Relationship Between Baseline Prostate-specific Antigen on Cancer Detection and Prostate Cancer Death: Long-term Follow-up from the European Randomized Study of Screening for Prostate Cancer

BACKGROUND

The European Association of Urology guidelines recommend a risk-based strategy for prostate cancer screening based on the first prostate-specific antigen (PSA) level and age.

OBJECTIVE

To analyze the impact of the first PSA level on prostate cancer (PCa) detection and PCa-specific mortality (PCSM) in a population-based screening trial (repeat screening every 2-4 yr).

DESIGN, SETTING, AND PARTICIPANTS

We evaluated 25589 men aged 55-59 yr, 16898 men aged 60-64 yr, and 12936 men aged 65-69 yr who attended at least one screening visit in the European Randomized Study of Screening for Prostate Cancer (ERSPC) trial (screening arm: repeat PSA testing every 2-4 yr and biopsy in cases with elevated PSA; control arm: no active screening offered) during 16-yr follow-up (FU).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We assessed the actuarial probability for any PCa and for clinically significant (cs)PCa (Gleason ≥7). Cox proportional-hazards regression was performed to assess whether the association between baseline PSA and PCSM was comparable for all age groups. A Lorenz curve was computed to assess the association between baseline PSA and PCSM for men aged 60-61 yr.

RESULTS AND LIMITATIONS

The overall actuarial probability at 16 yr ranged from 12% to 16% for any PCa and from 3.7% to 5.7% for csPCa across the age groups. The actuarial probability of csPCa at 16 yr ranged from 1.2-1.5% for men with PSA <1.0 ng/ml to 13.3-13.8% for men with PSA ≥3.0 ng/ml. The association between baseline PSA and PCSM differed marginally among the three age groups. A Lorenz curve for men aged 60-61 yr showed that 92% of lethal PCa cases occurred among those with PSA above the median (1.21 ng/ml). In addition, for men initially screened at age 60-61 yr with baseline PSA <2 ng/ml, further continuation of screening is unlikely to be beneficial after the age of 68-70 yr if PSA is still <2 ng/ml. No case of PCSM emerged in the subsequent 8 yr (up to age 76-78 yr). A limitation is that these results may not be generalizable to an opportunistic screening setting or to contemporary clinical practice.

CONCLUSIONS

In all age groups, baseline PSA can guide decisions on the repeat screening interval. Baseline PSA of <1.0 ng/ml for men aged 55-69 yr is a strong indicator to delay or stop further screening.

PATIENT SUMMARY

In prostate cancer screening, the patient's baseline PSA (prostate-specific antigen) level can be used to guide decisions on when to repeat screening. The PSA test when used according to current knowledge is valuable in helping to reduce the burden of prostate cancer.

Abstract CT204: A phase 1/2 study of VS-6766 in combination with sotorasib in patients with KRAS G12C mutant non-small cell lung cancer (NSCLC) (RAMP 203)

Background: KRAS is mutated (mt) in 25% of non-small cell lung cancer (NSCLC) adenocarcinoma, with KRAS G12C mt occurring in ~13% of patients. The G12C inhibitor (G12Ci) sotorasib has recently received FDA approval for patients with KRAS G12C mt NSCLC, however emerging data suggest that combinations may be necessary for maximal depth and duration of response. Unlike MEK-only inhibitors (MEKi), the dual RAF/MEK inhibitor VS-6766 is a potent allosteric inhibitor of MEK kinase activity and promotes a dominant negative RAF/MEK complex preventing phosphorylation of MEK by BRAF and CRAF. Thus, VS-6766 blocks MEK signaling without compensatory activation of MEK which limits the efficacy of MEKi. In vitro 3D proliferation and in vivo tumor models were used to assess anti-tumor efficacy of VS-6766 ± G12Ci. In KRAS G12C mt NSCLC cell lines, VS-6766 was synergistic with both sotorasib and adagrasib (G12Ci) in reducing tumor cell viability which correlated with deeper inhibition of RAS pathway signaling. In vivo, combination of VS-6766 with sotorasib induced strong tumor regressions in contrast to sotorasib monotherapy or sotorasib plus trametinib. Initial clinical activity of VS-6766 in KRAS G12C mt NSCLC is supported by the FRAME study [NCT03875820] results in which 4/6 patients with KRAS G12C mt NSCLC showed tumor reduction including 1 PR. These results support the clinical evaluation of VS-6766 in combination with a G12Ci for treatment of KRAS G12C mt NSCLC.

Methods: This is a Phase 1/2, multicenter, open label, dose evaluation/dose expansion study designed to evaluate the efficacy and safety of VS-6766 in combination with sotorasib in patients with KRAS G12C mt NSCLC who have not previously been treated with a KRAS G12Ci or have experienced disease progression while undergoing therapy with a KRAS G12Ci [NCT05074810]. The study will be conducted in two parts: Part A (dose evaluation) and Part B (dose expansion). Up to 3 dose levels will be evaluated in Part A to determine the Recommended Phase 2 Dose (RP2D) for Part B. Part B will assess the efficacy of the RP2D and will be conducted in 2 cohorts: patients who are G12Ci treatment naïve (cohort 1) and patients who have experienced disease progress during G12Ci therapy (Cohort 2). Patients enrolled must have histologic or cytologic evidence of NSCLC, measurable disease according to RECIST V1.1 and known KRAS G12C mutation. The study will enroll up to 121 patients with a minimum of 6 and a maximum of 12 patients (dose levels 1 and -1 have &gt;1 DLT in first 3 patients or dose levels 1 and 2 each enroll 6 patients) in Part A and an additional 109 patients in Part B (minimum of 41 patients RP2D stage 1 for cohort 1 and 2 or RP2D stages 1 and 2 in both cohorts).

Citation Format: Ramaswamy Govindan, Jonathan A. Pachter, Andrew G. Koustenis, Gloria Patrick, Louis J. Denis. A phase 1/2 study of VS-6766 in combination with sotorasib in patients with KRAS G12C mutant non-small cell lung cancer (NSCLC) (RAMP 203) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT204.

ENGOT-ov60/GOG-3052/RAMP 201: A phase 2 study of VS-6766 (RAF/MEK clamp) alone and in combination with defactinib (FAK inhibitor) in recurrent low-grade serous ovarian cancer (LGSOC)

TPS5615

Background: Low-grade serous ovarian cancer (LGSOC) constitutes up to 10% of all ovarian cancer and has clinical and molecular characteristics distinct from high-grade serous ovarian cancer. Approximately a third of patients (pts) with recurrent LGSOC harbor KRAS mutations (mt) and pts with KRAS wild-type (wt) LGSOC may have mutations in NRAS, BRAF, or other RAS pathway-associated genes. Prior clinical studies with single agent MEK inhibitors have shown response rates of 16-26% in recurrent LGSOC. VS-6766 is a unique small molecule RAF/MEK clamp that inhibits both RAF and MEK activities by trapping them in inactive complexes. This mechanism of blockade has been shown to limit compensatory MEK activation, thereby potentially enhancing efficacy of MEK inhibition. Focal adhesion kinase (FAK) activation is a putative resistance mechanism to RAF and MEK inhibition, and defactinib, a small molecule inhibitor of FAK, has shown synergistic anti-tumor activity with VS-6766 in preclinical models, including organoids from LGSOC pts. Furthermore, FAK inhibition combined with VS-6766 induces tumor regression in a KRAS mt ovarian cancer xenograft model. The combination of VS-6766 and defactinib is currently being evaluated in the ongoing Investigator Sponsored FRAME study (NCT03875820). In this proof-of-concept study, durable objective responses (ORR = 46%; 11/24) have been reported in recurrent LGSOC pts, including pts who have had a prior MEK inhibitor (Banerjee ESMO 2021) and the combination of VS-6766 + defactinib has received FDA Breakthrough Therapy Designation for recurrent LGSOC. These initial preclinical and clinical results support the ongoing phase 2 ENGOT-ov60/GOG-3052 in recurrent LGSOC. Methods: This is an international phase 2, adaptive, multicenter, randomized, open label study designed to evaluate the efficacy and safety of VS-6766 vs VS-6766 in combination with defactinib currently open to enrollment (NCT04625270). The study will be conducted in two parts. Part A will determine the optimal regimen based on confirmed overall response rate (independent radiology review) in KRAS mt and KRAS wt LGSOC. Part B will determine the efficacy of the optimal regimen identified in Part A in KRAS mt and KRAS wt LGSOC. The minimum expected enrollment is 104 pts, 52 pts with KRAS mt and 52 KRAS wt (64 pts in Part A and 40 pts in Part B). Pts will be randomized to receive VS-6766 (4.0 mg orally (PO), twice weekly 3 wks on, 1 wk off) or VS-6766 with defactinib (VS-6766 3.2 mg PO, twice weekly + defactinib 200 mg PO BID 3 wks on, 1 wk off) till progression. Key inclusion criteria include histologically confirmed LGSOC, known KRAS mutation status, prior systemic therapy including platinum for metastatic disease and up to 1 prior line of MEK inhibitor therapy permitted. Part A of this study has completed enrollment and Part B is currently enrolling pts. Clinical trial information: NCT04625270.

A phase 1/2 study of VS-6766 (RAF/MEK clamp) in combination with sotorasib (G12C inhibitor) in patients with KRAS G12C mutant non–small cell lung cancer (NSCLC) (RAMP 203)

TPS9148

Background: KRAS is mutated (mt) in 25% of non-small cell lung cancer (NSCLC) adenocarcinoma, with KRAS G12C mt occurring in ̃13% of patients. The G12C inhibitor (G12Ci) sotorasib has recently received FDA approval for patients with KRAS G12C NSCLC. Several studies have shown that simultaneous targeting of multiple nodes in the RAS pathway may be optimal for durable pathway inhibition and response. Furthermore, acquired mutations and amplifications in the RAS pathway occur clinically upon progression on sotorasib or adagrasib. Accordingly, combination of G12Ci with a downstream blocker of the RAS pathway may be needed for more durable response. VS-6766 is a unique small molecule RAF/MEK clamp that inhibits BRAF, CRAF and MEK, enabling VS-6766 to block MEK signaling more consistently without the compensatory activation of MEK that reduces the efficacy of MEK-only inhibitors. In vitro 3D proliferation and in vivo tumor models were used to assess anti-tumor efficacy of VS-6766 ± G12Ci. In KRAS G12C mt NSCLC cell lines, VS-6766 was synergistic with both sotorasib and adagrasib in reducing tumor cell viability which correlated with deeper inhibition of RAS pathway signaling. In vivo, combination of VS-6766 with sotorasib induced strong tumor regressions in contrast to sotorasib monotherapy or sotorasib plus trametinib. Initial clinical activity of VS-6766 in KRAS G12C mt NSCLC is supported by the FRAME study [NCT03875820] results, in which 4/6 patients with KRAS G12C mt NSCLC showed tumor reduction including 1 PR. These results support the clinical evaluation of VS-6766 in combination with a G12Ci for treatment of KRAS G12C mt NSCLC. Methods: This is a Phase 1/2, multicenter, open label, dose evaluation/dose expansion study designed to evaluate the efficacy and safety of VS-6766 in combination with sotorasib in patients with KRAS G12C mt NSCLC who have not previously been treated with a KRAS G12Ci or have experienced disease progression while undergoing therapy with a KRAS G12Ci [NCT05074810]. The study will be conducted in two parts: Part A (dose evaluation) and Part B (dose expansion). Up to 3 dose levels will be evaluated in Part A to determine the Recommended Phase 2 Dose (RP2D) for Part B. Part B will assess the efficacy of the RP2D and will be conducted in 2 cohorts: patients who are G12Ci treatment naïve (cohort 1) and patients who have experienced disease progress during G12Ci therapy (Cohort 2). Patients enrolled must have histologic or cytologic evidence of NSCLC, measurable disease according to RECIST V1.1 and known KRAS G12C mutation. The study will enroll up to 121 patients with a minimum of 6 and a maximum of 12 patients in Part A and an additional 109 patients in Part B (minimum of 41 patients at RP2D stage 1 for cohort 1 and 2 or RP2D stages 1 and 2 in both cohorts). Clinical trial information: NCT05074810.

A phase 2 study of VS-6766 (RAF/MEK clamp) RAMP 202, as a single agent and in combination with defactinib (FAK inhibitor) in recurrent KRAS mutant (mt) and BRAF mt non–small cell lung cancer (NSCLC)

TPS9147

Background: KRAS is mutated (mt) in 25% of NSCLC adenocarcinoma, with KRAS G12V and G12C mt occurring in ̃7% and ̃13% of patients (pts), respectively. Whereas G12C inhibitors have demonstrated promising activity in pts with KRAS G12C NSCLC, KRAS G12V NSCLC remains an unmet need. BRAF mt occurs in ̃4% of NSCLC with roughly equal split between BRAF V600E and non-V600E. VS-6766 is a small molecule RAF/MEK clamp that inhibits BRAF, CRAF and MEK, enabling VS-6766 to block MEK signaling without compensatory activation of MEK observed with MEK-only inhibitors. VS-6766 potently inhibits proliferation of KRAS and BRAF mt cell lines. Focal adhesion kinase (FAK) activation is a putative resistance mechanism to RAF and MEK inhibition, and defactinib, a small molecule FAKi, has shown synergistic anti-tumor activity with VS-6766 in KRAS mt NSCLC models. In a KRAS G12V mt NSCLC mouse model, which was shown to be especially dependent on CRAF, VS-6766 induced strong tumor regressions both as monotherapy and in combination with FAKi (Coma AACR 2021). Clinically, VS-6766 monotherapy has shown responses in KRAS mt NSCLC including pts with KRAS G12V and in pts with BRAF V600E solid tumors (Guo 2020; Martinez-Garcia 2012). The combination of VS-6766 + defactinib is currently being evaluated in the Investigator Sponsored FRAME study. In an updated analysis of response in 20 pts with KRAS mt NSCLC, there were 2 confirmed PRs, 1 unconfirmed PR and 10 SDs (ORR = 15%; DCR = 65%) with 7/20 pts remaining on treatment for ≥24 weeks. The 2 pts with KRAS G12V NSCLC both had confirmed PRs (ORR = 100%). This combination regimen exhibited a manageable safety profile with no NSCLC pts discontinuing for adverse events (Krebs AACR 2021). Methods: This is an international phase 2, adaptive, multicenter, randomized, open label study designed to evaluate the efficacy and safety of VS-6766 vs. VS-6766 + defactinib in pts with recurrent KRAS or BRAF mt NSCLC (NCT04620330). Part A will determine the optimal regimen, either VS-6766 monotherapy or VS-6766 + defactinib based on pts with KRAS G12V. Part A will consist of 5 NSCLC arms: Arm 1 VS-6766 monotherapy in KRAS G12V, Arm 2 VS-6766 + defactinib in KRAS G12V, Arm 3 the combination in KRAS non-G12V, Arm 4 the combination in BRAF V600E and Arm 5 the combination in BRAF non-V600E. Part B will determine the efficacy of the optimal regimen identified in Part A. Pts must have histologic or cytologic evidence of NSCLC, measurable disease according to RECIST V1.1, known KRAS or BRAF mt and at least 1 prior systemic therapy (appropriate therapy for activating mutation and/or platinum-based therapy). Part A will enroll 102 pts Arms 1 and 2 (KRAS G12V), and Arms 4 and 5 (BRAF V600E and non-V600E) are currently open. Arm 3 (KRAS non-G12V) enrollment is completed. The total number of pts in Part B will be determined by results from Part A. Clinical trial information: NCT04620330.

Phase I trial of the RAF/MEK clamp VS-6766 in combination with everolimus using an intermittent schedule with expansion in NSCLC across multiple KRAS variants

9018

Background: VS-6766 is a small molecule RAF/MEK clamp that results in the reduction of p-MEK and p-ERK. Preclinical data show synergy of VS-6766 with the mTOR inhibitor everolimus across a panel of KRAS mutated (mt) NSCLC cell lines. This clinical trial evaluated the safety and efficacy of a novel intermittent regimen of VS-6766 and everolimus with an expansion in KRAS mt NSCLC (NCT02407509). Methods: The trial used a 3+3 dose escalation design with an intermittent once a week schedule A, and if tolerated, twice a week schedule B (Mon-Thu or Tue-Fri) for both drugs on a 3 weeks on/1 week off, 28 day cycle. Patients with RAS or RAF mt cancers were eligible for the dose escalation cohort, and 20 patients with KRAS mt NSCLC will be treated in the dose expansion cohort. Toxicity was evaluated by NCI CTC V4 and efficacy was evaluated using RECIST 1.1. Results: A total of 28 patients have been treated; median age 60 yrs (range 36-78), and median lines of previous treatment 3 (range 0-7). Sixteen patients have been treated in the dose escalation (3 in schedule A and 13 in the schedule B). The doses of 4 mg of VS-6766 and 5 mg everolimus (once weekly) were tolerated with no dose limiting toxicities (DLTs) and the dose intensity escalated to schedule B (twice weekly). At 4 mg VS-6766 twice weekly, DLTs were observed in two out of six patients and included grade 4 CPK elevation and grade 3 rash. Thus, the dose in schedule B (twice weekly) was de-escalated to 3.2 mg VS-6766 and the dose of everolimus was kept at 5 mg. No DLTs were reported in 6 patients and thus this was declared as the recommended phase 2 dose (RP2D). At the RP2D, the grade 3-4 drug related AE were rash (18%) and pruritus (7%). In the dose escalation cohorts, 3 partial responses (PRs) were reported (2 KRAS G12D low grade serous ovarian cancer and 1 NRAS Q61K mt thyroid cancer). In the KRAS mt NSCLC expansion cohort, 10 patients are evaluable for efficacy and 2 confirmed responses were reported ( KRAS mutations G12V and G13A) with an objective response rate (ORR) 20% to date. The disease control rate (PR + SD) at the first scheduled evaluation was 90%. The median progression free survival (PFS) in the KRAS mt NSCLC cohort is 6.35 months (95% CI 3.52 – not reached). Updated ORR and PFS data will be presented. Conclusions: A tolerable intermittent dosing schedule targeting both the MAPK and PI3K pathways has been established. The combination of VS-6766 with everolimus has shown activity in patients with a variety of KRAS mutation variants including responses in KRAS mt NSCLC.

ASN004, A 5T4-targeting scFv-Fc Antibody-Drug Conjugate with High Drug-to-Antibody Ratio, Induces Complete and Durable Tumor Regressions in Preclinical Models

The 5T4 oncofetal antigen (trophoblast glycoprotein) is expressed in a wide range of malignant tumors but shows very limited expression in normal adult tissues. ASN004 is a 5T4-targeted antibody-drug conjugate (ADC) that incorporates a novel single-chain Fv-Fc antibody and Dolaflexin drug-linker technology, with an Auristatin F hydroxypropylamide payload drug-to-antibody ratio of approximately 10-12. The pharmacology, toxicology, and pharmacokinetic properties of ASN004 and its components were investigated in vitro and in vivo ASN004 showed high affinity for the 5T4 antigen and was selectively bound to and internalized into 5T4-expressing tumor cells, and potent cytotoxicity was demonstrated for a diverse panel of solid tumor cell lines. ASN004 induced complete and durable tumor regression in multiple tumor xenograft models, derived from human lung, breast, cervical, and gastric tumor cell lines having a wide range of 5T4 expression levels. A single dose of ASN004, as low as 1 mg/kg i.v., achieved complete tumor regression leading to tumor-free survivors in the A431 cervical cancer model. In head-to-head studies, superior activity of ASN004 was demonstrated against trastuzumab-DM1, in a low-5T4/high-HER2 expressing gastric tumor model, and 10-fold greater potency was found for ASN004 against the 5T4-targeted ADC PF-06263507 in a lung tumor model. In marmoset monkeys, ASN004 was well tolerated at doses up to 1.5 mg/kg Q3W i.v., and showed dose-dependent exposure, linear pharmacokinetics, and markedly low exposure of free payload drug. Taken together, these findings identify ASN004 as a promising new ADC therapeutic for clinical evaluation in a broad range of solid tumor types.

Abstract PR09: Phase 1 clinical safety and efficacy of ASN007, a novel oral ERK1/2 inhibitor, in patients with RAS, RAF or MEK mutant advanced solid tumors

Background: The oncogenic mitogen-activated protein kinase (MAPK) pathway is dysregulated in a broad range of cancers through mutations in BRAF, KRAS, NRAS, HRAS and MEK1 genes. ASN007 is a novel, potent and orally bioavailable inhibitor of ERK1/2 kinases (IC50 1-2nM) with a very long target residence time (550 min). Preclinical studies show strong anti-tumor activity in multiple RAS mutant xenograft and PDX models, irrespective of mutation subtype. ASN007 also maintains strong activity in BRAF mutant melanoma PDX models resistant to BRAF and MEK inhibition. Preclinical activity is seen with both intermittent as well as daily dosing. This is the initial report of ASN007 clinical data from this first-in-human Phase 1 Study. Methods: This Phase 1 trial evaluates ASN007 in patients (PS 0-1) with metastatic solid tumors refractory to standard therapies using an accelerated dose titration design for once daily (QD) and once weekly (QW) oral dosing (NCT03415126). Primary objectives in Part A (dose finding) include safety, tolerability, PK and PD to determine the Maximum Tolerated Dose (MTD). Part B (disease specific expansion) will evaluate clinical activity in cohorts of 15 patients each with tumors harboring specific mutations which include NRAS, HRAS, MEK1 and BRAF. Results: To date, 42 eligible patients (pts) were enrolled at dose levels ranging from 10mg to 80mg QD and 80 mg to 350mg QW. The respective MTDs are 40mg QD and 250mg QW. Reversible treatment-related adverse events (TRAEs) at 40mg QD (n=10) included rash ( 90%, Gr3 10%), nausea/vomiting (Gr1 30%), diarrhea (Gr1 30%), fatigue (20%, Gr3 10%) and central serous retinopathy (CSR) (30%, no G3) and at 250mg QW (n=9) included rash (33%, no Gr3), CSR (11%, Gr3 11%), blurred vision (44%, Gr3 11%), nausea/vomiting (33%, Gr3 11%) and diarrhea (33%, no Gr3). Dose limiting toxicities (DLTs) included Gr3 CSR at 60 and 80 QD, Gr3 rash at 80mg QD and Gr3 AST at 350mg QW. Durable clinical benefit was noted for 3 pts treated with QW ASN007 at doses 120 mg to 250 mg: a confirmed partial response (-57%) in a patient with HRAS-mutant salivary gland cancer for 5+ months, stable disease in KRAS mutant ovarian cancer for 9+ months and stable disease in BRAF V600E mutant thyroid cancer for 8+ months. Pharmacokinetic studies demonstrated dose dependent increase in the Cmax and AUC24 with both QD and QW dosing. QW dosing Cmax levels exceed average IC50 values more than &gt;30-fold. Inter-subject variability was moderate (≤ 50%) and the elimination t1/2 was 10-15 hours. Conclusions: ASN007 is a selective oral inhibitor of ERK1/2 with a long target residence time. QD or QW dosing is feasible with expected reversible and manageable AE profile and dose dependent exposure. The dose of 250mg QW was selected for further development due to favorable tolerability and encouraging signs of clinical activity. Part B of the study is open to enroll patients with solid tumors harboring BRAF, MEK1, and RAS mutations. Updated clinical, safety, PK/PD and efficacy data will be presented.

Citation Format: Anthony W. Tolcher, Ryan J. Sullivan, Drew W. Rasco, Zeynep Eroglu, Nehal Lakhani, Dana Kessler, Helen Usansky, Sanjeeva Reddy, Louis J. Denis, Filip Janku. Phase 1 clinical safety and efficacy of ASN007, a novel oral ERK1/2 inhibitor, in patients with RAS, RAF or MEK mutant advanced solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr PR09. doi:10.1158/1535-7163.TARG-19-PR09

Abstract B147: A phase 1 PK/PD study of ASN003, a novel, highly selective BRAF and PI3K dual inhibitor, in patients with advanced solid tumors

Background: RAS-RAF-MEK and PI3K-AKT-mTOR are two major pathways involved in tumor cell signaling and growth. Components of these pathways are frequently mutated in a broad range of tumors. ASN003 is a highly selective and potent (low nM IC50) inhibitor of BRAF and PI3K-α and -δ (low affinity for PI3K-β). ASN003 shows strong antitumor activity in tumor models harboring BRAF and PIK3CA or PTEN mutations, and also in patient-derived xenograft (PDX) models that are resistant to selective BRAF and MEK inhibitors. Patients and Methods: Oral once-daily ASN003 is being evaluated for safety/tolerability and preliminary efficacy in eligible patients with advanced solid tumors using an accelerated dose titration design (Part A) and enrolling cohorts of patients diagnosed with melanoma, CRC, NSCLC, and other solid tumors with a BRAF, PIK3CA, or PTEN mutation at MTD (Part B). Pharmacokinetic (PK) profile and the pharmacodynamic (PD) effects of ASN003 on tumor tissue biomarkers such as pERK and pS6 are investigated in both parts of the study. Results: Patient accrual in Part A is ongoing. As of June 2017, nine eligible patients are enrolled in dose levels ranging from 10 - 240 mg QD. ASN003 has been well tolerated. Treatment-related adverse events (TRAEs) were mild (G1) to moderate (G2). TRAEs include diarrhea (G2) (n=1), nausea/vomiting (G1), blurred vision (G1), and dry mouth/lips/skin (G1). Transient G1 elevation of glucose and insulin c-peptide levels has been noted in 1 pt. No G3/4 or serious TRAEs have been observed to date. The PK profile showed dose-dependent, systemic exposure with Cmax ranging from 74 to 1055 ng/mL, AUCT from 912 to 20100 ng.h/mL. Conclusions: ASN003 is a novel small molecule, with uniquely selective and potent inhibition of BRAF, PI3K-α and -δ kinases. To date, ASN003 was well tolerated at doses up to 240 mg QD and achieved good systemic exposure. Updated and detailed clinical safety/efficacy and PK/PD results will be presented.

Citation Format: Drew Rasco, Nehal Lakhani, Ryan Sullivan, Monica Mita, Jaimini Shah, Helena Usansky, Sanjeeva Reddy, Niranjan Rao, Louis J. Denis, Anthony Tolcher, Keith Flaherty. A phase 1 PK/PD study of ASN003, a novel, highly selective BRAF and PI3K dual inhibitor, in patients with advanced solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B147.

ASN003, a highly selective BRAF and PI3K inhibitor: Preclinical and phase 1 clinical data in patients with advanced solid tumors

e14102

Background: RAS-RAF-MEK and PI3K-AKT-mTOR are two major signaling pathways involved in tumorigenesis. Components of these two pathways are frequently mutated in a broad range of tumors. ASN003 is a novel and highly selective small-molecule inhibitor of the RAS-RAF-MEK and PI3K pathways. Methods: The activity of ASN003 was determined using PI3K and BRAF enzymes, and efficacy was studied in human tumor xenograft models in mice. ASN003 is currently being investigated in patients with solid tumors in a Phase 1 trial using an accelerated dose titration design. In Part A, safety and tolerability of ASN003 is being studied in patients with advanced solid tumors. In Part B, safety, tolerability and preliminary efficacy of ASN003 will be evaluated in melanoma, CRC and NSCLC patients with a BRAF, PIK3CA or PTEN mutation. Pharmacokinetic (PK) profile and the pharmacodynamic (PD) effects of ASN003 on biomarkers such as pERK and pS6 are investigated in both parts of the study. Results: ASN003 showed potent and highly selective inhibition of BRAF and PI3K-α and -δ, and low affinity for PI3K-ß. ASN003 showed strong antiproliferative activity in cell lines and caused significant tumor growth inhibition in xenograft models harboring BRAF and PIK3CA or PTEN mutations. ASN003 showed antiproliferative activity in B-RAF and MEK inhibitor resistant cell lines. ASN003 had a strong antitumor activity in a BRAFV600mutant melanoma PDX model resistant to BRAF inhibitors, vemurafenib and dabrafenib. In humans, to date, ASN003 was well tolerated at 10 and 20 mg QD. Adverse events were mild and peak plasma level of 120 nM at 10 mg QD was achieved with a half-life of > 12 h. Dose escalation is ongoing. Conclusions: ASN003 is a unique small molecule, with highly selective and potent inhibition of BRAF, PI3-α and -δ kinases. ASN003 has strong antitumor activity in various xenograft tumor models harboring both BRAF and PIK3CA/PTEN mutations, and in a BRAF inhibitor resistant melanoma PDX model. To date, ASN003 was well tolerated and achieved good systemic exposure. Updated and detailed clinical, PK and PD results will be presented. Clinical trial information: NCT02961283.

Clinical activity, safety and tolerability of ASN002, a dual SYK/JAK inhibitor, in patients non-Hodgkin lymphoma (NHL) and solid tumors

7545

Background: ASN002 is a novel, potent inhibitor of Spleen Tyrosine Kinase (SYK) and Janus Kinases (JAK). Pre-clinical studies indicate that ASN002 has low nM IC50s against SYK and JAK, decreases proliferation in ibrutinib-resistant cell lines, and suppresses tumor growth in rodent xenograft models of NHL and other hematologic malignancies. Methods: This Phase 1/2 clinical trial in patients with solid tumors and hematologic malignancies evaluates escalating ASN002 oral doses of 10, 20, 30, 40, 50 and’ 75 mg BID and 80 and 120 mg QD mg (NCT02440685). Phase 1 allows patients with solid tumors or hematologic malignancies; Phase 2 allows only patients with diffuse large B-Cell lymphoma (DLBCL), follicular lymphoma (FL) or mantle cell lymphoma (MCL). Endpoints include safety, tolerability, pharmacokinetics, serum markers of inflammation, and response using RECIST or Lugano Classification System. Results: Twenty-eight patients have enrolled in the DLT phase at doses of 10 mg – 75 mg BID and at 80 mg QD. All patients had multiple prior lines of treatment (range: 2 – 8). ASN002 was well tolerated. No dose limiting adverse events have been reported at these dose levels. Most drug-related adverse events were Gr 1/2 (e.g. headache, fatigue). Steady-state systemic exposure was high (Cmax, AUC (0-12h) and T1/2 at 40 mg BID were 0.7 µM, 6.3 µM.h and 18 h, respectively). High systemic exposure was also observed at 80 mg QD. Robust reduction of CRP, IL-18, MIP1β, VCAM-1, TNFR2 was observed at all doses. Stable disease (RECIST, 9+ months) in a patient with primary peritoneal cancer, about 50% reduction in target lesions at 3 months in a FL patient (Lugano, 6 prior lines) and stable disease and reduction of pruritus in a peripheral T-Cell lymphoma patient after 2 months (Lugano, 2 prior lines) of treatment were observed. ASN002 treatment continues in both lymphoma patients. Accrual of patients continues. Conclusions: ASN002 was safe and well tolerated. Encouraging preliminary evidence of efficacy in NHL patients was observed. MTD has not been reached and dose escalation continues. Updated and detailed results will be presented. Clinical trial information: NCT02440685.

Clinical activity and safety of ASN001, a selective CYP17 lyase inhibitor, administered without prednisone in men with metastatic castration-resistant prostate cancer (mCRPC): A phase 1/2 clinical trial

5041

Background: ASN001 is a novel, non-steroidal, potent inhibitor of CYP17 lyase that selectively inhibits synthesis of testosterone over cortisol in the adrenals to avoid the need for co-administration of prednisone. ASN001 also exhibits high oral bioavailability and low potential for drug-drug interaction. Methods: This Phase (Ph) 1/2 clinical trial in men with progressive mCRPC evaluates once-daily, oral ASN001 at escalating doses of 50, 100, 200, 300 and 400 mg (NCT02349139). While Ph 1 also allowed enrollment of pretreated patients, no prior enzalutamide (ENZA) or abiraterone (ABI) is permitted in Ph 2. Endpoints include maximum dose (MTD) and dose limiting toxicities, recommended Ph 2 dose, PK, effect on steroid hormone biosynthesis and clinical efficacy (PSA and imaging). Results: To date, 26 mCRPC pts have been enrolled. No prednisone was administered and no mineralocorticoid excess has been reported. Overall, ASN001 was well tolerated. Most drug-related adverse events were Gr 1/2 and included fatigue, constipation and nausea. At 400mg, two pts experienced asymptomatic, reversible Gr 3 ALT/AST elevation, but no recurrence when retreated at 300mg. Enrollment of ABI/ENZA naïve patients continues at lower doses to further evaluate safety and efficacy. Testosterone decrease to below quantifiable limits and DHEA decrease of up to 80% was observed. Systemic exposure was high (Cmax, AUC and T1/2 at 300 mg QD were 6.7 µM, 80 µM.h and 21.5 h, respectively). Stable disease up to 18+ months has been observed despite prior ABI and ENZA exposure. PSA decline of > 50% (up to 93% decline) and up to 37+ wks duration was observed in 3 of 4 ABI/ENZA naïve patients at starting doses of 300/400mg. Conclusions: Overall, ASN001 was safe and well tolerated. Prednisone co-administration was not needed. Encouraging preliminary evidence of efficacy is reflected by PSA declines in evaluable mCRPC pts not pretreated with ABI or ENZA and by durable disease stabilization in refractory disease. Enrollment is ongoing at doses below 400mg QD in ABI/ENZA naïve mCRPC pts. Updated and detailed results will be presented at the meeting. Clinical trial information: NCT02349139.

Clinical activity and safety of ASN001, a selective CYP17 lyase inhibitor, administered without prednisone in men with metastatic castration-resistant prostate cancer (mCRPC)

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Background: ASN001 is a novel, non-steroidal, potent inhibitor of CYP17 lyase. It selectively inhibits synthesis of testosterone over cortisol in the adrenals to avoid the need for co-administration of prednisone. ASN001 also exhibits high oral bioavailability and low potential for drug-drug interaction supporting its use in future combination trials. Methods: This Phase 1/2 clinical trial in men with progressive mCRPC evaluates once-daily, oral ASN001 at escalating doses of 50, 100, 200, 300 and 400 mg (NCT02349139). While the Phase 1 also allowed enrollment of pretreated patients, no prior enzalutamide (ENZA) or abiraterone (ABI) is permitted in Phase 2. Endpoints included maximum dose (MTD) and dose limiting toxicities, recommended Phase 2 dose, pharmacokinetics, effect on steroid hormone biosynthesis and clinical efficacy (PSA and imaging). Results: To date, 23 mCRPC pts have been enrolled. No prednisone was administered and no mineralocorticoid excess has been reported. Overall, ASN001 was well tolerated. Most drug-related adverse events were Gr 1/2 and included fatigue, nausea and dizziness. At 400mg, two pts experienced asymptomatic, reversible Gr 3 elevation of ALT/AST, but no recurrence when retreated at a lower dose (300mg). Testosterone decreased to below quantifiable limits and DHEA decrease of up to 80% was observed in ABI/ENZA naïve patients. Systemic exposure was high (Cmax, AUC and T1/2 at 300 mg QD was 6.7 µm, 80 µm.h and 21.5h, respectively). RECIST defined Stable Disease up to 15+ months has been observed at the 100mg cohort despite prior ABI and ENZA exposure. PSA decline of > 50% (51%-70%) was observed in 3 of 3 ABI/ENZA naïve patients at doses of 300/400mg. Conclusions: Overall, ASN001 was safe and well tolerated without need for prednisone co-administration. Encouraging preliminary evidence of efficacy is based on the PSA decline observed in evaluable mCRPC pts not pretreated with ABI or ENZA and based on durable disease stabilization after progression on ABI and ENZA. Enrollment is ongoing at doses below 400mg QD in ABI/ENZA naïve mCRPC pts. Updated and detailed results will be presented at the meeting. Clinical trial information: NCT02349139.

Absolute Effect of Prostate Cancer Screening: Balance of Benefits and Harms by Center within the European Randomized Study of Prostate Cancer Screening

PURPOSE

The balance of benefits and harms in prostate cancer screening has not been sufficiently characterized. We related indicators of mortality reduction and overdetection by center within the European Randomized Study of Prostate Cancer Screening (ERSPC).

EXPERIMENTAL DESIGN

We analyzed the absolute mortality reduction expressed as number needed to invite (NNI = 1/absolute risk reduction; indicating how many men had to be randomized to screening arm to avert a prostate cancer death) for screening and the absolute excess of prostate cancer detection as number needed for overdetection (NNO = 1/absolute excess incidence; indicating the number of men invited per additional prostate cancer case), and compared their relationship across the seven ERSPC centers.

RESULTS

Both absolute mortality reduction (NNI) and absolute overdetection (NNO) varied widely between the centers: NNI, 200-7,000 and NNO, 16-69. Extent of overdiagnosis and mortality reduction was closely associated [correlation coefficient, r = 0.76; weighted linear regression coefficient, β = 33; 95% confidence interval (CI), 5-62; R(2) = 0.72]. For an averted prostate cancer death at 13 years of follow-up, 12 to 36 excess cases had to be detected in various centers.

CONCLUSIONS

The differences between the ERSPC centers likely reflect variations in prostate cancer incidence and mortality, as well as in screening protocol and performance. The strong interrelation between the benefits and harms suggests that efforts to maximize the mortality effect are bound to increase overdiagnosis and might be improved by focusing on high-risk populations. The optimal balance between screening intensity and risk of overdiagnosis remains unclear.

Development of a Standardized Set of Patient-centered Outcomes for Advanced Prostate Cancer: An International Effort for a Unified Approach

BACKGROUND

There are no universally monitored outcomes relevant to men with advanced prostate cancer, making it challenging to compare health outcomes between populations.

OBJECTIVE

We sought to develop a standard set of outcomes relevant to men with advanced prostate cancer to follow during routine clinical care.

DESIGN, SETTING, AND PARTICIPANTS

The International Consortium for Health Outcomes Measurement assembled a multidisciplinary working group to develop the set.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We used a modified Delphi method to achieve consensus regarding the outcomes, measures, and case mix factors included.

RESULTS AND LIMITATIONS

The 25 members of the multidisciplinary international working group represented academic and nonacademic centers, registries, and patients. Recognizing the heterogeneity of men with advanced prostate cancer, the group defined the scope as men with all stages of incurable prostate cancer (metastatic and biochemical recurrence ineligible for further curative therapy). We defined outcomes important to all men, such as overall survival, and measures specific to subgroups, such as time to metastasis. Measures gathered from clinical data include measures of disease control. We also identified patient-reported outcome measures (PROMs), such as degree of urinary, bowel, and erectile dysfunction, mood symptoms, and pain control.

CONCLUSIONS

The international multidisciplinary group identified clinical data and PROMs that serve as a basis for international health outcome comparisons and quality-of-care assessments. The set will be revised annually.

PATIENT SUMMARY

Our international group has recommended a standardized set of patient-centered outcomes to be followed during routine care for all men with advanced prostate cancer.

Metastatic Prostate Cancer Incidence and Prostate-specific Antigen Testing: New Insights from the European Randomized Study of Screening for Prostate Cancer

BACKGROUND

The European Randomized Study of Screening for Prostate Cancer (ERSPC) has shown a 21% reduction in prostate cancer (PCa) mortality and a 1.6-fold increase in PCa incidence with prostate-specific antigen (PSA)-based screening (at 13 yr of follow-up). We evaluated PCa incidence by risk category at diagnosis across the study arms to assess the potential impact on PCa mortality.

DESIGN, SETTING, AND PARTICIPANTS

Information on arm, centre, T and M stage, Gleason score, serum PSA at diagnosis, age at randomisation, follow-up time, and vital status were extracted from the ERSPC database. Four risk categories at diagnosis were defined: 1, low; 2, intermediate; 3, high; 4, metastatic disease. PSA (≤100 or >100 ng/ml) was used as the indicator of metastasis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Incidence rate ratios (IRRs) for screening versus control arm by risk category at diagnosis and follow-up time were calculated using Poisson regression analysis for seven centres. Follow-up was truncated at 13 yr. Missing data were imputed using chained equations. The analyses were carried out on an intention-to-treat basis.

RESULTS AND LIMITATIONS

In the screening arm, 7408 PCa cases were diagnosed and 6107 in the control arm. The proportion of missing stage, Gleason score, or PSA value was comparable in the two arms (8% vs 10%), but differed among centres. The IRRs were elevated in the screening arm for the low-risk (IRR: 2.14; 95% CI, 2.03-2.25) and intermediate-risk (IRR: 1.24; 95% CI, 1.16-1.34) categories at diagnosis, equal to unity for the high-risk category at diagnosis (IRR: 1.00; 95% CI, 0.89-1.13), and reduced for metastatic disease at diagnosis (IRR: 0.60; 95% CI, 0.52-0.70). The IRR of metastatic disease had temporal pattern similar to mortality, shifted forwards an average of almost 3 yr, although the mortality reduction was smaller.

CONCLUSIONS

The results confirm a reduction in metastatic disease at diagnosis in the screening arm, preceding mortality reduction by almost 3 yr.

PATIENT SUMMARY

The findings of this study indicate that the decrease in metastatic disease at diagnosis is the major determinant of the prostate cancer mortality reduction in the European Randomized study of Screening for Prostate Cancer.

Screening and prostate cancer mortality: results of the European Randomised Study of Screening for Prostate Cancer (ERSPC) at 13 years of follow-up

BACKGROUND

The European Randomised study of Screening for Prostate Cancer (ERSPC) has shown significant reductions in prostate cancer mortality after 9 years and 11 years of follow-up, but screening is controversial because of adverse events such as overdiagnosis. We provide updated results of mortality from prostate cancer with follow-up to 2010, with analyses truncated at 9, 11, and 13 years.

METHODS

ERSPC is a multicentre, randomised trial with a predefined centralised database, analysis plan, and core age group (55-69 years), which assesses prostate-specific antigen (PSA) testing in eight European countries. Eligible men aged 50-74 years were identified from population registries and randomly assigned by computer generated random numbers to screening or no intervention (control). Investigators were masked to group allocation. The primary outcome was prostate cancer mortality in the core age group. Analysis was by intention to treat. We did a secondary analysis that corrected for selection bias due to non-participation. Only incidence and no mortality data at 9 years' follow-up are reported for the French centres. This study is registered with Current Controlled Trials, number ISRCTN49127736.

FINDINGS

With data truncated at 13 years of follow-up, 7408 prostate cancer cases were diagnosed in the intervention group and 6107 cases in the control group. The rate ratio of prostate cancer incidence between the intervention and control groups was 1·91 (95% CI 1·83-1·99) after 9 years (1·64 [1·58-1·69] including France), 1·66 (1·60-1·73) after 11 years, and 1·57 (1·51-1·62) after 13 years. The rate ratio of prostate cancer mortality was 0·85 (0·70-1·03) after 9 years, 0·78 (0·66-0·91) after 11 years, and 0·79 (0·69-0·91) at 13 years. The absolute risk reduction of death from prostate cancer at 13 years was 0·11 per 1000 person-years or 1·28 per 1000 men randomised, which is equivalent to one prostate cancer death averted per 781 (95% CI 490-1929) men invited for screening or one per 27 (17-66) additional prostate cancer detected. After adjustment for non-participation, the rate ratio of prostate cancer mortality in men screened was 0·73 (95% CI 0·61-0·88).

INTERPRETATION

In this update the ERSPC confirms a substantial reduction in prostate cancer mortality attributable to testing of PSA, with a substantially increased absolute effect at 13 years compared with findings after 9 and 11 years. Despite our findings, further quantification of harms and their reduction are still considered a prerequisite for the introduction of populated-based screening.

FUNDING

Each centre had its own funding responsibility.

Active surveillance for low-risk prostate cancer

Active surveillance (AS) is an important management strategy for men diagnosed with low-risk prostate cancer (PCa). The need for AS is increasing due to the awareness that many PCa are identified that show a low growth potential and therefore are likely to remain clinically asymptomatic during the lifetime of an individual. Currently there is no good method to prevent the overdiagnosis of indolent cancers upfront. During the last decade, several studies on AS around the world have made observations that feed the discussion on how to select and monitor these patients, how to proceed with the research to develop a better and more precise clinical definition of indolent cancers and how to manage men under AS clinically. Furthermore, patients' perspectives have become clearer, and quality of life studies give direction to the practical approach and care for patients and partners. This paper reflects the consensus on the state of the art and the future direction of AS, based on the Inside Track Conference "Active Surveillance for low risk prostate cancer" (Chairmen: C.H. Bangma, NL, and L. Klotz, CA; Co-Chairmen: L.J. Denis, BE, and C. Parker, UK; Scientific Coordinators: M. J. Roobol, NL, and E.W. Steyerberg, NL), organized by the European School of Oncology in collaboration with Europa Uomo in Rotterdam, the Netherlands in January 2012. Topics for discussion were the optimisation of patient selection based on indolent disease definition, the incorporation of therapeutic agents into AS programs, the optimisation of patient care, and the application of emerging technologies and biomarkers.

Prostate-cancer mortality at 11 years of follow-up

BACKGROUND

Several trials evaluating the effect of prostate-specific antigen (PSA) testing on prostate-cancer mortality have shown conflicting results. We updated prostate-cancer mortality in the European Randomized Study of Screening for Prostate Cancer with 2 additional years of follow-up.

METHODS

The study involved 182,160 men between the ages of 50 and 74 years at entry, with a predefined core age group of 162,388 men 55 to 69 years of age. The trial was conducted in eight European countries. Men who were randomly assigned to the screening group were offered PSA-based screening, whereas those in the control group were not offered such screening. The primary outcome was mortality from prostate cancer.

RESULTS

After a median follow-up of 11 years in the core age group, the relative reduction in the risk of death from prostate cancer in the screening group was 21% (rate ratio, 0.79; 95% confidence interval [CI], 0.68 to 0.91; P=0.001), and 29% after adjustment for noncompliance. The absolute reduction in mortality in the screening group was 0.10 deaths per 1000 person-years or 1.07 deaths per 1000 men who underwent randomization. The rate ratio for death from prostate cancer during follow-up years 10 and 11 was 0.62 (95% CI, 0.45 to 0.85; P=0.003). To prevent one death from prostate cancer at 11 years of follow-up, 1055 men would need to be invited for screening and 37 cancers would need to be detected. There was no significant between-group difference in all-cause mortality.

CONCLUSIONS

Analyses after 2 additional years of follow-up consolidated our previous finding that PSA-based screening significantly reduced mortality from prostate cancer but did not affect all-cause mortality. (Current Controlled Trials number, ISRCTN49127736.).

Prostate cancer from the horizon of the patient

The democratization of civil society and the development of modern medicine changed the sacrosanct doctor-patient relationship to a doctor-partner dialogue. Values and respect were lost in the process where common courtesy and empathy in trust were replaced by patient rights. LAUNCH OF EUROPA UOMO: Europa Uomo, the European prostate cancer coalition, represents 22 national, autonomous patient support groups. Its aim includes increasing the awareness of prostate diseases, support individualized treatment as a balance between optimal medical treatment and personalized care delivered by a multiprofessional team. We expect our information/education from dedicated professional societies while in return we share care for properly informed members as well as a fast, unbiased and cheap distribution of information/innovation across the European continent. THE ROLE OF A PATIENT GROUP: Our advocacy role is focused on quality of life, tailored treatment, knowledge of risk factors, support for research and last but not least active partnerships. We believe that we can play a modest but basic role in common actions to overcome inequalities in treatment and care in Europe. Our responsibilities range from defining patient obligations to facilitating translational research and saving scarce health resources. THE HORIZON OF THE PATIENT: Our hope is to plead for a treatment policy on the man first and then on his cancer and to improve treatment outcomes by multiprofessional collaboration and the development of expert Prostate Units. FUTURE EXPECTATIONS: A transparent, open communication line between the multiprofessional team and the patient is mandatory. The existing uncertainties should be discussed with common sense but always leave a factor of hope in survival or quality of life.

Phase I study of oral irinotecan as a single-agent and given sequentially with capecitabine

PURPOSE

To assess the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) of orally administered irinotecan in the semi-solid matrix (SSM) formulation, both as a single agent and in sequential combination with capecitabine, in patients with advanced solid tumors.

PATIENTS AND METHODS

Forty-three patients were treated with irinotecan given as a single oral daily dose on days 1-5 every three weeks. An additional forty patients were treated with sequential oral irinotecan given daily on days 1-5 followed by capecitabine given orally as a divided dose twice daily on days 6-14 of each three week cycle.

RESULTS

The MTD of single-agent oral irinotecan was estimated to be 60 mg/m(2)/day, and DLT included diarrhea, nausea, and neutropenia. In an initial group of patients with Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 to 2, the MTD of sequential oral irinotecan/capecitabine was estimated to be 40/1600 mg/m(2)/day with DLT of delayed diarrhea. In a subsequent group of patients with ECOG PS of 0 or 1, the MTD for the sequential combination was 50/2000 mg/m(2)/day. The most common adverse events were fatigue, diarrhea, nausea/vomiting and dehydration. Pharmacokinetic (PK) evaluation showed that oral irinotecan was rapidly absorbed and effectively converted to the active metabolite, SN-38, achieving approximately 50% of the SN-38 systemic exposure resulting from an equivalent IV dose.

CONCLUSIONS

Oral irinotecan can be safely administered as a single agent or in sequential combination with capecitabine. The efficacy of oral irinotecan should be explored further as a potentially convenient alternative to IV chemotherapy.

Predictive modeling in prostate cancer. Conclusions and reflections

Validated prognostic factors are an integral part of any cancer diagnosis. The available proliferation of new markers and randomized clinical trial results leads to a complex decision making looking for optimal treatment and outcome results. Advanced mathematic models have been developed to weigh each specific prognostic factor into a single outcome number in nomograms modeled for specific predictive accuracy in key phases of the treated history of the disease. Despite this progress, it is important to realize that the results are an outcome stratification for groups rather than for the individual patient. It is clear that in the tumor prognosis, host and environmental factors need to be evaluated before any clinical decision is made. Cancer 2009;115(13 suppl):3160-2. (c) 2009 American Cancer Society.

Screening and prostate-cancer mortality in a randomized European study

BACKGROUND

The European Randomized Study of Screening for Prostate Cancer was initiated in the early 1990s to evaluate the effect of screening with prostate-specific-antigen (PSA) testing on death rates from prostate cancer.

METHODS

We identified 182,000 men between the ages of 50 and 74 years through registries in seven European countries for inclusion in our study. The men were randomly assigned to a group that was offered PSA screening at an average of once every 4 years or to a control group that did not receive such screening. The predefined core age group for this study included 162,243 men between the ages of 55 and 69 years. The primary outcome was the rate of death from prostate cancer. Mortality follow-up was identical for the two study groups and ended on December 31, 2006.

RESULTS

In the screening group, 82% of men accepted at least one offer of screening. During a median follow-up of 9 years, the cumulative incidence of prostate cancer was 8.2% in the screening group and 4.8% in the control group. The rate ratio for death from prostate cancer in the screening group, as compared with the control group, was 0.80 (95% confidence interval [CI], 0.65 to 0.98; adjusted P=0.04). The absolute risk difference was 0.71 death per 1000 men. This means that 1410 men would need to be screened and 48 additional cases of prostate cancer would need to be treated to prevent one death from prostate cancer. The analysis of men who were actually screened during the first round (excluding subjects with noncompliance) provided a rate ratio for death from prostate cancer of 0.73 (95% CI, 0.56 to 0.90).

CONCLUSIONS

PSA-based screening reduced the rate of death from prostate cancer by 20% but was associated with a high risk of overdiagnosis. (Current Controlled Trials number, ISRCTN49127736.)

The prevention of prostate cancer

From our better understanding of the natural history of prostate cancer, it is not unreasonable to believe that the disease is preventable. Prostate cancer has become a major healthcare problem worldwide, as life expectancy increases. Moreover, the cancer is slow growing, with a period of about 20-25 years from initiation to the stage when the clinically detectable phenotype can be identified. This review provides a simple overview of the endocrinology of prostate cancer and discusses some of the pharmaceutical agents that have been or are being tested to restrain, possibly arrest, the progression of this slowly growing cancer. Also discussed are many of the dietary factors that may influence the molecular or endocrine events implicated in its development. Dietary factors are considered responsible for the geographical differences in prostate cancer incidence and mortality. Since about 50% of all men worldwide, from both East and West, show evidence of microscopic cancer by 50 years of age, growth restraint would appear to be the pragmatic option to the possibility of preventing initiation.

Estrogens and aspects of prostate disease

Estrogens have long been associated with the processes involved in prostate carcinogenesis, particularly in cancer suppression. However, the synergistic influence of low concentrations of estrogens, together with androgens, in promoting aberrant growth of the gland has also been recognized. As new insights into the complex molecular events implicated in growth regulation of the prostate are revealed, the role of the estrogens has become clearer. The present review considers this role in relation to the pathogenesis of prostate cancer and the potential cancer-repressive influence of the dietary estrogens.

Phase I and pharmacological study of the oral matrix metalloproteinase inhibitor, MMI270 (CGS27023A), in patients with advanced solid cancer

This Phase I study of MMI270, an p.o. administered matrix metalloproteinase inhibitor, assessed toxicity, pharmacokinetics, and tumor response data and investigated markers of biological activity to recommend a dose for Phase II studies. MMI270 was administered continuously at seven dose levels (50 mg once daily to 600 mg three times/day). Patients were evaluated for toxicity and tumor response, and blood and urine samples were taken for pharmacokinetics, bone resorption markers, direct targets of the inhibitor [matrix metalloproteinase-2 (MMP-2), MMP-8, and MMP-9], indirect targets [tissue inhibitor of metalloproteinase-1 (TIMP-1), TIMP-2, basic fibroblast growth factor, vascular endothelial growth factor, vascular cell adhesion molecule-1, soluble urokinase plasminogen activator receptor, and cathepsins B and H] and for a tumor necrosis factor-alpha cytokine release assay. Ninety-two patients were entered. There was no myelotoxicity. Eighteen patients developed a widespread maculopapular rash, which increased in frequency and severity at doses > or = 300 mg bid. Thirty nine patients developed musculoskeletal side effects, which were related to duration of treatment, not to dose level. Pharmacokinetics were linear, and MMI270 was rapidly absorbed and eliminated with minimal accumulation on chronic dosing. Sustained plasma concentrations in excess of 4 x mean IC(50) for the target enzymes were observed at dose levels > or = 150 mg bid. There were no tumor regressions; however, 19 patients had stable disease for > or = 90 days. There was a dose-response increase of MMP-2 and TIMP-1 with MMI270. Transient effects on the bone resorption markers were detected. MMI270 was generally well tolerated, with adequate plasma levels for target enzyme inhibition. The two main toxicities were rash, resulting in a maximum tolerated dose of 300 mg bid and musculoskeletal side effects. Biological marker data indicate drug effects. The rise in TIMP-1 suggests that a reflex rise in inhibitors could modify the effects of MMI270. The recommended Phase II dose is 300 mg bid.

Why phase III trials of maximal androgen blockade versus castration in M1 prostate cancer rarely show statistically significant differences

BACKGROUND

The meta-analysis of maximal androgen blockade (MAB) concluded that there is no survival advantage of MAB over castration alone. However, the results from the largest trials yield conflicting results.

METHODS

The design and results of three trials were examined.

RESULTS

Most studies were planned to detect an over-optimistic difference in survival and immature data were published. The survival curves show that statistical assumptions are not fulfilled. Excluding from the meta-analysis all trials where a negative impact of disease flare on survival could not be excluded resulted in no difference in survival between MAB and castration.

CONCLUSIONS

Trials of MAB should be planned to detect differences of no more than 5-10% in median survival. The analyses should only be carried out on mature data and should take into account the possibility of a negative impact on survival due to disease flare if no anti-androgen has been given initially with an LH-RH agonist.

The role of active treatment in early prostate cancer

The dramatic increase in the number of patients diagnosed with localized prostate cancer in the last decade presents a difficult challenge for physicians. Because the window of opportunity for cure is short it is vital to begin treatment before the cancer cells invade neighbouring tissues and organs or metastasise to other sites. This pressure of increased patient numbers provided clinicians with the opportunity to investigate other treatment options. New surgical techniques including laparoscopic radical prostatectomy, improving therapeutic radiation by the introduction of conformal radiotherapy, neutron radiation, cryosurgery, high intensity focussed ultrasound (HIF) and the revival of brachytherapy with or without external beam radiation are currently being investigated. The goal of these techniques is to treat localized prostate cancer based on the endpoints of disease specific mortality, no evidence of disease, absent or low levels of prostate-specific antigen (PSA), reduced side-effects, improved quality of life and importantly increased cost-efficacy. It is important to remember however, that watchful waiting and endocrine therapy are still valid therapy options in certain patient groups. The lack of randomized, prospective trials on local treatment of prostate cancer, makes it difficult to compare the efficacy of the different treatments, especially in terms of disease-specific survival. Trials are now in progress but it will be several years before results are available. In the meantime, we need to focus on surrogate endpoints, side effects, quality of life and the cost-efficacy of each treatment. It is also important to ensure that patients are kept informed and up-to-date with any new therapeutic developments.

Maximal androgen blockade: final analysis of EORTC phase III trial 30853. EORTC Genito-Urinary Tract Cancer Cooperative Group and the EORTC Data Center

OBJECTIVES

This prospective, randomized phase III study was initiated to compare the efficacy and side effects of bilateral orchiectomy versus a combination of a luteinizing hormone-releasing hormone agonist depot formulation, goserelin acetate (3.6 mg s.c. once every 4 weeks) and flutamide (250 mg 3 x daily) in patients with metastatic prostate cancer.

METHODS

Relative treatment efficacy was assessed by comparing the two treatment groups with respect to response, time to first progression, progression-free survival, duration of survival and time to death due to malignant disease.

RESULTS

There was a difference in response only with respect to a more frequent decrease to normal of the serum prostate acid phosphatase in patients assigned to maximal androgen blockade treatment. Additionally, maximal androgen blockade treatment showed significantly better results for duration of survival (p = 0.04), time to death due to malignant disease (p = 0.008), time to first progression (p = 0.009) and progression-free survival (p = 0.02). The most frequent side effects for both treatments included hot flushes and gynaecomastia.

CONCLUSIONS

Increased time to progression and duration of survival is achieved by the combination of flutamide and goserelin when compared to bilateral orchiectomy.

Oral paclitaxel and concurrent cyclosporin A: targeting clinically relevant systemic exposure to paclitaxel

Oral paclitaxel is not inherently bioavailable because of the overexpression of P-glycoprotein by intestinal cells and the significant first-pass extraction by cytochrome P450-dependent processes. This study sought to simulate the toxicological and pharmacological profile of a clinically relevant schedule of paclitaxel administered on clinically relevant i.v. dosing schedules in patients with advanced solid malignancies using oral paclitaxel administered with cyclosporin A, an inhibitor of both P-glycoprotein and P450 CYP3A. Nine patients were treated with a single course of oral paclitaxel in its parenteral formulation at a paclitaxel dose level of 180, 360, or 540 mg. Cyclosporin A was administered at a dose of 5 mg/kg p.o. 1 h before and concurrently with oral paclitaxel. Blood sampling was performed to evaluate the pharmacokinetics of paclitaxel, 6-alpha-hydroxypaclitaxel, 3-p-hydroxypaclitaxel, and cyclosporin A. The pharmacokinetic behavior of paclitaxel was characterized using both compartmental and noncompartmental methods. Model-estimated parameters were used to simulate paclitaxel concentrations after once daily and twice daily oral administration of paclitaxel and cyclosporin A. Aside from an unpleasant taste, the oral regimen was well tolerated, and there were no grade 3 or 4 drug-related toxicities. The systemic exposure to paclitaxel, as assessed by maximum plasma concentration (Cmax) and area under the plasma concentration versus time curve (AUC) values, did not increase as the dose of paclitaxel was increased from 180 to 540 mg, and there was substantial interindividual variability (4-6-fold) at each dose level. Mean paclitaxel Cmax values approached plasma concentrations achieved with clinically relevant parenteral dose schedules, averaging 268+/-164 ng/ml. AUC values averaged 3306+/-1977 ng x h/ ml, which was significantly lower than AUC values achieved with clinically relevant i.v. paclitaxel dose schedules. However, computer simulations using pharmacokinetic parameters derived from the present study demonstrated that pharmacodynamically relevant steady-state plasma paclitaxel concentrations of at least 0.06 microM would be achieved after protracted once daily and twice daily dosing with oral paclitaxel and cyclosporin A. Paclitaxel metabolites were detectable in three patients, and the 6-alpha-hydroxypaclitaxel: paclitaxel and 3-p-hydroxypaclitaxel:paclitaxel AUC ratios averaged 0.63 and 0.86, respectively; these values were substantially higher than values reported in patients treated with i.v. paclitaxel. Oral paclitaxel was bioavailable in humans when administered in combination with oral cyclosporin A 5 mg/kg 1 h before and concurrently with paclitaxel treatment, and plasma paclitaxel concentrations achieved with this schedule were biologically relevant and approached concentrations attained with clinically relevant parenteral dose schedules. However, treatment of patients with oral paclitaxel using a single oral dose administration schedule failed to achieve sufficiently high systemic drug exposure and pharmacodynamic effects. In contrast, computer simulations demonstrated that clinically relevant pharmacodynamic effects are likely to be achieved with multiple once daily and twice daily oral paclitaxel-cyclosporin A dosing schedules.

Phase I and pharmacological study of weekly administration of the polyamine synthesis inhibitor SAM 486A (CGP 48 664) in patients with solid tumors. European Organization for Research and Treatment of Cancer Early Clinical Studies Group

A single-agent dose-escalating Phase I and pharmacological study of the polyamine synthesis inhibitor SAM 486A was performed. A dosing regimen of four weekly infusions followed by 2 weeks off therapy was studied. Fifty patients were entered into the study. Dose levels studied were 1.25, 2.5, 5, 8, 16, 32, 48, 70, 110, 170, 270, and 325 mg/m2/week. Pharmacokinetic sampling was done on day 1, and trough samples were taken weekly during the first treatment cycle. Pharmacodynamic sampling was done on days 1 and 22. At 325 mg/m2/week, dose-limiting toxicity was seen (one patient each with grade 4 febrile neutropenia, grade 3 neurotoxicity, and grade 3 hypotension with syncope and T-wave inversions on electrocardiogram). The recommended dose for further testing was set at 270 mg/m2/week. Infusion time was increased from 10 to 180 min due to facial paresthesias and flushing and somnolence. Drug exposure increased linearly with dose. Mean +/- SD t1,2 at 70-325 mg/m2 doses was 61.4+/-26.2 h, with a large volume of distribution at steady state. In peripheral blood leukocytes, a clear relationship between dose and inhibitory effect on S-adenosylmethionine decarboxylase or changes in intracellular polyamine pools was not recorded. SAM 486A can be administered safely using a dosing regimen of four weekly infusions followed by 2 weeks off therapy. The recommended dose for Phase II studies using this regimen is 270 mg/m2/week.

Endocrine treatment in prostate cancer

Over its natural course, prostate cancer is a heterogeneous tumour with a generally slow but constant rate of growth. The androgen dependence of the prostate gland was demonstrated more than half a century ago by the landmark studies of Professor C. Huggins and colleagues. They established that androgens are implicated not only in growth regulation of the normal gland but also in the pathogenesis of prostate cancer, and that this malignant tissue retains some degree of androgen dependence. This concept was supported by studies of symptomatic clinical cancer, with androgen ablative therapy bringing relief to the patient in more than 80% of the cases. The classical treatment consisted of either bilateral orchiectomy, or administration of diethylstilbestrol (DES). Other forms of therapy followed, involving successive waves of new compounds that either withdrew androgen support from the cancer or blocked the androgens from their receptors in the prostate cancer cells. Chronologically, the progestagens can be well recognised, with one in particular: The successful derivative, cyproterone acetate (CPA). There also have been a number of oral vs. parenteral estrogens, the development of the luteinizing hormone-releasing hormone agonists (LH-RHA), the introduction of the non-steroidal anti-androgens characterised by flutamide and casodex, and more recently, the introduction of the LH-RHA. Moreover, there have been multiple possible forms of combination treatment to obtain maximal androgen blockade (MAB). However, no major differences in treatment outcome have been reported during the last 5 decades and most treatment choices have been based on tradition, associated side effects, the preferences of a particular doctor and patient, together with economic considerations. Furthermore, endocrine treatment has never been shown to cure clinical prostate cancer, which consequently has led to initiatives to defer endocrine treatment or to use it intermittently or use it as a form of neo-adjuvant or adjuvant treatment with surgery or radiotherapy. The history of endocrine therapy is replete with clinical trials that do not represent the patient population in general, and these trials share the clinical fact that they ignore the 20% to 30% of all patients who lack an initial response to a given endocrine treatment. Thus, it is no wonder that prognostic factors determine the outcome more than the treatment itself. Important to current endocrine treatment, however, is the shift to earlier stages of prostate cancer at initial diagnosis. Integration of endocrine treatment at this earlier phase in the pathogenesis of prostate cancer will substantially alter the treatment strategy in relation to long-term benefit with regard to survival, associated side effects, and costs. This complex adjustment is enhanced by recent discoveries in the molecular biology of the prostate which show, on the one hand, that the dihydrotestosterone-androgen receptor (DHT-AR) complex is important in the regulation of gene expression, but also that a number of intrinsic factors (e.g., peptide growth regulatory factors) can, through various paracrine, autocrine or intracrine interactions, exercise a major influence on cellular homeostasis and the regulation of prostatic growth.

Finasteride in association with either flutamide or goserelin as combination hormonal therapy in patients with stage M1 carcinoma of the prostate gland. International Prostate Health Council (IPHC) Trial Study Group

BACKGROUND

It was very reasonable to consider that the combination of the 5alpha-reductase, finasteride, and a pure antiandrogen such as flutamide should provide an effective form of maximal androgen blockade (MAB). Finasteride decreases intraprostatic levels of 5alpha-dihydrotestosterone (DHT), and the antiandrogen would restrain the biological action of the residual DHT by interfering with its association with androgen receptor. This form of MAB should sustain the concentration of testosterone in plasma, thereby maintaining sexual function and reasonable quality of life. In order to investigate this, a randomized multicenter phase II clinical trial of patients with untreated M1 cancer of the prostate was developed and undertaken.

METHODS

Patients were randomly allocated to one of three treatment schedules: 1) goserelin, 3.6 mg, s.c., monthly in combination with flutamide, 250 mg., t.i.d. and a placebo, daily, in the image of 2 x 5 mg finasteride; 2) goserelin, 3.6 mg., s.c., monthly in combination with finasteride, 10 mg (2 x 5 mg, daily) and a placebo (t.i.d.) in the image of flutamide; and 3) finasteride, 10 mg (2 x 5 mg, daily) in combination with flutamide (250 mg, t.i.d.). The reduction in concentration of serum PSA at 24 weeks was the endpoint of interest.

RESULTS

Baseline prostate-specific antigen (PSA) levels of the patients in the three groups were very similar. There was a substantial decrease in levels of PSA in the three groups prior to the end of the study, the percent decrease in the groups being: 1) goserelin and flutamide combination, 99.1% (95% Confidence interval (CI), 97.7, 99.6); 2) goserelin and finasteride combination, 98.75% (95% CI, 97.1, 99.5); and 3) finasteride and flutamide combination, 97.6%, 95% CI, 94.5, 98.9). In the Generalized linear model (GLM) analysis, there was no center by treatment group interaction (P = 20), and there were no significant differences between centers (P = 0.059) nor among the three treatment groups (P = 0.16).

CONCLUSIONS

The decrease in levels of PSA in such a group of patients with M1 cancer of the prostate over a 24-week period was surprisingly large, and the differences in these decreased levels between the three treatment arms were remarkably small. There were no apparent differences in bone scan scores, World Health Organization (WHO) performance status, and pain scores between the arms. With regard to sexual function associated with quality of life, there were the understandable difficulties of data collection from patients treated with goserelin.

Quality-adjusted survival (Q-TWiST) analysis of EORTC trial 30853: comparing goserelin acetate and flutamide with bilateral orchiectomy in patients with metastatic prostate cancer. European Organization for Research and Treatment of Cancer

BACKGROUND

The first data analysis of the European Organization for Research and Treatment of Cancer (EORTC) 30853 trial indicated a significantly longer time to progression and duration of survival for the maximal androgen blockade (MAB) treatment arm. However, the MAB treatment arm had a higher frequency of reported side effects.

METHODS

The quality-adjusted survival (Q-TWiST) method was applied to perform a secondary analysis of the EORTC 30853 trial in order to obtain a quality-adjusted survival (QAS) analysis. Two models with different definitions of the progression health state were used for the analysis. In the first model, progression was defined by both objective and subjective criteria, and in the second model only by increase in pain score. The approach was also extended to include an analysis using actual utility scores (Q-tility) of patients in the relevant health states.

RESULTS

Based on Q-tility scores obtained from a separate study of a cohort of prostate cancer patients, the QAS analysis resulted in a 5.2-month difference (95% CI, -1.1; 11.5 months) in favor of zoladex and flutamide, equal in magnitude to the benefit found in the unadjusted survival analysis.

CONCLUSIONS

A QAS analysis such as the Q-TWiST method may be preferred over the unadjusted approach in clinical trials where the health states are clearly distinct, and differ significantly in either duration or quality of life (QOL), or both. The second model, with progression defined as increase in pain score, made no difference to the results in this study because of the small difference in duration of the pain-progression health state between treatment arms. However, Q-tility scores from the separate cross-sectional study that was used in this Q-TWiST analysis showed that a subjective definition of health states better reflects differences in QOL between the health states that the patients experience during follow-up.

Matrix metalloproteinase inhibitors: present achievements and future prospects

Matrix metalloproteinases (MMPs) are a class of structurally related enzymes that function in the degradation of extracellular matrix proteins that constitute the pericellular connective tissue and play an important role in both normal and pathological tissue remodelling. Increased MMP activity is detected in a wide range of cancers and seems correlated to their invasive and metastatic potential. MMPs thus seem an attractive target for both diagnostic and therapeutic purposes. Several synthetic matrix metalloproteinase inhibitors (MMPIs) are currently being developed. Preclinical studies are promising as they suggest inhibition of several steps in the metastatic process. Marimastat is the first MMPI to enter comparative phase III trials after early clinical trials established the safety profile. Clinical trials will need to be specifically designed to optimally evaluate the therapeutic potential of this novel class of cytostatic drugs. Safety studies should consider the markedly different toxicity profile and determine the range of biologically active dosage, while efficacy studies should be performed in selected clinical settings with appropriate end-points. We review the present achievements in preclinical and clinical studies with MMPIs, discuss specific considerations for appropriate study design and reflect on the future prospects of this novel class of agents.

Prospective evaluation plan for randomised trials of prostate cancer screening. The International Prostate Cancer Screening Trial Evaluation Group

To enable pooled analyses of continuing and planned randomised trials of prostate cancer screening, guidelines for minimal data required for such analyses were developed in the recent meeting of the International Prostate Screening Trial Evaluation Group (IPSTEG). The aim of the pooled analysis with data on individual level will be: (a) Estimation of the effect of screening on prostate cancer mortality with greater precision than individual studies (b) Assessment of optimal screening procedures and interval (c) Identification of subgroups within the populations that might receive most benefit from screening (d) Evaluation of the quality of life effects and cost effectiveness of screening. All studies included in the combined analysis share a common core protocol with minimum data requirements. The protocol allows, however, adaptation of the procedures to local circumstances within defined options. It should be noted that the process is continuing and the protocol is subject to evaluation and revision in the meetings of the IPSTEG on a regular basis.