Granulocyte colony-stimulating factor (rh G-CSF) as an adjunct to interferon alpha therapy of neutropenic patients with hairy cell leukemia

Prompt Hematological Recovery in Response to a Combination of Pegylated Interferon α-2a and Rituximab in a Profoundly Immuno-Suppressed Hairy Cell Leukemia Patient with a Mycobacterial Infection at Onset: Benefits and Drawbacks of Rapid Immune Reconstitution

The present paper reports, to the best of our knowledge for the first time, the efficacy and tolerability of the combination of interferon (IFN)α-2a in pegylated formulation and rituximab after a “priming” phase with IFN in the frontline treatment of hairy cell leukemia (HCL) in a profoundly immunosuppressed patient with a Mycobacterium abscessus infection at onset. This immunotherapy combination may represent a potential therapeutic option in patients with active severe infection and for whom the use of purine nucleoside analogues (PNA) is contraindicated. The benefits and drawbacks of remarkably rapid immune reconstitution in the context of opportunistic infections are highlighted as well, as the potentially paradoxical effects of immune recovery as a result of effective immunotherapy strategies, known as immune reconstitution inflammatory syndrome (IRIS), have to be taken into account when dealing with patients with opportunistic infections.

Cost-effectiveness of growth factors during hepatitis C anti-viral therapy

BACKGROUND

Although the current standard of care for controlling anaemia and neutropenia during anti-viral therapy for hepatitis C is to use dose reduction of ribavirin and pegylated interferon, respectively, erythropoietin and granulocyte colony-stimulating factor are now being advocated as alternatives to dose reduction.

AIM

To determine the cost-effectiveness of erythropoietin and granulocyte colony-stimulating factor as an alternative to anti-viral dose reduction during antihepatitis C therapy.

METHODS

Decision analysis was used to assess cost-effectiveness by estimating the cost of using a growth factor per quality-adjusted life-year gained.

RESULTS

Under baseline assumptions, the cost per quality-adjusted life-year of using growth factors ranged from 16,247 US dollars for genotype 1 with neutropenia to 145,468 US dollars for genotype 2/3 patients with anaemia. These findings are sensitive to the relationship between dose reduction and sustained virological response.

CONCLUSIONS

Based upon our findings and the varying strength of the evidence for a relationship between dose reduction and sustained virological response: granulocyte colony-stimulating factor may be cost-effective for genotype 1 patients; erythropoietin is probably not cost-effective for genotype 2/3 patients; no conclusion can be reached regarding the cost-effectiveness of erythropoietin for genotype 1 patients or granulocyte colony-stimulating factor for genotype 2/3 patients. Randomized trials are needed to firmly establish the relationship between dose reduction and sustained virological response.

Bioequivalence of two recombinant granulocyte colony-stimulating factor formulations in healthy male volunteers

To evaluate the equivalence of the pharmacokinetic, pharmacodynamic and safety properties of two recombinant G-CSF formulations in healthy male volunteers, a standard 2-way randomized crossover double-blind study, with a 3 week washout period, was conducted. A single 300 microg G-CSF dose was administered subcutaneously. Hebervital (Heber Biotec, Havana, formulation A) and Neupogen (Hoffmann-La Roche S.A, formulation B) were compared. Twenty-four healthy male volunteers were included. The serum G-CSF level was measured by enzyme immunoassay (EIA) during the first 36 h after administration. Absolute neutrophils (ANC), white blood cells (WBC) and CD34+ cells counts were the pharmacodynamic variables measured up to 120 h. Other clinical and laboratory determinations were used as safety criteria. The pharmacokinetic parameters for formulation A and B were very close to each other (i.e. AUC, 235.9 vs 270.0 ng.h/ml; C(max), 29.2 vs 33.4 ng/ml; T(max), 4.2 vs 4.7 h; half-life, 3.2 vs 2.8 h; CL, 260.9 vs 277.2 ml/h; V(d), 1.2 vs 1.1 l; and MRT, 7.58 vs 7.38 h). The confidence intervals for the means ratio of all these parameters were within or very close to the 0.8-1.25 acceptance range. The pharmacodynamics showed high similarity since ANC and WBC had the same profiles for both products and no differences were detected for the estimated parameters. The CD34+ cells count increments were evident for both formulations in a similar way as well. The treatments were well tolerated. Registered adverse events were similar; back/spine pain was the most frequent. According to the overall results these formulations could be considered as clinically comparable.

The diagnosis and treatment of hairy-cell leukaemia

The diagnosis of HCL is usually straightforward and is based on the identification of typical HCs in the blood and bone marrow. The suspected diagnosis is confirmed by a combination of TRAP cytochemistry, a distinctive immunophenotype and characteristic BM trephine appearances. Nucleoside treatment is highly effective in inducing prolonged remissions; relapsing patients can usually be successfully retreated with nucleoside. Monoclonal antibody therapy is a promising novel approach to the treatment of resistant disease.

Interferons in dermatology. Present-day standard

Since the first clinical trials in the early 1980s with recombinant interferon, it was possible to show for a variety of indications that cytokines, especially interferons, at certain doses and at respective intervals, when applied in combination with other pharmaceutical compounds open new powerful therapeutic possibilities. Worldwide, recombinant interferon is licensed, especially in dermato-oncology, for the indication of HIV-associated Kaposi's sarcoma, cutaneous T-cell lymphoma, and recently for adjuvant therapy of high-risk malignant melanoma. Recombinant interferon is at present not licensed for dermatologic indication (septic granulomatosis). At the end of our century the indication spectrum for interferons as monotherapy and as combination therapy will undoubtedly be extended. Larger and controlled studies will prove the importance of interferons in dermato-oncology as well as in inflammatory and infectious dermatoses. The combination of interferons with standard therapies will surely be of the utmost importance in dermatotherapy.

Interferon-alpha inhibits CFU-GM mobilization following chemotherapy and G-CSF administration

Changes in routine hematologic data and in circulating granulocyte-macrophage colony-forming units (CFU-GM) during granulocyte colony-stimulating factor (G-CSF) administration were evaluated in non-small cell lung carcinoma (NSCLC) patients treated with a combination of 5-fluorouracil (5-FU) and cisplatin (DDP) with and without the addition of interferon-alpha (IFN-alpha). The patterns of leukocyte changes following chemotherapy plus G-CSF were similar in both the IFN-alpha-inclusive and the IFN-alpha-devoid courses. However, the twofold increase in CFU-GM observed in patients receiving chemotherapy plus G-CSF was completely absent following the course including IFN-alpha. The activity of G-CSF on the hematologic pattern is seemingly affected by its combination with IFN-alpha treatment. Mechanisms of the possible in vivo interaction among IFNs and hematopoietic growth factors remain to be elucidated.

Immunoaffinity measurement of recombinant granulocyte colony stimulating factor in patients with chemotherapy-induced neutropenia

A high-performance immunoaffinity chromatographic technique has been developed for the measurement of recombinant human granulocyte colony stimulating factor in human patients receiving this agent, following neutropenia, arising from cancer chemotherapy. The technique employs a short, biocompatible polymer column packed with minute, antibody-coated glass beads. This system was applied to the analysis of recombinant human granulocyte colony stimulating factor in three different human body fluids. A reasonable degree of correlation was achieved when comparing the immunoaffinity technique to a conventional immunoassay, although the immunoaffinity technique displayed greater specificity.