Intramural Research Program of the National Institutes of Health and National Cancer Institute.

Purpose Data suggest that DNA damage by poly (ADP-ribose) polymerase inhibition and/or reduced vascular endothelial growth factor signaling by vascular endothelial growth factor receptor inhibition may complement antitumor activity of immune checkpoint blockade. We hypothesize the programmed death-ligand 1 (PD-L1) inhibitor, durvalumab, olaparib, or cediranib combinations are tolerable and active in recurrent women's cancers. Patients and Methods This phase I study tested durvalumab doublets in parallel 3 + 3 dose escalations. Durvalumab was administered at 10 mg/kg every 2 weeks or 1,500 mg every 4 weeks with either olaparib tablets twice daily or cediranib on two schedules. The primary end point was the recommended phase II dose (RP2D). Response rate and pharmacokinetic analysis were secondary end points. Results Between June 2015 and May 2016, 26 women were enrolled. The RP2D was durvalumab 1,500 mg every 4 weeks with olaparib 300 mg twice a day, or cediranib 20 mg, 5 days on/2 days off. No dose-limiting toxicity was recorded with durvalumab plus olaparib. The cediranib intermittent schedule (n = 6) was examined because of recurrent grade 2 and non-dose-limiting toxicity grade 3 and 4 adverse events (AEs) on the daily schedule (n = 8). Treatment-emergent AEs included hypertension (two of eight), diarrhea (two of eight), pulmonary embolism (two of eight), pulmonary hypertension (one of eight), and lymphopenia (one of eight). Durvalumab plus intermittent cediranib grade 3 and 4 AEs were hypertension (one of six) and fatigue (one of six). Exposure to durvalumab increased cediranib area under the curve and maximum plasma concentration on the daily, but not intermittent, schedules. Two partial responses (≥15 months and ≥ 11 months) and eight stable diseases ≥ 4 months (median, 8 months [4 to 14.5 months]) were seen in patients who received durvalumab plus olaparib, yielding an 83% disease control rate. Six partial responses (≥ 5 to ≥ 8 months) and three stable diseases ≥ 4 months (4 to ≥ 8 months) were seen in 12 evaluable patients who received durvalumab plus cediranib, for a 50% response rate and a 75% disease control rate. Response to therapy was independent of PD-L1 expression. Conclusion To our knowledge, this is the first reported anti-PD-L1 plus olaparib or cediranib combination therapy. The RP2Ds of durvalumab plus olaparib and durvalumab plus intermittent cediranib are tolerable and active. Phase II studies with biomarker evaluation are ongoing.

Purpose: Preclinical studies suggest PARP inhibition (PARPi) induces immunostimulatory micromilieu in ovarian cancer thus complementing activity of immune checkpoint blockade. We conducted a phase II trial of PARPi olaparib and anti-PD-L1 durvalumab and collected paired fresh core biopsies and blood samples to test this hypothesis.Patients and Methods: In a single-center, proof-of-concept phase II study, we enrolled women aged ≥18 with recurrent ovarian cancer. All patients were immune checkpoint inhibitor-na€ ve and had measurable disease per RECISTv1.1, ECOG performance status 0-2, and adequate organ and marrow function. Patients received olaparib 300 mg twice daily and durvalumab 1,500 mg intravenously every 4 weeks until disease progression, unacceptable toxicity, or withdrawal of consent. Primary endpoint was overall response rate (ORR). Secondary objectives were safety and progression-free survival (PFS). Translational objectives included biomarker evaluation for relationships with clinical response and immunomodulatory effects by treatment.Results: Thirty-five patients with ovarian cancer [median, four prior therapies (IQR, 2-5.5), predominantly platinum-resistant (86%), BRCA wild-type (77%)] received at least one full cycle of treatment. ORR was 14% [5/35; 95% confidence interval (CI), 4.8%-30.3%]. Disease control rate (PRþSD) was 71% (25/35; 95% CI, 53.7%-85.4%). Treatment enhanced IFNg and CXCL9/CXCL10 expression, systemic IFNg/TNFa production, and tumorinfiltrating lymphocytes, indicating an immunostimulatory environment. Increased IFNg production was associated with improved PFS [HR, 0.37 (95% CI, 0.16-0.87), P ¼ 0.023], while elevated VEGFR3 levels were associated with worse PFS (HR, 3.22 (95% CI, 1.23-8.40), P ¼ 0.017].Conclusions: The PARPi and anti-PD-L1 combination showed modest clinical activity in recurrent ovarian cancer. Our correlative study results suggest immunomodulatory effects by olaparib/ durvalumab in patients and indicate that VEGF/VEGFR pathway blockade would be necessary for improved efficacy of the combination.

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The single agent activity of PARP inhibitors (PARPi) in germline BRCA mutated (gBRCAm) breast and ovarian cancer suggests untapped potential for this new class of drug in breast cancer. The US Food and Drug Administration has approved three PARPi (olaparib, rucaparib, and niraparib) so far to treat certain ovarian cancers, including those with gBRCAm and olaparib for treatment of gBRCAm breast cancers. Several PARPi are now under clinical development for breast cancer in the various treatment settings. Recently, two phase III trials of olaparib (OlympiaD) and talazoparib (EMBRACA) demonstrated 3-month progression-free survival improvement with PARPi compared to physician's choice single agent chemotherapy in metastatic gBRCAm breast cancer. To date, PARPi seems less efficacious in metastatic breast cancer patients than those with BRCA mutated platinum-sensitive recurrent ovarian cancer, perhaps reflecting the biologic heterogeneity and low somatic BRCA mutation rate in breast cancer. The use of PARPi is gradually evolving, including combination strategies with chemotherapy, targeted agents, radiotherapy, or immunotherapy in women with and without gBRCAm. The role of predictive biomarkers, including molecular signatures and homologous recombination repair deficiency scores based on loss of heterozygosity and other structural genomic aberrations, will be crucial to identify a subgroup of patients who may have benefit from PARPi. An improved understanding of the mechanisms underlying PARPi clinical resistance will also be important to enable the development of new approaches to increase efficacy. This is a field rich in opportunity, and the coming years should see a better understanding of which breast cancer patients we should treat with PARPi and where these agents should come in over the course of treatment.

Background Strategies to improve activity of immune checkpoint inhibitors are needed. We hypothesized enhanced DNA damage by olaparib, a PARP inhibitor, and reduced VEGF signaling by cediranib, a VEGFR1–3 inhibitor, would complement anti-tumor activity of durvalumab, a PD-L1 inhibitor, and the 3-drug combination would be tolerable. Methods This phase 1 study tested the 3-drug combination in a 3 + 3 dose escalation. Cediranib was taken intermittently (5 days on/2 days off) at 15 or 20 mg (dose levels 1 and 2, respectively) with durvalumab 1500 mg IV every 4 weeks, and olaparib tablets 300 mg twice daily. The primary end point was the recommended phase 2 dose (RP2D). Response rate, pharmacokinetic (PK), and correlative analyses were secondary endpoints. Results Nine patients (7 ovarian/1 endometrial/1 triple negative breast cancers, median 3 prior therapies [2–6]) were treated. Grade 3/4 adverse events include hypertension (1/9), anemia (1/9) and lymphopenia (3/9). No patients experienced dose limiting toxicities. The RP2D is cediranib, 20 mg (5 days on/2 days off) with full doses of durvalumab and olaparib. Four patients had partial responses (44%) and 3 had stable disease lasting ≥6 months, yielding a 67% clinical benefit rate. No significant effects on olaparib or cediranib PK parameters from the presence of durvalumab, or the co-administration of cediranib or olaparib were identified. Tumoral PD-L1 expression correlated with clinical benefit but cytokines and peripheral immune subsets did not. Conclusions The RP2D is tolerable and has preliminary activity in recurrent women’s cancers. A phase 2 expansion study is now enrolling for recurrent ovarian cancer patients. Trial registration ClinicalTrials.gov identifier: NCT02484404 . Registered June 29, 2015. Electronic supplementary material The online version of this article (10.1186/s40425-019-0680-3) contains supplementary material, which is available to authorized users.

Background: Brain metastases (BrM) incidence is 25% to 50% in women with advanced human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Radiation and surgery are currently the main local treatment approaches for central nervous system (CNS) metastases. Systemic anti-HER2 therapy following a diagnosis of BrM improves outcomes. Previous preclinical data has helped elucidate HER2 brain trophism, the blood-brain/blood-tumor barrier(s), and the brain tumor microenvironment, all of which can lead to development of novel therapeutic options. Recent findings: Several anti-HER2 agents are currently available and reviewed here, some of which have recently shown promising effects in BrM patients, specifically. New strategies driven by and focusing on brain metastasis-specific genomics, immunotherapy, and preventive strategies have shown promising results and are under development. Conclusions: The field of HER2+ breast cancer, particularly for BrM, continues to evolve as new therapeutic strategies show promising results in recent clinical trials. Increasing inclusion of patients with BrM in clinical studies, and a focus on assessing their outcomes both intracranially and extracranially, is changing the landscape for patients with HER2+ CNS metastases by demonstrating the ability of newer agents to improve outcomes.

• Monotherapy with prexasertib demonstrated modest activity in BRCA wild-type, recurrent triple-negative breast cancer, highlighting the unmet need for combination treatment strategies. • Neutropenia, anemia, and thrombocytopenia are common with the use of prexasertib but are manageable with supportive care measures. Prophylactic use of granulocyte colony stimulating factor should be considered to avoid dose reductions or treatment delays. • Pharmacodynamic studies showed prexasertib treatment induced DNA damage in peripheral immune cells.