Automation in cell and gene therapy manufacturing: from past to future

As more and more cell and gene therapies are being developed and with the increasing number of regulatory approvals being obtained, there is an emerging and pressing need for industrial translation. Process efficiency, associated cost drivers and regulatory requirements are issues that need to be addressed before industrialisation of cell and gene therapies can be established. Automation has the potential to address these issues and pave the way towards commercialisation and mass production as it has been the case for 'classical' production industries. This review provides an insight into how automation can help address the manufacturing issues arising from the development of large-scale manufacturing processes for modern cell and gene therapy. The existing automated technologies with applicability in cell and gene therapy manufacturing are summarized and evaluated here.

A retrospective analysis of the outcome of patients who have received two prior chemotherapy regimens including platinum and docetaxel for recurrent non-small-cell lung cancer

With the availability of chemotherapy agents for first- and second-line treatment of advanced non-small-cell lung cancer (NSCLC), the patient population that requires subsequent chemotherapy is increasing. This retrospective analysis was performed to describe the clinical course after two standard or approved chemotherapy agents in patients with good overall performance status. Data were selected from patients with advanced NSCLC who had received third- or fourth-line chemotherapy after two prior chemotherapy regimens that included platinum and docetaxel given concurrently or sequentially. Prior regiments had failed due to discase progression within 90 days of chemotherapy, or unacceptable toxicity. Examination of over 700 patient records between January 1993 and January 2000 at one US and one European cancer centre revealed 43 patients that fulfilled the inclusion criteria. Response rates decreased with each line of treatment: first line, 20.9%; second line, 16.3%; third line, 2.3%; and fourth line, 0%. The disease control rate (response plus stable disease) also decreased dramatically from first- to fourth-line treatment, although it was higher for second-line treatment (74.4%) than for first-line treatment (62.8%). The median overall survival time from diagnosis was 16.4 months. The median overall survival time from the start of the last treatment (either third or fourth line) was 4 months. Patients with stage III disease at diagnosis had a longer overall survival from diagnosis than patients with stage IV disease (P=0.02). This review highlights the need for novel therapy approaches for patients with recurrent NSCLC who have failed second-line therapy and provides a baseline for the statistical design of such studies.

A newly created splice donor site in exon 25 of the MyBP-C gene is responsible for inherited hypertrophic cardiomyopathy with incomplete disease penetrance

BACKGROUND

Hypertrophic cardiomyopathy is a myocardial disorder resulting from inherited sarcomeric dysfunction. We report a mutation in the myosin-binding protein-C (MyBP-C) gene, its clinical consequences in a large family, and myocardial tissue findings that may provide insight into the mechanism of disease.

METHODS AND RESULTS

History and clinical status (examination, ECG, and echocardiography) were assessed in 49 members of a multigeneration family. Linkage analysis implicated the MyBP-C gene on chromosome 11. Myocardial mRNA, genomic MyBP-C DNA, and the myocardial proteins of patients and healthy relatives were analyzed. A single guanine nucleotide insertion in exon 25 of the MyBP-C gene resulted in the loss of 40 bases in abnormally processed mRNA. A 30-kDa truncation at the C-terminus of the protein was predicted, but a polypeptide of the expected size ( approximately 95 kDa) was not detected by immunoblot testing. The disease phenotype in this family was characterized in detail: only 10 of 27 gene carriers fulfilled diagnostic criteria. Five carriers showed borderline hypertrophic cardiomyopathy, and 12 carriers were asymptomatic, with normal ECG and echocardiograms. The age of onset in symptomatic patients was late (29 to 68 years). In 2 patients, outflow obstruction required surgery. Two family members experienced premature sudden cardiac death, but survival at 50 years was 95%.

CONCLUSIONS

Penetrance of this mutation was incomplete and age-dependent. The large number of asymptomatic carriers and the good prognosis support the interpretation of benign disease.

Therapeutic trial for infant acute lymphoblastic leukemia: the Pediatric Oncology Group experience (POG 8493)

PURPOSE

Despite improved event-free survival of older children with acute lymphocytic leukemia (ALL), infants <1 year of age continue to have a very poor prognosis. A new therapy designed specifically for infants with ALL was initiated.

PATIENTS AND METHODS

From 1984 until 1990, 82 eligible infants <1 year of age were entered on a Pediatric Oncology Group (POG) protocol 8493 for infant ALL. Compared to older patients, infants at diagnosis had more overt CNS leukemia (26%), higher initial WBC count (56% >50,000/microl), and a higher likelihood of CD-10 (CALLA) negative lymphoblasts (55%). A translocation involving chromosome 11 at band q23 was detected in 27 of 64 cytogenetically informative cases. Treatment was based upon two institutional pilot studies utilizing chemotherapy doses based upon body weight. Important components included remission induction with cyclophosphamide (Ctx), vincristine (Vcr), cytosine arabinoside (Ara-C), and prednisone (Pred) (COAP); consolidation therapy with teniposide (VM-26) and Ara-C; and continuation therapy with alternating pulses of COAP with VM-26/Ara-C separated by a methotrexate (Mtx) and 6-mercaptopurine (6-MP) backbone plus CNS therapy consisting of standard triple intrathecal therapy (TIT) (Mtx/hydrocortisone/Ara-C), which avoided the use of radiotherapy in this population.

RESULTS

Seventy-six infants achieved a complete remission (93%). Fifty patients have relapsed: 35 isolated marrow relapses, five isolated CNS relapses, eight combined marrow and CNS relapses, and two other relapses. Actuarial event-free survival was 28% (SE = 5%) at 4 years. Infants >274 days (9 months) at diagnosis had a better outcome than those <274 days.

CONCLUSIONS

This study represents a modest outcome improvement in comparison to previous experience with ALL for infants treated on POG trials. More effective therapy is still needed for infants with ALL.

Bone marrow transplants from HLA-identical siblings as compared with chemotherapy for children with acute lymphoblastic leukemia in a second remission

BACKGROUND

It is unclear how best to treat children with acute lymphoblastic leukemia who are in a second remission after a bone marrow relapse. For those with HLA-identical siblings, the question of whether to perform a bone marrow transplantation or to continue chemotherapy has not been answered.

METHODS

We compared the results of treatment with marrow transplants from HLA-identical siblings in 376 children, as reported to the International Bone Marrow Transplant Registry, with the results of chemotherapy in 540 children treated by the Pediatric Oncology Group. A preliminary analysis identified variables associated with treatment failure in both groups. We selected cohorts by matching these variables. A possible bias associated with differences in the interval between remission and treatment was controlled for by choosing matched pairs in which the duration of the second remission in the chemotherapy recipient was at least as long as the time between the second remission and transplantation in the transplant recipient. A total of 255 matched pairs were studied.

RESULTS

The mean (+/- SE) probability of a relapse at five years was significantly lower among the transplant recipients than among the chemotherapy recipients (45 +/- 4 percent vs. 80 +/- 3 percent, P < 0.001). At five years the probability of leukemia-free survival was higher after transplantation than after chemotherapy (40 +/- 3 percent vs. 17 +/- 3 percent, P < 0.001). The relative benefit of transplantation as compared with chemotherapy was similar in children with prognostic factors indicating a high or low risk of relapse (the duration of the first remission, age, leukocyte count at the time of the diagnosis, and phenotype of the leukemic cells).

CONCLUSIONS

For children with acute lymphoblastic leukemia in a second remission, bone marrow transplants from HLA-identical siblings result in fewer relapses and longer leukemia-free survival than does chemotherapy.

Recombinant alpha-2B interferon treatment for childhood T--lymphoblastic disease in relapse. A Pediatric Oncology Group Phase II study

BACKGROUND

Children with chemotherapy refractory T-cell lymphoblastic leukemia/lymphoma were given alpha-interferon (alpha-IFN) to evaluate the efficacy and toxicity of this biologic response modifier.

METHODS

Twenty children with T-cell acute lymphoblastic leukemia (T-cell ALL) in marrow relapse and one patient with mediastinal recurrence of T-cell non-Hodgkin's lymphoma (T-cell NHL) were enrolled. All patients had failed at least two previous multiagent drug trials. Recombinant alpha-IFN was given at 30 million U/M2/dose intravenously or subcutaneously for 10 doses over 14 days, followed by 3 doses per week until disease progression occurred.

RESULTS

One child had a complete response (< 5% blasts) and three patients a partial response (5-25% blasts) in their bone marrow. All patients eventually showed signs of progressive disease. Significant toxicities included cardiac hypofunction in two patients and profound lethargy in two patients.

CONCLUSIONS

alpha-IFN is tolerated in children with T-cell ALL and T-cell NHL and has activity against chemotherapy resistant disease.

Long-term sequelae of therapy for childhood acute lymphoblastic leukaemia

Childhood ALL has provided the model for basic therapeutic principles in the past and now provides the model for late effects studies. Common threads which run throughout the literature in this area of clinical research are the importance of young age with increased vulnerability to long-term treatment induced sequelae and the relatively large contribution of radiation as compared with chemotherapy in the pathogenesis of adverse sequelae. Previous retrospective studies of long-term childhood ALL survivors focused on neuropsychologic changes and anatomic changes in the CNS after cranial irradiation. More recent retrospective studies have made the following new observations: (i) the high frequency of significant short adult stature in those less than 6 years of age at diagnosis who received 24 Gy cranial irradiation; (ii) actuarial risk of 2.5% of developing a second malignancy with approximately one-half of secondary malignancies occurring in the CNS in children 5 years of age or less who received cranial irradiation; (iii) the association of secondary ANLL with epipodophyllo-toxin use, and (iv) delayed cardiac toxicity despite anthracycline dosage reduction. Current therapy regimens, especially in high-risk patients, are both more successful and more intensive than those used in the past. While it will be another decade before many of the long-term sequelae begin to emerge, one can anticipate, based on current experience, some of the problems that will occur.

Phase I study of topotecan for pediatric patients with malignant solid tumors

PURPOSE

To determine the dose-limiting toxicity and potential efficacy of topotecan in pediatric patients with refractory malignant solid tumors.

PATIENTS AND METHODS

In this phase I clinical trial, 27 patients received topotecan 0.75-1.9 mg/m2 by continuous intravenous infusion daily for 3 days. Fifty-three treatment courses were given to these patients.

RESULTS

Myelosuppression was the dose-limiting toxicity at levels of 1.3 to 1.9 mg/m2 for 3 days, requiring significant support with transfused packed RBCs and platelets. Myelosuppression was variable in severity at the 1.0-mg/m2 dosage level; thus, additional patients were treated with this dosage, followed by human recombinant granulocyte-colony stimulating factor (G-CSF). Other toxicities were not significant. One patient with neuroblastoma had a complete response that lasted for 8 months. Stable disease activity was recorded for other patients with neuroblastoma, rhabdomyosarcoma, and islet cell carcinoma. Pharmacokinetic studies showed that topotecan plasma concentrations ranged from 1.6 to 7.5 ng/mL during infusions of 1.0 mg/m2/d, and that there was a biphasic plasma distribution with a mean terminal half-life of 2.9 +2- 1.0 hours.

CONCLUSION

Topotecan is a promising anticancer agent that deserves phase II testing in pediatric solid tumors. We recommend that pediatric phase II topotecan trials use 1.0 mg/m2/d for 3 days as a constant intravenous infusion, followed by G-CSF for 14 days, and that these treatment courses be repeated every 21 days.

Predominance of pilocytic histology in dorsally exophytic brain stem tumors

We report the magnetic resonance imaging (MRI) and clinico-histologic characterization of dorsally exophytic brain stem gliomas (DEBSGs). Between 1983 and 1991, 12 of 51 patients evaluated for the diagnosis of brain stem glioma were found to have DEBSGs emanating from the pons, pontomedullary junction or medulla. Eleven of the 12 patients had classic juvenile pilocytic astrocytomas. Unlike most other brain stem tumors, these patients were young (median 38 months, range 17-75), had a relatively long duration of symptoms (median 7 months, range 2-24) and displayed signs of increased intracranial pressure with limited cranial nerve paresis, absence of pyramidal tract findings, and near normal brain stem auditory-evoked potentials. MRI characteristically showed sharply demarcated lesions with decreased signal intensity on T1, and increased intensity on T2 sequences. Except for cystic areas, these tumors showed bright, uniform enhancement after gadolinium-DTPA. In all patients, 50-100% of the tumor volume could be resected. Three of 10 patients who received no immediate postoperative treatment eventually demonstrated disease progression, and 2 patients with subtotal resections who were treated with radiation and/or chemotherapy postoperatively remain disease-free for extended periods of time. The only death occurred in the 1 patient treated with chemotherapy who died of secondary leukemia. The overall and progression-free survival of these patients at 2 years is 100 and 67% as compared to 18 and 21%, respectively, for other concomitantly treated nonexophytic brain stem gliomas.2+ the ability to achieve significant degrees of resection.

High-dose chemotherapy and autologous bone marrow rescue followed by interstitial and external-beam radiotherapy in newly diagnosed pediatric malignant gliomas

PURPOSE

Evaluation of high-dose chemotherapy with autologous bone marrow rescue (ABMR) in pediatric malignant gliomas.

PATIENTS AND METHODS

Newly diagnosed (n = 11) and recurrent (n = 2) malignant glioma patients received high-dose chemotherapy within 4 weeks of surgery; three had near total and 10 had subtotal resection/biopsy. High-dose thiotepa (300 mg/m2) and cyclophosphamide (2 g/m2) daily for 3 days were followed by ABMR; response was evaluated at day 30. At day 60, patients with at least stable disease received hyperfractionated (n = 9) or conventional external-beam radiotherapy (n = 2) preceded by local radioactive iodine 125 implantation (n = 2) or radiosurgery (n = 1).

RESULTS

Grade III and IV toxicities after ABMR consisted of mucositis (n = 12), cardiomyopathy (n = 1), acute abdomen (n = 1), pneumonitis (n = 2), and infection (n = 2). One complete and three partial responses were observed; the objective response rate was 31% (95% confidence interval, 9% to 61%). Seven had stable disease, one had disease progression, and one died of toxicity before response evaluation. The median overall and progression-free survival durations after combined modality therapy were 14 months (range, 4 to 30+) and 9 months (range, 0 to 30+), respectively. One patient remains progression-free at 30+ months. Radionecrosis and white matter changes occurred in three patients: one after hyperfractionated irradiation, and two after 125I implants.

CONCLUSION

For patients with bulky residual disease after surgery, survival with this aggressive chemotherapy and radiation regimen is not better than that reported for conventional treatment regimens.

Expression of hepatitis B virus core gene products with specific immunoreactivity for e antigen (HBeAg) in Saccharomyces cerevisiae

The e antigen of the hepatitis B virus (HBeAg) was expressed in S. cerevisiae. Yeast-derived HBeAg exhibits high HBe antigenicity while lacking any HBc antigenicity. The production yield of HBeAg expressed in yeast is dependent on the host strains and the nature of the leader sequences used in the plasmid constructions. The recombinant antigen is not secreted into the medium, independent from the leader sequences which are used. A simple extraction procedure was developed, enabling the isolation of HBeAg from the cells without killing them. Recombinant HBeAg derived from yeast can replace plasma-derived antigen in ELISA for determining antibodies to HBeAg.

A phase I study of ifosfamide with Mesna given daily for 3 consecutive days to children with malignant solid tumors

BACKGROUND

The authors conducted a Phase I dose escalation trial of ifosfamide given daily for 3 consecutive days to 29 children with malignant solid tumors. Twenty-eight of these children had received prior chemotherapy.

METHODS

Patients were assigned to dosage cohorts separately on the basis of prior exposure to the platinum alkylating agents cisplatin or carboplatin (n = 20) or the absence of such exposure (n = 9). At least three patients in each category were treated at a starting dosage of 2133 mg/m2/d for 3 days. This dosage represented 80% of the total dose delivered in the prior study of ifosfamide given daily over 5 days with dosage escalation of 20% in subsequent cohorts.

RESULTS

Myelosuppression was dose-limiting at the second dosage level (2560 mg/m2/d) for patients previously treated with platinum and at the third dosage level (3072 mg/m2/d) for those not previously treated with platinum. Dose-limiting neurotoxicity was seen at 2560 mg/m2/d for the former group, but was not encountered in the latter group.

CONCLUSIONS

Delivery of ifosfamide daily for 3 days is feasible and safe at recommended dosages of 2133 mg/m2/d for children with prior exposure to platinum and 3000 mg/m2/d for those without prior exposure.

Impact of three methods of treatment intensification on acute lymphoblastic leukemia in children: long-term results of St Jude total therapy study X

Long-term follow-up observations are reported on 427 patients who received one of three different intensified therapies in total therapy study X for acute lymphoblastic leukemia (ALL). In the trial for 'standard-risk' ALL, 154 of 309 patients in complete remission were randomized to receive high-dose methotrexate (HDMTX, 1 g/m2) periodically during the first 72 of 120 weeks of standard continuation therapy with 6-mercaptopurine and oral MTX; the remaining 155 patients received 1800 cGy cranial irradiation and intrathecal MTX, followed by 6-mercaptopurine/MTX therapy interrupted from week 36-71 for substitution of two other pairs of drugs. At 9 years of follow-up, significantly higher proportions of patients in the HDMTX group have maintained complete remissions (64 +/- 7%, SE, vs. 52 +/- 6%, p = 0.03), hematologic remissions (73 +/- 6% vs. 62 +/- 6%, p = 0.03), and testicular remissions (94 +/- 5% vs. 80 +/- 8%, p = 0.03); however, the proportion continuing in central nervous system remission has been lower (84 +/- 5% vs 93 +/- 4%, p = 0.02). In the evaluation of teniposide/cytarabine and delayed cranial irradiation for 'high-risk' ALL, 36 +/- 9% of 101 patients are predicted to be event-free survivors at 9 years. Altogether, 217 (51%) of the 427 patients are event-free survivors after at least 7 years of follow-up (median, 9 years); an additional 75 patients are alive and free of leukemia for a median of 6.4 years after successful remission retrieval therapy, boosting the total number of long-term survivors to 292 (68%). These results establish the efficacy of HDMTX for patients with standard-risk ALL and indicate the potential of teniposide/cytarabine for use in multiagent regimens for patients with high-risk disease. The overall survival figure, 68%, affords a benchmark for other studies assessing long-term outcome in ALL.

Deterioration of intellect among children surviving leukemia: IQ test changes modify estimates of treatment toxicity

This study assessed the association of young age at treatment, cranial irradiation, and time since treatment with intellectual deterioration among 49 long-term survivors of childhood leukemia. Ss had been randomized to receive low-dose cranial radiation therapy or high-dose chemotherapy. Longitudinal assessments of intellect were conducted. No significant effects of treatment group or age at treatment were detected. A small but statistically significant decline in mean full-scale IQ was noted over time (M = -3.6). Reanalysis with IQ test version included as a covariate eliminated IQ declines found initially. Results suggest (a) that there has been reduced toxicity of these methods of treatment and (b) that the magnitude and direction of error introduced by changing tests may approximate the magnitude of adverse effects on IQ from treatment.

Response to alpha-interferon in children with Philadelphia chromosome-positive chronic myelocytic leukemia

The therapeutic efficacy and toxicity of alpha-interferon (alpha-IFN) (Roferon, Hoffmann-La Roche, Inc., Nutley, NJ) were determined in 15 children (age range, 6 to 20 years) with Philadelphia chromosome-positive chronic myelocytic leukemia (Ph+ CML). All patients had received cytoreductive therapy with either hydroxyurea (n = 13) or busulfan (n = 1) or both (n = 1) for 6 weeks to 46 months (median, 7 months) before beginning alpha-IFN therapy at a dose of 5 x 10(6) U/m2/d intramuscularly. This dose was escalated to 10 x 10(6) U/m2/d if leukemia was inadequately controlled. Ten children had a hematologic response, with nine showing a reduction in the percentage of Ph+ marrow cells, including four who had no detectable Ph+ cells in marrow samples collected 48 to 204 weeks after the initiation of therapy. Two of 15 patients remain free of Ph+ cells. Therapy was discontinued before week 104 in ten patients because of the following: (1) early hematologic responses without a decrease in Ph+ cells (three patients); (2) early resistant disease (one patient); (3) blast crisis (one patient); (4) progressive disease (two patients); (5) seizure attributed to high-dose alpha-IFN (one patient); or (6) an inadequate trial of alpha-IFN caused by aseptic necrosis or poor compliance (two patients). The most common side effects were mild and have included fever, malaise, headache, myalgias, and pain at the injection site. Adverse events causing interruption of therapy were seizures, aseptic necrosis, and myelofibrosis. alpha-IFN stabilizes the chronic phase of Ph+ CML in some children, is adequately tolerated when administered at a dose of 2.5 to 5 x 10(6) U/m2/d intramuscularly, and results in a significant decrease in the proportion of Ph+ metaphases in some patients. alpha-IFN in combination with an effective cytoreductive agent or agents appears worthy of further clinical testing in this disease.

A prospective comparison of neuropsychologic performance of children surviving leukemia who received 18-Gy, 24-Gy, or no cranial irradiation

To compare the late neuropsychologic toxicities of CNS prophylaxis for childhood acute lymphoblastic leukemia (ALL), longitudinal assessments were performed on three groups of patients: those who received repeated courses of moderate-dose (1 g/m2) intravenous (IV) and intrathecal methotrexate (IT MTX) without cranial irradiation (MTX group, n = 26), those who received IT MTX and 18 Gy cranial irradiation (18-Gy group, n = 23), and those who received IT MTX and 24 Gy cranial irradiation (24-Gy group, n = 28). All patients were free of CNS leukemia at diagnosis and had remained in continuous, complete remission 5 to 11 years (median, 7.4 years) following CNS prophylaxis. An analysis of serial intelligence quotient (IQ), achievement, and neuropsychologic studies revealed no significant influence of either age at CNS prophylaxis or CNS prophylaxis group on any neuropsychologic outcome measure. After adjusting for changes in IQ test versions that were necessitated by advancing patient age, no statistically significant declines in Verbal, Performance, or Full Scale IQs were noted for the three CNS treatment groups. However, comparisons of group means masked declines in individual children; 22% to 30% of children exhibited a clinically significant deterioration (greater than or equal to 15 points) in uncorrected IQ values over the study period. Female sex was associated with an increased risk of deterioration in Verbal IQ, but we were unable to identify risk factors associated with other declines in intellect and achievement. The inability to reliably predict individual patients at risk for clinically significant neuropsychologic toxicities on the basis of age at diagnosis or specific method of CNS prophylaxis suggests that other etiologic factors must be explored as the basis for these changes, such as ecologic factors and chemotherapy during the continuation phase of treatment.

Risk of adverse events in children completing treatment for acute lymphoblastic leukemia: St. Jude Total Therapy studies VIII, IX, and X

We studied the frequency, causes, and predictors of adverse events in 624 patients who had completed treatment for acute lymphoblastic leukemia (ALL) in three consecutive total therapy studies (VII, IX, and X, 1972 to 1983). Event-free survival in study X was significantly better overall than that in studies VIII and IX (P less than .0001 by the log-rank test). In study X, 75% of the patients were electively taken off therapy, compared with 54% in studies VIII and IX. However, the risks of having an adverse event during the first 5 years after completion of therapy were remarkably similar: 22% (95% confidence interval, 17% to 29%) in study X versus 24% (20% to 29%) in studies VIII and IX. Bone marrow, testicular, and CNS relapses accounted for the majority of failures in both groups (85% in study X and 92% in studies VIII and IX). Late adverse events consisted largely of hematologic relapses and the development of solid tumors. Black race (P = .001) and leukemia without an anterior mediastinal mass (P = .05) were associated with an increased risk of failure after completion of treatment in the two earlier clinical trials, whereas a lower leukemic cell DNA content (DNA index less than 1.16) was the only predictor of late treatment failure in the more recent trial (P = .019). None of the other presenting features that were examined (eg, age, leukocyte count, and sex) had value as predictors of late failure. Thus, improved treatment altered the impact of specific prognostic factors and the distribution of sites of relapse, but it did not significantly affect the risk of delayed failure.

Recombinant interferon alfa given before and in combination with standard chemotherapy in children with acute lymphoblastic leukemia in first marrow relapse: a Pediatric Oncology Group pilot study

Recombinant interferon alfa (rIFN-alpha) was given to 31 children with acute lymphoblastic leukemia (ALL) in first on-therapy marrow relapse as the sole treatment (30 megaunits/m2/d intravenously x 10 days) before standard four-drug reinduction and during multiagent continuation therapy (30 megaunits/m2 subcutaneously x 3 consecutive days every 3 weeks). After 10 days of rIFN-alpha, there were two partial remissions (PRs); seven additional patients had either greater than or equal to 25% reduction in the percentage of marrow blast cells or hypoplastic marrow. Two patients had progressive disease with an increase in leukocyte counts. All patients experienced influenza-like symptoms, and there were isolated instances of severe abdominal pain and personality change. Dose-limiting toxicity comprised grade III/IV transaminase elevation (two patients) and syncope with personality change (one patient). Twenty-three of 31 children (74%) subsequently achieved marrow remission using standard agents. One patient was taken off study during teniposide (VM-26) and cytarabine (ara-C) consolidation due to toxicity. Continuation therapy including rIFN-alpha pulse was well tolerated in the remaining children; only one patient required rIFN-alpha dosage reduction (for CNS toxicity). rIFN-alpha toxicity did not necessitate reductions in doses of standard chemotherapy agents or significant delays in therapy. Five patients remain in remission at 26+ to 36+ months; 13 patients relapsed in marrow, one in the meninges (7 months), and one in meninges, mediastinum, and lymph nodes (2 months). Two children were removed from study for marrow transplant. In summary, high-dose rIFN-alpha alone had a modest antileukemic effect. In contrast to the clinical experience with combined rIFN-alpha and chemotherapy in adults, rIFN-alpha given in a pulse-like manner throughout continuation therapy did not compromise the intensity of the standard chemotherapy regimen.

Expression of the human blood coagulation protein Factor XIIIa in Saccharomyces cerevisiae: dependence of the expression levels from host-vector systems and medium conditions

The human blood coagulation protein Factor XIIIa (FXIIIa) was expressed in Saccharomyces cerevisiae employing Escherichia coli-yeast shuttle vectors based on a 2-mu plasmid. Several factors affecting high production yield of recombinant FXIIIa were analysed. The use of the regulatable GAL-CYC1 hybrid promoter resulted in higher FXIIIa expression when compared with the constitutive ADCI promoter. Screening for suitable yeast strains for expression of FXIIIa under the transcriptional control of the GAL-CYC1 hybrid promoter revealed a broad spectrum of productivity. No obvious correlation between the expression rate and the genetic markers of the strains could be identified. The medium composition markedly influenced the FXIIIa expression rates. The expression of FXIIIa was strictly regulated by the carbon source. Glucose as the only sugar and energy source repressed the synthesis of FXIIIa, whereas addition of galactose induced FXIIIa expression. Special feeding schemes resulted in a productivity of up to 100 mg FXIIIa/l in shake flasks.

Parental report of everyday cognitive abilities among children treated for acute lymphoblastic leukemia

Compared ratings of everyday cognitive functioning made by parents of leukemic children to ratings made by parents of normal control and learning disabled (LD) children. The leukemic children had been randomly assigned to one of two CNS prophylaxis treatments, one including cranial irradiation and intrathecal methotrexate and another including only intrathecal methotrexate and intermediate dose infusions of methotrexate. Leukemic children were rated significantly worse than controls in areas related to schooling and academic skills. The type of CNS prophylaxis was not discriminated by parent ratings. LD children were rated as significantly worse than either of the two groups in all areas of cognitive functioning. Leukemic and LD children were both rated as having poor academic skills. Leukemic children missed significantly more school than control and LD children, and their poor ratings on academic skills were partially attributed to academic deprivation. These results suggest that studies should control for academic deprivation when evaluating the neuropsychological outcome of CNS prophylactic treatment and that reintegration and normalization programs should be designed to address the intellectual problems resulting from missed academic experiences.

A phase II study of combined methotrexate and teniposide infusions prior to reinduction therapy in relapsed childhood acute lymphoblastic leukemia: a Pediatric Oncology Group study

Teniposide (VM-26) can increase intracellular methotrexate (MTX) and its polyglutamate derivatives in vitro and thus has the potential to improve the therapeutic index of regimens containing MTX. In this phase II study, children and adolescents with acute lymphoblastic leukemia (ALL) in first or second marrow relapse were randomly assigned to receive either simultaneous (n = 11) or sequential (n = 12) continuous infusions of MTX and VM-26 prior to reinduction. Infusions of VM-26 were begun 12 hours after completion of MTX infusion in the sequential group. Dosages were individually adjusted to maintain plasma concentration levels of 10 microns for MTX and 15 microns for VM-26; total infusion times were 24 and 72 hours, respectively. Significant toxicity in the first six patients who received the scheduled 72-hour VM-26 infusion (including one drug-related death) prompted a 50% reduction in infusion duration. The reduced dose was associated with similar but more manageable toxicity. Examination of bone marrow aspirates 10 days after therapy was begun showed one complete and two partial marrow remissions; a fourth patient who had an aplastic marrow on day 10 received no further chemotherapy and had a complete remission (CR) documented on day 31. There was no obvious clinical advantage associated with either infusion schedule, although small sample sizes preclude definitive conclusions. The 17% response rate to the MTX/VM-26 therapeutic window in patients with refractory disease suggests the need for further investigation to evaluate alternative schedules and concomitant therapy for this drug combination.

Comparison of neuropsychologic functioning and clinical indicators of neurotoxicity in long-term survivors of childhood leukemia given cranial radiation or parenteral methotrexate: a prospective study

We prospectively compared neuropsychologic functioning and clinical indicators of neurotoxicity in 49 consecutive childhood leukemia patients in long-term continuous complete remission (CR) who had received two different regimens of CNS prophylaxis by random assignment. Twenty-three patients were treated with 1,800 cGy cranial radiation and intrathecal methotrexate (RT group) and 26 with parenteral methotrexate only (MTX group). Over half of the RT group had somnolence syndrome, and four developed cerebral calcifications late in their clinical course. Abnormal electroencephalograms (EEGs) were seen in 15 patients in the MTX group, and six had early, transient white-matter hypodensities apparent on computed tomographic (CT) scans. Mean scores on standard tests of intelligence and academic achievement, administered after remission induction and again at a median of 6 years after treatment cessation, did not differ significantly between the two groups. However, statistically significant decreases in overall and verbal intelligence quotients (IQs) and in arithmetic achievement were found within both treatment groups. Sixteen of 26 in the MTX group and 14 of the 23 in the RT group had clinically important decreases (greater than or equal to 15 points) on one or more neuropsychologic measures. These changes did not correlate with findings on CT scans, EEGs, or other clinical signs of neurotoxicity. We conclude that 1,800 cGy cranial radiation and parenteral methotrexate, as used in this study, are associated with comparable decreases in neuropsychologic function.

Teniposide (VM-26) and continuous infusion cytosine arabinoside for initial induction failure in childhood acute lymphoblastic leukemia. A Pediatric Oncology Group pilot study

Twenty-six evaluable children with newly diagnosed acute lymphoblastic leukemia (ALL) who failed to achieve initial remission after receiving two to seven drugs for at least a 4-week period were given teniposide (VM-26) and continuous infusion cytosine arabinoside (Ara-C). Twenty-two received 150 mg/m2 of VM-26 on days 1 and 2 with 100 mg/2 of Ara-C as a continuous infusion on days 1 through 5; a second shortened course was given on day 14 to eight patients who had evidence of some antileukemic effect or were clinically judged able to tolerate a second course. The last four patients received three daily doses of VM-26 and a 7-day infusion of Ara-C at the same daily dosages. Twelve (48%) achieved complete remission (CR) of ALL. There was a trend toward decreasing response rates with an increasing number of drugs used in the initial induction regimen, i.e., five CR among seven patients with a prior two-drug induction attempt, six CR among 14 patients with a prior three- to four-drug induction attempt, and one CR among four patients with a prior five- to seven-drug induction attempt (P = 0.14). Ten of 17 non-T-cell patients and two of nine T-cell patients achieved remission (P = 0.10). The median time required to achieve a complete remission from the initiation of treatment was 26 days (range, 14-72 days). This period was shorter in those who required one course compared with those who required two induction courses, i.e., 25 days median vs. 44 days median. Toxicity was significant and due mainly to marrow aplasia and infection; one patient had severe prolonged VM-26-induced hypotension. Of the 12 patients entering remission, two were removed for marrow transplant and one was removed due to parental request. In the remaining nine patients, median remission duration was only 2 months (range, 1-18 months). All nine patients relapsed in the marrow. Among the entire group of 26 patients, only one patient is alive and a long-term event-free survivor (after allogeneic marrow transplant). Due to the current use of more aggressive initial induction regimens and the extremely poor prognosis in children who fail to achieve initial remission, more intensive regimens of continuation therapy or alternative therapies, such as bone marrow transplant, should be considered.

Pharmacokinetics of continuous infusion of methotrexate and teniposide in pediatric cancer patients

Laboratory studies have demonstrated the ability of teniposide to markedly enhance the intracellular accumulation of methotrexate suggesting that combination therapy with these agents may produce clinical benefit. Studies of methotrexate and teniposide were conducted in 19 children with relapsed acute lymphocytic leukemia to evaluate the pharmacokinetics of this previously untested combination of agents given alone or in combination and to demonstrate the feasibility of a Bayesian dose optimization strategy. Patients were randomly assigned to receive intermediate dose methotrexate as a 24-h continuous infusion, administered either simultaneously with continuous infusion teniposide or sequentially with the teniposide infusion beginning 12 h after the end of the methotrexate infusion. Plasma samples were obtained during and after infusions at appropriate times for a comprehensive pharmacokinetic study of each drug. Two measured drug concentrations obtained during the infusion were used to adjust each patient's dose rate to achieve target values of 10 microM for methotrexate and 15 microM for teniposide. Pharmacokinetic parameters for teniposide were not different for patients given simultaneous methotrexate from parameters estimated for patients receiving teniposide 12 h after the end of the methotrexate infusion. Despite similar end of infusion methotrexate concentrations, 24-h postinfusion methotrexate concentrations were lower (0.137 versus 0.235 microM; P less than 0.05) in the patients receiving simultaneous infusions. The patient specific dose regimens yielded acceptably precise, minimally biased steady state drug concentrations. These pharmacokinetic results provide the basis for further clinical studies with this combination of antileukemic agents.

Intensified chemotherapy for childhood lymphoblastic leukemia: modifications and results of induction treatment in St. Jude Study XI

The value of intensified chemotherapy for improving event-free survival rates in childhood lymphoblastic leukemia (ALL) is now widely accepted among leukemia therapists. Still to be determined are (1) the optimal method of intensification, (2) the subset or subsets of patients for whom such treatment may be excessive, and (3) whether or not cure rates in ALL can be further improved by alternative approaches to intensification. St. Jude Total Therapy Study XI, based on predictions of the Goldie-Coldmand model of drug resistance, addresses some of these questions by use of rotational "non-cross-resistant" drug pairs throughout the course of therapy. A new method of risk classification has been developed to refine distinctions among prognostic subgroups, especially to identify patients with biologically unfavorable ALL. Unacceptable toxicity noted in the first 134 children enrolled in this study led to two protocol modifications. One hundred thirty-two patients have been treated subsequently without undue toxicity. The treatment is now being delivered safely. Our early experience with this regimen demonstrates some of the hazards of intensive multidrug combination treatment, but gains in leukemia control appear to justify this approach.

Removal of methotrexate, leucovorin, and their metabolites by combined hemodialysis and hemoperfusion

This article documents the case of a patient with severe renal failure immediately after having been given high-dose methotrexate; the patient was effectively treated with repeated hemodialysis, charcoal hemoperfusion, leucovorin, and thymidine. The methotrexate plasma concentration was reduced from 390 mumol/L to 7 mumol/L as a result of 24.5 hours of hemodialysis along with 39.5 hours of hemoperfusion. Although a rebound in the plasma methotrexate concentration occurred the first three times that hemodialysis and/or hemoperfusion was stopped, reinstitution of the procedure was always effective in further lowering methotrexate concentrations. The patient was subsequently managed with leucovorin and thymidine rescue. Simultaneous measurements before and after the hemodialysis-hemoperfusion apparatus and before and after the hemoperfusion device alone revealed a percent decrease in the concentration of d-leucovorin of 36% and 79%; 1-leucovorin, 82% and 75%; 5-methyltetrahydrofolate, 52% and 64%; methotrexate, 73% and 37%; and 7-hydroxymethotrexate, 21% and 24%, respectively. Gastrointestinal and hematologic toxicities were completely prevented, and serum creatinine normalized within 24 days.

Late effects of antileukemic treatment

Increasing numbers of childhood ALL survivors have increased the need to assess the physical and psychosocial functioning of this group in a careful manner. This article reviews data on the frequency and types of second malignancies, structural and functional changes in the central nervous system, endocrine effects on growth and reproduction, and psychosocial aspects of development. Most long-term survivors of ALL do not have serious or life-threatening medical problems; however, medical and psychosocial problems may not be insignificant and may require coordinated management over prolonged periods.

Efficacy of high-dose methotrexate in childhood acute lymphocytic leukemia: analysis by contemporary risk classifications

High-dose methotrexate (HDMTX) added to a basic regimen of chemotherapy proved superior to cranial irradiation and sequentially administered drug pairs (RTSC) in prolonging complete remissions in children with "standard-risk" acute lymphocytic leukemia. To extend this result to more contemporary risk groups, we reclassified the patients according to methods of the Pediatric Oncology Group (POG), the Childrens Cancer Study Group (CCG), the Rome workshop, and St Jude Total Therapy Study XI. By life table analysis, 70% to 78% of patients with a favorable prognosis would remain in continuous complete remission (CCR) at 4 years if treated with HDMTX. Uniformly lower CCR rates could be expected with RTSC, especially in St Jude better-risk patients. HDMTX also would show greater efficacy than RTSC in the CCG average-risk and POG poor-risk groups, but the results appear inferior to those being achieved with intensified regimens for high-risk leukemia. Although both therapies would provide adequate CNS prophylaxis in favorable-risk groups, RTSC would offer greater protection in patients classified as being in a worse-risk group by St Jude criteria. We conclude that HDMTX-based therapy, as described in this report, would be most effective in patients with a presenting leukocyte count of less than 25 x 10(9)/L, of the white race, aged 2 to 10 years, and having leukemic cell hyperdiploidy without translocations.

Memory function in disease-free survivors of childhood acute lymphocytic leukemia given CNS prophylaxis with or without 1,800 cGy cranial irradiation

Previous studies have found that CNS prophylaxis of children with leukemia, especially young children receiving cranial irradiation, causes neuropsychologic deficits. In the present study, 40 children in continuous complete remission from acute lymphocytic leukemia (ALL) were given a battery of tests to assess memory functioning 5 years after CNS prophylaxis. All children were free of CNS disease at diagnosis and had been randomly assigned to receive CNS prophylaxis with either 1,800 cGy cranial irradiation (CRT) plus intrathecal (IT) methotrexate (MTX) or IT MTX plus intravenous (IV) high-dose MTX (HDMTX). No treatment- or age-related differences were seen on 16 standardized memory measures. However, scores of the combined sample were significantly lower than age-corrected norms on a test of visual-spatial memory and on four scales of verbal memory. Differences in methods or intensity of CNS prophylaxis and study group selection criteria are proposed to explain our findings and to resolve discrepancies with previous reports. The long-term neuropsychological sequelae in these survivors of ALL may be attributable to some common factor, such as the disease itself or systemic and IT chemotherapy.

High-dose methotrexate improves clinical outcome in children with acute lymphoblastic leukemia: St. Jude Total Therapy Study X

High-dose methotrexate (HDMTX, 1,000 mg/m2) and cranial irradiation/sequential chemotherapy (RTSC) were compared for ability to extend complete remission durations in children with acute lymphoblastic leukemia (ALL). Three hundred thirty patients were enrolled in the study, according to our criteria for standard-risk ALL: a leukocyte count less than 100 X 10(9)/L, no mediastinal mass, no leukemic involvement of the central nervous system (CNS), and blast cells lacking sheep erythrocyte receptors and surface immunoglobulin. Prednisone-vincristine-asparaginase induced complete remissions in 95% of the patients, who were then randomized to receive either HDMTX (n = 154) or RTSC (n = 155). HDMTX was administered with intrathecal MTX for the first 3 weeks following remission induction, and then every 6 weeks with daily mercaptopurine (MP) and weekly oral MTX for a total of 18 months. The RTSC regimen consisted of 1,800 cGy cranial irradiation and intrathecal MTX for 3 weeks, followed by MP/MTX, cyclophosphamide/doxorubicin, and teniposide/cytarabine administered sequentially over 18 months. The final 12 months of treatment for both groups was MP and oral MTX; all patients received intrathecal MTX every 12 weeks. With a median follow-up of 5 years, complete remission durations have been significantly longer among children treated with HDMTX, compared with RTSC (P = .049) or historical institutional control regimens (P = .002). Approximately 67% of the patients receiving HDMTX and 56% of those receiving RTSC are expected to be in continuous complete remission at 4 years. Overall, isolated CNS relapse rates were similar (P = .17) in the two treatment groups, although by newer risk criteria cranial irradiation could be expected to provide better protection in patients with an unfavorable prognosis. These findings indicate that addition of intermittent HDMTX infusions to conventional chemotherapy is an effective method for extending complete remissions in children with ALL.

Cyclic combination chemotherapy for acute lymphoblastic leukemia recurring after elective cessation of therapy

Cyclic combination chemotherapy was administered to 26 patients with acute lymphoblastic leukemia who had relapsed in the bone marrow greater than or equal to 6 months after elective cessation of therapy. Each patient had been in initial continuous complete remission for 36-111 months (median, 47 months). Prednisone, vincristine, and doxorubicin induced second complete remissions in all patients within 1 month. Continuation therapy consisted of alternating 6-week courses of 6-mercaptopurine/methotrexate and vincristine/cyclophosphamide with intervening reinforcement courses of prednisone/doxorubicin, for a total of 18 months. All patients received 4 weeks of late intensification therapy with the same agents used for remission reinduction. Periodic intrathecal methotrexate was given as reprophylaxis for subclinical central nervous system leukemia. The estimated rate of continuous failure-free survival at 5 years is 31% +/- 17% (2 SE). Eight patients remain free of leukemia for 42 + to 65+ months after completing therapy a second time. Adverse second events included 11 hematologic, 1 testicular, and 3 meningeal relapses. Patients who relapsed at more than 12 months after the completion of initial treatment have had significantly longer second remissions than patients whose first remissions were shorter (p = .04). None of the other six factors we analyzed showed predictive strength. These end results indicate that intensive cyclic continuation chemotherapy, as described here, will secure durable second remissions in approximately one-third of the children with late bone marrow relapses.

Teniposide plus cytarabine improves outcome in childhood acute lymphoblastic leukemia presenting with a leukocyte count greater than or equal to 100 x 10(9)/L

Childhood acute lymphoblastic leukemia with an initial leukocyte count greater than or equal to 100 X 10(9)/L responds poorly to conventional chemotherapy. To extend event-free survival (EFS) in this disease, we devised a protocol that specifies intensive 2-week courses of teniposide (VM-26, 165 mg/m2) plus cytarabine (ara-C, 300 mg/m2), before and immediately after standard 4-week remission induction therapy with prednisone, vincristine, and L-asparaginase. The VM-26 and ara-C combination was also administered intermittently for the first year of continuation treatment with oral 6-mercaptopurine and methotrexate. CNS prophylaxis consisted of periodic intrathecal (IT) injections of methotrexate and delayed cranial irradiation. At a median follow-up of 4 years, the estimated EFS rate for 57 consecutive patients with leukocyte counts of 100 to 1,000 X 10(9)/L was 44%, compared with 10% for matched controls (P less than .001). Remission induction rates in the two groups were similar (82% v 72%, P = .16). Twenty-five patients in the VM-26/ara-C group have survived without adverse events for 2.7 to 6.8 years, whereas only nine of the controls achieved more than a year of EFS. The most common complications during early treatment were acute hyperkalemia from rapid tumor cell lysis and infections due to prolonged marrow aplasia. Continuation chemotherapy was well tolerated. We conclude that VM-26 plus ara-C, added to each phase of an otherwise basic regimen of chemotherapy, will substantially improve prognosis in this high-risk form of childhood leukemia.