Classification and General Characteristics
Colony-stimulating factors belong to a specific group of immunotropic drugs. Their primary pharmacological target is hematopoiesis (blood cell production). Notably, these agents do not directly affect antibody production, phagocytosis (as a primary class effect), or the complement system. Their main function is the regulation of blood cellular components.
Acting as hematopoietic growth factors, they stimulate bone marrow activity. Three main agents are used in clinical practice: filgrastim, lenograstim, and molgramostim.
Filgrastim: Prototype G-CSF
Filgrastim is an analogue of granulocyte colony-stimulating factor (G-CSF). Chemically, it is a non-glycosylated protein.
The drug is produced using modern genetic engineering methods as a recombinant protein. The manufacturing technology involves inserting a plasmid containing the human gene into the genetic material of the bacterium E. coli. As a result, the bacterium independently produces human G-CSF.
Pharmacodynamics:
- Regulates neutrophil production directly in the bone marrow.
- Stimulates the release of functionally active neutrophils from the bone marrow into the peripheral blood.
Indications: The drug is prescribed to treat neutropenia—a pathological decrease in neutrophil count. Most commonly, these clinical situations arise after bone marrow transplantation or aggressive chemotherapy courses, when suppressed hematopoiesis must be rapidly restored.
Contraindications: Pregnancy, lactation (breastfeeding), and leukemias. In leukemias, the drug is hazardous due to the high risk of stimulating the growth of malignant myeloid cells.
Lenograstim and Its Features
Lenograstim also belongs to the G-CSF group; however, chemically, it is a recombinant human glycosylated granulocyte colony-stimulating factor.
Its mechanism of action is identical to filgrastim: it specifically stimulates bone marrow activity, accelerates the maturation of neutrophils (rather than lymphocytes, eosinophils, or monocytes), and promotes their release into systemic circulation. Consequently, lenograstim reliably increases the absolute neutrophil count in peripheral blood.
Clinical applications, including all indications and strict contraindications, fully match those of filgrastim.
Molgramostim: Broad-Spectrum GM-CSF
Unlike the previous agents, molgramostim is a recombinant analogue of human granulocyte-macrophage colony-stimulating factor (GM-CSF).
Its pharmacodynamics are broader and encompass three main directions:
- Hematopoietic Regulation: The drug strongly stimulates the proliferation (multiplication) and differentiation of progenitor cells.
- Effects on Mature Cells: It impacts the growth and function not only of granulocytes but also of macrophages and eosinophils.
- Functional Activation: Significantly enhances phagocytosis, oxidative metabolism, and leukocyte cytotoxicity. This empowers blood cells to combat threats more effectively, including exerting cytotoxic activity against malignant cells.
Indications: Molgramostim is indicated for the treatment and prevention of leukopenia, the acceleration of myeloid recovery, and the prevention of severe infectious complications arising from leukopenia.
Contraindications: Like other CSFs, it is contraindicated in leukemias due to the risk of malignant cell stimulation, as well as during lactation.