1st-line Activity of Dovitinib and Correlation With Genetic Changes in RCC

The purpose of this prospective, single centre, non-randomised, open-label, phase II study will evaluate the activity of dovitinib in the treatment naïve population of patients with advanced RCC.

Background: Prior to the middle of last decade, the only systemic therapy for patients with advanced RCC was immunotherapy (interleukin-2 and interferon-alpha) with limited effectiveness and a multitude of side-effects. Since 2006, there have been 6 targeted therapies that have been FDA-registered for the treatment of advanced RCC; the anti-VEGFR tyrosine kinase inhibitors (sunitinib, sorafenib and pazopanib), the anti-VEGF antibody bevacizumab (with interferon-alpha) and the mTOR inhibitors (everolimus and temsirolimus). These treatments have significantly advanced outcomes for patients with this disease but unfortunately they do not represent cures. The median overall survival for patients treated with a standard first-line therapy (sunitinib) is just over 2 years and the median PFS for subjects receiving this agent is only 11 months. This means that the typical time it takes for subjects to develop resistance to standard first-line tyrosine kinase inhibitor (TKI) treatment, as evidenced by significant tumour growth on imaging, is under 1 year.

Despite the recent rapid advancements in the treatment options for subjects with advanced RCC, there is still an unmet need for more effective therapeutic options for patients with this disease so as to improve survival and make steps towards the ultimate treatment aim for patients with metastatic disease - cure. Available data suggests that dovitinib is a very active agent in metastatic RCC. If it has efficacy in the heavily pre-treated RCC population, one would expect it to be considerably more active when it is moved forward into the first-line setting.

Dovitinib is a broad-targeted receptor Tyrosine Kinase Inhibitor (TKI) primarily active against three receptors that mediate tumour growth and survival: vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR) and fibroblast growth factor receptor (FGFR). A distinguishing feature of dovitinib (compared to other anti-VEGFR TKI's) is its FGFR inhibition. Up-regulation of the fibroblast growth factor receptor 1 (FGFR1) pathway has been demonstrated in metastatic RCC and is a postulated mechanism of resistance to anti-VEGFR therapies. This is thought to be one of the reasons why dovitinib has activity in subjects treated with prior anti-VEGFR therapies. If we move the FGFR inhibition forward into the first-line setting (by using dovitinib) we hope to be able prevent or delay the development of resistance acquired through FGFR up-regulation. We hope this may allow subjects to remain on first-line therapy for much longer and in doing so improve survival and outcomes for this group of patients.

Dovitinib has been studied in heavily pre-treated subjects with metastatic RCC, and in these phase I/II studies it looks very active. If it has efficacy in the heavily pre-treated RCC population, it is possible it would be more active when it is moved forward in to the first-line setting.

While we have good prognostic markers to risk-stratify subjects with RCC, there is a lack of predictive markers to guide us as to which patients are best served with each of the different agents available for use. It is therefore imperative that drug development studies in this disease have companion biomarker analysis to identify potentially useful predictive biomarkers for future research. This study also aims to explore (using FISH) the amplification/deletion status of range of genes-of-interest, selected for their relevance to the biology of RCC and the mechanism-of-action of dovitinib. Amplification/deletion of these genes will be further validated using DNA sequencing. The status of these genes-of-interest will be correlated with outcomes of these subjects treated with dovitinib.

The hypothesis of this study is that dovitinib will demonstrate anti-tumour activity when administered to subjects with advanced RCC in the first-line setting and that this activity will correlate with FGFR gene amplification status.

The primary objective is to evaluate the activity of dovitinib in the treatment naïve population of patients with advanced RCC.

Secondary Objectives:

• To determine the gene amplification status for FGFR-1,-2,-3 in this patient population
• To measure the strength of the correlation between measures of clinical efficacy and FGFR gene amplification status
• To further evaluate safety

Exploratory Objectives:

• To assess for amplifications/deletions for genes related to RCC biology in this group of subjects treated with dovitinib.
• To correlate gene amplification status with DNA gene sequence.
• To evaluate differences in tumour gene status between primary and metastatic samples from same subject and again on post-treatment biopsy to elucidate mechanisms of resistance to dovitinib.
• To evaluate effects of dovitinib on bone metastases and pain.

Investigational treatment: Thirty patients from the greater Auckland region will be treated with dovitinib (500 mg p.o. o.d., 5 days on/2 days off) until disease progression, unacceptable toxicity, patient withdrawal or death.

The primary analysis will be performed when 20 progression and/or death events have occurred. No interim efficacy analysis is planned for this study. However, an independent Data Monitoring Committee (DMC) will review data collection (including analysing the adverse event information) and will meet at specified time points during the study.

Visit schedule: Patients will attend clinic visits every 3 weeks while on treatment. Tumour response assessments will occur every 9 weeks until week 54, then every 12 weeks thereafter until disease progression (estimated median time to disease progression = 16 months). Once all patients have completed study treatment, patients will continue to be followed up 3-monthly until approximately 2 months after 20 death events have occurred.

For each patient there will be three separate phases in the study: pre-treatment (screening \& baseline), treatment and follow-up.

Pre-treatment phase (Screening/Baseline): The patient must provide a signed informed consent form (ICF) prior to any study related procedure. A screening period of 28 days is allowed to assess eligibility. Radiologic evaluation (CT of the head, chest, abdomen and pelvis) and baseline tumour measurement using RECIST v1.1 will be performed. Other screening and baseline assessments include ECG \& echocardiogram to assess cardiac function, performance status assessment (ECOG \& WHO), physical examination (including the buccal cavity), height, weight \& vital signs. Laboratory investigations include haematology, chemistry, amylase, lipase, serum lipid profile, coagulation, urinalysis, thyroid function, cardiac enzymes and pregnancy test (if applicable). Disease specific information, general medical information including medical history, concomitant medications, prognostic group according to Heng criteria and demographic data will also be collected.

Treatment phase: This study does not have a fixed treatment duration, as patients will continue therapy until disease progression, intolerable toxicity or withdrawal. Following study inclusion and initiation of study treatment, the patient should visit the site on day 1, 8 and 15 during cycle 1, then day 1 of every subsequent cycle. Patients will have their first dose of study treatment on Day 1, Cycle 1. A study cycle is defined as a period of 21 days.

Tumour response will be evaluated every 3 cycles after registration until week 54, then every 4 cycles until documented disease progression. ECOG performance status will be assessed on day 1 of every cycle. Safety assessments are routinely performed including collection of adverse events (AEs), Serious Adverse Events (SAEs), concomitant medications, vital signs, physical examination, weight, haematological and biochemistry assessments, urinalysis, thyroid function and cardiac enzymes. ECG, amylase, lipase, serum lipids and coagulation will be measured if clinically indicated. An echocardiogram will be performed at weeks 12 and 24, and as clinically indicated. Plasma for storage will be collected on Day 1 of Cycles 1 and 3. Participants with bone metastases will have plasma collected for C-telopeptide testing on day 1 of weeks 1, 2 and 13, and will complete a Quality of Life questionnaire (FACT-BP) at 4 time points: on day 1 of weeks1, 2, 4 and 13.

The End of Treatment (EOT) visit will take place approximately 7 days after the last dose of dovitinib. At this visit the following assessments will be performed and the following data collected: physical examination, ECOG performance status, weight, vital signs, adverse events, concomitant medications, antineoplastic therapies, haematology, biochemistry, amylase and lipase measurements.

Safety follow-up: All patients who discontinue study treatment will have a safety follow-up visit within 30 days of the last dose of dovitinib. Safety assessments will include collection of AEs, SAEs, vital signs, concomitant medications and any new antineoplastic therapies. Patients who progress will be invited to provide an (optional) additional biopsy sample of their tumour, at least 10 days after the last dose of dovitinib, but before any new anticancer therapies are initiated.

Efficacy follow-up: Patients who discontinue the study treatment for reasons other than progression will continue to have radiologic assessments, using the same schedule as for patients who remain on treatment, until documented disease progression.

Survival follow-up: Patients who have discontinued study treatment will be followed-up for survival every 3 months by clinical visits or telephone call until death occurs, the patient is lost to follow-up, or withdraws consent for follow-up for survival. Further treatment will be at the discretion of the investigator.

Statistical Methods: All data will be presented descriptively as means, medians or proportions. Progression free and overall survival from the first dose of dovitinib until disease progression or death will be determined using the method of Kaplan-Meier. The correlation between PFS, OS and baseline biomarker status as well as FGFR gene amplification status will be measured using Spearman's rho. Generalized estimating equations (GEE) for repeated measures will also be used to test the significance of changes in biomarker amplification status relative to baseline. Ordinal logistic regression analysis using a repeated measures structure will be applied to compare bone pain control over the treatment period relative to baseline.

Sample Size Calculation and Expected Duration: The response rate (RR) reported for sunitinib, when studied in a phase III trial versus interferon in the first-line setting was approximately 31%, with a 95%CI ranging from 26 to 36% (Motzer, NEJM 356: 115, 2007). The target sample size in this phase II study is 30, which was based on the assumption that the RR for dovitinib would fall within the range of sunitinib. With such a sample size, the prevalence of dovitinib RR using RECIST 1.1 will be measured with a precision that extends to 15 percentage points, with a 95% probability.