Induction of Immunotolerance in Hemophilia for High Titre Inhibitor Eradication: A Long-Term Follow-Up

Three hemophiliacs with high titre inhibitor were treated with a medium-high FVIII dose schedule (100 IU/kg bw daily) with the aim of inducing the immunotolerance. These patients were followed-up extensively concerning their immunological status and HIV serology. In all of them the inhibitor disappeared and normal FVIII kinetics were obtained after 22, 15 and 29 months. After eradication of the inhibitor, no recurrence took place in any of the patients. All the patients were HIV Ab positive before the beginning of the treatment. In one of them CD4+ cells fell progessively 32 months after the treatment was started, a fullblown AIDS showed up, and the patient died 5½ years after the beginning of the treatment. In the second and third patient the CD4+ cells varied widely but remained >400/μl during the whole immunotolerance treatment. The latter two patients are AIDS and ARC free so far, but patient No. 2 developed a mild-to-severe thrombocytopenia.

Considering the high cost of the treatment and the possibility that such an intensive administration of FVIII concentrates might worsen the immunological status of patients, this therapeutic procedure should only be applied with caution.

The fibrinogen prothrombin time-derived method is not useful in patients anticoagulated with low molecular weight heparins or rivaroxaban

Essentials Fibrinogen prothrombin time-derived (FIBPT-d) behavior in anticoagulated patients is under studied. FIBPT-d method overestimates fibrinogen in rivaroxaban and low molecular weight heparin samples. Unfractionated heparin and dabigatran samples showed similar bias to the control group. Rabbit brain and human recombinant thromboplastin behavior was different in rivaroxaban samples.

SUMMARY

Background The fibrinogen prothrombin time-derived (FIBPT-d) method with photo-optical coagulometers is easy and economical. However, there are few reports on the behavior of this test on samples from patients anticoagulated with direct oral anticoagulants or low molecular weight heparin (LMWH). Objective To compare fibrinogen results obtained with the Clauss (FIB C) method and the FIBPT-d method with two thromboplastins in anticoagulated patients. Population The study population comprised 295 consecutive anticoagulated patients: 99 treated with vitamin K antagonists (VKAs), 49 treated with unfractionated heparin (UFH), 47 treated with LMWH, 50 treated with rivaroxaban, 50 treated with dabigatran, and 100 normal controls (NCs). Methods Dabigatran samples were analyzed by the use of FIB C with HemosIL Fibrinogen C or 100 NHI thrombin units mL-1 reagents; rabbit brain and human recombinant thromboplastins with HemosIL PTFibrinogen HS plus (HS) and Recombiplastin 2G (RP) were used for FIBPT-d method. Heparin and rivaroxaban levels were assessed with HemosIL Liq antiXa with specific calibrators; dabigatran levels were determined with the HemosIL Direct Thrombin Inhibitor Assay. All assays were performed on the ACL TOP platform in two laboratories. Percentage biases for the FIBPT-d method versus the FIB C method were calculated by the use of Bland-Altman plots. Results Positive biases of the FIBPT-d method versus the FIB C method with both thromboplastins were seen in NC samples (13.7% and 18.9% for HS and RP, respectively), but biases with HS in rivaroxaban and VKA patient samples were higher than that in NC samples, at 31.9% and 34.0%, respectively. LMWH patient samples showed higher bias than NC samples: 26.5% and 29.3.0% with HS and RP, respectively. UFH and dabigatran patient samples showed similar bias as NC samples. Conclusion The FIBPT-d method should not be used in anticoagulated patients, because the FIBPT-d mathematical algorithm has been validated only in normal subjects, so overestimation could occur in these patients.

Treatment by Splenic Irradiation in 22 Chronic Lymphocytic Leukemia Patients

Twenty-two patients with chronic lymphocytic leukemia, score 2 according to Rai et al. (10), who received only a course of splenic irradiation are reviewed. Splenic doses ranged from 420 to 1080 rad. Response to splenic irradiation was rated by evaluating peripheral lymphocytosis, hepatosplenomegaly, adenomegaly and disease-related symptoms. Following splenic irradiation, 8 patients showed a significant reduction in splenomegaly; 7 patients showed a significant reduction in peripheral lymphocytosis (< 10,000/mm3), which has lasted from 15–42 months without any other treatment. In 14 patients, response to splenic irradiation was partial, and it has successively been necessary to treat 12 patients with chemotherapy. Methods of splenic irradiation, survival, clinical and hematologic behavior are discussed in detail.

Paclitaxel Activity in Anthracycline Refractory Breast Cancer Patients

Aims and background

We investigated the efficacy and tolerability of two doses of paclitaxel, 175 mg/m2 and 135 mg/m2, over a 3-hr infusion, without prophylactic G-CSF, in heavily pretreated patients with anthracycline-resistant breast cancer. Although paclitaxel may share with anthracyclines a common mechanism of drug resistance, there is evidence that the two drugs are not completely cross resistant.

Methods

From July 1994 to January 1996, 42 patients were treated every 3 weeks, for a maximum of 6 cycles; paclitaxel dose was established according to pretreatment extension.

Results

In 41 assessable patients we observed 9 partial responses, for an overall response rate of 22% (95% CI, 10–34%). There was no difference in response rate between the two dose levels. Median duration of response was 9 months, median time to progression 5 months, and median survival 9 months. The dose-limiting toxicity was neutropenia, which was grade 3–4 in 40% (135 mg/m2) and 62% (175 mg/m2) of the patients (P = 0.28); neutropenic fever occurred in 24% of the patients, without significant differences between the two dose levels. Other toxicity was mild to moderate.

Conclusions

Paclitaxel at doses of 175 mg/m2 or 135 mg/m2 is active and well tolerated in advanced breast cancer patients resistant to anthracyclines. The prophylactic use of colony-stimulating factors seems appropriate in heavily pretreated patients given the higher dose level.

Sequential Subcutaneous Thymopentin, Interferon Alpha-2A and Interleukin-2 in Metastatic Renal Cell Cancer

To determine the activity of sequential administration of thymopentin (TP-5), interferon alpha-2a (IFN) and interleukin-2 (IL-2) in metastatic renal cell cancer (RCC), 17 patients with RCC were treated with TP-5 50 mg/d on days 1 to 14, IFN 3 MIU/d on days 14, 15, 21, 22 and IL-2 18 MIU/d on days 16 to 20, and 23 to 27. Treatment was given subcutaneously and cycles were repeated every 6 weeks. All patients were assessed for toxicity and response. No objective responses were observed. Two patients had a short-lived disease stabilization. Median survival was 9 months. Toxicity was generally moderate. The most important side-effects were related to IL-2 administration. In view of the lack of antitumor activity, the combination of TP-5 + IFN + IL-2 in the doses and schedule used in this trial cannot be recommended. The investigation of chemotherapeutic and immunological agents that can effectively synergize with IFN or IL-2 is essential.

5-Fluorouracil, Adriamycin and Cyclophosphamide Combined with High-Dose Medroxyprogesterone Acetate in Advanced Breast Cancer

Seventy-six patients with metastatic breast cancer were treated with fluorouracil, adriamycin (doxorubicin) and cyclophosphamide (FAC) plus high-dose medroxyprogesterone acetate (HD-MPA). MPA was given for 21 days at the dose of 500 mg/day i.m., then on a randomized basis, either 500 mg/week i.m. (FAC+HD-MPA i.m.) or 300 mg/day p.o. (FAC+HD-MPA p.o.). Objective response rates were 79% in 39 patients on FAC+HD-MPA i.m. and 73% in the 37 patients on FAC+HD-MPA p.o. There was no significant difference in the median duration of response and median survival for the 2 regimens (respectively, 17 months and 22 months, and 15 months and 21 months for FAC+HD-MPA i.m. and FAC+HD-MPA p.o.). Toxicity was mild and similar in both groups. Although FAC+HD-MPA was highly effective, at present it is difficult to select which regimen provides the best initial treatment for metastatic breast cancer.

Abstract P5-06-02: Ex vivo CSC assays for personalized testing of drug susceptibility in advanced breast cancer

In the developing area of personalized medicine, targeted therapies are mainly based on genomic characterization of each tumor, and is currently proposed as promising strategies for advanced breast cancer (ABC). Despite the promises of advanced genome sequencing, many patients still fail therapy, resulting in disease progression, recurrence, and metastases. Cancer stem cells (CSCs) concept illustrates the non-genetic intrinsic resistance, recapitulates tumor heterogeneity that creates hierarchically organized tumor tissues where a subpopulation of self-renewing cancer stem cells (CSCs) sustains the long- term clonal maintenance of the neoplasm. Evidences indicate that CSCs survive many commonly employed cancer therapeutics. Patient-derived tumor xenograft (PDXs) models recapitulate tumor complexity and heterogeneity at cellular and molecular level.

We aimed to specifically address the therapeutic sensitivity in ABC, by using an ex vivo assay based on PDX prospective collection, fully characterized for genomic alterations.

In this work, we aim at defining for each tumor the best therapy to target breast cancer intratumor heterogeneity, the CSC component. For that, we defined a panel of 44 FDA-approved compounds used for cancer treatment, including breast and other types of cancer, cancer stem cell drugs, chemo or targeted therapies. For each drug, we screened the differential sensitivity of the bulk tumor cells and the CSC components for 12 PDX models using an ex vivo screening approach on short term culture. To assess intra tumor heterogeneity, we set up an original dual strategy: for the bulk cells, an ex vivo assay based on IC50, and for breast CSC component a miniaturized Aldefluor assay. First, we demonstrate that bulk cells and CSCs sensitivity may be dissociated for the same drug in the same PDX models. Then, we observed that whereas bulk cell sensitivity may be correlated to tumor genomic abnormalities, CSC drug sensitivity seems not to follow the rule.CSC are selectively sensitive to specific compounds. We are exploring the pathways that sustain this selective sensitivity in the CSCs components. We are currently identifying targets using mass spectrometry in CSCs and bulk cells.Then, we validated the hits predicted from ex vivo screening assays by in vivo treatment of using PDX models for the selected drugs, and in a patient with ABC.

In that work, we demonstrated that CSCs display different sensitivity profiles than bulk cells to the same agents, irrespective to their genomic background and are identifying the CSC specific targets. Here, we propose a new model of precision medicine based on ex vivo CSC assays for personalized testing of drug susceptibility in advanced breast cancer.

Citation Format: Charafe-Jauffret E, Wicinski J, Cabaud O, Lopez M, Audebert S, Adelaide J, Chaffanet M, Guille A, Goncalves A, Bertucci F, Birnbaum D, Ginestier C. Ex vivo CSC assays for personalized testing of drug susceptibility in advanced breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-06-02.

Thrombininduziertes Tumorwachstum

Das zentrale Gerinnungsenzym, die Serinproteinase Thrombin, kann über die Protease-aktivierten Rezeptoren 1 und 4 der Tumorzellen in deren Wachstum modulierend eingreifen. Das Thrombin ist im Tumormikroenvironment permanent verfügbar, Meizothrombin wird an einem tumorspezifischen Aktivierungskomplex aus Prothrombin generiert und kann ebenfalls das Tumorzellwachstum via PAR-1 und dem 7-Transdomänen-Protein-Rezeptor-Signalweg beeinflussen. PEG-gekoppelte direkte Thrombininhibitoren, die eine spezielle pharmakokinetische Charakteristik aufweisen und für eine langzeitige Wirksamkeit im extrazellulären Wasserraum designt wurden, kontrollieren die Serinproteinaseaktivität im Tumormikroenvironment und haben damit eine hohe potenzielle tumortherapeutische Wirksamkeit. In xenografischen Tumormodellen hat diese neue Substanzklasse einen signifikanten kanzerostatischen Effekt gezeigt.

Imaging Manifestations of Pseudoprogression in Metastatic Melanoma Nodes Injected with Talimogene Laherparepvec: Initial Experience

Talimogene laherparepvec is an oncolytic virus recently approved for targeted treatment of advanced melanoma. Because of an inflammatory reaction, treated lesions may increase in size and develop infiltrative margins that can be construed as disease progression or extracapsular spread. In this report, we describe our initial experience imaging the response of metastatic nodes injected with talimogene laherparepvec. Six of 12 nodes (50%) showed growth from baseline followed by decreased size, 5 of 12 nodes (42%) showed a downward size trend, and 1 node showed continued increase in size. Seven of 9 nodes (78%) developed infiltrative margins at a median of 79 days, and 6 of 9 (67%) nodes became necrotic at a median of 76 days after injection, all showing decreased size at final follow-up. An increase in the size of nodes injected with talimogene laherparepvec does not necessarily indicate progression. Infiltrative margins are also frequently seen and may be confused with extracapsular disease.