Regorafenib plus Vincristine and Irinotecan in Pediatric Patients with Recurrent/Refractory Solid Tumors: An Innovative Therapy for Children with Cancer Study.

PURPOSE: This phase Ib study defined the safety, MTD, and recommended phase II dose (RP2D) of regorafenib combined with vincristine and irinotecan (VI). Secondary objectives were evaluation of antitumor activity and pharmacokinetics (PK) of regorafenib and irinotecan. PATIENTS AND METHODS: Patients aged 6 months to <18 years with relapsed/refractory solid malignancies [≥50% with rhabdomyosarcoma (RMS)] received regorafenib (starting dose 72 mg/m2/day) concomitantly or sequentially with vincristine 1.5 mg/m2 on days 1 and 8, and irinotecan 50 mg/m2 on days 1-5 (21-day cycle). Adverse events (AE) and tumor response were assessed. PK (regorafenib and irinotecan) were evaluated using a population PK model. RESULTS: We enrolled 21 patients [median age, 10 years; 12, RMS; 5, Ewing sarcoma (EWS)]. The MTD/RP2D of regorafenib in the sequential schedule was 82 mg/m2. The concomitant dosing schedule was discontinued because of dose-limiting toxicities in 2 of 2 patients treated. Most common grade 3/4 (>30% of patients) AEs were neutropenia, anemia, thrombocytopenia, and leukopenia. The overall response rate was 48% and disease control rate [complete response (CR)/partial response/stable disease/non-CR/non-progressive disease] was 86%. Median progression-free survival was 7.0 months [95% confidence interval (CI), 2.9-14.8] and median overall survival was 8.7 months (95% CI, 5.5-16.3). When combined with VI, regorafenib PK was similar to single-agent PK in children and adults (treated with regorafenib 160 mg/day). CONCLUSIONS: Regorafenib can be combined sequentially with standard dose VI in pediatric patients with relapsed/refractory solid tumors with appropriate dose modifications. Clinical activity was observed in patients with RMS and EWS (ClinicalTrials.gov NCT02085148).

Regorafenib plus nivolumab in patients with mismatch repair-proficient/microsatellite stable metastatic colorectal cancer: a single-arm, open-label, multicentre phase 2 study.

Background: Anti-programmed cell death protein 1 antibodies plus multikinase inhibitors have shown encouraging activity in several tumour types, including colorectal cancer. This study assessed regorafenib plus nivolumab in patients with microsatellite stable/mismatch repair-proficient metastatic colorectal cancer. Methods: This single-arm, open-label, multicentre phase 2 study enrolled adults from 13 sites in the USA with previously treated advanced microsatellite stable/mismatch repair-proficient metastatic colorectal cancer. Eligible patients had known extended RAS and BRAF status, progression or intolerance to no more than two (for extended RAS mutant) or three (for extended RAS wild type) lines of systemic chemotherapy and an Eastern Cooperative Oncology Group performance status of 0 or 1. Regorafenib 80 mg/day was administered orally for 3 weeks on/1 week off (increased to 120 mg/day if 80 mg/day was well tolerated) with intravenous nivolumab 480 mg every 4 weeks. Primary endpoint was objective response rate. Secondary endpoints included safety, overall survival, and progression-free survival. Exploratory endpoints included biomarkers associated with antitumour activity. Patients who received at least one dose of study intervention were included in the efficacy and safety analyses. Tumour assessments were carried out every 8 weeks for the first year, and every 12 weeks thereafter until progressive disease/end of the study, and objective response rate was analysed after all patients had met the criteria for primary completion of five post-baseline scans and either 10-months' follow-up or drop out. This trial is registered with ClinicalTrials.gov, number NCT04126733. Findings: Between 14 October 2019 and 14 January 2020, 94 patients were enrolled, 70 received treatment. Five patients had a partial response, yielding an objective response rate of 7% (95% CI 2.4-15.9; p = 0.27). All responders had no liver metastases at baseline. Median overall survival (data immature) and progression-free survival were 11.9 months (95% CI 7.0-not evaluable) and 1.8 months (95% CI 1.8-2.4), respectively. Most patients (97%, 68/70) experienced a treatment-related adverse event; 51% were grade 1 or 2, 40% were grade 3, 3% were grade 4, and 3% were grade 5. The most common (≥20%) events were fatigue (26/70), palmar-plantar erythrodysesthesia syndrome (19/70), maculopapular rash (17/70), increased blood bilirubin (14/70), and decreased appetite (14/70). Higher baseline expression of tumour biomarkers of immune sensitivity correlated with antitumour activity. Interpretation: Further studies are warranted to identify subgroups of patients with clinical characteristics or biomarkers that would benefit most from treatment with regorafenib plus nivolumab. Funding: Bayer/Bristol Myers Squibb.

Phase 1b study of the BET protein inhibitor RO6870810 with venetoclax and rituximab in patients with diffuse large B-cell lymphoma.

Bromodomain and extraterminal (BET) proteins are transcriptional activators for multiple oncogenic processes in diffuse large B-cell lymphoma (DLBCL), including MYC, BCL2, E2F, and toll-like receptor signaling. We report results of a phase 1b dose-escalation study of the novel, subcutaneous BET inhibitor RO6870810 (RO) combined with the BCL-2 inhibitor venetoclax, and rituximab, in recurrent/refractory DLBCL. RO was delivered for 14 days of a 21-day cycle, whereas venetoclax was delivered continuously. A 3 + 3 escalation design was used to determine the safety of the RO+venetoclax doublet; rituximab was added in later cohorts. Thirty-nine patients were treated with a median of 2.8 cycles (range, 1-11). Dose-limiting toxicities included grade 3 febrile neutropenia, grade 4 diarrhea, and hypomagnesemia for the doublet; and grade 3 hyperbilirubinemia and grade 4 diarrhea when rituximab was added. The doublet maximum tolerated dose (MTD) was determined to be 0.65 mg/kg RO+600 mg venetoclax; for RO+venetoclax+rituximab, the MTDs were 0.45 mg/kg, 600 mg, and 375 mg/m2, respectively. The most frequent grade 3 and 4 adverse events were neutropenia (28%) and anemia and thrombocytopenia (23% each). Responses were seen in all cohorts and molecular subtypes. Sustained decreases in CD11b on monocytes indicated pharmacodynamic activity of RO. Overall response rate according to modified Lugano criteria was 38.5%; 48% of responses lasted for ≥180 days. Complete response was observed in 8 patients (20.5%). Optimization of the treatment schedule and a better understanding of predictors of response would be needed to support broader clinical use. This trial is registered on www.clinicaltrials.gov as NCT03255096.

A dose escalation study of RO6870810/TEN-10 in patients with acute myeloid leukemia and myelodysplastic syndrome.

Bromodomain and extra-terminal (BET) proteins can drive carcinogenesis and therapy resistance. RO6870810 (RO) is a novel, small-molecule BET inhibitor. We conducted a study in 32 patients with relapsed/refractory acute myeloid leukemia and hypomethylating agent-refractory myelodysplastic syndrome (NCT02308761). Pharmacodynamic assessments showed decreases in CD11b in peripheral blood mononuclear cells at RO concentrations above 120 ng/mL. Treatment emergent adverse events were generally mild and the most frequent were fatigue, injection site reactions, diarrhea, decreased appetite and nausea. There were no treatment-related deaths. Potential drug-related dose limiting toxicities included decreased appetite, congestive cardiac failure, hypertension, fatigue, increased conjugated bilirubin and increased gamma glutamyltransferase. One AML patient achieved complete remission after withdrawal from study. Eleven AML patients experienced SD. For AML, the median OS was 72.0 days. For MDS, two patients experienced SD. Further development of RO as monotherapy was discontinued due to lack of efficacy, but combinations with other agents are under consideration.

Assessing the translational value of pre-clinical studies for clinical response rate in oncology: an exploratory investigation of 42 FDA-approved small-molecule targeted anticancer drugs.

PURPOSE: To assess the translational value of anticancer preclinical models, we retrospectively investigated the relationships between preclinical data and clinical response rate for 42 small-molecule targeted anticancer drugs approved by the US FDA from 2001 to 2018. METHODS: For 42 FDA-approved drugs, relevant pre-clinical (IC50, mouse PK/efficacy) and clinical (overall response rates [ORR], PK) data were extracted from the public domain. Relationships were investigated overall and separately by mechanism of action and solid vs liquid tumors. Binomial-normal regression analysis was performed using R. RESULTS: A significant correlation was found between the ratio of free human average plasma concentration (hCave) at the approved clinical dose to biochemical IC50 and ORR for kinase inhibitors with solid tumor indications (KIST). We also identified that, for KIST, the ratios of (i) total and (ii) free human-to-mouse average plasma concentration at efficacious doses were correlated to ORR ((i) R2 = 0.72, n = 10; (ii) R2 = 0.78, n = 10)). CONCLUSION: Relationships were identified for ratios of efficacious clinical exposures to typical preclinical pharmacology data and ORR for KIST in this retrospective analysis. Although the obtained datasets are limited, the relationships demonstrate that a systemic exposure relative to established pre-clinical pharmacology experiments for an investigational KIST could be used as a reference to assess if desired efficacy could be achieved. This approach may assist selection of the recommended phase 2 dose (RP2D) of an investigational drug.

Characterization of the transmembrane transport and absolute bioavailability of the HCV protease inhibitor danoprevir.

BACKGROUND AND OBJECTIVES: Understanding transmembrane transport provides a more complete understanding of the pharmacokinetics of a drug and mechanistic explanations for drug-drug interactions. Here, the transmembrane transport of danoprevir (hepatitis C virus protease inhibitor) and the effects of ritonavir and ciclosporin on transmembrane transport of danoprevir were evaluated and clinical pharmacokinetic studies of danoprevir co-administered with/without ritonavir and ciclosporin were conducted. METHODS: Transcellular transport of danoprevir was evaluated in Lewis lung cancer porcine kidney, Madin-Darby canine kidney, or Chinese hamster ovary cells transfected with human transport proteins, and in human hepatocytes. The pharmacokinetics of intravenous and oral danoprevir administered with/without ritonavir, and the impact of ciclosporin on danoprevir pharmacokinetics were evaluated in randomized, open-label, crossover studies in healthy subjects. RESULTS: Danoprevir transport in vitro involved organic anion transporting polypeptide (OATP) 1B1, OATP1B3, P-glycoprotein, and multidrug resistance protein-2, but not breast cancer resistance protein. Ritonavir and ciclosporin inhibited transport of danoprevir by human hepatocytes. The pharmacokinetics of intravenous danoprevir 6 mg were not altered by oral ritonavir 100 mg. In contrast, exposure to oral danoprevir 100 mg increased two- to threefold when co-administered with ritonavir. Absolute bioavailability of danoprevir 100 mg was low (1.15%), but increased more than threefold (3.86%) when co-administered with ritonavir. Oral ciclosporin 100 mg increased exposure to intravenous danoprevir 2 mg and oral ritonavir 100 mg. CONCLUSION: Collectively, these studies provide insight into the transmembrane transport and pharmacokinetics of danoprevir and the mechanisms that underlie a recently reported, three-way drug-drug interaction involving danoprevir, ritonavir, and ciclosporin.

Pharmacokinetics of a three-way drug interaction between danoprevir, ritonavir and the organic anion transporting polypeptide (OATP) inhibitor ciclosporin.

BACKGROUND: Danoprevir (RG7227) is a potent macrocyclic inhibitor of the hepatitis C virus NS3/4A protease, which is currently in development in combination with low-dose ritonavir for the treatment of chronic hepatitis C infection. Danoprevir is a substrate of cytochrome P450 3A4, and the organic anion transporting polypeptides (OATP) 1B1 and 1B3. OBJECTIVE: The objective of this study was to evaluate the effect of a potent OATP inhibitor, ciclosporin, on danoprevir pharmacokinetics, when administered as danoprevir/ritonavir. The effect of danoprevir/ritonavir on ciclosporin pharmacokinetics was also investigated. METHODS: This was a single-dose, randomized, open-label, two-sequence, three-period, crossover study in healthy volunteers. In the first period, subjects were randomized to receive either a single oral dose of danoprevir 100 mg in combination with ritonavir 100 mg or a single oral dose of ciclosporin 100 mg. After a 14-day washout, patients were crossed over to receive the opposite treatment. In period 3, all subjects received the combination of danoprevir/ritonavir and ciclosporin following a 14-day washout from period 2. Blood samples were collected serially with each dose for pharmacokinetic assessment. Pharmacokinetic parameters were estimated using non-compartmental analysis. Geometric mean ratios (GMRs) and 90 % confidence intervals (CIs) were used to compare pharmacokinetic parameters [maximum concentration (C max), area under the concentration-time curve from time zero to infinity (AUC∞), and concentration 12 h post-dose (C 12h)] of danoprevir/ritonavir and ciclosporin when administered alone or in combination. Measures of safety and tolerability were also evaluated. RESULTS: A total of 18 subjects were enrolled, and 17 completed the study. The C max, AUC∞, and C 12h GMRs (90 % CI) when danoprevir/ritonavir and ciclosporin were co-administered versus danoprevir/ritonavir or ciclosporin alone were 7.22 (5.42-9.62), 13.6 (11.2-16.6), and 22.5 (17.4-29.3), respectively, for danoprevir, 1.97 (1.72-2.27), 2.23 (2.07-2.42), and 2.50 (2.22-2.81), respectively, for ritonavir, and 1.42 (1.29-1.57), 3.65 (3.27-4.08), and 6.15 (5.32-7.11), respectively, for ciclosporin. All treatments were well tolerated, with no laboratory abnormalities, and no clinically significant changes in vital signs, electrocardiograms, or physical examinations observed. CONCLUSIONS: A significant drug-drug interaction was observed between ciclosporin and danoprevir/ritonavir, leading to substantial increases in exposure to danoprevir and a lesser impact on exposure to ritonavir. Therefore, co-administration of danoprevir/ritonavir with potent OATP inhibitors should be undertaken with appropriate precautions.

Value of cytology in the intraoperative assessment of ovarian tumors: a review of 402 cases and comparison with frozen section diagnosis.

BACKGROUND: Intraoperative pathological assessment is frequently requested in patients with suspected ovarian neoplasia so that optimal surgical management can be performed. In this study the accuracy of intraoperative cytology has been assessed and the results compared with frozen section diagnosis. METHODS: The study comprised 402 ovarian tumors that were submitted for intraoperative assessment in which both cytology preparations, usually scrape smears, and conventional frozen sections were examined. Each technique was evaluated independently, although the diagnosis transmitted to the surgeon was based upon the combination of the clinical, macroscopic, histological, and cytological information. The results were compared with the final pathological diagnosis in each case and cases with discordant diagnoses were reviewed. RESULTS: There were 226 benign lesions, 35 borderline epithelial neoplasms, and 141 malignant tumors according to the final pathological diagnosis. All benign lesions were accurately categorized using both frozen section and cytology. Thirty (86%) of the borderline tumors and 137 (97%) of the malignant tumors were accurately identified on frozen section, whereas the corresponding results for cytology were 23 (66%) and 131 (93%), respectively. There were no false-positive diagnoses with either technique and the overall accuracy was 97.8%. Cytological evaluation provided better morphologic detail, permitted wider tumor sampling, and directed appropriate ancillary investigations in some cases. CONCLUSIONS: Overall, frozen section was more accurate than smear preparations in this series. However, cytology has a complementary role in the intraoperative assessment of ovarian neoplasia and provides a more specific diagnosis in some cases.

Comparison of proliferation indices in primary adult-type granulosa cell tumors of the ovary and their corresponding metastases: an analysis of 14 cases.

Adult-type granulosa cell tumors (GCTs) of the ovary are generally low-grade malignancies, but late metastases are relatively common. Limited data suggest that recurrent GCTs may exhibit altered morphology and/or biologic behavior, but few studies have directly compared primary and recurrent tumors in individual patients. Fourteen GCTs in which histologic material was available from both the primary tumor and one or more metastases were reviewed, and the mitotic index (MI) and Ki-67 labelling index (KI) were evaluated using carefully specified methodology. The findings were also correlated with the time interval to tumor recurrence. The median interval to first recurrence was 6.6 years (range: 2.2 to 12.2 yr). There were only minor differences in tumor morphology between the primary and metastatic GCTs. None of the cases exhibited high-grade (sarcomatoid) transformation. There was a wide range in MI and KI in the GCTs and no consistent correlation was seen between these indices in the paired primary and recurrent neoplasms. There was also no association between the MI and the KI and the time interval to metastasis. In conclusion, metastatic GCTs generally maintain their morphologic features even after multiple recurrences over many years. Cellular proliferation in GCT is variable, and there is no uniform alteration in proliferation indices between paired primary and metastatic lesions. Therefore, data derived from the analysis of primary GCT may not always be applicable to recurrent tumors. These findings may have implications for management including the potential response of GCT to adjuvant therapies.

Intraoperative assessment of clear cell carcinoma of the ovary.

Frozen section is a reliable technique in gynecologic pathology and is widely used to guide intraoperative management in patients presenting with ovarian masses. However, there are limited data regarding the diagnostic accuracy of frozen section in specific subtypes of ovarian neoplasia. Our impression that primary clear cell carcinoma (CCC) causes disproportionate diagnostic difficulty led us to review the intraoperative and final histopathologic reports from a consecutive series of 44 CCC that were subject to frozen-section assessment and to compare the results with a similar number of primary serous and endometrioid carcinomas. The original intraoperative slides from those CCC with discordant diagnoses were also reviewed. Review of the diagnostic reports showed that CCC was less frequently specifically identified than serous or endometrioid carcinomas on frozen section (44% cases compared with 55% and 65%, respectively), although the differences were not statistically significant. Difficulties in distinguishing primary ovarian carcinoma from tumors metastatic to the ovary occurred in a minority of cases of all histologic subtypes, but was slightly more frequent in CCC. Two CCC were misdiagnosed as borderline epithelial tumors and 1 case as a dysgerminoma. Review of the frozen-section slides from the CCC with discrepant intraoperative diagnoses showed features suggestive or indicative of the correct diagnosis in 7 (39%) of 18 cases.

Intraoperative assessment of ovarian tumors: a 5-year review with assessment of discrepant diagnostic cases.

Frozen section is often requested in the intraoperative assessment of patients, presenting with ovarian masses, to provide guidance for appropriate surgical management. To assess the accuracy of frozen section and identify causes of diagnostic error, we reviewed 914 consecutive ovarian frozen sections performed over a 5-year period in 2 laboratories; one of which provides a general surgical pathology service and, the other, a specialist gynecologic pathology service. Cases, in which there were significant diagnostic discrepancies between the intraoperative and the final histological diagnoses, were reviewed. The series included 552 benign lesions (60.4%), 96 borderline (atypical proliferating) epithelial tumors (10.5%), and 266 malignancies (29.1%). The overall accuracy of frozen section diagnosis was 95.3%. There were 43 cases with diagnostic discrepancy; 20 (3.8% cases) of which were reported in the specialist laboratory and 23 (5.9% cases) in the general laboratory. Underdiagnosis of tumor type accounted for 32 of 43 discrepant cases and was most frequent in borderline mucinous tumors. The most common cause of overdiagnosis was the misinterpretation of serous cystadenofibroma as borderline serous tumor. Slide review of the 41 assessable cases indicated that sampling error, pathologist misinterpretation, and suboptimal slide preparations contributed to misdiagnoses in 17, 23, and 9 tumors, respectively (in 9 cases, 2 factors were contributory), whereas no specific error was identified in the remaining case. Technical factors and pathologist misinterpretation were more common in the general pathology laboratory. This study confirms that ovarian frozen section is a generally reliable technique, but there are problematic areas, particularly involving the assessment of borderline tumors.

Accuracy of frozen section in distinguishing primary ovarian neoplasia from tumors metastatic to the ovary.

Frozen section is widely used in the intra-operative assessment of patients with ovarian tumors. The diagnosis of malignancy is usually straightforward but in some cases it may be difficult to distinguish whether tumors are of ovarian origin or represent matastases from other sites. Recently, Seidman and colleagues presented a simple algorithm based on tumor size and unilateral versus bilateral involvement to aid in intra-operative assessment of ovarian mucinous neoplasms. In this study we have reviewed the accuracy of frozen section in distinguishing primary ovarian malignancies from tumors metastatic to the ovaries encountered in two hospitals over a 5-year period. The algorithm was also applied to our cases retrospectively irrespective of histological type. Nine hundred fourteen ovarian frozen sections were performed in the study period including 266 cases with a final diagnosis of malignancy. Thirty-seven malignancies (13.9%) were of metastatic origin (exclusing one lymphoma), 21 of which (58.8%) were correctly identified on frozen section. In 5 additional cases metastatic origin was included in the differential diagnosis while a primary ovarian tumor was favored un 11 cases (29.7%). Application of the algorithm to the metastatic tumors led to correct classification in 26/33 (78.8%) assessable cases. Conversely, 195/228 primary ovarian malignancies were correctly identified intra-operatively but the possibility of extra-ovarian malignancy was considered or not excluded in 33 cases (14.5%). Application of the algorithm to the latter problematic primary ovarian tumors overall was not helpful in distinguishing primary or metastatic origin. However if only low-grade primary adenocarcinomas were considered then 10/12 assessable cases were correctly assigned. In conclusion frozen section is only moderately successful in distinguishing primary ovarian malignancies fron tumors metastatic to the ovaries. The simple algorithm proposed by Seidman and colleagues for assessment of ovarian mucinous tumors is helpful and can be applied to low-grade adenocarcinomas of other histological types.

Superficial cervico-vaginal myofibroblastoma: a report of five cases.

AIMS: To describe the pathological and immunohistochemical features of five cases of superficial cervico-vaginal myofibroblastoma (SCVM), a recently described mesenchymal tumour affecting middle-aged and elderly females. METHODS: The histological features of five cases of SCVM arising in four patients were reviewed including one case which recurred locally 9 years after initial excision biopsy. All cases were immunostained using the streptavidin-biotin technique using antisera to vimentin, smooth muscle actin, desmin, S100 protein, cytokeratin, h-caldesmon, calponin, CD99, CD117 (c-kit), bcl-2, oestrogen receptor and progesterone receptor. RESULTS: The patients were aged from 40 to 71 years (mean 55.2 years). The tumours were situated within the vagina (four cases) and cervix (one case) and ranged from 16 to 45 mm in greatest dimension. One patient had two separate vaginal SCVM. The tumours were characterised by uniform spindle and stellate-shaped cells separated by a collagenous or myxoid stroma. No mitotic activity was identified. Characteristically the tumours were well circumscribed and separated from the surface epithelium by a rim of normal stroma. The initial and recurrent tumours in one patient were similar except for increased stromal collagen in the recurrence. All tumours were immunoreactive for vimentin, desmin, CD34, CD99, bcl-2, calponin and hormone receptors while two tumours showed focal smooth muscle actin expression. There was no expression of S100 protein, h-caldesmon, CD117 or cytokeratin. CONCLUSIONS: SCVM appears to be a relatively distinct lesion although there is some histological and immunophenotypical overlap with other mesenchymal tumours, particularly fibroepithelial polyp, leiomyoma and solitary fibrous tumour. As local recurrence developed 9 years after intial treatment in one patient, long-term clinical follow-up would seem appropriate.

Gangliocytic paraganglioma of the bronchus: a case report with follow-up and ultrastructural assessment.

We report a case of gangliocytic paraganglioma of bronchus. A 54-year-old woman underwent bronchoscopy following two episodes of right lower lobe pneumonia over the previous 5 months with unresolved chest radiographic changes. A computerized tomographic scan showed a right lower lobe endobronchial lesion, and at bronchoscopy there was a mass partly occluding the lumen of the bronchus. The biopsy and subsequent bronchoscopic resection showed a tumor with morphologic, immunohistochemical, and ultrastructural features of paragangliomatous, gangliocytic, and Schwann cell differentiation consistent with a gangliocytic paraganglioma. The lesion was treated conservatively with bronchoscopic resection and laser therapy. Histopathologic examination of recurrent tumor at 6 months showed features consistent with paraganglioma. Ten months after initial diagnosis, there was no bronchoscopic evidence of residual tumor. The occurrence of gangliocytic paraganglioma in diverse sites gives cause for the reappraisal of the histogenesis of this fascinating lesion. The variable morphology of this lesion may be an expression of the potential for divergent differentiation of a pluripotent stem cell.