No abstract

Summary Docetaxel has shown remarkable radiosensitizing in vitro properties. In a previous phase I/II dose escalation study in nonsmall-cell lung cancer (NSCLC) we observed a high response rate after concomitant boost radiotherapy and weekly docetaxel. The maximum tolerated dose was 30 mg m -2 week -1 . In the present phase II study we evaluated whether weekly docetaxel and conventionally fractionated radiotherapy could be better tolerated and equally effective in the treatment of locally advanced NSCLC. Thirty-five patients with T3, T4/N2, T3/M0-staged disease were recruited. Docetaxel (30 mg m -2 ) was given as a 30 min infusion once a week. Asthenia and radiation-induced oesophagitis were the main side-effects of the regimen enforcing 2-week treatment delay in 6/35 (17%) patients and minor delay (3-7 days) in another 11/35 (31%) patients. Neutrophil, platelet and haemoglobin toxicity was minimal, but pronounced lymphocytopenia was observed. Complete response (CR) of the chest disease was observed in 12/35 (34%) patients and partial response in 16/35 (46%). Although not statistically significant (P = 0.19), a higher CR rate (8/18; 44%) was observed in patients who accomplished their therapy within the scheduled treatment time (44-47 days) as compared to patients that interrupted their treatment for several days due to treatment-related toxicity (CR 4/17; 23%). The overall survival and the local progression-free survival at 1 year was 48% and 60% respectively. We conclude that docetaxel combination with radiotherapy is a promising approach for the management of locally advanced NSCLC that results in high CR rate. Further trials with docetaxel-based radiochemotherapy should integrate accelerated radiotherapy together with cytoprotection.

The substantial augmentation of the radiation sequelae during chemo -radiotherapy with novel drugs masks the real potential of such regimens. In this study we examined whether subcutaneous administration of amifostine can reduce the toxicity of a highly aggressive chemo -radiotherapy scheme with Stealth Ò liposomal doxorubicin (Caelyx Ò ) and Docetaxel (Taxotere Ò ) in non-small cell lung cancer. Twenty-five patients with stage IIIb non-small cell lung cancer were recruited in a phase I/II dose escalation trial. The starting dose of Taxotere Ò was 20 mg m 72 week and of Caelyx Ò was 15 mg m 72 every two weeks, during conventionally fractionated radiotherapy (total dose of 64 Gy). The dose of Taxotere Ò /Caelyx Ò was, thereafter, increased to 20/25 (five patients) and 30/25 mg m 72 (15 patients). Amifostine 500 mg was given subcutaneously before each radiotherapy fraction, while an i.v. amifostine dose of 1000 mg preceded the infusion of docetaxel. The 'in-field' radiation toxicity was low. Grade 3 esophagitis occurred in 9 out of 25 (36%) patients. Apart from a marked reduction of the lymphocyte counts, the regimen was deprived from any haematological toxicity higher than grade 1. No other systemic toxicity was noted. The CR and CR/PR rates in 15 patients treated at the highest dose level was 40% (6 out of 15) and 87% (13 out of 15) respectively. It is concluded that the subcutaneous administration of amifostine during high dose Taxotere Ò / Caelyx Ò chemo -radiotherapy is a simple and effective way to render this aggressive regimen perfectly well tolerated, by reducing the systemic and the 'in-field' toxicity to the levels expected from simple conventional radiotherapy. The impressive tolerance and the high CR rate obtained encourages the conduct of a relevant randomized trial to assess an eventual survival benefit in patients with non-small cell lung cancer.

Taxanes have been shown to interact with anti-apoptotic proteins. In the present study we investigated whether the addition of taxane in combination with DNA damaging drugs can further enhance tumor shrinkage in cases with incomplete response to radiotherapy. Since the dose of docetaxel in combination with carboplatin is not known, the above hypothesis was tested in the context of a dose escalation phase I study. Twenty-eight patients with locally advanced chest or pelvic tumors, showing residual disease on CT scans performed 40 d following docetaxel radio-chemotherapy, were recruited in a dose escalation protocol of docetaxel/carboplatin supported with amifostine and GM-CSF. The starting dose of docetaxel was 40 mg/m2 every 2 weeks. Carboplatin dose was calculated using the Calvert formula and was escalated in cohorts of 4 patients (starting dose AUC2 every two weeks; AUC0.5 increments up to AUC3). Thereafter the docetaxel dose was increased to 50 and 60 mg/m2, while carboplatin was escalated (by AUC0.5 increments) starting from AUC3 and AUC4 respectively. Amifostine (600 mg/m2) was administered i.v. before carboplatin and GM-CSF (480 microg) was injected s.c. on days 5, 6 and 10, 11 of each cycle. Six cycles were given and response was assessed 2 weeks after the end of chemotherapy. None out of four patients treated in the 6th dose level cohort (50 mg/m2 of docetaxel and AUC4 of carboplatin every 2 weeks) showed any grade 2-4 hematologic toxicity. Mild non-hematologic toxicity such as neuropathy, leg edema, pleural effusion, pyrexia, alopecia grade 2 and hypersensitivity was observed in 4-12% of patients. Out of four patients treated in a 7th cohort (docetaxel 60 mg/m2 and carboplatin AUC4), one developed grade IV neutropenia and two developed grade 3 severe asthenia requiring treatment delay for 2 weeks. Out of 11 patients with PR following docetaxel radio-chemotherapy, 7 (63%) showed CR after docetaxel/carboplatin additional chemotherapy. Eight out of 17 patients with MR following docetaxel radio-chemotherapy showed PR (47%) and one showed CR (6%) after additional chemotherapy. High dose combined docetaxel (50 mg/m2) and carboplatin (AUC4) chemotherapy can be safely administered on a two-weekly basis if supported with amifostine and GM-CSF. Such an additional therapy may be important in patients with incomplete response after chemo-RT. Broad spectrum cytoprotection with amifostine and GM-CSF may also contribute to the reduction of incidence of neurosensory reactions and asthenia in patients treated with taxanes.