Biologic Antineoplastics - Fitz Flashcards
What are the three chemical types of Drugs that Interrupt Mitosis/Antimitotics/Spindle Poisons?
- Vinca alkaloids
- vincristine, etc.
- Taxanes
- paclitaxel, etc.
- Epilone
- ixabepilone
(All CCS: M-phase)
What are the two groups of Plant Alkaloids?
- Vinca Alkaloids
- Taxanes
What are the 3 Antimitotic Vinca Alkaloid drugs that we need to know?
- Vinblastine
- Vincristine
- Vinorelbine
What are the 3 Antimitotic Taxane drugs that we need to know?
- Paclitaxel
- Capazitaxel
- Docataxel
What is the only Antimitotic Epilone (antibotic) drug that we need to know?
Ixabepilone
What is the MOA of Antimitotic Vinca Alkaloid antineoplastic drugs?
bind to tubulin at the forming end of microtubules and TERMINATE (disrupt) spindle assembly
What are potential forms of resistance to Antimitotic Vinca Alkaloids?
- decreased accumulation via increased P-glycoprotein expression → MDR
- changes in target proteins
- mutations to tubulin that prevent binding
- cross reactivity among vinca alkaloids is not absolute
What are the specific therapeutic uses of Antimitotic Vinca Alkaloids?
- routinely used in combination therapy because of distinct mechanisms of action and toxicities
- regimens:
- VINCRISTINE (Oncovin):
- MOPP for Hodgkin’s disease
- CHOP for non-Hodgkin’s lymphoma
- VINBLASTINE:
- ABVD for Hodgkin’s disease
- PVB for testicular cancer
- VINCRISTINE (Oncovin):
- regimens:
As a drug class, the Antimitotic Vinca Alkaloids may cause what possible adverse side effects?
bone marrow suppression & neurotoxicity
What specific adverse side effects may be caused by Vincristine?
- VINCRISTINE = CNS toxicity
- more lipid soluble → fatal if given intrathecally
-
neurotoxicity
- prominent because of the requirement for microtubules in axon transport
- common symptoms:
- motor: loss of reflexes
- autonomic: constipation, paralytic ileus, orthostatic hypotension
- sensory: paresthesias (“pins and needles”)
What particular symptom is used as an indication of sufficient dose for Vincristine? What symptoms indicate the need to decrease the dose?
-
depression of deep tendon reflexes occurs within 2-3 weeks in 100% of patients
- used as an indication of sufficient dose
- this can be followed by severe paresthesias and mild-moderate sensory loss which is an indication to decrease the dose
What specific adverse side effects may be caused by Vinblastine?
- Vinblastine = bone marrow suppression
- Nausea & vomiting
- Vesicant
- Alopecia
What is the MOA of Antimitotic Taxanes (Paclitaxel, etc.)?
bind to tubulin and ENHANCE AND STABILIZE spindle assembly
What is one potential form of resistance to Antimitotic Taxanes?
decreased accumulation via
increased P-glycoprotein expression → MDR
What is important to know about the metabolism (pharmacokinetics) of Antimitotic Taxanes?
eliminated by extensive CYP 450 metabolism- hepatobiliary excretion
(i.e. liver function is critical)
What are some possible toxic side effects of Antimitotic Taxanes?
- bone marrow suppression
- hypersensitivity/allergic reactions
- peripheral neuropathy
- nausea and vomiting
- hypotension, arrhythmias
What is the MOA of the Antimitotic Epilone: Ixabepilone?
antibiotic that binds to tubulin and ENHANCES AND STABILIZES spindle assembly
(similar to paclitaxel)
What is Ixabepilone used to treat?
IXABEPILONE does not produce MDR, and is therefore approved for use in breast cancer patients who have failed anthracycline antibiotic and taxane treatments.
- used in combination with CAPECITABINE for the treatment of metastatic breast cancer following treatment failure with an anthracycline antibiotic and PACLITAXEL
- (i.e., it is a 3rd line treatment)
What are the potential toxic side effects of Ixabepilone?
- causes bone marrow suppression
- especially neutropenia
- peripheral neuropathy
- cardiac arrhythmias
- can also produce hypersensitivity reactions
What are the 3 chemical classes of Immunosuppressives?
- Glucocorticoids
- Antibiotics
- Antibodies and fusion proteins
What is the MOA of Glucocorticoids?
- interfere with the concentration, distribution and function of leukocytes
- increases the concentration of neutrophils; decreases T & B lymphocytes, monocytes, eosinophils and basophils
- end result is decrease in cytokine release, including decreases in IL-2 and TNF α
What is the naturally occurring compound associated with Glucocorticoids?
Cortisol
How are Glucocorticoids administered in chemotherapy treatments compared to their use in treating inflammatory diseases (asthma, arthritis, lupus, etc.)?
- Chemotherapy:
- given in higher doses, using a “pulse” regimen
- Conventional Immunosuppression:
- low dose, continuous
What are the four Immunosuppressive Antibiotics that we need to know?
- Cyclosporine
- Everolimus
- Tacrolimus
- Temsirolimus
What are Immunosuppressive Antibiotics used for?
- prevent rejection following bone marrow transplants
- Cyclosporine, Tacrolimus
- angiogenesis inhibitors
- Everolimus, Temsirolimus
What are the two pathways that Imunosuppressive Antibiotics are involved in?
- NFAT-mediated regulation of interleukin synthesis
- mTOR regulation of cell growth and angiogenesis
What effect does Cyclosporine and Tacrolimus have on calcineurin in Antirejection? What is the ultimate result?
- bind to cytoplasmic proteins and inhibit calcineurin
- CYCLOSPORINE binds to cyclophilin
- TACROLIMUS binds to FK-binding protein
- calcineurin is necessary for activation of NFAT
- a T cell-specific transcription factor that is involved in the synthesis of interleukins by activated T cells → decreased release of IL-2 → decreased activation of IL-2 receptor → decreased cell proliferation
What signalling molecule do tyrosine kinases increase expression of but Everolimus and Temsirolimus inhibit in order to prevent angiogenesis/proliferation?
- receptor tyrosine kinases can also increase expression of mTOR
- intracellular signaling molecule that:
- increases cell division
- increases bioenergetics
- facilitates angiogenesis in many cell types
- intracellular signaling molecule that:
- therefore, EVEROLIMUS and TEMSIROLIMUS function as mTOR inhibitors
Antibodies have been designed to target what CD molecules?
-
CD20 in Non-Hodgkin’s Lymphoma
- Rituximab
- Ibritumomab
- Tositumomab
-
CD52 in B-Cell Chronic Lymphoblastic Leukemia
- Alemtuzumab
Antibodies have been designed to target what cell surface proteins that are overexpressed in specific cancers?
HER2, VEGF, EGFR
What is the MOA of the fusion protein, DENILEUKIN DIFTITUX, that has diphtheria toxin coupled to IL-2?
- diphtheria toxin catalyzes the ADP-ribosylation of elongation factor-2 →
- inhibits protein translation by inactivating EF2
- goal is to kill cells expressing IL-2 receptors (activated T-lymphocytes, B lymphocytes and macrophages)
What is a potential form of resistance to immunosuppressive antibodies?
changes in target protein that prevent the antibody from recognizing its antigen
How are immunosuppressive antibodies administered? Half life?
- IV administration
- long half-lives - detectable at least 3-6 months after completion of treatment
What are the possible toxic effects of immunosuppressive antibodies and fusion proteins?
- infusion reactions (77% of patients on rituximab)
-
hypersensitivity reactions: fever, muscle aches, headaches, rashes, anaphylaxis
- mouse (MO) >> chimeric (XI) > humanized (ZU) for HAMA reaction
-
infections
- esp reactivation of tuberculosis
- unknown effects on immunization, carcinogenesis, mutagenesis, impairment of fertility, pregnancy, nursing infants (human IgG is secreted in milk)
What are possible specific toxicities of immunosuppressive anti-CD antibodies?
- cardiac arrhythmias
- tumour lysis syndrome
What are possible unique toxic side effects of Alemtuzumab?
- cough
- tightness in chest
What are the two types of Immune System Stimulants?
- Cytokines
- (biological response modifiers)
- Hematopoietic Growth Factors
- (supporting agents)
What are the three Cytokines (that we need to know) that are used as Immune System Stimulants?
- Interferon alpha
- Interleukin 2
- Tumor Necrosis Factor Alpha
What are 3 common characteristics that all cytokines used for cancer chemotherapy have in common?
- Short half-lives
- Not cytotoxic themselves
- Recruit immune cells to do the actual cell killing
- means the immune system has to recognize the tumor cells as foreign
What immune system response does Interleukin 2 induce?
induces and expands a T-cell response cytolytic for tumor cells