<h3>Background</h3> Motexafin gadolinium is a tumor-selective antineoplastic agent that disrupts redox-dependent pathways by targeting oxidative stress-related proteins such as thioredoxin reductase, which is often overexpressed in non–small-cell lung cancer (NSCLC) and is associated with a poor prognosis. Inhibition of thioredoxin reductase reverses tumor phenotype in lung carcinoma cells in vitro and in vivo. Three trials are under way to evaluate motexafin gadolinium as a single agent (PCYC-0227) and in combination with pemetrexed (PCYC-0228) and docetaxel (PCYC-0229) for second-line treatment of NSCLC. <h3>Patients and Methods</h3> For all 3 trials, patients with locally advanced or metastatic NSCLC with or without brain metastases, Eastern Cooperative Oncology Group performance status 0/1, and who had received 1 previous platinum agent–based chemotherapy regimen with or without kinase inhibitor were eligible. Treatments were as follows: for PCYC-0227, patients were randomized to receive intravenous motexafin gadolinium 10 mg/kg per week (group A) or motexafin gadolinium 15 mg/kg per week (group B). For PCYC-0228, patients received motexafin gadolinium 15 mg/kg and pemetrexed 500 mg/m<sup>2</sup> on day 1. For PCYC-0229, patients received motexafin gadolinium 10 mg/kg and docetaxel 75 mg/m<sup>2</sup> on day 1. For all 3 trials, treatment was given in 21-day cycles and response was evaluated by Response Evaluation Criteria in Solid Tumor every 6 weeks. <h3>Results</h3> PCYC-0227 had 58 evaluable patients with a median age of 62 years (range, 4185 years) with locally advanced (14%) or metastatic (86%) tumors (adenocarcinoma [48%], squamous-cell [14%], large cell [9%] or other NSCLC [29%]) received 1-12 cycles (mean, 3.3 cycles) of motexafin gadolinium. The most common grade ≥ 3 adverse events (AEs) were hypophosphatemia (24.1%), fatigue (10.3%), and dyspnea (8.6%). Fifty-eight patients were evaluable for response, with a response rate of 5.3% (3 partial responses: 2 in group A, and 1 in group B), and 31.6% had stable disease (SD). Median time to progression was 7 weeks. Median survival was 8.1 months (95% confidence interval [CI], 6.2-11.6 months), with 1-year survival of 27%. For PCYC-0228: 27 patients with a median age of 64 years (range, 51-83 years), with stage IIIB (7.4%), stage IV (59.3%) or recurrent (33.3%) cancers (squamous [41%], adenocarcinoma [30%], or other NSCLC [29%]) received 1-9 cycles (mean, 3.1 cycles) of motexafin gadolinium/pemetrexed. The most common grade ≥ 3 AEs were pneumonia (11.1%), thrombocytopenia (11.1%), and fatigue (11.1%). Of 20 patients with response data, 17 (85%) have SD (of whom 10 are still on treatment), and 3 (15%) had progressive disease. Median survival and time to progression have not been reached. One-year survival is estimated at 69%. For PCYC-0229: 24 patients, median age of 62 years (range, 41 -85 years), with locally advanced (35%) or metastatic (65%) disease (squamous cell [50%], adenocarcinoma [35%], or other NSCLC [15%]) received 1-7 cycles (mean, 3.2 cycles) of motexafin gadolinium/docetaxel. The most common grade ≥ 3 AEs were neutropenia (20.8%), asthenia (16.7%) and febrile neutropenia (12.5%). Of 14 patients with response data, 13 (86.7%) have SD (of whom 4 are still on treatment), and 1 had progressive disease (6.7%). Median survival was 8.2 months (95% CI, 3.9 months, not reached). One-year survival is 20%. <h3>Conclusion</h3> Motexafin gadolinium appears active as a single agent and for second-line treatment of patients with NSCLC with advanced or metastatic disease that has failed previous platinum agent–based chemotherapy. The single-agent response and survival rates are comparable with other approved agents. Motexafin gadolinium in combination with pemetrexed or docetaxel is well tolerated and resulted in a high percentage of patients with SD, many of whom are still on treatment and might convert to responders with ongoing therapy.
Read full abstract