, 30 Hz flicker (FLK) and oscillatory potential (OP) white flash electroretinograms (ERGs), were recorded before treatment, after the third and sixth therapeutic cycle, and at the end of the programmed regimen. Pretreatment: Abnormal VEP and OP and FLK changes occurred more than 75% of patients; transient ERGs were normal in more than 90%. Serial recordings: VEPs remained unchanged in both goups. In group A, ERG b-wave latency significantly increased (ANOVA P<0.005), and OP and FLK were characterised by non-significant mild attenuation. Several combinations of ERG, OP, FLK and VEP changes occurred in 50% of the patients. The association between transitory lightining scotoma or blurred vision (reported by 12 patients) and VEP, ERG and FLK was poor, whereas that with OP was satisfactory. A few patients showed stable and persistent subclinical electrophysiological changes. Electrophysiological changes during treatment revealed the involvement of both the retina and anterior optic pathway. There was only a weak correlation between visual symptoms and electrophysiology. We suggest that the most likely mechanism of visual symptoms and electrophysiological changes during paclitaxel administration is vascular dysregulation in the retina, or ischemic mechanisms when the optic nerve is involved.

A randomized phase II study of combination, alternating and sequential regimens of doxorubicin and docetaxel as first-line chemotherapy for women with metastatic breast cancer

BACKGROUND

This randomized phase II study was conducted to evaluate the efficacy of doxorubicin and docetaxel (DOC) administered either as a combination, an alternating or a sequential regimen in women with metastatic breast cancer. Secondary objectives included overall response, time to progression, survival and safety.

PATIENTS AND METHODS

Patients with breast cancer (n=123) were randomized to receive doxorubicin and DOC either in combination (60 mg/m2 of each drug), or by alternated or sequential schedule (100 mg/m2 DOC and 75 mg/m2 doxorubicin) every 3 weeks for a maximum of eight cycles as first chemotherapy for stage IV disease. A second randomization allocated patients from each arm to receive prophylactic oral ciprofloxacin or no therapy to prevent febrile neutropenia.

RESULTS

Patients received a median of eight cycles. In an intention-to-treat analysis, the overall response was 63%, 52% and 61% in the combination, alternating and sequential schedules, respectively. Corresponding rates of complete response were 15%, 14% and 11%. Grade 4 neutropenia was common in all arms (81%) and, together with febrile neutropenia, was significantly more frequent with the combination. Prophylaxis with ciprofloxacin did not reduce the incidence of febrile neutropenia or infection. Other frequent non-hematological adverse events included alopecia, nausea, vomiting, stomatitis and asthenia. Congestive heart failure only occurred in the combination arm (10%).

CONCLUSION

All three schedules are feasible and endowed of good therapeutic activity. In view of the more pronounced toxicity and the risk of cardiac events because of the higher exposure to doxorubicin, the combination should be least favored when treating women with metastatic breast cancer. Prophylaxis with ciprofloxacin was ineffective and is not recommended.

Phase IB and pharmacological study of the novel taxane BMS-184476 in combination with doxorubicin

The aim of this study was to define the maximum tolerated dose (MTD) and the pharmacological profile of the paclitaxel analogue BMS-184476 given once every 3 weeks, or on days 1 and 8 every 3 weeks (d1&8), in combination with a fixed dose of 50 mg/m(2) of Doxorubicin (Doxo) administered on day 1 of a 21-day cycle. Adult patients with advanced solid malignancies received escalating doses of BMS-184476 infused over 1 h after bolus Doxo. Pharmacokinetics (PK) of BMS-184476, Doxo and metabolites were investigated. The effect of BMS-184476 on doxorubicinol formation was studied in the cytosol from human myocardium. The MTD of 3-weekly BMS-184476 was 30 mg/m(2). The MTD/recommended Phase II dose was 35 mg/m(2)/week (70 mg/m(2) per cycle) in the d1&8 schedule. The dose-limiting toxicity was neutropenia for both schedules. Other toxicities were loss of appetite, asthenia, and mild, cumulative peripheral neuropathy. The objective response rate in 17 previously untreated or minimally pretreated patients with breast cancer treated at 35 mg/m(2)/week of BMS-184476 was 59% (95% Confidence Interval (CI): 33-82%). Two of the 7 patients not responding to the study regimen later responded to Doxo and paclitaxel. Plasma disposition of BMS-184476 at 30, 35 and 40 mg/m(2) was linear without evidence of a PK interaction with Doxo. In studies with cytosol from human myocardium, the formation of cardiotoxic doxorubicinol was not enhanced by BMS-184476. Dosing of BMS-184476 for 2 consecutive weeks allowed the administration of larger doses of the taxane with a promising antitumour activity in patients with untreated or minimally pretreated breast cancer. The higher than expected myelotoxicity of the 3-weekly schedule is unexplained by the investigated interactions. Lack of enhanced doxorubicinol formation in human myocardium is consistent with the cardiac safety of the regimen.

Clinical and pharmacologic study of the epirubicin and paclitaxel combination in women with metastatic breast cancer

PURPOSE

A pharmacokinetic interaction may cause increased cardiotoxicity of paclitaxel (PTX) and high cumulative dose of doxorubicin. We tested antitumor activity, tolerability, and pharmacokinetics of the lesser cardiotoxic epirubicin (EPI) and PTX (ET combination).

PATIENTS AND METHODS

Twenty-seven women with untreated metastatic breast cancer, median age of 56 years, and prominent visceral involvement (74%) were studied. Three-weekly EPI (90 mg/m(2)) and PTX (200 mg/m(2) over 3 hours) were given for a maximum nine cycles. EPI was administered 24 hours before PTX (E --> T) in cycle 1, and 15 minutes before PTX (ET) thereafter. EPI, epirubicinol (EOL), EPI-glucuronide (EPI-glu), EOL-glucuronide (EOL-glu), PTX, and 6alpha-OH-PTX were measured in plasma and urine in 14 women.

RESULTS

Patients received 205 cycles of ET and a median EPI dose of 720 mg/m(2). Grade 4 neutropenia (49% of cycles) was the most frequent toxicity. Cardiac contractility was decreased in five patients. Mild congestive heart failure occurred in two (7.4%). Response rate was 76% (28% complete). Median overall survival was 29 months. On the basis of intrapatient comparison in the first 24 hours of E --> T and ET cycles, PTX did not affect EPI disposition, but significantly increased plasma exposure to EOL (by 137%), EPI-glu (threefold) and EOL-glu (twofold). Urinary excretion of EPI dose went from 8.2% in E --> T to 11.8% in ET cycles. Clearance of PTX was 30% slower in ET than E --> T. ET cycles caused lower neutrophil nadir than E --> T (644 +/- 327 v 195 +/- 91, P <.05)

CONCLUSION

ET is feasible, devoid of excessive cardiac toxicity, and active. A reciprocal pharmacokinetic interference between the two drugs has pharmacodynamic consequences, and suggests a direct effect of PTX on EPI metabolism requiring ad hoc investigation.

Adjuvant and neoadjuvant treatment of breast cancer

Treatment of early breast cancer has been revolutionized during the past 30 years and new data continue to refine our knowledge of systemic treatments for this stage of disease. The updated worldwide overview has confirmed that, in terms of recurrence and survival, the balance of the known long-term benefits and risk favors some months of adjuvant polychemotherapy and/or a few years of tamoxifen for a wide range of patients. Both the overview and individual trials have shown that anthracycline-containing regimens can achieve additional reduction of the risk of disease relapse and death over cyclophosphamide, methotrexate, and fluorouracil (CMF)-like regimens. Paclitaxel-containing regimens appear promising, but require additional confirmation with longer follow-up. By contrast, controversy still exists on the role of high-dose chemotherapy in high-risk patients. Primary (neoadjuvant) chemotherapy is a new modality to treat large operable breast cancers and offers the possibility of breast conservation with treatment results at least similar to those achieved with classical adjuvant regimens. In the near future, newer agents and information gained on the role of prognostic and predictive factors will probably increase the effectiveness of adjuvant and neoadjuvant treatments.

Clinical and pharmacological phase I study with accelerated titration design of a daily times five schedule of BBR3464, a novel cationic triplatinum complex

OBJECTIVES

To define the maximum tolerated dose (MTD), the toxicity and pharmacokinetic profile of BBR3464, a novel triplatinum complex.

PATIENTS AND METHODS

Fourteen patients with advanced solid tumors not responsive to previous antitumor treatments received BBR 3464 on a daily x 5 schedule every twenty-eighth day. The drug was given as a one-hour infusion with pre-and post-treatment hydration (500 ml in one hour) and no antiemetic prophylaxis. The starting dose was 0.03 mg/m2/day. A modified accelerated titration escalation design was used. Total and free platinum (Pt) concentrations in plasma and urine were assessed by ICP-MS on days 1 and 5 of the first cycle.

RESULTS

Dose was escalated four times up to 0.17 mg/m2/day. Short-lasting neutropenia and diarrhea of late onset were dose-limiting and defined the MTD at 0.12 mg/m2. Nausea and vomiting were rare, neither neuro- nor renal toxic effects were observed. BBR3464 showed a rapid distribution phase of 1 hour and a terminal half-life of several days. At 0.17 mg/m2 plasma Cmax and AUC on day 5 were higher than on day 1, indicating drug accumulation. Approximately 10% of the equivalent dose of BBR3464 (2.2%-13.4%) was recovered in a 24-hour urine collection.

CONCLUSIONS

The higher than expected incidence of neutropenia and GI toxicity might be related to the prolonged half-life and accumulation of total and free Pt after daily administrations. Lack of nephrotoxicity and the low urinary excretion support the use of the drug without hydration. The single intermittent schedule has been selected for clinical development.

Putting taxanes to work in operable breast cancer: a search for selective indications from empirical studies

The taxanes paclitaxel and docetaxel are the prototype drugs of a new class of anticancer drugs that exploits a completely new mechanism of action. Their testing in metastatic breast cancer has been extensive. The results indicating very high response rate with either taxane have given rise to an unprecedented effort in the scientific community to define their optimal application in all stages of the disease. In metastatic breast cancer, initial data suggest that paclitaxel may increase the survival obtained with standard combinations such as CMFP, and similarly promising studies of docetaxel are almost complete. Significant therapeutic benefit has also been observed by the addition of sequential paclitaxel after adjuvant doxorubicin plus cyclophosphamide in operable breast cancer. Overall, more than 20 randomized studies with paclitaxel or docetaxel, either as single agents or in combination, are ongoing or planned in women with high-risk operable breast cancer. This massive effort is mainly based on empirical study designs. However, some preclinical characteristics of the taxanes, such as their increased antitumor effect in tumors overexpressing HER2/neu, the preclinical and clinical evidence of potential synergism with monoclonal antibodies directed against the HER2 receptor, and preclinical evidence of antiangiogenic properties should be pursued to test whether the use of taxanes in breast cancer could be tailored to individual tumor characteristics rather than following the usual pattern of indiscriminate application.

Scintigraphic imaging and turnover studies with iodine-131 labelled serum amyloid P component in systemic amyloidosis

Radiolabelled serum amyloid P component (SAP) is a specific tracer for amyloid. Iodine-123 has ideal physical characteristics for scintigraphy but is expensive and not widely available. Here we report serial imaging and turnover studies in which we labelled SAP with iodine-131, a cheap alternative isotope which would be expected to yield poorer images but permit more prolonged turnover measurements. Imaging and plasma clearance and whole body retention (WBR) of tracer were studied for up to 7 days in ten patients with proven systemic AL amyloidosis and two patients in whom the diagnosis was suspected, after i.v. administration of about 37 MBq of 131I-SAP. Normal blood pool images were obtained in the latter two subjects and amyloidosis was subsequently refuted histologically. WBR at 48 h was <60% and 6-h plasma activity was >65% of the injected dose (i.d.). Among the other ten patients, amyloid deposits were identified in the spleen in eight cases, liver in five and kidneys in four; other sites that gave positive results included bone, joints and soft tissues, and the myocardium in one case. Up to 95% of the tracer localised into amyloid within 6-h, and the values for WBR became progressively more discriminating during the study period, exceeding the normal reference value (<25%) in all cases by day 7. The optimal imaging time was found to be between 24 and 48 h. The duration of the study enabled us to measure the tracer elimination half-life which was increased in all cases by up to tenfold. Follow-up studies performed after 2-24 months in four patients who were treated with iododoxorubicin showed regression of amyloid in one patient and a small increase in one case; in the other two patients the imaging and turnover studies were identical to baseline. Despite its unfavourable imaging characteristics, 131I-SAP produced diagnostic scans in every patient in this series and, coupled with the detailed turnover information, is adequate for monitoring disease progress.

Biweekly paclitaxel and cisplatin in patients with advanced head and neck carcinoma. A phase II trial

BACKGROUND

Cisplatin is an active drug in head and neck cancer. Paclitaxel seems a promising drug. This article reports a phase II assessment of the combination of the two.

PATIENTS AND METHODS

Twenty-three patients were treated with paclitaxel 90 mg/m2 over three hours plus cisplatin 60 mg/m2 every other week. Sixteen patients had locoregional disease and seven had metastatic disease. None of the patients had previously been treated with chemotherapy. Nine patients had had radiotherapy to the target lesions.

RESULTS

One patient was not evaluable for response. Partial responses were observed in 32% of evaluable patients. Toxicity included asthenia (56%), neutropenia, peripheral neuropathy, anemia and vomiting.

CONCLUSIONS

The overall response rate observed in this study does not seem to justify the use of this chemotherapy regimen in the palliative setting.

Pilot study of primary chemotherapy with doxorubicin plus paclitaxel in women with locally advanced or operable breast cancer

A pilot study of primary chemotherapy with bolus doxorubicin plus paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) infused over 3 hours was performed in 38 women with locally advanced and 41 with stage II/III breast cancer. Patients received four cycles of primary chemotherapy followed by surgery and treatment with cyclophosphamide/methotrexate/5-fluorouracil for six cycles. Preliminary data are available on 73 patients. Doxorubicin plus paclitaxel was well tolerated. Primary toxicity consisted of grade 1 or 2 reversible peripheral neuropathy and grade 3 alopecia. After a median follow-up of 13 months, none of the patients have developed cardiac toxicity or any significant alteration of the left ventricular ejection fraction, which was measured before treatment, at each cycle of doxorubicin plus paclitaxel, and every 3 months thereafter. Major clinical response of the breast tumor was observed in 88% of patients. At pathologic examination of the surgical specimen, 40% were pT1, 15% had no macroscopic tumor residue, and 7% had complete disappearance of invasive neoplastic cells. After a median follow-up of 17 months for patients with locally advanced breast cancer, freedom from progression was 67%, disease-free survival was 71%, and overall survival was 74%. The same end points were 100% for patients with stage II/III disease, with a shorter median follow-up of 10 months. In conclusion, doxorubicin plus paclitaxel is safe, feasible, and effective, and can be used as primary or adjuvant chemotherapy to assess its actual therapeutic role in women with early breast cancer.

Human pharmacokinetic characterization and in vitro study of the interaction between doxorubicin and paclitaxel in patients with breast cancer

PURPOSE

We performed a pharmacologic investigation of paclitaxel (PTX) infused over 3 hours and bolus doxorubicin (DOX) to assess the role of sequence, interval between drugs, and duration of doxorubicin infusion on paclitaxel and anthracycline plasma disposition. We also explored possible mechanisms of pharmacokinetic interference involving the physiologic role of the multidrug resistance phenotype in anthracycline and taxane biliary excretion.

PATIENTS AND METHODS

Pharmacokinetics was performed in 80 cycles and 36 women with previously untreated metastatic breast cancer. PTX, DOX, and their metabolites 6 alpha-hydroxyl-PTX (6 alpha OH-PTX) and doxorubicinol (DOL) were measured by high-pressure liquid chromatography (HPLC). Human breast cancer MCF-7 wild-type (WT) and resistant (TH) cell lines were cultured in whole human plasma to study anthracycline retention after treatment with different combinations of PTX, Cremophor EL (CEL) (PEG35 castor oil; BASF, Parsippany, NJ), and DOX.

RESULTS

Pharmacokinetic interference between PTX and DOX was responsible for nonlinearity of DOX plasma disposition and increased concentrations of DOX and DOL. These effects were PTX dose-dependent, DOX concentration-dependent, and likely a result of interference at the level of liver elimination. In view of the physiologic role of P-glycoproteins (P-gp) in xenobiotic biliary excretion, retention of DOX was assessed in MCF-7 WT and MCF-7 TH cells. Intracellular was significantly higher in MCF-7 WT than MCF-7 TH (P < .05). However, concomitant exposure to DOX, PTX, and CEL caused similar DOX retention in both MCF-7 WT and TH cells.

CONCLUSION

PTX, as clinically formulated in CEL, is responsible for a nonlinear disposition of DOX and DOL. Nonlinearity is PTX- and DOX-dependent, and possibly caused by competition for biliary excretion of taxanes and anthracyclines mediated by P-gp. Nonlinearity indicates that even minor modifications of dose and infusion duration of DOX and PTX may lead to unpredictable pharmacodynamic consequences. The postulated role of P-gp suggests that CEL is clinically active, and advises caution in designing combinations of PTX with other drugs that are substrate for P-gp.

Experience at the Istituto Nazionale Tumori with paclitaxel in combination with doxorubicin in women with untreated breast cancer

This report summarizes the clinical experience of investigators at the istituto Nazionale Tumori in Milan, Italy, with intravenous paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) infused over 3 hours plus bolus doxorubicin in women with untreated breast cancer. The overall experience indicates that the combination of paclitaxel/doxorubicin is a very active primary chemotherapy for stage IV breast carcinoma and is associated with manageable toxicity. The results suggest that the incidence of cardiotoxicity and duration of neutropenia can be reduced by limiting the total cumulative dose of doxorubicin to 360 mg/m2 and by adding granulocyte colony-stimulating factor to the primary chemotherapeutic regimen. In addition, the study indicates that continuous treatment of responding patients with single-agent paclitaxel after this combination increases the patients' chances of complete response. These favorable results indicate that this regimen could be a very effective treatment option as adjuvant or neoadjuvant chemotherapy in women with early stage operable breast cancer as well as those with advanced breast cancer.

The role of taxanes in the treatment of breast cancer

The taxanes paclitaxel and docetaxel are undergoing extensive evaluation in women with breast cancer in the United States and in Europe. Their dose-limiting toxicity is neutropenia. Paclitaxel also causes peripheral neuropathy, while docetaxel can cause unpredictable and severe skin toxicity, as well as edema and effusions due to a capillary leak syndrome. Due to threshold pharmacodynamics and nonlinear pharmacokinetics, tolerability of paclitaxel is schedule dependent. Single-agent paclitaxel was very active in multiple phase II trials in patients with different numbers and types of prior chemotherapy and disease extent (20% to 60% complete plus partial responses). Effective doses ranged from 135 to 250 mg/m2. Activity was observed with all infusion schedules (1, 3, and 24 hours) and in women with anthracycline-resistant tumors (25% to 38%). The use of a 96-hour infusion schedule was very active in anthracycline-refractory patients (48%) and in women who failed short infusion taxanes. The drug is undergoing extensive evaluation in combination with doxorubicin, cyclophosphamide, cisplatin, and antimetabolites. Very promising efficacy was observed for paclitaxel by 3-hour infusion plus bolus doxorubicin (approximately 40% complete responses and 50% partial responses). The combination also caused a high incidence of clinically reversible congestive heart failure(14% to 18%). Docetaxel also has very good efficacy in breast cancer, with approximately 70% major responses in untreated patients and more than 50% in anthracycline-resistant tumors. There is no evidence that efficacy and tolerability are schedule dependent as is the case for paclitaxel. At recommended doses (100 or 75 mg/m2 by 1-hour infusion every 3 weeks), docetaxel causes a fluid retention syndrome that may affect quality of life. Its common onset after multiple cycles may limit the use of docetaxel for palliation in metastatic breast cancer. These results clearly indicate that the taxanes will become a standard component of initial chemotherapy for women with breast cancer. The definition of their actual role still requires an answer to the unresolved questions of their optimal dose and combination with other anticancer agents. Most importantly, the drugs should be prospectively evaluated in a randomized study using comparable doses and schedules to assess which of the two has the better therapeutic index in breast cancer.

Paclitaxel by 3-hour infusion in combination with bolus doxorubicin in women with untreated metastatic breast cancer: high antitumor efficacy and cardiac effects in a dose-finding and sequence-finding study

PURPOSE

To define the maximum-tolerated dose (MTD) and better tolerated sequence of paclitaxel by 3-hour infusion plus bolus doxorubicin (DOX) and to evaluate antitumor efficacy.

PATIENTS AND METHODS

Thirty-five women with metastatic breast cancer (dominant visceral metastases in 56%, and involvement of > or = three sites in 67%) who never received chemotherapy of any type were studied. Paclitaxel every 3 weeks (125 mg/m2 starting dose) was increased by 25-mg/m2 steps in subsequent cohorts of patients. DOX (60 mg/m2 fixed dose) was administered 15 minutes before the start of or after the end of paclitaxel for a maximum of eight cycles. Subsequently, patients in continuous response could receive single-agent paclitaxel (175 to 200 mg/m2 every 3 weeks). The drug sequence was alternated in consecutive patients and in the first two cycles.

RESULTS

Severe neutropenia that lasted greater than 7 days (n = 4), febrile neutropenia (n = 7) and grade III oral mucositis (n = 6) defined the MTD of paclitaxel at 200 mg/m2 in 34 assessable patients. Grade II peripheral neuropathy occurred in 33% of patients. Six women (18%) developed clinically reversible congestive heart failure (CHF) after a median of 480 mg/m2 total DOX. Drug sequence had no effect on toxicities. High efficacy on all metastatic sites in 32 assessable patients accounted for a 41% complete response (CR) rate (95% confidence interval [CI], 24% to 59%) and 94% overall-response rate (95% CI, 79% to 99%). After a median follow-up of 12 months (range 3 to 18), the median response duration is 8 months (range, 2+ to 18+) for complete responders and 11 months (range 1+ to 15+) for partial responders.

CONCLUSION

The rate of CR and incidence of CHF may be an expression of therapeutic and toxic enhancement due to the schedule used in this trial. Until clarification of this possibility, this promising combination should be used in investigational trials.

Paclitaxel in metastatic breast cancer: a trial of two doses by a 3-hour infusion in patients with disease recurrence after prior therapy with anthracyclines

BACKGROUND

To date, anthracyclines are the most active drugs against breast tumors, and the taxane paclitaxel (Taxol) looks very promising. Both classes of drugs are affected by cellular multidrug-resistance mechanisms, and therefore their sequential use raises the possibility of clinical cross-resistance. It is therefore important to assess the activity of paclitaxel in patients with clinical resistance to anthracyclines.

PURPOSE

We assessed the safety and efficacy of paclitaxel administered by the logistically convenient 3-hour infusion to breast cancer patients who had disease progression within 12 months since prior therapy with anthracyclines.

METHODS

Fifty-one patients with metastatic breast cancer who had all relapsed or whose disease had progressed within 12 months from completion of an anthracycline-containing chemotherapy protocol (six receiving adjuvant therapy, 19 receiving neoadjuvant therapy, and 26 receiving treatment for metastatic disease) were enrolled in this phase II trial from June 1992 to May 1994. After medication to prevent type I acute hypersensitivity reactions, paclitaxel was given intravenously over 3 hours at 175 mg/m2 to the first 15 patients and at 225 mg/m2 to the next 36 patients. The median age was 50 years (range, 31-62 years), and the median Eastern Cooperative Oncology Group performance status was 0 (range, 0-2).

RESULTS

Patients received a median of five cycles (range, one to 11 cycles). After initial doses of 175 and 225 mg/m2, paclitaxel could be increased by 25 mg/m2 in 73% and 58% of cycles, respectively. Among 50 assessable patients, seven achieved a complete response and 12 achieved a partial response (response rate, 38% [95% confidence interval = 25%-53%]). The median duration of response was 7 months (range, 4-16 months), and the median time to disease progression for all patients was 5 months. Grade 4 neutropenia occurred in 3% of the cycles and in 12% of the patients and was never associated with fever and infection. Common toxic effects were myalgia and arthralgia (94% of the patients; 4% grade 3), peripheral neuropathy (92% of the patients; 8% grade 3), and alopecia (all patients). Pruritus and neuropathy were significantly more frequent and severe, respectively, with the higher dose (P < .01 by chi 2 test). Frequency and severity of other toxic effects were similar at either starting dose. Ten patients had symptoms of neuro-optic toxicity. Only one patient had a grade 2 hypersensitivity reaction.

CONCLUSIONS

Paclitaxel at starting doses of 175 and 225 mg/m2 given as a 3-hour infusion can safely be administered to, and is active in women whose disease has progressed after prior treatment with anthracyclines. There was evidence of increased toxicity at the higher dose but no suggestion of better efficacy.

IMPLICATION

Paclitaxel by a 3-hour infusion in combination with doxorubicin should be investigated in patients with metastatic breast cancer. Unless randomized trials demonstrate greater efficacy of the more toxic higher dose, it is suggested that a dose of 175-200 mg/m2 be administered with the 3-hour infusion schedule.

Nonlinear pharmacokinetics and metabolism of paclitaxel and its pharmacokinetic/pharmacodynamic relationships in humans

PURPOSE

To characterize and model the disposition of paclitaxel in humans and define a pharmacodynamic relationships between paclitaxel disposition and its toxicity and efficacy.

PATIENTS AND METHODS

Paclitaxel pharmacokinetics were studied in 55 courses of therapy in 30 patients. Paclitaxel was administered at 135 mg/m2 or 175 mg/m2 by either a 3- or a 24-hour infusion schedule to patients with advanced ovarian cancer (n = 15), or at 225 mg/m2 by 3-hour infusion to patients with advanced breast cancer (n = 15). Paclitaxel and 6 alpha-hydroxylpaclitaxel were quantified by high-performance liquid chromatography (HPLC). Pharmacokinetics were assessed by noncompartmental and model-dependent methods. Pharmacodynamic correlations were evaluated statistically and by regression models.

RESULTS

Paclitaxel disposition is nonlinear in humans and, on the 3-hour schedule, 6 alpha-hydroxylpaclitaxel was identified in the plasma of all patients treated. The plasma disposition of paclitaxel and 6 alpha-hydroxylpaclitaxel was well described by a model that featured multiple nonlinear processes. Neutropenia was not related to the areas under the curves (AUCs) of paclitaxel or 6 alpha-hydroxylpaclitaxel, or to palitaxel peak concentrations (Cmax). Neutropenia was related to the duration that plasma concentrations were > or = 0.05 mumol/L, a relationship that is well described by a sigmoid maximum response (Emax) model.

CONCLUSION

The disposition of paclitaxel in humans is nonlinear. Paclitaxel metabolism to 6 alpha-hydroxylpaclitaxel is likely an important detoxification pathway. Myelosuppression is related to the duration that plasma paclitaxel concentrations are > or = 0.05 mumol/L. Trials of new doses and schedules of paclitaxel should take into account its nonlinear disposition to rule out adverse clinical consequences, especially if the drug is administered by short infusion. Our pharmacokinetic model should prove to be a powerful tool in predicting paclitaxel disposition, regardless of dose and schedule, and should facilitate further pharmacodynamic investigations.

Paclitaxel (Taxol) efficacy in patients with advanced breast cancer resistant to anthracyclines

We assessed the efficacy of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) when administered by 3-hour intravenous infusion in 15 patients with advanced breast cancer resistant to anthracyclines. Paclitaxel was administered at 175 mg/m2. In the event of severe toxicity, dose reductions to 150 or 125 mg/m2 could be made; otherwise, the dose was subsequently increased to 200 mg/m2. Patients received a median of five cycles of treatment (range, one to nine cycles). Paclitaxel induced three complete responses and four partial responses, for an overall response rate of 47%. The most frequently observed toxicities associated with paclitaxel administration were neutropenia and alopecia, which occurred in all patients. The frequency and severity of the observed toxicities were never of clinical concern. We conclude that paclitaxel is active in breast cancer patients clinically resistant to anthracyclines and that it can be safely administered by 3-hour infusion with standard premedication. Considering the good tolerability, higher doses of paclitaxel in advanced breast cancer should be explored.

Activity and toxicity of 4'-iodo-4'-deoxydoxorubicin in patients with advanced breast cancer

Based on our previous Phase I study indicating good tolerability of the drug, we have evaluated therapeutic activity and acute and subacute toxicities associated with repeated courses of the new anthracycline 4'-iodo-4'-deoxydoxorubicin (I-Dox) at the maximum tolerated dose (80 mg/m2) every three weeks. Thirty-three patients (31 evaluated for activity and 32 for toxicity) with relapsed (11 cases) or advanced breast cancer at presentation (22 cases) were treated with 108 cycles (median 3, range 1-7) for a median cumulative dose of 240 mg/m2. We observed no complete and 11 (35%) partial responses. Minor response was documented in 5 additional patients. The most frequent and severe toxicity was hematological. In 47% of the cycles and 34% of the patients I-Dox administration was associated with WHO grade 4 neutropenia. Severe neutropenia was more frequent after repeated cycles. Similar cumulative toxicity was observed for thrombocytopenia and anemia. In three patients (7 cycles) fever and possible infection occurred during neutropenia and required oral antibiotics. Extra-hematological side-effects were limited to mild/moderate nausea lasting for a few hours and mild fatigue lasting 1-7 days. Alopecia or oral mucositis were minimal or absent in the majority of patients. One case of potential reversible cardiac toxicity was observed after 240 mg/m2 I-Dox in a patient with preexistent cardiac risk factors. In view of the reported activity, good general tolerability, and selective hematological toxicity, I-Dox should be evaluated at higher than the conventionally defined maximum tolerated dose in combination with recombinant human hemopoietic growth factors.