Pharmapoet

Tag: cancer

  • Pertuzumab Mechanism of Action. New Hope – Old target

    Table of Contents

    Scientists and researchers have their odd ways of solving problems, and when they team up with one of the biggest biotech companies, their ideas can go beyond research papers—and become real-world solutions we get to see.

    Brief History of Pertuzumab

    Pertuzumab (Parjeta) is a clear example of a scientific and marketing genius. It entered the market in 2012 to treat breast cancer in combination with Herceptin (trastuzumab) and one of the taxenes (a group of chemotherapeutic agents).

    So what is so interesting about pertuzumab?

    Genentech has marketed Herceptin (Trastuzumab) in 1998. It was a scientific and clinical breakthrough. Trastuzumab became the first monoclonal antibody to target the HER-2 receptor on the surface of the cancer cells. It made the company billions of dollars and cemented itself as a standard of care.

    Trastuzumab secret

    Although Herceptin delivered the expectation of improving clinical outcomes for many patients with breast cancer, scientists were particularly unsettled with one trastuzumab issue – they do not exactly know how it works!

    Trastuzumab and HER2

    Trastuzumab binds the Human Epidermal Growth factor Receptor-2 ( HER-2), which is found in every fifth case of breast cancer. Breast cancer cells express HER-2 to survive, grow, and spread, which makes HER-2 an attractive target for targeted agents and chemotherapy.

    The tigh has formed, but the process, which follows next is still a subject of the scientific debate. The research community has identified four most probable scenarios:

    • It stops the process of heterodimerization of HER-2;
    • It adds phosphorus to the HER-2 protein;
    • It facilitates the removal of the HER-2 from the cell surface;
    • It attracts immune cells that destroy cancer.

    Heterodimerization

    HER-2 is a unique protein in the family of four tyrosine kinases. All representatives exist in two forms:

    • Monomer or inactive form.
    • Dimer form or active form. The dimer is essentially two monomers bonded together.

    HER-2 cannot cannot bind another HER-2, it can only bind other members of the family (usually HER-1 or HER-3). The process is called heterodimerization, and it is crucial for activating cancer growth, expansion, and

    Another way, scientists thought Herceptin works is by invoking a phosphorylation of the HER-2 receptor. Phosphorylation is adding a phosphorus residue to one of the amino acids (usually tyrosine). Phosphorylation makes HER-2 less stable and overall leads to a better prognosis for cancer patients.

    More recent studies suggest that trastuzumab facilitates endocytosis of the HER-2 receptor – the cancer cells just swallow their receptors removing it from the surface.

    Finally, some scientists believe trastuzumab binds the HER-2 receptor and “calls” the immune system to fight cancer cells. This theory is supported by microscopic evidence – cancer tissues treated with trastuzumab, were heavily infiltrated by different immune cells.

    Pertuzumab is an “open book” for researchers.

    Similar to trastuzumab, pertuzumab is a monoclonal antibody, that binds HER-2 receptor. Unlike its “enigmatic friend, trastuzumab’s mechanism of action is clear – upon binding the target, it prevents dimerization of HER-2.

    Pertuzumab in action

    Pertuzumab Basics

    Pertuzumab is a humanized monoclonal antibody primarily used in cancer therapy. It targets the HER2 receptor, playing a crucial role in inhibiting tumor growth in HER2-positive breast cancer. Understanding its classification and properties helps in appreciating its impact on treatment.

    Classification and Overview

    Pertuzumab is classified as a recombinant humanized monoclonal antibody. It specifically targets the extracellular domain II of the HER2 receptor.

    This mechanism blocks dimerization with other HER family receptors, inhibiting downstream signaling pathways. Pertuzumab is used in combination with trastuzumab and chemotherapy to enhance therapeutic efficacy.

    It is particularly effective in treating metastatic breast cancer and has been shown to improve survival rates in patients.

    Chemical and Biological Properties

    Pertuzumab has a molecular weight of approximately 148 kDa. It is composed of 4 heavy chains and 4 light chains, which form its unique structure.

    The drug is produced using recombinant DNA technology in Chinese hamster ovary cells. Pertuzumab’s stability and half-life allow for effective dosing in clinical settings.

    Administration is typically via intravenous infusion, with dosages tailored to the patient’s specific needs. Understanding these properties is essential for optimizing its therapeutic use.

    Mechanism of Action

    Pertuzumab acts through a specific mechanism involving multiple interactions with HER2 receptors, playing a significant role in cancer treatment. Its primary functions include binding to HER2 receptors, inhibiting dimerization, and enhancing immune responses.

    Binding to HER2 Receptors

    Pertuzumab binds selectively to the extracellular domain of the HER2 receptor. This process blocks the receptor’s ability to interact with other molecules involved in cell signaling.

    The binding alters how cancer cells receive growth signals. By preventing HER2 signaling, pertuzumab reduces proliferation and survival of these cancerous cells. Clinically, this provides an effective strategy in treating HER2-positive breast cancer.

    Inhibition of HER2 Dimerization

    Dimerization is crucial for HER2 function. Pertuzumab prevents HER2 from forming dimers with other related receptors, such as HER3. This inhibition is essential because dimerization activates pathways that promote tumor growth.

    Blocking this process disrupts signaling networks that would otherwise support cancer cell survival. The result is decreased cell division and increased apoptosis in tumor cells, enhancing therapeutic outcomes.

    Activation of Antibody-Dependent Cellular Cytotoxicity

    Pertuzumab also enhances immune response through antibody-dependent cellular cytotoxicity (ADCC). The binding of pertuzumab to HER2 helps recruit immune cells.

    These immune cells, such as natural killer (NK) cells, are activated to target and destroy HER2-expressing cancer cells. This mechanism provides an additional layer of antitumor activity, contributing to the effectiveness of pertuzumab in HER2-positive cancers.

    Trastuzumab with Pertuzumab

    The combination of trastuzumab and pertuzumab has become an important strategy in the treatment of HER2-positive breast cancer. This section explores how these two therapies work together to improve patient outcomes.

    Breast Cancer Treatment

    Trastuzumab, a monoclonal antibody, specifically targets the HER2 receptor, blocking signaling pathways that promote cancer cell growth. Pertuzumab also targets HER2 but binds to a different site, preventing receptor dimerization, which is essential for activating downstream signaling.

    When used together, these agents enhance therapeutic efficacy. Studies have shown that their combination leads to improved progression-free survival rates in patients with early-stage and metastatic HER2-positive breast cancer.

    This dual blockade not only targets the cancer more effectively but may also reduce the chances of resistance. The synergy between trastuzumab and pertuzumab represents a significant advancement in personalized cancer treatment, offering hope to many patients.

    Clinical Efficacy

    Pertuzumab has demonstrated significant clinical efficacy in the treatment of certain cancers, notably HER2-positive breast cancer. Its unique mechanism of action enhances the effectiveness of standard therapies. This section details relevant clinical trials, survival and response rates, and its comparison with other treatments.

    Relevant Clinical Trials

    Several key clinical trials have assessed the efficacy of pertuzumab in combination with trastuzumab and chemotherapy. The pivotal study, CLEOPATRA, involved over 800 patients and reported a significant improvement in progression-free survival (PFS). Patients receiving pertuzumab showed a median PFS of 18.5 months, compared to 12.4 months for those receiving the control regimen.

    Clinical Data

    Moreover, results from the APHINITY trial indicated a similar benefit in the adjuvant setting, where pertuzumab combined with trastuzumab increased the invasive disease-free survival compared to trastuzumab alone. These findings underline the drug’s role in improving outcomes for patients with HER2-positive breast cancer.

    Survival and Response Rates

    Pertuzumab has significantly enhanced survival rates among treated patients. In the CLEOPATRA trial, the addition of pertuzumab resulted in an overall survival rate of 86% at three years, compared to 84% for the control group. This difference highlights its impact on long-term outcomes.

    Response rates also reflect its efficacy. In the APHINITY trial, a notable 94.1% of patients exhibited a pathologic complete response when treated with both pertuzumab and trastuzumab preoperatively. These figures demonstrate its effectiveness in promoting favorable responses.

    Comparison to Other Treatments

    When compared to traditional therapies, pertuzumab shows improved efficacy in HER2-positive cancer management. For instance, the combination of pertuzumab and trastuzumab performs better than trastuzumab alone, resulting in improved PFS and overall survival rates.

    Other HER2-targeted therapies, such as lapatinib, provide different mechanisms but often have lower response rates. Studies have shown that patients on pertuzumab plus chemotherapy benefit from a robust treatment regimen, positioning it as a critical option in therapy for HER2-positive cancers.

    Future Directions in Research

    Research on pertuzumab continues to expand, focusing on ongoing clinical trials and exploring potential new therapeutic indications. These efforts aim to enhance understanding of its effectiveness and broaden its application.

    Ongoing Clinical Trials

    Numerous clinical trials are currently assessing the efficacy and safety of pertuzumab in various cancer types. One significant trial is investigating its use combined with trastuzumab and chemotherapy for HER2-positive breast cancer.

    Additional studies are exploring the sequencing of pertuzumab with other novel agents, such as immune checkpoint inhibitors, to evaluate potential synergistic effects. This research may offer insights into improved patient outcomes through combination therapies.

    Researchers are also examining different dosing regimens and administration methods to optimize treatment schedules. These trials aim to understand patient response based on specific biomarkers and genetic profiles.

    Potential New Indications

    Beyond breast cancer, there is growing interest in using pertuzumab for other malignancies. Investigations are underway to determine its effectiveness in gastroesophageal cancers, where HER2 overexpression is present.

    Researchers are also testing pertuzumab in combination with targeted therapies for lung and ovarian cancers. Exploring its role in these contexts may uncover new therapeutic avenues for patients who have limited options.

    Additionally, studies are exploring pertuzumab’s potential in neoadjuvant settings, where it could be used before surgery to shrink tumors. This could enhance surgical outcomes and improve long-term prognosis for patients.

  • Teclistamab Mechanism of Action. Twice more Powerful

    I am Taclistamab, designed in the lab,
    A mighty bi-specific mAb.
    One end binds cancer, holding it tight,
    One end finds T-cells to join the fight.
    I help the immune system take its aim,
    And snipe myeloma, ending its game.

    How Taclistamab helps Immune System to fight Myeloma

    Teclistamab is a new approach of cancer treatment. It has two targets:

    1. CD3 receptor of an immune cell, called T lymphocyte or simply T-cell
    2. B-cell maturation antigen (BCMA) receptors on the surface some cancers, particularly myeloma cells (multiple myeloma).
    Taclistamab bi-specific antibody

    Taclistamab belongs to the broader group of biothechnology drugs, called monoclonal antibodies.

    Scientists refer monoclonal antibodies (mAbs), which can bind two targets simultaneously bispecific mAbs.

    Being bispecific can significantly boost your therapeutic value:

    1. One side of a protein can recognise a cancer
    2. Another can attach to T-cell, which fights this type of cancer

    When you bridge two cells toghether, T-cell would recognise adversary immediately and release cytotoxic chemicals to destoy cancer. The release of cancer DNA and proteins alerts other nearby cells, guiding them directly to the cancer site.

    Talistamab can initiate a strong, self-sustained immune response against multiple myeloma. It makes a drug is crucial for both advanced stage of disease or cases where cancer is resistant to the other more conventional type of treatments.

    Multiple myeloma

    Your bones has tissue, called “bone marrow”. It is a main factory of all blood cells: red (erythrocytes), white (leucocytes), and platelets (thrombocytes).

    Healthy bone marrow illustration
    Healthy bone marrow produces red and white blood cells and platelets

    Normally, your bone marrow produces 100 billion white blood cells each day to protect the body form intruders. Most of them venture to the blood, lymphoid tissues, and other organs. However, one type never leaves the area – B-cells would mature and turn inot the plasma cells. Plasma cells stay in bone marrow.

    Plasma cells are bulky, have a lifespan of 2-3 days, and produce an anourmous number of antibodies. Their main function is to learn about a foe and produce a specific proten to fight it.

    Multiple myeloma is a cancer of plasma cells. Unlike their normal counterparts, myeloma cells exhibit several distinct characteristics:

    • They aggresively multiply through cell division. As their number and volume increases, the pressure builds inside the tight spaces within the leading to pain,bone destructuion, and fractures.
    • They can hijack the supply chain redirecting the blood flow and nutrients to fuel their growth, depriving healthy tissues of the bone marrow. Clinically, it will manifest as an anemia and an immune difficiency.
    • They fabricate abnormal antibodies, called M-protein. M-protein is a junk and doesn’t fight infections. Kidneys try to keep up eliminating it, but at certain levels it would turn into the amyloid deposites in various organs, leading to organ failures.
    Myeloma cells redirects the blood flow and

    Teclistamab Background

    • Teclistamab is a bispecific monoclonal antibody against multiple myeloma.
    • It is classified as a bi-specific T-Cell engager (BiTe)
    • On October 25, 2022, FDA granted accelerated approval to teclistamab-cqyv 
    • It was developed by Janssen Biotech, Inc under the name TECVAYLI®

    Clinical Trials

    FDA granted an accelerated approval based on the clinical trial MajesTEC-1 (NCT03145181; NCT04557098), a single-arm, multi-cohort, open-label, multi-center study.

    Patients, who had previously received at least four more conventional therapies for myeoloma (and still relapsed) have been given the taclistamab. Among 110 in the treatment group, 61.8% acheived a partial or complete remission.

    Mechanism of Action

    The drug targets the B-cell maturation antigen (BCMA) on malignant plasma cells and CD3 on T cells.

    CD3 is protein specific to normal T-cells. It has three chains with the longest having a similar structure to antibody. Tha’s why CD3 belongs to antibody superfamily.

    It triggers an initiall stage of immune reaction, so many scientists consider it “a gas or a brakes” of an immune cascade.

    Step 1. Activation of T-Cells

    Upon binding to CD3, T-cells undergo activation, leading to several crucial responses:

    • Increase in cytokine production, especially interferon-gamma and tumor necrosis factor-alpha.
    • Being cytotoxic, different cytokines recruite even more immune cells to the cancer site.

    Once several cancer cells are destroyed and their by-products enter the bloodstream, more immune cells get attracted by the myeloma site. Scientists call this phenomena amplification of immune response.

    This amplification of the immune response is essential for improving therapeutic outcomes but also reponsible for serous side effects, such as Cytokine release syndrome and Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS).

    Step 2. Binding to the Myeloma Cell

    BCMA is a valid theraupeutic target, as health plasma cells do not usually express them, while myeloma cells enjoy this “decorum” on their membraines. BCMA helps cancer cell to survive and proliferate.

    Taclistamab cancer demise

    The activation and proliferation of T-cells lead to a direct cytotoxic effect on myeloma cells. Once activated, T-cells release perforins and granzymes, inducing apoptosis in targeted cancer cells.

    The localized action of teclistamab allows for effective tumor cell elimination while sparing surrounding healthy tissue. This targeted approach maximizes therapeutic benefits and minimizes adverse effects, contributing to an effective treatment for multiple myeloma.

    Clinical use of Teclistamab

    Teclistamab plays a significant role in treating multiple myeloma, particularly for patients with limited treatment options. This section outlines its place in therapy and the recommended treatment regimen.

    Place of Teclistamab in Myeloma Treatment

    Teclistamab is indicated for patients with relapsed or refractory multiple myeloma who have received at least four prior lines of therapy:

    • liproteasome inhibitors;
    • immunomodulatory agents;
    • anti-CD38 therapies.

    The drug targets B-cell maturation antigen (BCMA), which is critical myeloma life cycle. Solid results from the clinical trials inspire an optimism among researchers and clinicians, suggesting they may soon have a tool to target resistant cancer — a potential breakthrough.

    Treatment Regimen and Dosage

    Teclistamab is typically administered via subcutaneous (under the skin) injection. The initial dose is 1500 µg, followed by maintenance doses of 750 µg.

    Dosing is conducted every week for the first month and then once every two weeks. It’s essential to monitor for potential adverse effects, which may include cytokine release syndrome (CRS).

    Careful patient selection and monitoring can help maximize the benefits of teclistamab while minimizing risks. Regular follow-ups ensure timely management of side effects and dosage adjustments if necessary.

    Teclistamab Side Effects

    Teclistamab can lead to a variety of side effects. Understanding these effects is crucial for managing them effectively during treatment.

    Cytokine Release Syndrome

    Cytokine Release Syndrome (CRS) is a common reaction associated with Teclistamab. It occurs when the immune system is activated rapidly upon exposure to the drug.

    You may experience symptoms ranging from mild to severe.

    Common symptoms include:

    • Fever
    • Chills
    • Nausea
    • Fatigue
    • Headache

    Severe cases can lead to hypotension and difficulty breathing. Monitoring for signs of CRS is essential, particularly in the days following administration.

    CRS Symptoms

    Symptoms of CRS can manifest quickly, often within hours of treatment. Early recognition is key to managing this reaction.

    Mild symptoms may resolve with supportive care.

    Severe reactions might require treatment interventions such as corticosteroids or anti-inflammatory medications. If symptoms worsen, it is vital to contact your healthcare provider immediately.

    Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS)

    Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) is another serious potential side effect of Teclistamab. This condition can affect the central nervous system and may occur concurrently with CRS.

    Symptoms typically include confusion, difficulty speaking, or seizures. The severity of ICANS can vary, and monitoring is crucial.

    If you notice any neurological changes, communicate these to your healthcare team.

    Management may involve steroid treatment or close observation depending on severity. Your doctor will determine the best approach based on your specific situation.

    Teclistamab and Future of Myeloma Treatment

    Teclistamab represents a significant advance in myeloma treatment. It targets both B-cell maturation antigen (BCMA) and CD3, engaging T-cells to attack myeloma cells.

    Key Benefits:

    • Dual-target mechanism: By targeting BCMA, teclistamab effectively directs the immune response against malignant plasma cells.
    • Durable responses: Early studies suggest that this therapy can lead to prolonged remission in patients with previously treated myeloma.

    Clinical Trials:

    Ongoing trials are investigating teclistamab’s efficacy and safety compared to standard treatments. These studies are crucial for understanding its role in the treatment landscape.

    Considerations for Clinicians:

    • Combination therapies: Teclistamab may be used in combination with other treatments, enhancing its effectiveness.
    • Diverse patient populations: It is being tested across various stages of myeloma, which may broaden its applicability.

    Future Implications:

    As more data emerges, teclistamab could redefine treatment protocols. Its innovative approach may lead to new standards of care in managing myeloma, offering more avenues for relapsing and resistant cases of this cancer.

    Summary of mechanism of Action of Taclistamab

    Teclistamab has two binding sites, that brings two cells toghether:

    • Our foe, containing BCMA (B-cell maturation antigen)
    • Our friend, expressing CD3 on T-cells

    This dual-targeting capability allows the antibody to bridge the gap between T-cells and malignant cells effectively.

    This bridging facilitates a localized immune response, directing T-cells precisely where they are needed. The specialized design of teclistamab enhances its ability to engage the immune system directly against tumor cells while minimizing damage to normal tissues.