A phase II study of lapatinib, a dual EGFR and HER-2 tyrosine kinase inhibitor, in patients with castration-resistant prostate cancer.

OBJECTIVES: Epidermal growth factor receptor (EGFR) and HER-2 tyrosine kinases may be involved in activation of androgen receptor and progression of prostate cancer. They represent potential therapeutic targets in prostate cancer. Lapatinib is an oral inhibitor of EGFR and HER-2. The objective of this study is to assess the preliminary clinical efficacy of lapatinib in the therapy of castration-resistant prostate cancer. METHODS: In this multicenter, open-label trial, patients with rising PSA on androgen deprivation therapy and not having received chemotherapy were eligible. They were treated with lapatinib at a dose of 1,500 mg once daily. The primary end point was a >50% confirmed PSA decline from baseline; safety, tolerability, and time to PSA progression were secondary outcomes. RESULTS: Twenty-nine patients enrolled in the study had a median age of 73 years and a baseline PSA of 21.6 ng/ml. Seven patients had no radiologic evidence of metastatic disease, while the remaining patients had bone or measurable disease or both. Treatment was well tolerated with only grade 3 treatment-related toxicities being diarrhea (14%) and rash (3%). One of 21 evaluable patients had >50% reduction in PSA, while another patient had 47% reduction in PSA with an ongoing duration of response of 45+ months. The median time to PSA progression was 29 days. CONCLUSIONS: Lapatinib showed single agent activity in a small subset of unselected patients with castration-resistant prostate cancer, as measured by PSA. Future trials should explore a trial design with time-to-event end points and predictive biomarkers and a combination with other agents.

Neoadjuvant docetaxel/estramustine prior to radical prostatectomy or external beam radiotherapy in high risk localized prostate cancer: a phase II trial.

BACKGROUND: Patients with locally advanced or organ confined, high risk, prostate cancer are at significant risk of having disease recurrence despite definitive local therapy. We evaluated the 2-year progression-free survival of subjects treated with chemotherapy administered prior to definitive therapy with surgery or radiation. PATIENTS AND METHODS: Patients (n = 24) with locally advanced and high risk localized prostate cancer were treated with neoadjuvant docetaxel 36 mg/m2 i.v. weekly for 3 weeks and estramustine 140 mg orally 3 times daily for 3 consecutive days every 28 days prior to definitive treatment with prostatectomy or radiation. RESULTS: All evaluable patients, except 1, completed the proposed cycles of neoadjuvant chemotherapy with minimal dose reductions or delays. Of the 22 evaluable patients, 12 underwent radical prostatectomy and 10 underwent external beam radiation therapy. Twenty-one of 22 patients achieved a prostate-specific antigen (PSA) reduction > 25%. There were no pathologic complete responses. With a median follow-up of 24 months, the 2-year progression-free survival was 45%. CONCLUSIONS: Our findings support the safety, tolerability, and efficacy of neoadjuvant chemotherapy in patients with men with high risk, locally advanced prostate adenocarcinoma, although the relative contributions of androgen deprivation therapy and docetaxel cannot be determined. The effectiveness of neoadjuvant chemotherapy in preventing prostate cancer relapses should be studied in a randomized trial.

Phase II trial of sorafenib plus interferon alfa-2b as first- or second-line therapy in patients with metastatic renal cell cancer.

PURPOSE: We undertook this study to determine the activity and tolerability of sorafenib administered with interferon alfa-2b (IFN-alpha-2b) as first- or second-line therapy in metastatic renal cell cancer (RCC). PATIENTS AND METHODS: Between November 2004 and October 2006, 40 patients at two sites were enrolled onto a phase II trial of sorafenib plus IFN-alpha-2b. Treatment consisted of 8-week cycles of sorafenib 400 mg orally bid plus IFN-alpha-2b 10 million U subcutaneously three times a week followed by a 2-week break. Patients were eligible to receive additional cycles of therapy until disease progression. Dose reduction of both drugs by 50% was permitted once for toxicity. RESULTS: The response rate was 33% (95% CI, 19% to 49%; 13 of 40 patients), including 28% partial responses (n = 11) and 5% complete responses (n = 2). Responses were seen in treatment-naïve and interleukin-2 (IL-2) -treated patients within the first two cycles. The median duration of response was 12 months. With a median follow-up time of 14 months, median progression-free survival time was 10 months (95% CI, 8 to 18 months), and median overall survival time has not yet been reached. Fatigue, anorexia, anemia, diarrhea, hypophosphatemia, rash, nausea, and weight loss were the most common toxicities. Grade 3 toxicities were uncommon but included hypophosphatemia, neutropenia, rash, fatigue, and anemia. Dose reductions were required in 65% of patients. CONCLUSION: The combination of sorafenib and IFN-alpha-2b has substantial activity in treatment-naïve and IL-2-treated patients with RCC. The toxicity exceeded that of either drug alone, but dose reductions and breaks between cycles allowed for chronic therapy. A larger, randomized trial would determine whether there is any advantage to this regimen compared with sorafenib alone.