Public health response to an imported case of canine melioidosis

Melioidosis in humans presents variably as fulminant sepsis, pneumonia, skin infection and solid organ abscesses. It is caused by Burkholderia pseudomallei, which in the United States is classified as a select agent, with "potential to pose a severe threat to both human and animal health, to plant health or to animal and plant products" (Federal Select Agent Program, http://www.selectagents.gov/, accessed 22 September 2016). Burkholderia pseudomallei is found in soil and surface water in the tropics, especially South-East Asia and northern Australia, where melioidosis is endemic. Human cases are rare in the United States and are usually associated with travel to endemic areas. Burkholderia pseudomallei can also infect animals. We describe a multijurisdictional public health response to a case of subclinical urinary B. pseudomallei infection in a dog that had been adopted into upstate New York from a shelter in Thailand. Investigation disclosed three human contacts with single, low-risk exposures to the dog's urine at his residence, and 16 human contacts with possible exposure to his urine or culture isolates at a veterinary hospital. Contacts were offered various combinations of symptom/fever monitoring, baseline and repeat B. pseudomallei serologic testing, and antibiotic post-exposure prophylaxis, depending on the nature of their exposure and their personal medical histories. The dog's owner accepted recommendations from public health authorities and veterinary clinicians for humane euthanasia. A number of animal rescue organizations actively facilitate adoptions into the United States of shelter dogs from South-East Asia. This may result in importation of B. pseudomallei into almost any community, with implications for human and animal health.

Phase II study of everolimus (E) with imatinib (IM) in patients with previously-treated renal carcinoma (RCC)

e16075

Background: Inhibitors of mTOR improve progression-free survival (PFS) in advanced RCC. We hypothesized that co-administration of the mTOR inhibitor E with an upstream receptor tyrosine kinase inhibitor could augment activity in advanced RCC. We chose to study IM due to its inhibition of PDGFR, a relevant target for RCC with potential activity at both the tumor cell and the pericyte. Methods: Eligible patients had metastatic or unresectable clear cell renal carcinoma, at least one prior systemic therapy, no prior mTOR inhibitor therapy, performance status 0–2, and measurable disease. Treatment consisted of E 2.5 mg p.o. daily and IM 600 mg p.o. daily, a dose determined from a phase I study in GIST. A two-stage design was employed to test for a 3-month PFS of ≥ 70% vs. ≤ 50%. Results: 19 subjects were evaluable for toxicity and 18 for response. Median age 65; number of prior systemic therapies 1:2:3+ (47%:32%:21%); prior sorafenib and/or sunitinib 89%; MSKCC prognostic categories favorable:intermediate:poor (42%:47%:11%). There were no objective responses. Best response was stable disease (67%) and progressive disease (33%). The 3-month PFS rate was 49% (95% C.I. 23%, 72%). The median PFS was 2.9 months (95% C.I. 1.9, 6.2) and the median overall survival was 14.4 months (95% C.I. 11.3, N.R.). Toxicities and lab abnormalities affecting >50% of subjects were: nausea, elevated creatinine, edema, anemia, hypocalcemia, fatigue, diarrhea, vomiting, and dyspnea, and leucopenia. Most common grade 3+ events were: fatigue (16%), pleural effusion (16%), edema (11%), and renal failure (11%). The study was closed after the first stage as the 3-month PFS did not meet continuation criteria. Conclusions: The combination of E 2.5 mg with IM 600 mg in previously-treated patients with advanced RCC did not meet the study-defined level of activity to warrant further investigation. The natural history assumptions for this pretreated RCC population may have been overly optimistic. While the observed PFS is comparable to that reported with E 10mg monotherapy, there appears to be no advantage to combination IM therapy and the incidence of adverse events is high. Further development of this regimen for RCC is not recommended.

[Table: see text]

The Advanced Renal Cell Carcinoma Sorafenib (ARCCS) expanded access trial: Long-term outcomes in first-line patients (pts)

5096

Background: Sorafenib (SOR) doubled median progression-free survival (PFS) versus placebo in a phase III study (TARGETs) for previously treated pts with clear cell renal cell carcinoma (RCC). We report on pts who had not received any prior systemic anti- cancer therapy (1st line) for advanced RCC from the ARCCS program in the US and Canada, which enrolled a broad range of pts. Methods: Pts received SOR 400 mg bid in the ARCCS open-label, nonrandomized treatment protocol if they were =15 years old with advanced (unresectable, recurrent or metastatic) RCC and had ECOG PS 0–2. In the US, ARCCS enrollment ended with SOR approval in 12/05, and pts were transitioned to commercial drug with 1st line pts being eligible for an additional 6-mo follow-up in an extension protocol (EP); Canadian enrollment completed in 8/06. Response evaluation (baseline and =1 post-baseline radiologic assessment) was conducted every 4 wks in the main study and every 8 wks during the EP. Pts without a confirmatory scan were classified as unconfirmed PR. The primary efficacy analysis on PFS was pre-specified to be performed only on the EP-enrolled pts. Results: Of the 2,488 pts valid for safety in ARCCS, nearly 50% were 1st line (n=1239) of which 69% were male with median age 65 yrs; 77% had prior nephrectomy and 29% had prior radiotherapy. Time from diagnoses to treatment was <1 yr for 52% and =1 yr 36% in these 1st line pts. Grade 3 and 4 adverse events with >2% incidence included hand-foot skin reaction 7.7%, fatigue 4.7%, hypertension 3.8%, rash/desquamation 5.2%, dehydration 2.9, diarrhea and dyspnea 2.6%. Confirmed responses are reported in the table ; 15% had unconfirmed PRs. For the 224 1st line pts enrolled in the EP, median PFS was 35.1 wks (95% CI; 32.7, 41.9). Conclusions: SOR toxicity in 1st line pts appeared similar to that in both overall and 2nd line populations previously reported in the phase III study. The PFS among patients enrolled in the EP is encouraging, but may be biased by low enrollment and selection for non-progressors.

[Table: see text]

[Table: see text]

PN, Beer TM, Mack PC, Drabkin HA, Holland WS, Crawford E, Ryan CW. Clinical and molecular factors predictive of outcome with first-line sorafenib-based therapy in advanced renal carcinoma (RCC): An analysis of SWOG 0412

5108

Background: SWOG 0412 was a phase II study of sorafenib and interferon-a2b (IFN) as first-line therapy for RCC. Response rate was 19%, median PFS was 7 months, and estimated median OS was 17 months (Ryan ASCO 2006). We investigated several potential risk factors among participants in SWOG 0412. Methods: Hemoglobin (hgb), LDH, number of metastatic sites, grade, gender, time from diagnosis to treatment, and MSKCC risk category were analyzed in 62 patients. Von Hipel-Lindau (VHL) gene status was determined by direct sequencing of DNA amplified by PCR methods from archival tumor. Immunohistochemistry for p-MAPK, p-p38, and p- AKT was performed to assess for enhanced signaling through the RAS-RAF and related pathways. Survival differences between subgroups were assessed by the logrank test. Results: Clinical factors associated with improved PFS and OS: favorable MSKCC risk category, time from diagnosis to treatment = 1 year, normal hgb. Fewer metastatic sites was also associated with improved OS but not PFS. No association was found with gender, grade, or LDH. VHL mutations were detected in 4 of 18 (22%) archival tumor specimens. P-p38 was overexpressed in all tumor specimens and p-MAPK was absent in all but one specimen. p-AKT was overexpressed (>20% staining) in 18 (82%) of patients. In this limited subset analysis, none of these tumor markers was found to be significantly predictive of survival. Conclusions: Time from diagnosis, hgb, and MSKCC risk grouping were predictive of PFS and OS in patients receiving sorafenib + IFN. The median PFS of 18 months for favorable MSKCC risk patients is higher than the 8 months expected for first-line patients treated with IFN-based therapy, while the median PFS of 4 months for intermediate and poor risk patients is similar to the expected 5 months (Motzer JCO 2002). This observation is consistent with a hypothesis that the benefit of first-line sorafenib-based therapy may be most profound in or limited to favorable MSKCC risk patients.

[Table: see text]

[Table: see text]

The Advanced Renal Cell Carcinoma Sorafenib (ARCCS) expanded access trial in North America: Safety and efficacy

5011

Background: A prior phase III trial (TARGETs) demonstrated that sorafenib (SOR) doubled median progression-free survival versus placebo in previously treated clear cell renal cell cancer (RCC) patients (pts). The ARCCS trial made SOR available to a broader range of RCC pts through an expanded access program. Methods: This open-label, nonrandomized trial enrolled pts with advanced RCC not eligible for, or without access to, other SOR clinical trials; ECOG PS 0–2 with waivers granted for pts with ECOG PS 3–4; age =15 yrs; and adequate prior treatment of brain metastases. Major exclusion criteria included treatment <4 wks prior, life expectancy <2 mos, uncontrolled hypertension, and severe renal impairment requiring dialysis. Objectives were to analyze the safety and efficacy (response by RECIST) of 400 mg bid SOR in a community-based setting. Enrollment ceased on 12/20/05 when SOR became commercially available in the US, and those with no prior therapy or non-clear cell RCC continued in an extension protocol. Enrollment completed in Canada in 8/06. Results: A total of 2488 pts were valid for safety: 69% male with median age 63 yrs and most (83%) had prior nephrectomy; histologies included 78% clear-cell, 7% papillary, 1% chromophobe, and <1% collecting duct and oncocytoma. Median time from diagnosis for all pts was 1.4 yrs (range <1–34). Of those pts receiving prior therapy (n=1249), treatments included interferon alfa (54%), interleukin 2 (43%), bevacizumab (23%), thalidomide (12%), and sunitinib (2%). Grade 3 and 4 adverse events occurring in > 2% pts were hand- foot skin reaction 7.2%, fatigue 5.3%, hypertension 4.4%, rash/desquamation 4%, dehydration and dyspnea 2.7%, and diarrhea 2.5%. Efficacy assessment, mainly PFS, was limited by the short median time (14 wks) on study due to many pts enrolling during the last 2 months of the study. Of 1,850 pts evaluable for response, 17.5% had unconfirmed PR. One (0.1%), 67 (3.6%), 1479 (79.9%) and 303 (16.4%) had CR, PR, SD, and PD, respectively. Conclusions: ARCCS pts were representative of the broader range of RCC pts in the community including those excluded from previous SOR trials. Toxicity and response rates were similar to those reported previously, supporting the generalizability of the phase III trial data.

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C-reactive protein as a prognostic marker for men with androgen-independent prostate cancer (AIPC): Results from the ASCENT trial

5074

Background: Concentrations of blood proteins such as PSA, hemoglobin (HGB), and LDH are associated with survival in men with AIPC. We sought to identify additional blood proteins associated with prognosis in chemotherapy-treated AIPC patients. Methods: Baseline plasma samples were stored (-80°C) from 160 patients enrolled in the ASCENT trial, a randomized placebo-controlled phase 2 trial comparing weekly docetaxel plus DN-101, an oral high-dose formulation of calcitriol, to weekly docetaxel. Multiplex immunoassays measured 16 cytokine/chemokine or cardiovascular/inflammation markers including IL-1a, IL-1β, IL-2, IL-6, IL-8, IL-10, TNFa, MCP-1, EGF, VEGF, PAI-1, MMP-9, sE-Selectin, sICAM-1, sVCAM-1 and C-reactive protein (CRP). Cox’s proportional hazard model was used to assess association between baseline biomarkers and survival or skeletal-related event (SRE)-free survival, and logistic regression for PSA Working Group Criteria response. Results: Baseline characteristics were similar to those of the 90 patients without samples, except for age (mean 68.0 vs. 70.6 yrs) and HGB (12.8 vs. 12.2 g/dL). CRP was the only biomarker that significantly predicted shorter overall survival (HR 1.41, 95% CI 1.20–1.65, p < 0.0001). When CRP (continuous) was entered into a multivariate model using 13 baseline variables (including PSA, LDH, alkaline phosphatase, HGB, ECOG Performance Status, age) only elevated CRP remained a significant predictor (p<0.0001) of shorter survival. When categorized as normal (= 8 mg/L) or abnormal (> 8 mg/L), elevated CRP was a significant predictor of shorter survival (HR 2.96 95% CI 1.52–5.77, p = 0.001) as was HGB (p=0.007). Elevated CRP was also associated with a lower probability of PSA response (OR 0.74, 95% CI 0.60–0.92, p = 0.007) and a shorter SRE-free survival (HR 1.30, 95% CI 1.15–1.48, p < 0.0001). Conclusions: Elevated levels of plasma CRP appear to be a strong predictor of poor survival and development of SREs in AIPC patients receiving docetaxel-based therapy. The use of CRP as a risk marker and its potential as a surrogate marker of treatment effect should be prospectively evaluated in future clinical trials in advanced prostate cancer.

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Distinct patterns of PSA modulation by single-agent sunitinib before combination with docetaxel and prednisone in patients with metastatic castrate-resistant prostate cancer (CRPCa)

5134

Background: We are conducting a phase I study of the oral, multitargeted tyrosine kinase inhibitor sunitinib malate in patients with CRPCa as a single agent lead-in, followed by combination with docetaxel and prednisone, to determine the optimal dose, safety, efficacy and pharmacokinetic profile of the combination. The lead-in with sunitinib alone was included to evaluate whether PSA is modulated differently than with imatinib (Mathew et al. JCO 2004;22:3323–9), and if this is predictive of response and toxicity to the combination. In addition to blocking PDGF signaling (imatinib), sunitinib also blocks VEGF. Preliminary safety and efficacy were previously reported (ASCO Prostate Symposium 2007). Here we present PSA modulation results. Methods: All patients receive a lead-in of daily sunitinib 50 mg for 4 weeks (wks) on, 2 wks off, prior to starting combination therapy. To date, 3 successive cohorts have received 60 mg/m2 docetaxel every 3 wks combined with prednisone 5 mg bid and escalating sunitinib doses (12.5, 37.5 or 50 mg/d) on a 2/1 schedule (2 wks on, 1 wk off). An ongoing cohort is receiving 75 mg/m2 docetaxel + 37.5 mg/d sunitinib. Dose-limiting toxicities (DLTs) are evaluated over the first 3-wk cycle. Results: PSA results are available for 21 patients (pts) enrolled across the 4 cohorts (median age 68 yrs, PSA 42 ng/mL, Gleason score 8). Preliminary data showed 3 patterns of sunitinib-induced PSA modulation during the lead-in: PSA reduction (6 pts; mean decrease 37.8%; >50% in 2 pts), initial increase followed by drop during the off-sunitinib period (10 pts; mean decrease 32.5%), and PSA increase (5 pts; mean increase 61%). Conclusions: Single-agent sunitinib induces PSA decline in a subset of patients with CRPCa in contrast to that observed with agents targeting PDGF or VEGF alone. The predictive value of the “lead-in PSA kinetics” in determining later response to the sunitinib plus docetaxel and prednisone combination will require completion of the study. These data support the hypothesis that blocking VEGFR may alter the phenotype of CRPCa and be synergistic with blocking PDGFR.

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A phase II study of mammalian target of rapamycin (mTOR) inhibitor RAD001 plus imatinib mesylate (IM) in patients with previously treated advanced renal carcinoma (RCC)

15600

Background: The serine-threonine kinase mTOR is a valid target for RCC therapy with temsirolimus treatment resulting in improved overall survival in poor-risk patients (Hudes G et al., ASCO 2006). RAD001 is an oral inhibitor of mTOR which has demonstrated activity in RCC at 10mg/day (Amato R et al., ASCO 2006). IM is a tyrosine kinase inhibitor (TKI) of platelet-derived growth factor receptor (PDGFR), a target that may promote angiogenesis and growth of RCC. Combined mTOR and PDGFR inhibition with RAD001 and IM may achieve vertical blockade through the PI3K/AKT pathway. Methods: Eligibility: metastatic clear cell RCC, performance status (PS) 0–2, adequate organ function, and prior treatment with = 1 systemic therapy. Doses were based on a phase I study of the combination in GIST (Van Oosterom AT et al., ASCO 2005): RAD001 2.5 mg p.o. daily and IM 600 mg p.o. daily. Patients were reimaged every 6 weeks. This is a 2-stage phase II study to determine the 3-month progression-free rate. Results: 14 pts have been enrolled. Median age 66 years (51–79). 6 pts PS 0 and 8 pts PS 1. Median number of prior therapies 1.5 (1–4). 12 of 14 patients had prior TKI therapy. Prior therapies included sorafenib (11 pts), interferon (7), sunitinib (3), bevacizumab (2), erlotinib (1), panitumumab (1), high-dose IL-2 (1). Of 10 pts evaluable for the primary endpoint, 3 are progression-free = 3 months. Best response for 9 pts evaluable by RECIST: PR/CR 0, SD 7, PD 2. Most common adverse events in 11 evaluable patients include nausea (8), edema (7), increased creatinine (7), fatigue (7), transaminase elevation (6), thrombocytopenia (5), leukopenia (5), cough (5), diarrhea (5). Grade 3 adverse events include fatigue (3), LE edema, rash, pleural effusion, increased creatinine, abdominal pain, and thrombocytopenia (1 each). There were no grade 4 toxicities. Unique suspected RAD001 toxicities include grade 3 pneumonitis (1) and angioedema (1). Conclusions: The combination of RAD001 and IM has moderate toxicity. This is one of the first studies in RCC patients predominantly pretreated with a TKI. 3 month progression-free rate appears to be a clinically relevant endpoint in this population.

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A phase II trial of docetaxel plus carboplatin in hormone refractory prostate cancer (HRPC) patients who have progressed after prior docetaxel chemotherapy: Preliminary results

14533

Background: Treatment options for HRPC patients who progress after docetaxel chemotherapy are limited. Carboplatin may enhance the efficacy of docetaxel chemotherapy. Methods: We prospectively treated HRPC patients with documented PSA or radiographic progression during a minimum of 2 cycles of docetaxel-based chemotherapy or within 45 days of completing therapy. No prior platinum was allowed, though patients may have received other prior chemotherapy. Patients received docetaxel 60 mg/m2 and carboplatin AUC (4) every 21 days until progression or unacceptable toxicity. Measurable response was assessed by RECIST criteria. PSA declines were assessed per PSA Working Group; 2 patients were not evaluable as they received only 1 cycle of therapy but are included in the denominator. Results: Interim data is available on the 1st stage of patients (n = 16) enrolled in this ongoing phase II trial. Median age was 69 years (range 46–81), 94% white. Baseline performance status was 0 or 1 in 88%. Prior therapies included antiandrogens (80%) and ketoconazole (47%); docetaxel was used alone (33%), with estramustine (33%) or another agent (33%). Median PSA at baseline was 44 ng/ml (range 4.9–4801). Patients received a median of 3 cycles of docetaxel/carboplatin (range 1–12+). PSA declines of ≥50% were noted in 3 of 16 patients (19%, 90% C.I. 5–42%). In addition, 5 patients had SD, suggesting clinical benefit in 50% (90% C.I. 28–72%). Of 10 patients with measurable disease at baseline, 2 (20%; 90% C.I. 4–51%) had confirmed PR. Therapy was well-tolerated, with no treatment-related deaths and five grade 3 toxicities, including anemia (1), leukopenia (3) and hyperglycemia (1). Median time to progression was 2.7 months (range 0–13.4); median survival was 11.7 months (95% C.I. 6.7–14.0). Conclusions: In preliminary analyses, docetaxel plus carboplatin demonstrated encouraging activity in patients who progressed after docetaxel-based therapy. PSA declines ≥50% were seen in 19%; measurable responses in 20%. Accrual is ongoing. Final analyses will include correlation of response to serum markers of neuroendocrine differentiation. (Supported by BMS).

No significant financial relationships to disclose.

Sorafenib plus interferon-α2b (IFN) as first-line therapy for advanced renal cell carcinoma (RCC): SWOG 0412

4525

Background: Sorafenib is a RAF and multiple receptor tyrosine kinase inhibitor active in RCC. IFN has modest activity in RCC and has immunologic, anti-angiogenic, and anti-proliferative effects. Sorafenib and IFN may simultaneously target anti-angiogenic and MAP kinase pathways, providing the basis for this phase II combination study. Methods: Eligible patients (pts) had metastatic or unresectable RCC with a clear cell component, no prior systemic therapy, performance status 0–1, measurable disease. Treatment: IFN 10 x 106 IU s.c. 3x/week and sorafenib 400 mg p.o. BID. Response assessment was performed q8 weeks. This was a single-stage trial with a planned sample size of 55. Primary endpoint was RECIST response rate. Results: Of 67 registered pts, 58 are eligible & evaluable. Pt characteristics: median age 61 years (42–84), male:female (40:18), prior nephrectomy 86%. MSKCC prognostic categories (42 pts) were good:intermediate:poor (28%:67%:5%). With a median follow-up of 6.5 months, 79% (46/58) of pts are alive, 41% (24/58) remain on treatment. Assessment of progression-free survival is premature. Overall response rate (53 pts) is 19% (95% CI: 9%, 32%) with CR 2% and PR 17% (9% confirmed, 8% unconfirmed). Toxicities affecting >50% of subjects were: fatigue, anorexia, diarrhea, nausea, rigors/chills, fever, anemia, leukopenia. Most common Grade 3+ toxicities were fatigue (24%), leukopenia (10%), anorexia (6%), diarrhea (6%), hyponatremia (6%). All pts experienced some toxicity, with 36 (62%) experiencing at least one Grade 3+ toxicity. Hand-foot syndrome, a common side effect of sorafenib, was seen in only 10% of pts. Conclusions: The overall response rate of 19% for the combination of sorafenib and IFN in advanced RCC is greater than expected with either IFN or sorafenib alone. Toxicity is typical of IFN and notable for minimal hand-foot syndrome. Further studies with this combination are warranted.

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Intermittent chemotherapy in metastatic androgen-independent prostate cancer (AIPC): Initial results from ASCENT

4518

Background: Phase III studies document a survival benefit for 10–12 cycles of docetaxel-containing chemotherapy in AIPC. Further management of patients who complete chemotherapy in response status remains ill-defined. Single-institution phase II data suggest that re-treatment with the same regimen after a treatment holiday is feasible in selected patients. This approach was prospectively tested in a multi-institutional trial. Methods: ASCENT was a multi-institution randomized clinical trial designed to compare the activity and safety of weekly DN-101 (45 μg on day 1) plus docetaxel (36 mg/m2 iv on day 2 for 3 weeks of a 4-week cycle) to placebo + docetaxel in patients with chemotherapy-naïve metastatic AIPC. ASCENT was the first large trial to prospectively evaluate intermittent chemotherapy. Patients could opt to suspend treatment if they had a confirmed ≥ 50% reduction in serum PSA and a serum PSA ≤ 4 ng/ml. PSA was monitored every 4 weeks (CT scans every 8 weeks in patients with measurable disease) during the treatment holiday. Treatment was resumed when serum PSA rose by ≥ 50% and was ≥ 2 ng/ml or for other evidence of disease progression. The study was not powered to compare treatment holiday outcomes between the two arms. Results: 250 patients were randomized 1:1. Overall PSA response rates were: DN-101: 63%, Placebo 52% (p = 0.07). Overall 18% (DN-101: 20%, Placebo: 16%) of patients entered the intermittent chemotherapy. The median duration of the first chemotherapy holiday was 16 weeks (range 4–74+) (DN-101: 15 weeks, Placebo: 16 weeks). Upon resumption of treatment after the first holiday, 50% of patients responded with a ≥ 50% reduction in serum PSA from their post-holiday baseline, 35% met criteria for stable PSA for at least 12 weeks, and 15% progressed on therapy. Conclusions: This is the first report of intermittent chemotherapy in AIPC prospectively tested in a large multi-institutional trial. This strategy results in a clinically meaningful duration of chemotherapy holidays and can be offered to a minority (18%) of patients. Upon re-treatment, most patients (85%) again respond or stabilize PSA values.

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Skeletal related events (SREs) in metastatic androgen independent prostate cancer (AIPC) treated with docetaxel-based chemotherapy: Results from ASCENT

4614

Background: Docetaxel prolongs survival in AIPC patients and zoledronic acid (ZA) reduces the incidence of SREs. The SRE incidence of patients treated with docetaxel-based chemotherapy has not previously been reported. Methods: ASCENT was a randomized clinical trial that compared weekly DN-101 (calcitriol, 45 μg p.o. on day 1) plus docetaxel (36 mg/m2 iv on day 2 for 3 weeks of a 4-week cycle) to placebo plus docetaxel in patients with chemotherapy-naïve metastatic AIPC. ZA use was not restricted. SRE-free survival was described for the entire group and then compared for patients randomly assigned to DN-101 or placebo and stratified by ZA use. Statistical comparisons were conducted using Cochran-Mantel-Haenszel for incidence and log-rank for SRE-free survival. Results: With a median follow-up of 18.3 months, 33% of subjects experienced at least one SRE and the overall median SRE-free survival was 13 (95% CI 10.5–14.3) months. The incidence of SRE by type was: radiation to bone (18.8%), fracture (10%), spinal cord compression (4%), surgery to bone (0.4%). Eighty-five (34%) patients received ZA. The study was not adequately powered to measure the impact of DN-101 or ZA on SRE endpoints. Exploratory analyses showed a trend for an increase in SRE-free survival (HR 0.78, p = 0.13) of DN-101-treated patients. SRE-free survival and incidence for subgroups were examined ( Table ). Conclusions: This is the first report of SRE incidence in a large, prospective study of docetaxel-based therapy. Improved therapies for reducing SREs in AIPC are needed because the risk of SREs remains high despite the use of modern chemotherapy and ZA.

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