BRCA1- and BRCA2-related mutations: therapeutic implications in ovarian cancer

Ovarian cancer is the deadliest among gynecologic cancers. Hereditary cancer related to BRCA1/2 gene mutations account for ~10%-12% of ovarian cancers. The BRCA1/2 proteins are important in homologous recombination (HR) repair of DNA. Patients with BRCA1/2 mutations have been reported to have improved chemosensitivity to platinum agents, longer disease-free intervals, and longer survivals than nonhereditary counterparts. Recent interest in poly(ADP-ribosyl) polymerase (PARP) proteins which are key components of base excision repair, has led to the development of PARP inhibitors; tumors arising in BRCA1/2 mutation carriers and/or with HR deficiency (HRD) are particularly sensitive to the action of these drugs. As 60%-80% of all advanced ovarian cancers are high-grade serous type, exhibiting HRD in at least 50% (referred as BRCAness) future antitumor strategies may depend on identifying these defects through molecular testing. Once HRD becomes amenable to routine testing, a larger group of ovarian cancer patients than are currently considered for PARP inhibitor trials, may benefit from such targeted therapy.

Phase II study of bevacizumab with liposomal doxorubicin for patients with platinum- and taxane-resistant ovarian cancer

BACKGROUND

Suppression of neoangiogenesis and pegylated liposomal doxorubicin (PLD) each contribute to the management of platinum-resistant/refractory ovarian cancer. The aim of this study is to test the combination of bevacizumab and PLD in women with resistant or refractory ovarian cancer.

METHODS

Eligibility criteria were no more than two prior treatments with platinum-containing regimens and one additional regimen, without anthracyclines. Treatment was administered every 3 weeks (bevacizumab 15 mg/kg beginning on cycle 2 and PLD 30 mg/m(2)). The primary end point was progression-free survival (PFS) at 6 months; the secondary end points included side-effects, overall response rates (ORR) and survival (OS).

RESULTS

Forty-six patients were enrolled. The average number of courses administered was 7. The median PFS was 6.6 months (range 1-24.6 months) according to Gynecologic Cancer Intergroup Committee (GCIC) criteria and 7.8 months (range 2-13.3 months) according to Response Evaluation Criteria in Solid Tumors (RECIST). The median OS was 33.2 months (range 3-37.5+ months). The ORR was 30.2% [95% confidence interval (CI) 17.2-46.1] and the clinical benefit rate (CBR) was 86.1% (95% CI 72.1-94.7). Adverse events included mucosal and dermal erosions (30% grade 3) and asymptomatic cardiac dysfunction. Additional toxic effects included hypertension, headache, renal dysfunction and proteinuria, wound healing delay, and one episode each of central nervous system (CNS) ischemia and hemolytic uremic syndrome.

CONCLUSION

PLD with bevacizumab has improved activity in recurrent ovarian cancer with increased toxicity.

Pegylated liposomal doxorubicin (PLD) with bevacizumab (B) in second-line treatment of ovarian cancer (OC): Pharmacokinetics (PK), safety, and preliminary outcome results

5548

Background: PLD activity in platinum-resistant OC is modest. B, with its activity in platinum(Plat)-sensitive and Plat-resistant patients (pts), has not been combined with PLD. PLD intratumoral concentrations, if affected by B, might be reflected in PLD PK. This phase II study of PLD + B was started in 2007 to accrue 48 pts, unless 4 serious (> grade 3) adverse events (AEs) supervened. Methods: Improvement in progression-free survival (PFS) at 6 m from 25 to 40% at 6 m in Plat-resistant OC is primary endpoint. PK of PLD alone at 1h, d 7 and d 21 (cycle 1) vs with B (cycle 2), safety, and response rates (RECIST and CA125 criteria) were secondary endpoints. Dosing: PLD 30 mg/m2 followed by B 15 mg/kg on cycles 2–7 (with option to continue) d 1 every 3 w. Pts recurring within 6 m of platinum-based treatment for OC after < 3 prior regimens (but no PLD or B) were eligible. Exclusions: bowel obstruction, prior perforation, uncontrolled hypertension, or vascular disease. Hematologic, mucocutaneous and renal toxicities were evaluated prior to each cycle, MUGA scans every third cycle; disease status by CA125 and/or RECIST every third cycle. Results: 21 of 24 pts enrolled to date are evaluable. Median age is 65, range 52–83; most had 2 prior chemotherapy regimens. Median 6 (range 3–12) cycles were given with 6 off study with progression at 3–7 cycles. RECIST and CA125 responses are under review; in 11 pts with baseline CA125 of > 40 IU/mL, median increase was 31% by cycle 2; later falling to -57%. AEs did not exceed grade 3; hand-foot syndrome led to PLD dose reduction in 8 pts (33%); asymptomatic decreases in left ventricular ejection fraction (LVEF) >10% in 3 pts were noted, with treatment discontinuation in 1. The mean (±SEM) secondary PK parameter estimates for Cmax, AUC, and elimination half life were 4.5 ± 0.5 ug/mL, 651.7 ± 61 ug/mL x h, and 93.3 ± 19.7 h, respectively. Conclusions: Cycles 1 and 2 PLD PK do not differ. PLD + B is tolerable with PLD dose modifications. Declines in LVEF in 1 institution have uncertain causality. Midway into the trial, safety and time on study encourage completion for study primary endpoint.

[Table: see text]