Pemigatinib for metastatic or surgically unresectable urothelial carcinoma with FGF/FGFR genomic alterations: final results from FIGHT-201

BACKGROUND

Fibroblast growth factor receptor 3 (FGFR3) alterations are oncogenic drivers of urothelial carcinoma (UC). Pemigatinib is a selective, oral inhibitor of FGFR1-3 with antitumor activity. We report the efficacy and safety of pemigatinib in the open-label, single-arm, phase II study of previously treated, unresectable or metastatic UC with FGFR3 alterations (FIGHT-201; NCT02872714).

PATIENTS AND METHODS

Patients ≥18 years old with FGFR3 mutations or fusions/rearrangements (cohort A) and other FGF/FGFR alterations (cohort B) were included. Patients received pemigatinib 13.5 mg once daily continuously (CD) or intermittently (ID) until disease progression or unacceptable toxicity. The primary endpoint was centrally confirmed objective response rate (ORR) as per RECIST v1.1 in cohort A-CD. Secondary endpoints included ORR in cohorts A-ID and B, duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Overall, 260 patients were enrolled and treated (A-CD, n = 101; A-ID, n = 103; B, n = 44; unconfirmed FGF/FGFR status, n = 12). All discontinued treatment, most commonly due to progressive disease (68.5%). ORR [95% confidence interval (CI)] in cohorts A-CD and A-ID was 17.8% (10.9% to 26.7%) and 23.3% (15.5% to 32.7%), respectively. Among patients with the most common FGFR3 mutation (S249C; n = 107), ORR was similar between cohorts (A-CD, 23.9%; A-ID, 24.6%). In cohorts A-CD/A-ID, median (95% CI) DOR was 6.2 (4.1-8.3)/6.2 (4.6-8.0) months, PFS was 4.0 (3.5-4.2)/4.3 (3.9-6.1) months, and OS was 6.8 (5.3-9.1)/8.9 (7.5-15.2) months. Pemigatinib had limited clinical activity among patients in cohort B. Of 36 patients with samples available at progression, 6 patients had 8 acquired FGFR3 secondary resistance mutations (V555M/L, n = 3; V553M, n = 1; N540K/S, n = 2; M528I, n = 2). The most common treatment-emergent adverse events overall were diarrhea (44.6%) and alopecia, stomatitis, and hyperphosphatemia (42.7% each).

CONCLUSIONS

Pemigatinib was generally well tolerated and demonstrated clinical activity in previously treated, unresectable or metastatic UC with FGFR3 mutations or fusions/rearrangements.

Integrative radiomics expression predicts molecular subtypes of primary clear cell renal cell carcinoma

AIM

To identify combined positron-emission tomography (PET)/magnetic resonance imaging (MRI)-based radiomics as a surrogate biomarker of intratumour disease risk for molecular subtype ccA and ccB in patients with primary clear cell renal cell carcinoma (ccRCC).

MATERIALS AND METHODS

PET/MRI data were analysed retrospectively from eight patients. One hundred and sixty-eight radiomics features for each tumour sampling based on the regionally sampled tumours with 23 specimens were extracted. Sparse partial least squares discriminant analysis (SPLS-DA) was applied to feature screening on high-throughput radiomics features and project the selected features to low-dimensional intrinsic latent components as radiomics signatures. In addition, multilevel omics datasets were leveraged to explore the complementing information and elevate the discriminative ability.

RESULTS

The correct classification rate (CCR) for molecular subtype classification by SPLS-DA using only radiomics features was 86.96% with permutation test p=7×10^-4. When multi-omics datasets including mRNA, microvascular density, and clinical parameters from each specimen were combined with radiomics features to refine the model of SPLS-DA, the best CCR was 95.65% with permutation test, p<10^-4; however, even in the case of generating the classification based on transcription features, which is the reference standard, there is roughly 10% classification ambiguity. Thus, this classification level (86.96-95.65%) of the proposed method represents the discriminating level that is consistent with reality.

CONCLUSION

Featured with high accuracy, an integrated multi-omics model of PET/MRI-based radiomics could be the first non-invasive investigation for disease risk stratification and guidance of treatment in patients with primary ccRCC.

Androgen receptor targeting drugs in castration-resistant prostate cancer and mechanisms of resistance

Reactivated androgen receptor (AR) signaling drives castration-resistant prostate cancer (CRPC). The novel AR targeting drugs abiraterone and enzalutamide have improved survival of CRPC patients. However, resistance to these agents develops and patients ultimately succumb to CRPC. Potential mechanisms of resistance include the following: 1) Expression of AR splice variants, such as the AR-V7 isoform, which lacks the ligand-binding domain; 2) AR missense mutations in the ligand-binding domain, such as F876L and T877A; and 3) Mutation or overexpression of androgen biosynthetic enzymes or glucocorticoid receptor. Several novel agents may overcome resistance mechanisms. Galeterone acts through multiple mechanisms that include degradation of AR protein and is being evaluated in CRPC patients positive for AR-V7. EPI-001 and related compounds inhibit AR splice variants by targeting the N-terminal transactivation domain of AR. Promising therapies and novel biomarkers, such as AR-V7, may lead to improved outcomes for CRPC patients.

Germline single nucleotide polymorphisms associated with response of urothelial carcinoma to platinum-based therapy: the role of the host

BACKGROUND

Variations in urothelial carcinoma (UC) response to platinum chemotherapy are common and frequently attributed to genetic and epigenetic variations of somatic DNA. We hypothesized that variations in germline DNA may contribute to UC chemosensitivity.

PATIENTS AND METHODS

DNA from 210 UC patients treated with platinum-based chemotherapy was genotyped for 80 single nucleotide polymorphisms (SNPs). Logistic regression was used to examine the association between SNPs and response, and a multivariable predictive model was created. Significant SNPs were combined to form a SNP score predicting response. Eleven UC cell lines were genotyped as validation.

RESULTS

Six SNPs were significantly associated with 101 complete or partial responses (48%). Four SNPs retained independence association and were incorporated into a response prediction model. Each additional risk allele was associated with a nearly 50% decrease in odds of response [odds ratio (OR) = 0.51, 95% confidence interval 0.39-0.65, P = 1.05 × 10(-7)). The bootstrap-adjusted area under the curves of this model was greater than clinical prognostic factors alone (0.78 versus 0.64). The SNP score showed a positive trend with chemosensitivity in cell lines (P = 0.115).

CONCLUSIONS

Genetic variants associated with response of UC to platinum-based therapy were identified in germline DNA. A model using these genetic variants may predict response to chemotherapy better than clinical factors alone.

NCI 6896: A phase I trial of suberoylanilide hydroxamic acid (SAHA) and 13-cis retinoic acid in the treatment of patients with advanced renal cell carcinoma (RCC)

349

Background: Retinoid resistance in RCC inversely correlates with levels of intracellular retinol and retinyl esters suggesting that increasing intracellular levels of all-trans retinoic acid (RA) or enabling RA to become a more potent initiator of transcription will improve RA mediated anti-tumor effects. The combination of all-trans RA and a histone deacetylase (HDAC) inhibitor inhibited renal cancer cell proliferation and tumor growth in a xenograft model more than either drug alone. We performed a phase I clinical trial to evaluate the safety and preliminary efficacy of combining the oral HDAC inhibitor SAHA (vorinostat) plus oral 13-cis RA (isotretinoin) in patients with advanced RCC. Secondary endpoints include analysis of peripheral blood samples to study the effects on retinoid metabolites and retinoid related genes.

Methods: Patients (pts) with metastatic RCC (any histology) who have failed at least two lines of prior therapy were eligible. Vorinostat (300 mg bid x 3 consecutive days per week + isotretinoin co-administered at 0.25 mg/kg, 0.375 mg/kg, or 0.5 mg/kg PO bid x 3 days per week in cohorts using standard 3+3 dose escalation. Dose limiting toxicity (DLT) was defined as any grade > 3 toxicity during the first cycle.

Results: 14 pts have enrolled on the trial of which 12 are evaluable for toxicity (6 cohort 1; 3 cohort 2; 3 cohort 3) and 11 for tumor response. Common grade 1-2 toxicities included fatigue and GI effects (nausea, diarrhea, anorexia). One pt on dose-level 1 experienced a DLT (grade 3 depression). One patient experienced a partial response and 10 patients had stable disease lasting a median of 4 months (range 2–10 mos). Three patients progressed with brain metastases in the setting of stable systemic disease for at least 6 months. Pharmacokinetic and correlative studies examining expression of retinoid related genes are ongoing.

Conclusions: The recommended phase II dose is vorinostat (300 mg bid) + isoretinoin (0.5 mg/kg PO bid) 3 days per week. The combination of vorinostat and isotretinoin was well tolerated, and there was evidence of antitumor activity in this heavily pretreated population of patients with refractory metastatic RCC.

[Table: see text]

Germline single-nucleotide polymorphisms (SNPs) associated with response of urothelial carcinoma (UC) to platinum-based therapy: The role of the host

236

Background: Platinum-based therapy improves outcome in neoadjuvant and metastatic UC. Since cell-line and human subject studies in other cancers show germline associations with platinum response, we hypothesized that germline variation also identifies genes that determine UC response to platinum-based therapy.

Methods: Saliva or blood was prospectively collected from 651 UC patients (pts) diagnosed between 1984 and 2010. SNPs (n=80) were selected based on previously reported associations with UC and/or platinum response and genotyped using Sequenom MassArray iPLEX system. Samples and SNPs were filtered for genotyping rate (<0.8), minor allele frequency (<0.05) and departures from Hardy-Weinberg equilibrium (<1E-03). Clinical data were ascertained and linked with the genomic data in an anonymized manner. This analysis focused on 199 pts who received cisplatin or carboplatin and were eligible for response assessment (RES=partial response or complete response, n=90). Associations between SNPs and RES were tested using one and two degree of freedom tests.

Results: Sixty-nine pts received neoadjuvant therapy (RES=54%), 126 chemo-naive pts received first-line metastatic treatment (RES=37%) and 4 received systemic treatment after prior chemoradiotherapy (RES=25%). We expected 4 associations due to chance alone at p < 0.05. However, on univariate analysis using a 2 degree of freedom test, 9 SNPs were associated (p < 0.05) with RES. Individual odds ratios (ORs) ranged from 0.32 to 3.29 with p-values ranging from 0.006 to 0.05. In analysis of rs9344 (CCND1) in all treated pts, 75/148 (51%) responded with AG/GG compared to 12/44 (27%) with AA [p=0.005312, OR 2.74 (CI 1.34, 5.92)]. In neoadjuvant pts treated with cisplatin, rs9344 analysis showed 29/48 (60%) responses in AG/GG pts compared to 5/17 (29%) with AA [p=0.026, OR 3.66 (CI 1.16, 13.1)].

Conclusions: We identified associations between 9 SNPs and response of UC to platinum-based therapy that are biologically and clinically relevant. A larger study will be required to independently validate these findings. Additional investigation of associations with time to metastasis and overall survival is ongoing.

[Table: see text]

Phase II study of everolimus (RAD001) in metastatic transitional cell carcinoma (TCC) of the urothelium

245

Background: Second-line chemotherapy has limited activity in advanced TCC with a median progression free survival (PFS) of 2-3 months. We have previously demonstrated the overexpression of activated mTOR pathway markers in invasive TCC specimens (BJU Int. 2010 Jul 26). Everolimus selectively inhibits mTOR, a central regulator of cell growth, proliferation, survival, and angiogenesis. This trial was designed to assess the efficacy of everolimus in patients (pts) with advanced TCC.

Methods: The primary objectives of this single-institution phase II trial of everolimus in pts with TCC who have failed prior chemotherapy are 1) to measure PFS as determined by RECIST and 2) to evaluate toxicity. Prior therapy is restricted to ≤ 4 chemotherapy drugs. Pts receive everolimus 10 mg oral daily continuously (1 cycle = 4 weeks). A Simon 2-stage design requires ≥13 of 23 pts to be progression free at 2 months to proceed to maximal accrual of 37.

Results: 43 pts (31 M, 12 F) with a median age of 65 yrs (32-84) and median KPS of 90 (70-90) were enrolled between 02/16/2009 and 09/30/2010. Primary tumor sites include bladder (32 pts) and ureter/renal pelvis (11 pts). Prior therapy included 28 pts with 2 drugs, 13 with 3 and 2 with 4. 34 pts have visceral metastases including lung (21), liver (19), and bone (5), and 9 pts have lymph node only disease. 8 pts who received ≤ 1 cycle secondary to rapid progression or toxicity unrelated to everolimus were deemed inevaluable for PFS endpoint and were replaced. To date, 33 pts are evaluable for the primary PFS endpoint; 2 pts are too early for PFS assessment. 22 of 33 pts are progression-free at 2 months. The median PFS for 33 evaluable pts is 2.9 months (1.4-9). One partial response has been seen. The most common grade 3-4 toxicities at least possibly related to everolimus include: anemia (7), infection (6), hyperglycemia (5), lymphopenia (4), hypophosphatemia (4), fatigue (3), hyponatremia (3), mucositis (2), dehydration (2), renal (2) and liver (2).

Conclusions: Everolimus has clinical activity in pts with advanced TCC. An ongoing analysis of pretreatment tumor tissue specimens for markers of activated mTOR pathway will be correlated with PFS.

[Table: see text]

Alterations in genes regulating cell cycle and apoptosis in high-grade urothelial carcinoma

237

Background: Dysregulations of cell cycle and inhibition of apoptosis are crucial factors in tumorigenesis of multiple malignancies, including urothelial carcinoma (UC). Deletions of TP53 and CDKN2A and amplification of MDM2 have been observed in UC, but their exact frequency and functional consequence is less known. We sought to determine the frequency of copy number alteration (CNA) and mutations of genes that regulate cell cycle or apoptosis in a panel of 96 cases of high-grade UC (HGUC) of bladder.

Methods: 96 frozen cases of HGUC were studied, including 11 bladder small cell carcinomas. DNA was isolated and analyzed for CNA by comparative genomic hybridization (CGH) using a one million oligonucleotide probe array from Agilent. The targeted genes included TP53, MDM2, CCND1, CCNE1, CDKN2A/B, E2F3 and Rb1. Traditional Sanger sequencing for mutations within TP53, Rb1, and CDKN2A was also performed.

Results: The frequency of CNA and mutations are listed in the table. Overall, 54 of 96 cases (56%) showed CNA (45) or mutation (13). Deletion of CDKN2A/B and amplification of E2F3 were the most common alterations in cell cycle regulatory genes (13 cases each, 14%), followed by amplification of CCND1 (11 cases, 11%). There was no co-amplification of CCND1 and CCNE1 in any sample. Rb1 deletion was present in five cases. CNA in E2F3 and Rb1 were mutually exclusive in 14 of 16 cases (88%) and were both present in two cases only. Mutations in TP53 were noted in 13 cases and deletions in nine. Amplification of MDM2 was noted in four cases, none of which overlapped with TP53 deletions or mutations. Overexpression of E2F3 was significantly more common in small cell carcinoma (5/11) compared to conventional UC (8/85, p = 0.006).

Conclusions: Regulators of cell cycle and apoptosis are amplified, deleted or mutated in more than half of cases (56%) of high-grade urothelial carcinoma. The overwhelming majority of these abnormalities are nonoverlapping. Amplification of E2F3 seems to be overrepresented in small cell carcinoma of bladder.

[Table: see text]

No significant financial relationships to disclose.

Phase II trial of gemcitabine, carboplatin, and bevacizumab in chemotherapy-naive patients (Pts) with advanced/metastatic urothelial carcinoma (UC)

248

Background: Effective treatment for pts with advanced UC unfit to receive cisplatin-based therapy remains an unmet need. A recent phase III study showed limited benefit of gemcitabine-carboplatin (GC) alone (median OS 9.3 months) (DeSantis ASCO 2010). We recently identified the VEGF-axis as a viable pathway for UC treatment (JCO 2010;Mar 10). We propose that bevacizumab, a monoclonal antibody against VEGFR, may be safely added to GC and improve time to progression (TTP) in pts with advanced UC.

Methods: Primary endpoints (N=47 planned enrollment) were median TTP, to test an improvement of 50% over a 4.8 months median TTP seen with GC alone (Urology 2004;64:479), and safety. Secondary endpoints were response rate (RR) and overall survival (OS). Pts first received a single dose of bevacizumab 10 mg/kg. 2 weeks later they received 6 cycles of gemcitabine 1,000 mg/m2 on day(D) 1 and D 8, and both carboplatin AUC 4.5 and bevacizumab 15 mg/kg on D1 every 21 days. Pts who achieved at least stable disease were eligible to receive maintenance bevacizumab at 15 mg/kg q21 days for 18 additional doses. Restaging evaluations were performed after every 3 cycles of therapy.

Results: 51 pts (37 M, 14 F; median age 67 (Range 42-83)) were enrolled from 6/06 to 6/10. Primary tumor sites include bladder (31), renal pelvis (17) and ureter (2). 38 pts (74.5%) had visceral disease including lung (22), liver (13), bone (9) and adrenal (2). 13 pts had LN only disease. 46 of 51 pts were evaluable for response rate (RR) and TTP, 51 for toxicity. RR by RECIST was 46% (21 pts; PR 18, CR 3). 12 achieved stable disease; 1 too early to assess. Responses by MSKCC Risk Scores of 0, 1 and 2 were seen in 8/11(73%), 10/29 (35%), and 3/6 (50%) pts, respectively. 39% of pts had grade 3/4 toxicity, notably vascular thromboembolic events (VTE) in 18%.

Conclusions: Bevacizumab can be safely added to GC in the treatment of advanced UC. The 16% VTE rate is similar to the 17% rate seen at MSKCC with GC alone. (JCO 2009;27:15s). Addition of bevacizumab does not improve the RR seen with GC alone in phase II and III studies (Bellmunt Eur J Cancer 2001; DeSantis ASCO 2010). Analysis of bevacizumab's impact on TTP and OS is ongoing and will be updated.

[Table: see text]

Vascular thromboembolic events in patients (pts) with advanced urothelial cancer (UC) treated with carboplatin/gemcitabine alone or in combination with bevacizumab

5074

Background: Vascular thromboembolic events (VTE) occur in 13% of UC pts treated with cisplatin-based therapy ( J Urol 160:2021, 1998). Carboplatin-based therapy is used in UC pts intolerant of cisplatin but the frequency of VTE is unknown. Bevacizumab added to chemotherapy increases VTE in non-small cell lung cancer (NSCLC; 5% vs 3%) (Oncologist 12:713, 2007), breast cancer (7.4% vs 5.5%) and colorectal cancer (19% vs 16%) (JAMA. 2008;300:2288). This study evaluated VTE in UC pts treated with carboplatin/gemcitabine alone or with bevacizumab. Methods: Pts with advanced UC treated on a Memorial Sloan-Kettering Cancer Center protocol from June 2006 to September 2008 were analyzed prospectively. Therapy included > 3 cycles of bevacizumab (15 mg/kg on day 1) plus carboplatin (AUC 5 or 4.5 on day 1) and gemcitabine (1000 mg/m2 on days 1,8) every 21 days. Evaluation for VTE on a contemporary UC control group of pts receiving carboplatin plus gemcitabine alone during the exact same time period was conducted retrospectively. VTE were defined as pulmonary embolism (PE), deep venous thrombosis (DVT), myocardial infarctions (MI) and cerebral vascular accidents (CVA). Pts with simultaneous PE and DVT were considered to have one VTE. Results: 89 pts were evaluated. Of the 25 pts treated with bevacizumab plus chemotherapy, 4 pts (16.0%; 95% CI 5–36%) had a VTE of which there were 2 PE alone, 1 DVT alone, and 1 DVT and PE. No MI was observed in bevacizumab-treated pts. Of the 64 contemporary control pts treated with gemcitabine plus carboplatin alone, there were 11 pts (17%; 95% CI 9–29%) who had a VTE of which there were 4 PE alone, 4 DVT alone, 2 DVT and PE, and 1 MI. No CVA were seen in either group. Conclusions: Pts with advanced UC receiving carboplatin plus gemcitabine have a very high rate of VTE (17%). The VTE incidence is similar to colon cancer (16%) and greater than NSCLC (3%) and breast cancer (5.5%). The VTE rate is similar for both cisplatin and carboplatin, suggesting that it is intrinsic to the UC disease state. In this study, the addition of bevacizumab to carboplatin/gemcitabine was not associated with an increase in VTE over that seen for carboplatin/gemcitabine alone.

No significant financial relationships to disclose.

A phase II study of sunitinib on a continuous dosing schedule in patients (pts) with relapsed or refractory urothelial carcinoma (UC)

5072

Background: Suntinib has demonstrated activity in the second-line setting for pts with advanced UC when administered on a 4 week on/2 week off schedule. This study was designed to evaluate an alternative 37.5 mg/day continuous dosing schedule for sunitinib in the same setting. Methods: The primary objectives of this single institution phase II study of sunitinib in pts with UC who have failed prior chemotherapy were: 1) to determine the response rate (by RECIST); and 2) to evaluate toxicity. Secondary endpoints include: 1) correlation of response and toxicity with HIF and mTOR pathway marker expression; and 2) phamacokinetics. Pts may not have received >4 prior cytotoxic agents. Pts received sunitinib 37.5 mg/day continuous dosing.. Response was assessed after each of the initial 4 cycles and every other cycle thereafter. A minimax 2-stage design was used (maximal 32 pts). Results: 31 pts (21 M, 10 F) with a median age of 68 yrs and median KPS of 90 were enrolled between 10/15/07 and 12/18/08. Primary sites included bladder (28), and renal pelvis (3). Prior therapy included 1 pt with 1 drug, 19 pts with 2, 7 with 3 and 4 with 4. 25 pts had visceral metastases and 6 pts had lymph node only metastases. 25 pts were evaluable for response after completing at least 1 cycle. One pt achieved PR, 12 pts had SD, 12 had PD, 2 are too early to assess for response, and 4 patients did not complete cycle 1 (2 related to toxicity, and 2 related to non-treatment-related deaths). Radiographic regression was seen in liver, lung, soft tissue and lymph nodes. With a median follow up of 4 months, median progression free survival was 2 months (95% CI, 1 - 4 months) and median overall survival was 7 months (95% CI, 4 months - not achieved). Clinically significant toxicity (Grade 3/4) included: abdominal pain (1), anorexia (1), diarrhea (1), fatigue (4), hand and foot syndrome (2), hemorrhage (2), hypertension (2), mucositis (2), thrombosis (2), and emesis (1). Conclusions: Sunitinib has modest activity when administered on a 37.5 mg continuous dosing schedule to patients with relapsed or refractory UC with a similar toxicity profile to the 50 mg in the 4 /2 schedule. Upcoming trials will evaluate sunitinib in combination with standard chemotherapy in pts with UC.

[Table: see text]

Detection of circulating tumor cells in patients with urothelial cancer

BACKGROUND

Approximately 50% of patients with metastatic urothelial cancer (UC) respond to chemotherapy and several months of therapy is required to assess for radiographic response. Blood-based biomarkers may identify patients in whom a specific therapy provides clinical benefit, and this study sought to characterize circulating tumor cells (CTCs) in patients with metastatic UC.

PATIENTS AND METHODS

Peripheral blood from patients with metastatic UC was evaluated for CTCs using the CellSearch system. We assessed for associations between CTC counts and the number and sites of metastatic disease.

RESULTS

CTC evaluations were carried out in 33 patients with metastatic UC. Fourteen of 33 patients (44%; 95% confidence interval 27% to 59%) had a positive assay (range 0-87 cells/7.5 ml of blood) with 10 patients (31%) having five or more CTCs. A significantly higher number of CTCs was seen in patients with two or more sites of metastases compared with those with less than one or one site of metastases (3.5 versus 0, P = 0.04).

CONCLUSIONS

CTCs, detected by antibody capture technology, are present in 44% of patients with metastatic UC. Higher numbers of CTCs are seen in patients with a greater number of metastatic sites. One-third of patients have five or more CTCs providing a potential early marker to monitor response to chemotherapy.

Phase II study of sunitinib in patients (pts) with relapsed or refractory urothelial carcinoma (UC)

5080

Background: Second-line chemotherapy has limited activity in advanced UC. Pre-clinical evidence demonstrates an important role for angiogenesis in UC biology, thus supporting this study of the novel VEGF targeted agent, sunitinib, in pts with UC. Methods: The primary objectives of this single institution phase II trial of sunitinib in pts with UC who have failed prior chemotherapy are: 1) to determine the response rate (RECIST); and 2) to evaluate toxicity. Prior therapy is restricted to = 4 chemotherapy drugs. Pts receive sunitinib 50 mg orally daily for 4 weeks followed by 2 weeks off (one cycle). Response is assessed after each of the initial 4 cycles and every other cycle thereafter. The Simon 2-stage design requires = 2 responses in the first 21 pts to proceed to maximal accrual of 41 evaluable pts. Results: 21 pts (19 male, 2 female) with median age of 64 yrs (39–76) and median KPS of 80 (70–90) were enrolled between 9/15/06 and 1/4/07. Primary tumor sites include bladder (14 pts), ureter/renal pelvis (6 pts) and urethra (1). Prior therapy included 10 pts with 2 drugs, 9 with 3 and 2 with 4. 14 pts have metastatic visceral disease [lung (11), liver (8) and bone (1)], and 7 pts have only lymph node metastases. To date, 15 pts are evaluable for radiographic response after completing at least one cycle of therapy; 6 pts are too early for response assessment. One pt experienced a treatment-related death. Responses include: 1 PR seen after cycle 1 and confirmed after cycle 2, 8 with SD (range -29% to +16% change compared to baseline) and 6 with POD. Radiographic regression has been observed in liver, lung, soft tissue and lymph node metastases. Clinically significant toxicity (Grade 3/4) includes: hematuria (n= 1 pt, 2 events in a bladder primary), mucositis (2 pts), thrombocytopenia (2 pts), infection (1), stomatitis (1), fatigue (1), rash (1), diarrhea (1), and abdominal pain (1). Conclusions: Sunitinib has clinical activity in pts with advanced UC. Accrual is ongoing to define further the level of activity, the duration of response, and the time to progression.

[Table: see text]

A nomogram predicting survival of patients (pts) with metastatic or unresectable urothelial cancer (UC) treated with cisplatin-based chemotherapy

5055

Background: Cisplatin-based chemotherapy is the standard of care for pts with metastatic or unresectable UC with phase III studies reporting median survivals of 12–15 months. Even more survival variation exists in phase II studies and this disparity is most frequently due to prognostic factors and not individual regimens. Thus, better tools are needed to predict survival both for individual pts and to balance phase III trials. Nomograms have utility in predicting short- and long-term outcome in muscle-invasive UC treated by surgery but they have not been explored in more advanced UC. Methods: We identified 308 pts with metastatic and/or unresectable UC treated on prospective phase II MSKCC protocols of cisplatin-based therapy containing 3–5 total chemotherapy agents. 203 pts received methotrexate, vinblastine, doxorubicin and cisplatin (MVAC), 45 had ifosfamide, paclitaxel and cisplatin (ITP) and 60 pts received doxorubicin plus gemcitabine (AG) followed by ITP (AG-ITP). Survival distributions were compared across trials. Pre-treatment characteristics were then assessed for impact on survival and a nomogram from a fitted Cox model was created to predict 1-yr, 2-yr, 5-yr and median survival. Results: No difference in median survivals were seen among the 3 regimens; median survival was 14.8 months for MVAC, 18.0 months for ITP and 16.1 months for AG- ITP (p=NS). Median survival for all pts was 12.99 months; 268 pts died and 40 pts were censored. 288 pts had all pre-treatment data. Characteristics most associated with survival included visceral metastases (present versus absent, p=.00001) and Karnofsky poor performance status (≥ 80 versus < 80, p= .0005) followed by hemoglobin (normal versus < normal, p=.01) and albumin (actual values, p<.02). These characteristics were then used to construct a nomogram utilizing all 4 factors to predict probabilities of 1-yr, 2-yr, and 5-yr survival. Conclusions: The number and sequence of drugs utilized in cisplatin-based chemotherapy did not substantially impact survival of pts with advanced UC. A nomogram of pre-treatment clinical factors can predict probability of pt survival at 1 yr, 2yrs, and 5 yrs. This nomogram may also be useful to balance treatment arms in phase III trials.

No significant financial relationships to disclose.

Phase II trial of the anti-prostate specific membrane antigen (PSMA) monoclonal antibody (mAb) J591 plus low-dose interleukin-2 (IL-2) in patients (pts) with recurrent prostate cancer (PC)

15558

Background: The de-immunized mAb J591 recognizes the extracellular domain of PSMA and was engineered to induce antibody-dependent cellular cytotoxicity (ADCC). Low-dose IL-2 results in the clonal expansion of NK cells and may enhance ADCC. We conducted a phase 2 trial to determine the efficacy and toxicity of mAb J591 plus low-dose subcutaneous (SC) IL-2 in pts with recurrent PC. Methods: 17 pts with recurrent PC (2 groups: 11 with PSA relapse only; and 6 with progressive castrate metastatic disease) received continuous low-dose SC IL-2 (1.2 x 106 IU/m2/day) daily for 8 weeks with mAb J591 (25 mg/m2 IV) weekly on weeks 4, 5 and 6 (1 cycle). Pts could receive a maximum of 3 cycles. Results: 16 evaluable pts received up to 3 cycles of therapy (16 pts, one cycle, 9 two cycles and 2 three cycles). Toxicity was mild and limited to fatigue and injection site reactions. At the end of cycle 1, PSA was stable (-50%<change in PSA<25%) in 9 of 16 patients, with PSA declines up to 34%. No PSA decline >50% was observed. A post-hoc analysis of PSA kinetics showed 5 patients had a reduction in their PSA slope of =25%; 8 of the remaining 11 patients demonstrated PSA stabilization (- 25%<change in PSA slope<25%). PSA response was most commonly observed during weeks 4–6 of the cycle correlating with mAb administration. Flow cytometric analysis of peripheral blood mononuclear cells revealed an average increase in absolute NK cell count of 107% at week 4 and 117% at the end of cycle 1. Conclusions: The combination of mAb J591 with low-dose IL-2 was well tolerated and inhibited PSA kinetics in some patients, however no responses were seen. Repetitive dosed mAb J591 is a viable strategy for use in combination with immune modulatory or other therapies in recurrent prostate cancer.

No significant financial relationships to disclose.

Phase II trial of 177Lutetium radiolabeled anti-prostate-specific membrane antigen (PSMA) monoclonal antibody J591 (177Lu- J591) in patients (pts) with metastatic androgen-independent prostate cancer (AIPC)

15523

Background: A phase 1 trial of 177Lu-J591 in pts with metastatic AIPC demonstrated acceptable toxicity, excellent targeting of metastatic sites and biologic activity. Methods: Pts with progressive, metastatic AIPC receive one dose of 177Lu-J591 in two- cohorts: cohort 1 (65 mCi/m2), 15 pts; cohort 2: (70 mCi/m2), 17 pts. The primary endpoint is PSA and/or measurable disease response; secondary endpoint is toxicity. A 177Lu-J591 imaging study is done to confirm tumor targeting. Results: 21 pts (8 chemo-naive), median age 73, have been treated to date, 15 in cohort 1, 6 in cohort 2. Two pts with bone-only metastases achieved PSA declines of >50%. One had an 87% PSA decline lasting 126 days with resolution of bone pain. A 2nd pt has a PSA decline of 58% that continues without progression at 6 mo post-rx. PSA stabilization (<25% PSA rise above baseline) occurred in an additional 9 pts (43%), 7 through wk 8 (1 of whom is still under follow-up) and 2 pts through wk 12. Of 7 pts with measurable disease, 6 have had post-rx CT scans completed, 3 were stable, 3 progressed. In these pts with measurable disease, PSA was more likely to diagnose progression, with only 1 stable and 5 progressed by PSA criteria. Platelet nadir <20 x 10e9/L occurred in 6 pts, 3 of whom required platelet transfusions (mean = 2). 17/19 evaluable pts recovered normal platelet counts; the remaining 2 pts had rapidly progressive disease, 1 of whom had biopsy confirmed marrow replacement by tumor. Neutropenia </= 0.5 x 10e9/L occurred in 4 pts, 2 of whom received brief rx with growth factors. All 19 evaluable pts had normal neutrophil recovery. No significant drug-related non-hematologic toxicity has occurred. Targeting of known sites of PC metastases has been observed in all pts. Conclusions: Single dose 177Lu-J591 demonstrates anti-tumor activity in pts with progressive, metastatic AIPC with reversible myelosuppression. Accrual is continuing.

[Table: see text]

Phase I trial of a histone deacetylase inhibitor (HDACI) and retinoid acid (RA) in patients (pts) with advanced solid tumor malignancies

13114

Background: Transcription of RA responsive genes is inhibited by co-repressor complexes which have HDAC activity. Pre-clinical data demonstrates that addition of an HDACI to RA enhances transcription of genes that augment anti-tumor and differentiation response, and results in tumor inhibition in a RCC model (Clin Cancer Res. 2005;11:3558). Valproic Acid (VPA) has potent HDCAI activity and ATRA-IV is a liposomal RA with excellent bioavailability. The objective of this trial is to determine safety, pharmacokinetics (PK) of combination therapy, as well as correlative studies of RA receptor expression and histone acetylation status. Methods: Adults with a refractory metastatic solid tumor malignancy, KPS >60%, adequate organ function, life expectancy >3 months are eligible. 3-pt cohorts in a 2-step dose escalation: Oral VPA (Abbott Pharmaceutical) is dosed (starting at 10 mg/kg/d every 8 hrs) until trough VPA serum concentration of 50–80; 80–100 and 100–120 μg/ml. IV ATRA (Antigenics) is then administered at 60mg/m2 IV weekly. Once VPA MTD is determined, ATRA-IV is then escalated to 90, 120 and 140 mg/m2 unless DLT’s are seen. Dose levels are escalated in cohorts of 3–6 pts and cycle length is 4 weeks. Results: 9 pts have been enrolled and 5 are evaluable for toxicity of both drugs (renal cell, prostate, GE junction, bladder and small blue cell tumor). 4 pts withdrew from VPA toxicity prior to ATRA-IV. Median age 67 (range 26–79), pts received between 1–4 prior therapies (non-palliative surgery, chemotherapy, radiation, PBSCT). VPA did not alter ATRA-IV pharmacokinetics. The MTD of VPA has not yet been reached and the ATRA escalation phase has not yet been initiated. Most common toxicities observed were pain, dyspnea, gastrointestinal and neurologic. One grade 3 neurotoxic event occurred related to POD. 1 pt had a transient decline in PSA. Correlative studies are ongoing. Conclusions: Epigenetic modifications induced by HDACIs may allow the anti-tumor effects of retinoids to be realized. Toxicity of VPA has limited the addition of RA to this HDACI. HDACI + RA is a rationale approach to treat progressive RCC and future studies will incorporate more potent and less toxic HDACI + RA to treat RCC.

No significant financial relationships to disclose.

Phase I/II trial of the prostate-specific membrane antigen (PSMA)-targeted immunoconjugate MLN2704 in patients (pts) with progressive metastatic castration resistant prostate cancer (CRPC)

4500

Background: MLN2704 is an immunoconjugate that utilizes the PSMA-targeted monoclonal antibody MLN591 to deliver the maytansinoid antimicrotubule agent DM1 directly to prostate cancer cells. This multicenter trial was designed to determine the tolerability, optimal dosing schedule and efficacy of MLN2704 in pts with progressive metastatic CRPC. Methods: Pts aged ≥18 yrs with progressive metastatic CRPC received MLN2704 i.v. over 2.5 hr q1wk, q2wks or q3wks for 12 wks, with additional doses permitted in responders. Doses within a given schedule were escalated in 40% increments in the absence of excessive dose-limiting toxicity (DLT). Results: 61 pts have been treated. The most common adverse events (AEs) were nausea, fatigue, and schedule-dependent neurotoxicity. The only DLT was gr 3 hepatic transaminitis in 1/6 pts at 330 mg/m2 q2wks; the only gr 4 AE was transient neutropenia, in 2 pts (330 mg/m2 q2wks and q3wks). Declines in PSA were most frequent at 330 mg/m2 q2wks ( table ), including 49–88% PSA declines in 4/6 pts. However, given the frequency of grade 2–3 peripheral neuropathy an additional cohort is being treated with 330mg/m2 on days 1 and 15 of a 6-wk cycle. Initial results with this 6-wk schedule indicate PSA declines with a lower incidence of gr 2–3 toxicities, particularly neuropathy. Conclusions: Accrual to the dose-escalation phase is complete. Dose-dependent antitumor effects were seen. Peripheral neuropathy has limited continuous dosing at higher dose levels prompting a schedule change. Accrual to the 6-wk schedule is continuing.

[Table: see text]

[Table: see text]

Perioperative chemotherapy treatment patterns in stage III transitional cell carcinoma (TCC) (1998–2003): A report from the National Cancer Data Base (NCDB)

4540

Background: Studies have demonstrated benefits of perioperative chemotherapy in locally advanced TCC. We reviewed chemotherapy treatment patterns in patients with stage III TCC of the bladder and upper urinary tract (UUT) between 1998–2003 to investigate the use of perioperative chemotherapy. Methods: The NCDB collects data on approximately 75% of all newly diagnosed cancer cases annually in the U.S. We queried for all treatments in male and female (≥18 years old) TCC cases diagnosed between 1998 and 2003. Cancer stage (1998–2002) was forward converted to AJCC 6th edition. A total of 223,050 bladder and 11,625 UUT TCC cases were found. Results: Treatment patterns were analyzed in 11,328 patients with stage III bladder TCC and 1,840 patients with stage III UUT TCC, representing 5.0% and 15.8% of all cases, respectively (Table). Satisfactory follow-up was available for approximately 51% of patients. 5.4% (bladder) and 3.5% (UUT) of patients received pre-operative or adjuvant (within 4 mos of surgery) chemotherapy. No significant difference was seen comparing 1998 and 2003 perioperative chemotherapy use for bladder or UUT cancers. Conclusions: No increase in perioperative chemotherapy use occurred over the 5-year period (1998–2003), suggesting chemotherapy is underutilized in the management of surgically resectable stage III TCC of the bladder or UUT. This may reflect a delay in implementing the results of randomized trials recently reported or a low incidence of referral by urologists for perioperative chemotherapy. Further follow-up will determine if this pattern changes over the next 5 years.

[Table: see text]

No significant financial relationships to disclose.

Pharmacokinetics (PK), safety and tolerability of atrasentan (ABT-627, ATN) in combination with docetaxel (DOC) in men with hormone refractory prostate cancer (HRPC)

14512

Background: ATN (Xinlay) is an oral selective endothelin A receptor antagonist in Phase III clinical development for the treatment of HRPC. ATN is extensively metabolized by oxidation and glucuronidation. In vitro, CYP3A is the predominant isozyme involved in oxidative metabolism of ATN and DOC; ATN inhibits CYP3A with an IC50 of ∼3 μM (15-fold the mean plasma Cmax for 10 mg/d ATN). Methods: 11 men with HRPC received DOC 75 mg/m2 by 1-h IV infusion on day (D) 1 of each 21-D cycle (C), and ATN 10 mg po qd starting D8C1 and prednisone(Pred) 5 mg orally twice daily.Three oral doses of dexamethasone 8 mg were administered starting 12 hours before DOC. On coadministration days, ATN was taken at the start of the DOC infusion. PK were to be determined over 24 h following DOC alone (D1C1) and in combination with ATN (D1C2), and following ATN alone (D20C1) and in combination with DOC (D1C2). Plasma concentrations of ATN and DOC were determined using a validated LC/MS/MS method. Results: Preliminary PK results are summarized (N = 10, mean ± SD) in the table below. Some patients (pts) had D1C2 PK performed D1C4 (N = 4), D1C5 (N = 3) or not at all (N = 1). No unexpected adverse events (AE) were observed. One subject experienced neutropenic fever related to DOC. This resolved with treatment and ATN/DOC was resumed. Efficacy: 3/5 DOC naive and 2/6 DOC resistant pts had a >50% post treatment PSA decline. One DOC resistant pt demontrated post treatment calcicfication of liver metastases accompanied by a >45% PSA decline. Conclusions: No PK interaction was observed between ATN and DOC when coadministered at full standard single agent dosages implying 10 mg QD ATN did not alter CYP3A4 activity in gut or liver. Treatment with ATN/DOC was well tolerated and demonstrated activity in DOC resistant pts, further justifying a planned Southwest Oncology Group phase III study comparing ATN/DOC/Pred to DOC/Pred. [Table: see text]

[Table: see text]

Phase 2 trial of 177Lutetium (177Lu) radiolabeled anti-prostate-specific membrane antigen (PSMA) monoclonal antibody (mAb) J591 (177Lu-J591) in patients (pts) with metastatic androgen-independent prostate cancer (AIPC)

4613

Background: J591 is an anti-PSMA mAb targeting the extracellular domain of PSMA, a highly PC restricted glycoprotein. 177Lu linked to J591 via a DOTA chelate was evaluated in a phase 1 trial in pts with metastatic AIPC demonstrating acceptable toxicity (MTD = 70 mCi/m2), excellent targeting of metastatic sites and biologic activity. Methods: Pts with progressive metastatic AIPC receive a single dose of 177Lu -J591 in two cohorts (65 and 70 mCi/m2). Cohort 1: 15 pts; Cohort 2: 17 pts. The primary endpoint is PSA and measurable disease response assessed at wk 12. Secondary endpoint is to evaluate toxicity. One 177Lu imaging study is done at 1 week post-treatment to confirm tumor targeting. Results: 14 pts, median age 73 (5 chemo-naïve), have been treated on this ongoing 2-center study. One pt with bone-only metastases achieved an 87% decline in PSA by day 85 with resolution of bone pain. Bone scan at wk 12 revealed a flare response. As of day 222, the pt has not required additional therapy. PSA stabilization (< 25% PSA rise above baseline) has been seen in 4 pts lasting 16 wks in 2 pts, 18 wks (1 pt) and 23 wks (1 pt), respectively. One pt withdrew at wk 56 without PSA progression. Of 5 pts with measurable disease, no objective responses were seen. Grade 3 and 4 thrombocytopenia occurred in 6 and 4 pts, respectively. 12/14 pts recovered plt counts to ≥ 150 x 109/L (median time to recovery = 22 d). Grade 3 and 4 neutropenia occurred in 7 and 1 pts, respectively. 13/14 pts had ANC recovery to ≥ 2 x 109/L (median time to recovery = 13 d). No significant drug-related non-hematologic toxicity has occurred. Excellent targeting of known sites of PC metastases has been observed in all pts. Conclusions: 177Lu-J591 demonstrates anti-tumor activity in pts with AIPC with one pt achieving the primary endpoint (≥ 50% PSA decline) and 4 pts with PSA stabilization at a dose of 65 mCi/m2. Support: NIH CA102544 , NCRR M01RR00047, DOD PC031175 , David H. Koch Foundation, Cancer Research Institute, MSKCC Experimental Therapeutics Ctr, McCoey Fund, BZL Biologics, Inc. and Millennium Pharmaceuticals, Inc.

No significant financial relationships to disclose.

Advanced renal cell carcinoma

Advanced renal cell carcinoma (RCC) is a disease that is highly resistant to systemic therapy and is difficult to treat. Nephrectomy should be seriously considered in patients who present with metastatic disease prior to systemic therapy, and surgery remains a reasonable option in patients who present with resectable metastases. Numerous studies with many different treatment modalities, including chemotherapy, immunotherapy, and radiation therapy, have failed to consistently benefit patients, with no single agent or combination therapy showing a reproducible response proportion of 20% or higher. Interleukin-2 (IL-2) and interferon-alfa (IFN alfa)-based therapies remain the most commonly used agents to treat patients with advanced disease, demonstrating low but reproducible response proportions in the 10% to 20% range, with durable responses of 5% or less. Recent randomized studies demonstrate a survival advantage for patients receiving systemic IFN-based therapy, but this advantage is marginal. Novel treatment strategies are being investigated, with some encouraging early results using vaccines and allogeneic bone marrow transplant. The identification of new agents with more effective antitumor activity is a high priority in the treatment of advanced RCC.

Neutral endopeptidase inhibits neuropeptide-mediated transactivation of the insulin-like growth factor receptor-Akt cell survival pathway

G-protein coupled receptor (GPCR) agonists such as neuropeptides activate the insulin-like growth factor-1 receptor (IGF-IR) or the serine-threonine protein kinase Akt, suggesting that neuropeptides-GPCR signaling can cross-communicate with IGF-IR-Akt signaling pathways. Neutral endopeptidase 24.11 (NEP) is a cell-surface peptidase that cleaves and inactivates the neuropeptides endothelin-1 (ET-1) and bombesin, which are implicated in progression to androgen-independent prostate cancer (PC). We investigated the mechanisms of NEP regulation of neuropeptide-mediated cell survival in PC cells, including whether neuropeptide substrates of NEP induce phosphorylations of IGF-IR and Akt in PC cells. Western analyses revealed ET-1 and bombesin treatment induced phosphorylation of IGF-IRbeta and Akt independent of IGF-I in TSU-Pr1, DU145, and PC-3 PC cells, which lack NEP expression, but not in NEP-expressing LNCaP cells. Recombinant NEP and induced NEP expression in TSU-Pr1 cells using a tetracycline-repressive expression system inhibited ET-1-mediated phosphorylation of IGF-IRbeta and Akt, and blocked the protective effects of ET-1 against apoptosis induced by serum starvation. Incubation of TSU-Pr1 cells with specific kinase inhibitors together with ET-1 or bombesin showed that IGF-IR activation is required for neuropeptide-induced Akt phosphorylation, and that neuropeptide-induced Akt activation is predominantly mediated by Src and phosphatidylinositol 3-kinase but not by mitogen-activated protein kinase or protein kinase C. These data show that the neuropeptides ET-1 and bombesin stimulate ligand-independent activation of the IGF-IR, which results in Akt activation, and that this cross-communication between GPCR and IGF-IR signaling is inhibited by NEP.