The use of a single von Willebrand factor-containing, plasma-derived FVIII product in hemophilia A immune tolerance induction: the US experience

BACKGROUND

Inhibitors are a serious complication for patients with severe hemophilia A. Immune tolerance induction (ITI) is the primary method for eradicating these inhibitors. The role of type of concentrate and in particular the use of von Willebrand factor-containing, plasma-derived factor VIII (VWF/pd-FVIII) concentrate in primary or rescue ITI remains unclear.

OBJECTIVES

To report retrospective collection of data on the use of a single VWF/pd-FVIII concentrate in primary and rescue ITI.

METHODS

Retrospective chart review of hemophilia A inhibitor patients at 11 US institutions who received VWF/pd-FVIII concentrate in primary or rescue ITI.

RESULTS

Primary ITI was carried out in eight inhibitor patients with a 75% complete and partial success. Secondary ITI was carried out in 25 inhibitor patients, with 52% attaining complete or partial success.

CONCLUSIONS

This report represents the largest group of primarily pediatric, high-titer inhibitor patients treated with a single VWF/pd-FVIII concentrate. It adds retrospective data to the use of VWF-containing plasma-derived factor VIII concentrate in primary and rescue ITI, particularly in those patients with characteristics of poor response to ITI.

Immune tolerance therapy utilizing factor VIII/von Willebrand factor concentrate in haemophilia A patients with high titre factor VIII inhibitors

Factor VIII (FVIII) inhibitors remain a serious complication of treatment for patients with haemophilia A. Immune tolerance induction (ITI) can eliminate inhibitors in the majority of patients, but there are major concerns related with this therapy. Investigators have raised the possibility that the use of FVIII/von Willebrand factor (FVIII/VWF) concentrates may improve the success rate of ITI and may shorten the duration of therapy necessary to attain tolerance. This retrospective study describes 25 patients at five institutions in the USA, who were treated with FVIII/VWF concentrate as part of their ITI. These were all patients who were considered poor prognosis because of clinical and laboratory characteristics, which made ITI less likely to be successful or because of a poor response to initial ITI with a monoclonal/recombinant FVIII concentrate. Overall success (complete tolerization) was 32% with another 40% attaining partial tolerization, but not complete tolerization. Of those patients attaining only partial tolerization, two patients ultimately discontinued ITI and had return of their high titre inhibitors. Eight percent of patients failed to attain either partial or complete tolerization and discontinued ITI. Another 24% are continuing with ITI but have titres of >10 BU. This study adds further retrospective data to the information regarding the use of FVIII/VWF concentrate in ITI.

Germline origins in the human F9 gene: frequent G:C-->A:T mosaicism and increased mutations with advanced maternal age

The factor IX gene (F9) is an advantageous system for analyzing recent spontaneous germline mutation in humans. Herein, the male:female ratio of mutation ("r") in F9 have been estimated by Bayesian analysis from 59 germline origin families. The overall "r" in F9 was estimated at 3.75. The "r"s varied with the type of mutation. The "r"s ranged from 6.65 and 6.10 for transitions at CpG and A:T to G:C transitions at non-CpG dinucleotides, respectively, to 0.57 and 0.42 for microdeletions/microinsertions and large deletions (>1 kb), respectively. The "r" for the two subtypes of non-CpG transitions differed (6.10 for A:T to G:C vs 0.80 for G:C to A:T). Somatic mosaicism was detected in 11% of the 45 origin individuals for whom the causative mutation was visualized directly by genomic sequencing of leukocyte DNA (estimated sensitivity of approximately one part in 20). Four of the five defined somatic mosaics had G:C to A:T transitions at non-CpG dinucleotides, hinting that this mutation subtype may occur commonly early in embryogenesis. The age at conception was analyzed for 41 US Caucasian families in which the age of the origin parent and the year of conception for the first carrier/hemophiliac were available. No evidence for a paternal age effect was seen. However, an advanced maternal age effect was observed (P=0.03) and was particularly prominent for transversions (average of the 79th percentile when maternal age was normalized for the year of conception). This suggests that an increased maternal age results in a higher rate of transmitted mutation, whereas the increased number of mitotic replications associated with advanced paternal age has little, if any, effect on the rate of transmitted mutation.

Therapy of refractory or recurrent childhood acute myeloid leukemia using amsacrine and etoposide with or without azacitidine: a Pediatric Oncology Group randomized phase II study

PURPOSE

A randomized study compared the combination of amsacrine (100 mg/m2/d on days 1 to 5) and etoposide (200 mg/m2/d on days 1 to 3) with the same two agents plus azacitidine (250 mg/m2/d on days 4 to 50) for the therapy of induction-resistant or relapse childhood acute myeloid leukemia (AML).

PATIENTS AND METHODS

One hundred sixty-seven assessable children with AML who either had failed to respond to primary induction therapy (group 1, n = 41) or had relapsed (group 2, n = 126) were randomized.

RESULTS

Overall, there were 56 complete responses (34%; SE 4%). Among primary refractory patients (group 1), the complete response rate was higher with the three-drug regimen (18% vs 53%, P = .03). In the relapsed patients (group 2), there was no difference in complete response rates related to treatment (31% vs 35%, P = .3). There were 17 early deaths. The major toxicities for both regimens were myelosuppression and infection.

CONCLUSION

The overall complete response rate of 34% in this patient population is indicative of effective antileukemic activity. For patients with relapsed leukemia, the addition of azacitidine to etoposide and amsacrine did not improve response. The suggested advantage of the three-drug regimen for induction failures warrants further investigation.

Esthesioneuroblastoma presenting as an orbital mass in a young child

A 3-year-old boy presented with uniocular proptosis and ophthalmoplegia. Investigation revealed a mass involving the right orbit with extension into the left orbit and paranasal sinuses, and intracranial extension involving both frontal lobes. Biopsy of an enlarged cervical node and the intranasal mass revealed esthesioneuroblastoma. This tumor has been reported rarely in a child this age, and only 12 case reports document patients under 10 years of age. The presentation as an orbital mass is previously unreported and must now be considered in the differential diagnosis of proptosis in childhood. The usual clinical, radiological, and pathological features of olfactory esthesioneuroblastoma are reviewed.

A multicenter study of viral hepatitis in a United States hemophilic population

Hemophilia A and B patients seen at nine US regional treatment centers were tested for serologic markers of hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis delta virus (HDV) during 1987 and 1988. Because human immunodeficiency virus (HIV) infection, a potentially confounding variable, was present in 53% of the group, the population was divided by HIV status for analysis purposes. In the HIV-positive group (N = 382), less than 1% had not been infected with HBV, HCV, or HDV, whereas 75% had evidence of infection with HBV and 98% with HCV. HBsAg, a marker of active HBV infection, was present in 12% of subjects; 96% of these were HCV positive. Anti-HDV was detected in 35 subjects (9.1%); all were anti-HBc positive. Ten of the 35 (29%) also were positive for IgM anti-HDV, indicating current infection. All 10 were HBsAg positive and 7 of the 9 tested were HDV RNA positive. Severe/moderate hemophilia B patients were more likely to have experienced an HBV infection and to be anti-HDV positive than were similar hemophilia A patients (22% v 8%, P < .05). In the HIV-negative group (N = 345), the subjects were younger and had less severe hemophilia than the HIV-positive patients. No evidence of HBV, HCV, or HDV infection was found in 18%, whereas 33% had experienced HBV infection and 79% were anti-HCV positive. Within this group, 4% were HBsAg positive. All 13 subjects with anti-HDV (4% of the HIV-negative group) also possessed anti-HBc. One (7.7%) was IgM anti-HDV positive and the serum from another contained HDV RNA. Both of these individuals were HBsAg positive. As in the HIV-positive group, severe/moderate hemophilia B patients were more likely to be HBV and HDV positive than were hemophilia A patients (9% v 3%, P < .05). A prevalence study of viral hepatitis in a large US hemophilic population showed that active infection with HCV is common, occurring in 89% of all study patients regardless of HIV status. Evidence of active HBV infection was found in 8%; 19% of these were actively infected with HDV. HDV was more common in hemophilia B patients after controlling for disease severity.

Toxicity trials of amsacrine (AMSA) and etoposide +/- azacitidine (AZ) in childhood acute non-lymphocytic leukemia (ANLL): a pilot study

Recurrent or induction therapy-resistant ANLL carries a grave prognosis. The combination of AMSA at 100 mg/M2 daily for 5 days and etoposide at 200 mg/M2 daily for the first 3 days of therapy was given to 40 patients with refractory ANLL. An additional 17 patients received those two agents plus azacitidine at a dosage of 250 mg/M2 on days 4 and 5. All three drugs were given as one-hour infusions. All patients had normal electrolyte determinations daily and were on cardiac monitors during the period of drug administration. No arrhythmias were detected in 522 doses of AMSA. Toxicities observed were primarily related to myelosuppression. Forty-nine of the 57 patients required hospitalization for suspected or proven infection. Nausea/vomiting and mucositis were the next most commonly occurring toxicities. Responses were seen in 22 patients.

High-dose cytarabine for intensification of early therapy of childhood acute myeloid leukemia: a Pediatric Oncology Group study

In June 1984, the Pediatric Oncology Group (POG) initiated a pilot study (8498) using high-dose cytarabine (HdA; 3 g/m2) for intensification of early therapy in childhood acute myelogenous leukemia (AML) (group I). Remission induction therapy consisted of two courses of daunorubicin, cytarabine (Ara-C), and thioguanine (DAT). Postremission therapy consisted of four sequential courses, each consisting of (1) four doses of HdA (HdA4) followed by asparaginase (L-Asp), (2) etoposide (VP) plus azacytidine (Az), (3) prednisone, vincristine, methotrexate, and mercaptopurine (POMP), and (4) Ara-C daily for 5 days by continuous infusion. Six doses of intrathecal Ara-C were given for CNS prophylaxis. In December 1986, the protocol was amended (group II) to substitute six doses of HdA (HdA6) for the second DAT (two + five) induction course; postinduction, a single course of HdA6 was given instead of four HdA/L-Asp courses, and the remainder of the therapy was unchanged. One hundred forty group I patients and 145 group II patients were assessable. The two groups were similar with regard to clinical prognostic groups. No significant differences were noted in the two groups with regard to remission induction (85% [SE = 2%] in each group), induction deaths (6.5% v 7.0%), or deaths in remission (one in each group). Cerebellar toxicity was reported in three patients in group II (with HdA6) but none in group I (HdA4). At present, patients who received HdA6 (group II) had higher event-free survival than patients in group I (EFS at 3 years, 34% [SE = 11%] v 29% [SE = 4%]), and disease-free survival (DFS at 3 years, 42% [SE = 14%] v 34% [SE = 4%]), but the differences were not statistically significant. In both groups, children less than 2 years and those with WBCs less than 100,000/microL had significantly better outcome (EFS of 55% [SE = 10%] and 36% [SE = 5%] at 3 years, respectively) than children greater than or equal to 2 years and those with WBCs greater than or equal to 100,000/microL (EFS of 27% [SE = 5%] and 20% [SE = 9%] at 3 years, respectively.

Reversible treatment-related leukoencephalopathy

We present two children with acute lymphocytic leukemia who developed leukoencephalopathy following administration of a combination of intravenous ara = C and methotrexate during the consolidation phase of chemotherapy. Cranial magnetic resonance imaging showed widespread, abnormally high signal intensity in the deep white matter in both patients, though one patient had normal cranial computed tomographic scan. Treatment was modified, symptoms resolved in 1 to 2 weeks, and the white-matter changes resolved over 6 to 12 months. Intravenous cytarabine and methotrexate appear to act synergistically to enhance the potential for central nervous system toxicity. Awareness of this potentially serious complication of chemotherapy can facilitate timely recognition of leukoencephalopathy with the use of magnetic resonance imaging.

Novantrone for childhood malignant solid tumors. A pediatric oncology group phase II study

One hundred one patients with advanced pediatric malignant solid tumors, refractory to conventional chemotherapy, were given Novantrone in a Phase II study. A dosage of 18 mg/m2 was administered as a short intravenous infusion every 3 weeks. One complete and 2 partial responses were observed among 26 patients treated for rhabdomyosarcoma; one of 22 patients with neuroblastoma developed a partial response. Nausea and vomiting were uncommon. Leukopenia and/or granulocytopenia developed in 90 of 98 evaluable entries. Two patients developed fatal congestive heart failure, which may have been related to the fact that these patients previously had received doxorubicin; 3 other patients developed evidence of changes in cardiac function, without congestive heart failure. Evidence of activity of this agent in patients who had previously received doxorubicin suggests that Novantrone should be evaluated in pediatric subjects with malignant solid tumors who have had no prior exposure to anthracyclines.

Adjuvant chemotherapy for medulloblastoma and ependymoma using iv vincristine, intrathecal methotrexate, and intrathecal hydrocortisone: a Southwest Oncology Group Study

In a prospective, randomized, cooperative group trial, the value of iv vincristine and intrathecal methotrexate and hydrocortisone as adjuvant therapy to radiotherapy in children with medulloblastoma and ependymoma was evaluated. The data showed no improvement in the survival of such children when adjuvant therapy was given.

Negative pion irradiation of mammalian cells. III. A comparative analysis of DNA strand breakage, repair and cell survival after exposure to pi-mesons and X-rays

The yields of immediate and residual breaks in DNA of X- and peak pion irradiated Chinese hamster cells were measured by hydroxylapatite chromatography in order to investigate the r.b.e. of immediate break production and the relation between residual breaks and survival in the same low dose range of up to 10 Gy. A linear dose response for immediate break induction was observed with an r.b.e. of 0.37 for peak pions, whereas the formation of residual breaks showed a linear-quadratic dose dependence for both types of radiation. The dose-effect curves of residual break can directly be correlated with the corresponding survival curves for both radiation types used indicating that residual breaks are lethal events (most probably unrepaired double strand breaks) formed in this low dose range by single- and multi-hit interactions. Despite their lower efficiency in formation of immediate breaks peak pions produce more residual breaks per dose than X-rays.

Evaluation of a MOPP-type regimen in histiocytosis X--a Southwest Oncology Group study

The overall 38% response rate in histiocytosis X for cyclophosphamide, vincristine (Oncovin), prednisone, and procarbazine was not superior to responses that can be achieved with the component single agents. This is in contrast to the higher response rates that can be achieved by the combination of these agents in Hodgkin's disease. This is the second study of combination chemotherapy with individually effective agents that has failed to improve the response rates in histiocytosis patients with poor prognostic indicators.