A phase 1 study of veliparib (ABT-888) plus weekly carboplatin and paclitaxel in advanced solid malignancies, with an expansion cohort in triple negative breast cancer (TNBC) (ETCTN 8620).

BACKGROUND: Veliparib is a poly-ADP-ribose polymerase (PARP) inhibitor, and it has clinical activity with every 3 weeks carboplatin and paclitaxel. In breast cancer, weekly paclitaxel is associated with improved overall survival. We aimed to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of veliparib with weekly carboplatin and paclitaxel as well as safety, pharmacokinetics, and preliminary clinical activity in triple negative breast cancer (TNBC). METHODS: Patients with locally advanced/metastatic solid tumors and adequate organ function were eligible. A standard 3 + 3 dose-escalation design was followed by a TNBC expansion cohort. Veliparib doses ranging from 50 to 200 mg orally bid were tested with carboplatin (AUC 2) and paclitaxel (80 mg/m2) given weekly in a 21-day cycle. Adverse events (AE) were evaluated by CTCAE v4.0, and objective response rate (ORR) was determined by RECIST 1.1. RESULTS: Thirty patients were enrolled, of whom 22 had TNBC. Two dose-limiting toxicities were observed. The RP2D was determined to be 150 mg PO bid veliparib with weekly carboplatin and paclitaxel 2 weeks on, 1 week off, based on hematologic toxicity requiring dose reduction in the first 5 cycles of treatment. The most common grade 3/4 AEs included neutropenia, anemia, and thrombocytopenia. PK parameters of veliparib were comparable to single-agent veliparib. In 23 patients with evaluable disease, the ORR was 65%. In 19 patients with TNBC with evaluable disease, the ORR was 63%. CONCLUSION: Veliparib can be safely combined with weekly paclitaxel and carboplatin, and this triplet combination has promising clinical activity.

Overcoming Taxane Resistance: Preclinical and Phase 1 Studies of Relacorilant, a Selective Glucocorticoid Receptor Modulator, with Nab-Paclitaxel in Solid Tumors.

PURPOSE: Chemotherapy resistance remains a major problem in many solid tumors, including breast, ovarian, and pancreatic cancer. Glucocorticoids are one potential driver of chemotherapy resistance as they can mediate tumor progression via induction of cell-survival pathways. We investigated whether combining the selective glucocorticoid receptor (GR) modulator relacorilant with taxanes can enhance antitumor activity. PATIENTS AND METHODS: The effect of relacorilant on paclitaxel efficacy was assessed in OVCAR5 cells in vitro and in the MIA PaCa-2 xenograft. A phase 1 study of patients with advanced solid tumors was conducted to determine the recommended phase 2 dose of relacorilant + nab-paclitaxel. RESULTS: In OVCAR5 cells, relacorilant reversed the deleterious effects of glucocorticoids on paclitaxel efficacy (P < 0.001). Compared with paclitaxel alone, relacorilant + paclitaxel reduced tumor growth and slowed time to progression in xenograft models (both P < 0.0001). In the heavily pretreated phase 1 population [median (range) of prior regimens: 3 (1-8), prior taxane in 75.3% (55/73)], 33% (19/57) of response-evaluable patients achieved durable disease control (≥16 weeks) with relacorilant + nab-paclitaxel and 28.6% (12/42) experienced longer duration of benefit than on prior taxane (up to 6.4×). The most common dose-limiting toxicity of the combination was neutropenia, which was manageable with prophylactic G-CSF. Clinical benefit with relacorilant + nab-paclitaxel was also associated with GR-regulated transcript-level changes in a panel of GR-controlled genes. CONCLUSIONS: The observed preclinical, clinical, and GR-specific pharmacodynamic responses demonstrate that selective GR modulation with relacorilant combined with nab-paclitaxel may promote chemotherapy response and is tolerable. Further evaluation of this combination in tumor types responsive to taxanes is ongoing.

Infigratinib (BGJ398) in previously treated patients with advanced or metastatic cholangiocarcinoma with FGFR2 fusions or rearrangements: mature results from a multicentre, open-label, single-arm, phase 2 study.

BACKGROUND: Treatment options are sparse for patients with advanced cholangiocarcinoma after progression on first-line gemcitabine-based therapy. FGFR2 fusions or rearrangements occur in 10-16% of patients with intrahepatic cholangiocarcinoma. Infigratinib is a selective, ATP-competitive inhibitor of fibroblast growth factor receptors. We aimed to evaluate the antitumour activity of infigratinib in patients with locally advanced or metastatic cholangiocarcinoma, FGFR2 alterations, and previous gemcitabine-based treatment. METHODS: This multicentre, open-label, single-arm, phase 2 study recruited patients from 18 academic centres and hospitals in the USA, Belgium, Spain, Germany, Singapore, Taiwan, and Thailand. Eligible participants were aged 18 years or older, had histologically or cytologically confirmed, locally advanced or metastatic cholangiocarcinoma and FGFR2 fusions or rearrangements, and were previously treated with at least one gemcitabine-containing regimen. Patients received 125 mg of oral infigratinib once daily for 21 days of 28-day cycles until disease progression, intolerance, withdrawal of consent, or death. Radiological tumour evaluation was done at baseline and every 8 weeks until disease progression via CT or MRI of the chest, abdomen, and pelvis. The primary endpoint was objective response rate, defined as the proportion of patients with a best overall response of a confirmed complete or partial response, as assessed by blinded independent central review (BICR) according to Response Evaluation Criteria in Solid Tumors, version 1.1. The primary outcome and safety were analysed in the full analysis set, which comprised all patients who received at least one dose of infigratinib. This trial is registered with ClinicalTrials.gov, NCT02150967, and is ongoing. FINDINGS: Between June 23, 2014, and March 31, 2020, 122 patients were enrolled into our study, of whom 108 with FGFR2 fusions or rearrangements received at least one dose of infigratinib and comprised the full analysis set. After a median follow-up of 10·6 months (IQR 6·2-15·6), the BICR-assessed objective response rate was 23·1% (95% CI 15·6-32·2; 25 of 108 patients), with one confirmed complete response in a patient who only had non-target lesions identified at baseline and 24 partial responses. The most common treatment-emergent adverse events of any grade were hyperphosphataemia (n=83), stomatitis (n=59), fatigue (n=43), and alopecia (n=41). The most common ocular toxicity was dry eyes (n=37). Central serous retinopathy-like and retinal pigment epithelial detachment-like events occurred in 18 (17%) patients, of which ten (9%) were grade 1, seven (6%) were grade 2, and one (1%) was grade 3. There were no treatment-related deaths. INTERPRETATION: Infigratinib has promising clinical activity and a manageable adverse event profile in previously treated patients with locally advanced or metastatic cholangiocarcinoma harbouring FGFR2 gene fusions or rearrangements, and so represents a potential new therapeutic option in this setting. FUNDING: QED Therapeutics and Novartis.

Exposure-response analysis to inform the optimal dose of veliparib in combination with carboplatin and paclitaxel in BRCA-mutated advanced breast cancer patients.

PURPOSE: Veliparib, a poly(ADP-ribose)-polymerase (PARP) 1 and 2 enzyme inhibitor, was administered at 120 mg twice daily (BID) for 7 days in a 21-day cycle with carboplatin/paclitaxel in the Phase 2 BROCADE study in patients with BRCA-deficient recurrent or metastatic breast cancer, a dose based on Phase 1 results. Population pharmacokinetic (PK) and exposure-response analyses were undertaken to retrospectively evaluate whether an optimal dose was used in BROCADE. METHODS: A population PK analysis was performed using data from 168 patients in BROCADE along with data from 288 subjects in another 5 studies. The relationship between veliparib exposure and efficacy variables (including progression-free survival [PFS] and objective response rate [ORR]) and safety variables (selected grade 3 or greater hematological adverse events) were analyzed. RESULTS: Veliparib PK parameters in BROCADE were comparable to the previous studies. Creatinine clearance on veliparib apparent clearance and lean body weight on veliparib apparent volume of distribution were identified as covariates. A trend of better efficacy (PFS and ORR) in the veliparib arm compared to placebo was observed. However, veliparib exposure-efficacy response was relatively flat with higher veliparib exposures not showing better efficacy. No exposure-response relationship was observed in grade 3 or greater hematological toxicities (anemia, neutropenia, leukopenia, and thrombocytopenia). CONCLUSIONS: The exposure-response analysis suggested that intermittent 7-day veliparib 120 mg BID dosing in a 21-day cycle provided additional efficacy without meaningfully impacting the safety and tolerability when co-administered with carboplatin and paclitaxel in patients with BRCA-deficient breast cancer. A higher dose of veliparib is unlikely to provide greater benefit in this combination in patients with BRCA-deficient recurrent or metastatic breast cancer.

A phase 1 dose-escalation study of veliparib with bimonthly FOLFIRI in patients with advanced solid tumours.

BACKGROUND: Veliparib is a potent poly(ADP-ribose) polymerase inhibitor. This phase 1 study aimed to establish the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of veliparib combined with various FOLFIRI regimens in patients with solid tumours. METHODS: Patients received veliparib (10-270 mg BID, days 1-5, 15-19) and FOLFIRI (days 1-3, 15-17) in three regimens containing 5-fluorouracil 2,400 mg/m2: irinotecan 150 mg/m2 and folinic acid 400 mg/m2 (part 1); irinotecan 180 mg/m2, folinic acid 400 mg/m2, and 5-fluorouracil 400 mg/m2 bolus (part 2), or irinotecan 180 mg/m2 (part 3). The RP2D was further evaluated in safety expansion cohorts. Preliminary antitumour activity was also assessed. RESULTS: Ninety-two patients received ≥1 veliparib dose. MTD was not reached; RP2D was set at 200 mg BID veliparib plus FOLFIRI (without 5-fluorouracil bolus). Most common treatment-emergent adverse events were neutropenia (66.3%), diarrhoea, and nausea (60.9% each). Dose-limiting toxicities (n = 4) were grade 3 gastritis and grade 4 neutropenia and febrile neutropenia. Veliparib exposure was dose-proportional, with no effects on the pharmacokinetics of FOLFIRI components. Fifteen patients had a partial response (objective response rate, 17.6%). CONCLUSIONS: The acceptable safety profile and preliminary antitumour activity of veliparib plus FOLFIRI support further evaluation of this combination.

A phase 1 study of PARP-inhibitor ABT-767 in advanced solid tumors with BRCA1/2 mutations and high-grade serous ovarian, fallopian tube, or primary peritoneal cancer.

Purpose This phase 1 study examined safety, pharmacokinetics (PK), and efficacy of the poly(ADP-ribose) polymerase (PARP) inhibitor ABT-767 in patients with advanced solid tumors and BRCA1/2 mutations or with high-grade serous ovarian, fallopian tube, or primary peritoneal cancer. Methods Patients received ABT-767 monotherapy orally until disease progression or unacceptable toxicity. Dose was escalated from 20 mg once daily to 500 mg twice daily (BID). Dose-limiting toxicities, recommended phase 2 dose (RP2D), food effect, objective response rate, and biomarkers predicting response were determined. Results Ninety-three patients were treated with ABT-767; 80 had a primary diagnosis of ovarian cancer. ABT-767 demonstrated dose-proportional PK up to 500 mg BID and half-life of ~2 h. Food had no effect on ABT-767 bioavailability. Most common grade 3/4 treatment-related adverse events were nausea, fatigue, decreased appetite, and anemia. Anemia showed dose-dependent increase. RP2D was 400 mg BID. Objective response rate by RECIST 1.1 was 21% (17/80) in all evaluable patients and 20% (14/71) in evaluable patients with ovarian cancer. Response rate by RECIST 1.1 and/or CA-125 was 30% (24/80) in patients with ovarian cancer. Mutations in BRCA1 or BRCA2, homologous recombination deficiency (HRD), and platinum sensitivity were associated with tumor response. Median progression-free survival was longer for HRD positive (6.7 months) versus HRD negative patients (1.8 months) with ovarian cancer. Conclusions ABT-767 had an acceptable safety profile up to the established RP2D of 400 mg BID and dose-proportional PK. Patients with BRCA1 or BRCA2 mutation, HRD positivity, and platinum sensitivity were more sensitive to ABT-767.

Population pharmacokinetics of ABT-767 in BRCA1 or BRCA2 mutation carriers with advanced solid tumors or in subjects with high grade serous ovarian, primary peritoneal or fallopian tube cancer.

PURPOSE: The objective of the manuscript is to describe the development of a population pharmacokinetic model for ABT-767, a potent and orally bioavailable inhibitor of poly (ADP-ribose) polymerase enzyme, and to evaluate the potential influence of patient demographics and baseline covariates on the pharmacokinetics of ABT-767. METHODS: A total of 1809 plasma ABT-767 concentrations from 90 subjects were used for population pharmacokinetic modeling. Covariates screened for influence on pharmacokinetic parameters were body weight, lean body weight, body surface area, albumin, creatinine clearance, serum creatinine, liver function tests, and age. The effect of food on absorption and bioavailability were also evaluated. Model validation was performed using bootstrap analysis and visual predictive check. RESULTS: A two-compartment model with firstorder absorption adequately described the pharmacokinetics of ABT-767. The population estimates of apparent clearance from central compartment (CL/F), volume of central compartment (V c/F), and absorption rate constant (k a) were 7.34 L/h, 25.8 L, 1.45 h-1, respectively. The estimates of interindividual variabilities (%CV) in CL/F, V c/F, and k a were 40.4, 40.5, and 53.8%, respectively. The k a was influenced by food. Albumin on CL/F was a statistically significant covariate; however, it explained only 8% of the variability in the pharmacokinetics of ABT-767. CONCLUSIONS: Albumin on CL/F was the only statistically significant baseline covariate affecting ABT-767 pharmacokinetics, but it only explained a fraction of the pharmacokinetic variability. Dosage adjustments based on body size, age, or mild renal impairment are not needed for ABT-767. The developed model will be used to evaluate ABT-767 exposure-response analyses and to perform simulations for different dose and dosing regimens.