Pilot study of dovitinib in patients with VHL disease

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Background: Von Hippel-Lindau (VHL) is an autosomal dominant inherited disease occurring in 1 in 35,000 births. Individuals with germline mutations in the VHL gene may phenotypically express a variety of lesions including hemangioblastomas (HBs), pancreatic cysts, renal cysts, and renal cell carcinomas (RCC). Previous studies have shown differentially increased FGFR3 levels in HBs compared to RCC. In this pilot trial, we investigated the safety and efficacy profile of TKI 258 (dovitinib), a tyrosine kinase inhibitor of VEGF and FGF receptors, in VHL related lesions, focusing on HBs. Methods: A MDACC IRB-approved protocol planned to enroll 25 subjects who had genetically confirmed VHL disease or clinical diagnosis of VHL, and measurable HBs with no immediate risk of needing intervention. Dovitinib 500mg/day was given in a 4 week cycle on 5 day on/2 day off schedule. In the absence of adverse events (AE), treatment lasted 6 cycles or until disease progression. Evaluation of response to treatment was done every 8 weeks including imaging, laboratory, and clinical evaluation. The trial design used a continuous Bayesian stopping rule based on toxicities that resulted in discontinuation of dovitinib and another for lack of efficacy. Signed informed consent completed on all patients enrolled. Results: Trial stopped after six patients enrolled due to toxicity stopping rule. Patients’ ages ranged 18-61 with 5/6 being male. With regards to safety, 6/6 subjects had at least one AE with the most common AEs being rash, diarrhea, and fatigue including a grade 3 AE (severe rash) in one patient. 1/6 was stopped due to noncompliance, 1/6 stopped due to progression, 3/6 stopped due to side effects despite dose reduction, and 1/6 completed full six cycles at full dose. Best response in 6/6 subjects was stable disease (SD) in HBs. Conclusions: This pilot study of dovitinib in patients with VHL disease with measureable HBs did not show a favorable safety or efficacy profile for this dose and schedule. Half of the patients discontinued the drug due to AEs before study completion, and the best achieved response was SD. Further investigation into alternative scheduling and other FGFR inhibitors in the treatment of HBs is warranted given the strong pre-clinical data. Clinical trial information: NCT01266070.

Targeting the interleukin-11 receptor α in metastatic prostate cancer: A first-in-man study

BACKGROUND

Receptors in tumor blood vessels are attractive targets for ligand-directed drug discovery and development. The authors have worked systematically to map human endothelial receptors (“vascular zip codes”) within tumors through direct peptide library selection in cancer patients. Previously, they selected a ligand-binding motif to the interleukin-11 receptor alpha (IL-11Rα) in the human vasculature.

METHODS

The authors generated a ligand-directed, peptidomimetic drug (bone metastasis-targeting peptidomimetic-11 [BMTP-11]) for IL-11Rα–based human tumor vascular targeting. Preclinical studies (efficacy/toxicity) included evaluating BMTP-11 in prostate cancer xenograft models, drug localization, targeted apoptotic effects, pharmacokinetic/pharmacodynamic analyses, and dose-range determination, including formal (good laboratory practice) toxicity across rodent and nonhuman primate species. The initial BMTP-11 clinical development also is reported based on a single-institution, open-label, first-in-class, first-in-man trial (National Clinical Trials number NCT00872157) in patients with metastatic, castrate-resistant prostate cancer.

RESULTS

BMTP-11 was preclinically promising and, thus, was chosen for clinical development in patients. Limited numbers of patients who had castrate-resistant prostate cancer with osteoblastic bone metastases were enrolled into a phase 0 trial with biology-driven endpoints. The authors demonstrated biopsy-verified localization of BMTP-11 to tumors in the bone marrow and drug-induced apoptosis in all patients. Moreover, the maximum tolerated dose was identified on a weekly schedule (20-30 mg/m²). Finally, a renal dose-limiting toxicity was determined, namely, dose-dependent, reversible nephrotoxicity with proteinuria and casts involving increased serum creatinine.

CONCLUSIONS

These biologic endpoints establish BMTP-11 as a targeted drug candidate in metastatic, castrate-resistant prostate cancer. Within a larger discovery context, the current findings indicate that functional tumor vascular ligand-receptor targeting systems may be identified through direct combinatorial selection of peptide libraries in cancer patients. Cancer 2015;121:2411–2421. © 2015 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

The authors report on the development of a new ligand-directed peptidomimetic (termed bone metastasis-targeting peptidomimetic-11) for interleukin-11 receptor-based human vascular targeting, including the translation from preclinical studies to a first-in-class, first-in-man clinical trial in patients with metastatic, castrate-resistant prostate cancer.

Using presurgical sunitinib to select patients with newly diagnosed metastatic clear cell renal cell carcinoma for cytoreductive nephrectomy: A phase II study

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Background: Timing of cytoreductive nephrectomy (CN) is still a matter of debate in mRCC. This study was designed to test the hypothesis that lead-in treatment with sunitinib (Su) selects patients (pts) most likely to benefit from nephrectomy, and can aid in assessing determinants of response and resistance. Methods: Pts with biopsy proven, newly diagnosed clear cell mRCC with measurable disease, performance status of 0/1, and resectable primary tumor were eligible. Pts received one cycle of sunitinib 50mg PO QD on a 28 day on/14 day off cycle, were restaged, and if stable/responding underwent nephrectomy between day 7 and 21 of second cycle of Su. If disease remained stable on postop scans, pts continued Su. Mutations in a 200 gene cancer gene panel as well as copy number variation were used to correlate molecular changes with clinical outcome. Results: 50 pts were enrolled: 36 (72%) were male and 38 (76%) Caucasian, Median age 61 years (range: 43–84). 44 had intermediate MSKCC score and 6 were poor risk. 45 pts (90%) were evaluable. No drug-related perioperative complications were noted. A total of 9 (18%) pts did not have nephrectomy: 6 because of progression, 2 because of drug related toxicity, and one who required emergency surgery during the first cycle for bowel obstruction. Median primary tumor shrinkage after 1 cycle was 4 percent (range -18 to +11%). 4 (8%) pts were found to have nonclear cell pathology at nephrectomy (2 sarcomatoid, 1 papillary, 1 unclassified). Among the 45 evaluable pts, the median PFS was 8.7 months (95% CI: 5.8 – 37.3 months). 24 (53%) pts came off for progressive disease, and five (11%) pts came off for toxicity. With a median follow-up time of 27.3 months, median OS was 32.2 months (95% CI: 17.2 – Not estimable). To date, 20 (40%) pts have died. Copy number and genomic data analysis are underway, and will be presented and correlated with clinical outcome. Conclusions: Pretreatment with Su safely triaged mRCC pts into nephrectomy versus nonnephrectomy groups, with acceptable efficacy and OS. Ongoing studies will define molecular characteristics defining subgroups most likely to benefit from Su. Clinical trial information: NCT00715442.