Convergence of Immunotherapy, Targeted Therapy, and Biomaterials: A Comprehensive Review of Integrated Approaches in Oncology

Cancer is a bunch of diseases. What they all have in common is that the cells in the body start to grow out of control. These cells can invade the tissues around them. Even spread to other parts of the body.

We have made some progress with the ways of treating cancer like surgery, radiation and chemotherapy. Even with these advances cancer is still the second leading cause of death around the world. The number of people getting cancer is going up everywhere.

If you look at the numbers you can see that this is a big problem, especially, in countries that are not as wealthy. In India, cancer incidence has escalated from approximately 609,000 cases in 1991 to an estimated 1.15 million cases in 2018, with projections suggesting nearly 1.7 million cases by 2035[3,4].

The limitations of conventional cancer therapies have long been recognised. Traditional chemotherapy exhibits poor selectivity, causing substantial collateral damage to healthy tissues and resulting in severe adverse effects that compromise patient quality of life[5]. These therapeutic constraints have spurred intensive research into alternative approaches that leverage the patient's innate biological defence mechanisms.

Immunotherapy has emerged as a revolutionary treatment paradigm that harnesses the body's own immune system to combat cancer. Unlike chemotherapy, which directly attacks dividing cells, immunotherapy awakens and trains the immune system to selectively recognise and eliminate cancer cells [6,7]. This approach has demonstrated unprecedented clinical success, with immune checkpoint inhibitors, chimeric antigen receptor (CAR) T cells, and therapeutic cancer vaccines showing dramatic responses in previously intractable malignancies [8].

Concurrently, targeted therapy has transformed cancer treatment by addressing specific molecular aberrations that drive oncogenic transformation. By targeting proteins and genetic mutations unique to cancer cells, targeted agents achieve high selectivity while minimising damage to normal tissues [9]. However, both immunotherapy and targeted therapy, when used as mono-therapies, face significant limitations: immune checkpoint inhibitors can cause delayed responses and autoimmune complications, while targeted therapies frequently encounter acquired resistance within 6 months of initiation [10].

The integration of biomaterials engineered materials including nanoparticles, hydrogels, and scaffolds represents a third pillar in modern oncology. These materials serve as sophisticated drug delivery platforms, enabling controlled release at tumor sites, enhanced cellular uptake, and modulation of the immunosuppressive tumor microenvironment [11-16]. When rationally designed, biomaterials can be functionalized with targeting ligands, loaded with multiple therapeutic agents, and engineered to respond to stimuli specific to the tumor microenvironment, such as pH, enzyme activity, and hypoxia [17,18].

The convergence of these three therapeutic domains—immunotherapy, targeted therapy, and biomaterials science—offers unprecedented opportunity to overcome individual limitations and achieve synergistic therapeutic benefit. This review synthesises current evidence regarding combination strategies, explores the mechanistic basis for their synergy, and examines both preclinical and clinical validation of integrated approaches in oncology.

2. FUNDAMENTALS OF CANCER IMMUNOTHERAPY

2.1 Overview and Classification

Immunotherapy encompasses a diverse array of strategies designed to augment, modulate, or engineer the patient's immune system to achieve anti-tumor immunity [19]. The field has evolved from empirical observations—such as Coley's 1891 report of infectious agent-induced tumor regression—to sophisticated molecular interventions targeting specific immune pathways [20].

Contemporary cancer immunotherapies are classified into five major categories: (1) immune checkpoint inhibitors, (2) CAR-T cell therapies, (3) monoclonal antibodies, (4) cancer vaccines, and (5) adoptive cell transfer therapies.

2.2 Immune Checkpoint Inhibitors

Mechanism of Action: The immune system possesses intrinsic regulatory mechanisms that prevent excessive inflammation and autoimmunity. Cancer cells exploit these "immune checkpoints" by expressing ligands that interact with inhibitory receptors on T cells, thereby suppressing anti-tumor immune responses [21].

Immune checkpoint inhibitors are monoclonal antibodies that block interactions between checkpoint molecules, thereby liberating T cells from immune suppression and enabling enhanced anti-tumor immunity. The most clinically relevant checkpoint pathways include PD-1/PD-L1 and CTLA-4[22].

PD-1/PD-L1 Pathway: Programmed cell death protein 1 (PD-1), expressed on the surface of exhausted T cells, binds to programmed cell death ligand 1 (PD-L1) on tumor cells and antigen-presenting cells, delivering an inhibitory signal that suppresses T cell function. PD-1 inhibitors (Nivolumab, Pembrolizumab) and PD-L1 inhibitors block this interaction, restoring T cell cytotoxicity [23].

CTLA-4 Pathway: Cytotoxic T-lymphocyte antigen 4 (CTLA-4), constitutively expressed on regulatory T cells and activated T cells, binds to B7 ligands (CD80/CD86) on antigen-presenting cells. CTLA-4 engagement delivers inhibitory signals that suppress T cell activation. Ipilimumab, a CTLA-4 inhibitor, has demonstrated survival benefits in melanoma and has received FDA approval for multiple cancer types [24].

Clinical Approvals: Three major classes of immune checkpoint inhibitors have received FDA approval: PD-1 inhibitors (nivolumab, pembrolizumab), PD-L1 inhibitors, and CTLA-4 inhibitors (ipilimumab).

2.3 CAR-T Cell Therapy

Chimeric antigen receptor (CAR) T cell therapy represents an engineered adoptive cellular approach wherein patient-derived T lymphocytes are genetically modified to express synthetic receptors that combine antigen-binding domains with intracellular signalling modules[25].CAR-T cells recognise target antigens independently of major histocompatibility complex presentation and deliver potent cytotoxic signals.

Mechanism: CARs enable T cells to recognise and eliminate cancer cells through multiple mechanisms: direct cytotoxicity, production of pro-inflammatory cytokines, and activation of additional immune cells. The therapeutic efficacy of CAR-T cells is amplified when target antigens are expressed at high levels on tumor cells and not on vital normal tissues [26].

Clinical Success: CAR-T cell therapies targeting CD19 have achieved complete remission rates exceeding 90% in B-cell acute lymphoblastic leukaemia, representing one of the most successful cancer immunotherapies to date.

2.4 Monoclonal Antibodies

Monoclonal antibodies (mAbs) constitute a major immunotherapeutic class, functioning through multiple mechanisms including receptor blockade, antibody-dependent cellular cytotoxicity (ADCC), and complement-dependent cytotoxicity. mAbs demonstrate extreme specificity with brief half-lives in vivo, thereby minimising off-target effects [27].

EGFR-Targeted mAbs: Epidermal growth factor receptor (EGFR) is over-expressed in up to 90% of head and neck squamous cell carcinomas, driving tumor proliferation and metastasis. Anti-EGFR mAbs including Cetuximab (chimeric IgG1) and Panitumumab (fully human IgG2) induce apoptosis by blocking ligand binding and preventing receptor dimerisation [28].

HER2-Targeted mAbs: Human epidermal growth factor receptor 2 (HER2), a tyrosine kinase receptor over-expressed in breast and ovarian carcinomas, functions through heterodimerization with other growth factor receptors. Trastuzumab, the first FDA-approved anti-HER2 monoclonal antibody, inhibits heterodimerization and internalisation, serving as a vital component of HER2-directed therapy [29].

2.5 Cancer Vaccines

Cancer vaccines are subdivided into prophylactic and therapeutic modalities [30].

Prophylactic Vaccines: Administered to healthy individuals, prophylactic vaccines alert the immune system to cancer-causing viruses, enabling recognition and attack before malignant transformation occurs. The FDA-approved hepatitis B and human papillomavirus (HPV) vaccines represent exemplary successes, preventing hepatocellular carcinoma and cervical cancer respectively [31].

Therapeutic vaccines are given to people with cancer. These therapeutic vaccines help the body fight cancer that's already there. They do this by making the body’s defences against cancer stronger. There are kinds of therapeutic vaccines. We can group vaccines by what is in them. The types of vaccines include cell therapeutic vaccines, which can come from cancer cells or, from immune cells. There are also protein and peptide vaccines. Then there are therapeutic vaccines, which are based on DNA or RNA. Bacillus Calmette-Guérin (BCG) is FDA-approved for early-stage bladder cancer, while Sipuleucel-T (Provenge), which induces immune responses targeting prostatic acid phosphatase, is approved for asymptomatic metastatic castrate-resistant prostate cancer [32,33].

2.6 Adoptive Cell Transfer

Adoptive cell transfer (ACT) exploits the central principle that expanded T cells can augment anti-tumor immunity. Two major approaches exist: (1) tumor-infiltrating lymphocyte (TIL) therapy using unmodified autologous T cells, and (2) engineered T cell receptor (TCR) therapy using genetically modified T cells [34,35].

TIL Therapy: T cells isolated from tumor tissue are expanded ex vivo following lymphocyte-depleting preparatory regimens and rein-fused into patients. The increased availability of activated tumor-specific T cells amplifies anti-tumor immunity [36].

TCR Engineering: Modern genetic engineering enables introduction of specific antigen receptors into T cells, allowing recognition of tumor-specific antigens in an MHC-dependent manner. TCR gene therapy targeting melanoma differentiation antigen MART-1 demonstrated clinical feasibility in 17 patients with progressive metastatic melanoma, with objective responses in 5 patients [37].

2.7 Recent Advances and Current Research Directions

Cancer immunotherapy research is intensively focused on four key areas:

Deciphering the Tumor Microenvironment: Understanding the complex ecosystem of immune cells within tumours is crucial for predicting immunotherapy response. Detailed characterization of immune cell infiltration, activation status, and spatial distribution informs personalised treatment strategies [38].

Biomarker-Driven Prediction: Identification of predictive biomarkers—measurable indicators in blood, tissue, or genes—enables personalised immunotherapy selection, maximising efficacy while minimising unnecessary adverse effects [39].

Understanding Resistance Mechanisms: Investigation of both intrinsic and acquired resistance mechanisms guides the rational development of strategies to overcome resistance and enhance treatment durability [40].

Next-Generation Therapeutics: Innovation is driving development of more precise checkpoint inhibitors, next-generation CAR-T cells with enhanced targeting and persistence, personalised vaccines targeting individual patient mutations, and improved Oncolytic viruses with enhanced immune stimulation [41].

2.8 Challenges in Cancer Immunotherapy

Despite remarkable advances, cancer immunotherapy faces significant hurdles:

Tumor Heterogeneity: Tumours harbour diverse cancer cell populations with distinct mutations and characteristics, making development of universally effective therapies challenging [42].

Cancer-Type Specificity: Immunotherapy efficacy varies substantially based on cancer type and biology. Some malignancies are inherently less susceptible to immune attack, requiring tailored approaches [43].

Immunosuppressive Tumor Biology: Certain tumours are adept at suppressing immune responses through multiple mechanisms, creating barriers to immunotherapy 44].

Prior Treatment Effects: Preceding therapies such as radiation or chemotherapy may compromise immune function, complicating subsequent immunotherapy [45].

Limited Biomarker Identification: Currently available predictive biomarkers explain response heterogeneity only partially, necessitating discovery of additional markers [46].

3. TARGETED THERAPY IN CANCER TREATMENT

3.1 Overview and Classification

Targeted therapies represent a paradigm shift from non-selective chemotherapy by specifically addressing cancer-driving molecular aberrations while sparing normal tissues [47]. These therapies are broadly classified into two categories: (1) small molecule inhibitors and (2) monoclonal antibodies.

3.2 Small Molecule Inhibitors

Tyrosine Kinase Inhibitors (TKIs): Protein kinases catalyse phosphorylation of tyrosine residues on substrate enzymes, initiating signal transduction cascades that regulate cell growth, migration, differentiation, apoptosis, and death 48]. Dysregulation of kinase signalling through mutation, over expression, or constitutive activation is a hallmark of cancer. Nearly 40% of human genes encode protein kinases, with approximately half mapping to disease loci or cancer amplicons [49].

The FDA approval of Imatinib in 2001—a TKI targeting BCR-Abl in Philadelphia chromosome-positive chronic myelogenous leukaemia—inaugurated the modern era of kinase-targeted therapy [50]. Subsequent TKI development has targeted multiple kinases including EGFR, ALK, ROS1, and others, establishing TKIs as foundational cancer therapeutics [51].

Serine Threonine Kinase Inhibitors are very important. The RAS-RAF-MEK-ERK signalling axis is like a pathway that helps our cells grow normally survive and multiply. Sometimes there are problems with this pathway. For example, when there are mutations in the BRAF gene the V600E variant it can cause big problems. This can lead to tumours growing out of control.

To fight this, we have inhibitors like vemurafenib and dabrafenib. We also have MEK inhibitors like Trametinib. These are approved by the FDA to help people with melanoma that has spread and cannot be removed with surgery and who have mutations.

Using than one of these treatments at the same time, which is called combination therapy can be very effective. It can help make the treatment work better and also stop the cancer from becoming resistant to the treatment. This is a thing for people, with Serine Threonine Kinase Inhibitors and BRAF mutations. While ERK inhibitors remain investigational, combination strategies employing multiple pathway inhibitors or incorporating additional agents such as CDK4/6 inhibitors or immunotherapy show improved outcomes and prolonged progression-free survival [53].

Cyclin-Dependent Kinase Inhibitors are very important. They help stop Cyclin-Dependent Kinases, which're necessary for cell growth. Sometimes these Cyclin-Dependent Kinases get out of control and that can lead to cancer. Cyclin-Dependent Kinase Inhibitors work by stopping CDK4 and CDK6 which are two types of Cyclin-Dependent Kinases. These Cyclin-Dependent Kinases are activated by something called cyclin D. When that happens, they change the RB1 protein. That helps the cell move to the next stage of growth. This is a problem in some types of breast cancer especially the kind that has hormone receptors.

The good news is that there are medicines called CDK4/6 inhibitors that can help. These medicines include Palbociclib, Ribociclib and Abemaciclib. They are approved by the FDA to help people with a type of breast cancer that is positive for hormone receptors and negative, for something called HER2. Often these medicines are used along with treatments that help balance out the hormones in the body. Resistance mechanisms include RB1 loss and upstream pathway mutations. New CDK inhibitors, including Trilaciclib and PF-06873600, are under clinical investigation [55]. Common side effects include neutropenia and diarrhoea, with rare but serious lung inflammation [56].

PARP Inhibitors are really important because they stop the PARP enzymes from working. These enzymes help fix the DNA when it gets broken. There are kinds of breaks called single-strand breaks that these enzymes are good at fixing. When there are problems with the BRCA1 and BRCA2 genes the DNA has a hard time fixing the double-strand breaks.

When we use PARP Inhibitors it is like blocking both ways that the DNA can be fixed. This is very bad for the tumor cells because they cannot fix their DNA so they die. The Food and Drug Administration has approved four PARP Inhibitors: Olaparib, Rucaparib, Niraparib and Talazoparib. We use these to treat breast and ovarian cancers in people who have problems with the BRCA genes.

These PARP Inhibitors do more than just stop the enzymes from working. They also trap the PARP enzymes on the DNA, which causes damage to the DNA. This damage is very bad, for the tumor cells. Helps to kill them. PARP Inhibitors are a way to treat these kinds of cancers because they can help kill the tumor cells by stopping the PARP enzymes from fixing the DNA. Resistance develops through restored homologous recombination, PARP1 mutations, or drug efflux mechanisms. New combination strategies employing ATR, CHK1, or WEE1 inhibitors are being explored to overcome resistance, though myelosuppression remains a concern [58].

The PI3K/AKT/mTOR pathway is really important in our bodies. This pathway helps our cells to grow, multiply survive and get the energy they need. Sometimes the PI3K/AKT/mTOR pathway gets messed up in people with cancer. This can happen because of changes in the PIK3CA gene. Because the AKT gene is too active or because the PTEN gene is not working right. The PI3K/AKT/mTOR pathway is a deal, in many types of cancer. There are some medicines that doctors can use to treat types of cancer. These medicines are called PI3K inhibitors. One of these medicines is idelalisib. It is used to treat blood cancers. Another medicine is copanlisib. It works on all types of PI3K. Then there is duvelisib. It targets two types of PI3K called gamma and delta. Alpelisib is also a PI3K inhibitor. It is used to treat breast cancer. This is especially true for breast cancer with PIK3CA mutations.

Doctors are also looking at medicines called AKT inhibitors. These include Ipatasertib, capivasertib and MK-2206. These medicines show promise for treating tumours with PIK3CA mutations or PTEN loss. However, when used alone they do not always work well. PI3K inhibitors, like idelalisib, copanlisib duvelisib and alpelisib are still being studied to see how well they work. mTOR inhibitors are classified as first-generation rapalogs (everolimus, temsirolimus) selectively inhibiting mTORC1, or second-generation ATP-competitive inhibitors (sapanisertib, vistusertib) blocking both mTORC1 and mTORC2. Dual PI3K/mTOR inhibitors (BEZ235, GDC-0084) are under evaluation. Major challenges include pathway cross-talk, negative feedback loops, drug resistance, and adverse effects including hepatotoxicity and immunosuppression. Over 70 kinase inhibitors have received global approval, targeting fewer than 30 kinases, indicating vast potential for future development.

3.3 Monoclonal Antibodies in Targeted Therapy

HER2 and EGFR-Targeted Antibodies: Monoclonal antibodies targeting over-expressed growth factor receptors induce tumor cell death through multiple mechanisms. EGFR blockade by cetuximab perturbs pro-tumor growth signalling by inhibiting ligand binding and receptor dimerisation, inducing apoptosis in EGFR-overexpressing tumours. HER2-targeting by trastuzumab inhibits heterodimerization and promotes receptor internalisation, forming a vital component of HER2-directed breast cancer therapy.

ADCC-Enhanced Antibodies: Antibody-dependent cellular cytotoxicity (ADCC) emerges as a critical mechanism for monoclonal antibody efficacy. FcγR polymorphisms on immune effector cells predict clinical response to mAb therapy. Patients with high-affinity FcγR polymorphisms demonstrate superior responses to mAbs regardless of cancer type. ADCC functionality is enhanced through site-directed mutagenesis of the Fc domain, glycosylation modification, and removal of Fc fucosylation. Next-generation afucosylated monoclonal antibodies demonstrate promising clinical efficacy.

VEGF-Targeted Antibodies: Vascular endothelial growth factor (VEGF) family members are critical drivers of tumor angiogenesis. Anti-VEGF-A antibodies such as bevacizumab are approved for various solid cancers including colorectal, lung, and breast cancers, as well as glioblastoma and renal cell carcinoma. Additional VEGF pathway-targeting antibodies including ramucirumab (VEGFR-2 directed) and IMC-18F1 (VEGFR-1 directed) are under clinical investigation. Aflibercept (VEGF-Trap) is a peptide-antibody fusion being tested in clinical trials.

3.4 Limitations and Future Directions

Targeted therapy encounters several significant challenges:

Drug Resistance: Cancer cells develop resistance through target mutation, activation of compensatory pathways, or epigenetic changes, often necessitating combination therapy.

Structural Constraints: Drugs targeting certain identified molecular targets remain difficult to develop due to target structure or regulatory complexity.

Mutation Dependency: Not all tumours harbour identifiable or targetable mutations, limiting applicability of targeted approaches.

Cumulative Toxicity: Combination targeted therapies may cause unexpected or amplified toxicity.

4. BIOMATERIALS IN CANCER THERAPY

4.1 Definition and Classification

Biomaterials are engineered natural or synthetic materials designed to enhance, deliver, or modulate therapeutic agents including immune cells, antibodies, drugs, and antigens in precise, controlled, biocompatible manners. Biomaterials are classified into inorganic and organic categories.

4.2 Inorganic Biomaterials

Metal-Peroxide Nanoparticles: Inorganic nano-materials have emerged as promising cancer therapeutic candidates due to unique physicochemical properties including small size, large surface area, and high stability. Metal-peroxide nanoparticles (CuO?, CaO?) generate hydrogen peroxide within the tumor microenvironment, producing highly toxic hydroxyl radicals via Fenton-like reactions, thereby inducing tumor cell death while alleviating tumor hypoxia and enhancing photodynamic and radiotherapy.

Metal oxide nanoparticles are really useful. They include things like zinc oxide, iron oxide and manganese oxide. These metal oxide nanoparticles are very safe for people. Can be changed to do different things. Zinc oxide nanoparticles are special because they are approved by the FDA. They can help kill cancer cells by making them produce things that hurt them and by helping our immune system work better. Iron oxide nanoparticles are also very useful. They can help doctors see what is going on inside our body. They can also help our immune system fight off bad things. They do this by changing the way some of our cells work and by making our T cells more active. Metal oxide nanoparticles, like zinc oxide and iron oxide are really good, at helping our body fight off cancer and other bad things. MONs is redox-responsive and improve antitumor immunity by reducing tumor antioxidant levels and activating immune pathways such as cGAS-STING.

Mesoporous Silica Nanoparticles: Mesoporous silica nanoparticles (MSNs) are valued for high surface area and controlled pore structure, making them ideal for stimuli-responsive drug delivery. These particles release drugs specifically in acidic or glutathione-rich tumor environments, ensuring targeted delivery with minimal side effects. Collectively, inorganic nano-materials are transforming cancer treatment through precise, immune-responsive, and environment-sensitive therapeutic strategies.

4.3 Organic Biomaterials

Synthetic Polymers: Synthetic polymers such as poly (lactic-co-glycolic acid) (PLGA) and polyethylene glycol (PEG) are widely utilised for their biocompatibility and delivery capabilities. PLGA is FDA-approved and effectively targets tumours but may release immunosuppressive byproducts such as lactic acid affecting tumor microenvironment behaviour. PEG enhances circulation time and drug targeting, particularly under acidic tumor conditions.

Natural Biopolymers: Natural biopolymers including hyaluronic acid (HA) and silk fibroin (SF) exhibit excellent biocompatibility and immune-modulating properties. HA targets CD44 receptors, promoting T cell activation, while SF-based systems encourage macrophage polarisation and improve antigen presentation.

Cell-Derived Biomaterials: Cell-derived biomaterials including cell membranes and exosomes are increasingly recognised for high biocompatibility and immune-regulating potential [5]. Nanoparticles coated with red blood cell or immune cell membranes enhance immune evasion and targeting. Exosomes offer natural drug delivery capabilities, low immunogenicity, blood-brain barrier penetration, T cell activation, and potential as vaccine adjuvants [6].

5. BIOMATERIALS SUPPORTING IMMUNOTHERAPY

5.1 Engineered Biomaterials for Localised Immunotherapy Delivery

Implantable Biomaterials: Implantable systems deliver immunotherapeutic agents locally, enhancing immune responses against cancer [7]. Common scaffold materials include PLG, alginate, porcine gelatine, collagen, hyaluronic acid, and mesoporous silica. These materials are functionalized with cytokines, antigens, or adjuvants before implantation, releasing bioactive agents in controlled, sustained manners [8]. Dendritic cells (DCs), key antigen-presenting cells, are recruited to implant sites, take up tumor antigens, and migrate to lymph nodes to activate tumor-specific T cells [9].

PLG is a material that can break down naturally. It is safe for the body. The Food and Drug Administration has also approved PLG. One of the things about PLG is that we can control how fast it breaks down.

We can make PLG scaffolds that have holes in them using a technique that involves gas. This helps cells get into the scaffolds. We can also load them with other things we need.

PLG scaffolds are really good at releasing immune agents for a long time. Up to two weeks. This helps keep the system active for a long time.

Some studies have used PLG scaffolds in mice, with melanoma. These PLG scaffolds were loaded with helpers called granulocyte-macrophage colony-stimulating factor and CpG-ODNs. These helpers make the immune system stronger. The studies showed that the mice lived longer when they got the PLG scaffolds with these helpers. SBA-15 silica scaffolds similarly support sustained GM-CSF release and effective DC recruitment [2].

Injectable Biomaterials: Injectable systems offer surgery-free localised delivery of cancer therapeutics. Hydrogels, the most common injectable biomaterials, mimic the natural extracellular matrix [3]. Hydrogels are formed in vivo following injection of liquid copolymers that undergo sol-gel transition at body temperature. Smart hydrogels self-assemble and encapsulate agents like GM-CSF and tumor antigens. Injectable hydrogels recruit dendritic cells and trigger potent immune responses, with some releasing nanoparticles that stimulate antibody production and immune memory [4].

Combination therapies employ hydrogels to deliver both chemotherapeutic and immunotherapeutic agents (e.g., cyclophosphamide + anti-PD-L1), with staggered controlled release enhancing synergy [5]. Radiotherapy + immunotherapy combinations utilise gels with CpG and radioactive iodine to boost systemic immune responses. Hydrogel sprays containing calcium carbonate nanoparticles and anti-CD47 antibodies prevent tumor recurrence post-surgery. ROS-responsive hydrogels reduce oxidative stress in tumours and improve immune activation. Challenges include precise control of gelation kinetics and drug release behaviour [7].

Transdermal Biomaterials: Micro-needles are tiny, painless devices that enhance transdermal drug delivery by creating micro-channels bypassing the stratum corneum barrier. Made from polymers or metals, micro-needles effectively deliver cancer Immunotherapeutic including immune checkpoint inhibitors [8]. In melanoma models, micro needle-based anti-PD-1 and anti-CTLA-4 delivery demonstrated improved survival and tumor suppression compared to injections. Hybrid micro-needles delivering anti-PD-L1 and indoleamine 2,3-dioxygenase (1-MT) inhibitors enhanced drug retention and immune activation [9].

5.2 Engineered Biomaterials for Immunomodulation

Hydrogels are like helpers that can hold a lot of water. They are made up of networks that are very good for our bodies. Hydrogels are biocompatible which means they do not hurt us and they can break down easily. We can also make them stronger or weaker as needed.

Hyaluronic acid or HA is a type of hydrogel that's very good at attaching to certain cells in our immune system like macrophages and NK cells. This is because HA naturally binds to these cells. Hydrogels can be used to deliver medicine, such as dexamethasone, which helps with inflammation and anti-TNF-α antibodies, which help our system. The good thing about hydrogels is that they can release this medicine over time so we do not need to take it as often.

There are also hydrogels like PEG hydrogels that can be made to work even better. We can add peptides, like RGD to these hydrogels, which helps them attach to our cells and makes our immune system work better. Hydrogels are really helpful because they can deliver medicine and help our bodies in a targeted way. Advanced microporous annealed particle (MAP) hydrogels provide injectable flowable scaffolds with enhanced tissue regeneration and improved wound healing [4]. Natural hybrid hydrogels such as alginate/gelatine methacrylate demonstrate significant success in diabetic wound healing [5].

Scaffolds are really important for helping our bodies heal. One thing that is often used in these scaffolds is Stromal cell-derived factor 1-alpha, which is also called SDF-1α. This SDF-1α is a type of chemokine that can cause inflammation and help build blood vessels.

We can put SDF-1α into materials like PLGA, gelatine, alginate, silk-collagen and PEGylated fibrin. The SDF-1α helps bring in stem cells and reduces inflammation by talking to the CXCR4 receptor.

When we use these materials with SDF-1α they cause less inflammation and make fewer bad chemicals, like IL-1α, IL-6 and TNF-α. At the time they help make more of a good chemical called VEGF, which helps our tissues grow back. Anti-inflammatory gene delivery strategies incorporating IL-10 plasmid polyplexes into collagen or PLGA scaffolds demonstrate reduced macrophage infiltration and improved stem cell survival [9].

Nanoparticles: Nano-material-based carriers offer significant immunomodulation potential through physicochemical property engineering [10]. Amine-functionalized graphene oxide stimulates dendritic and T cells, while PEGylation reduces immune recognition and extends nanoparticle circulation [11].

6. BIOMATERIALS SUPPORTING TARGETED THERAPY

6.1 Smart Drug Delivery and Stimuli-Responsiveness

Smart biomaterials including nanoparticles, hydrogels, and nano gels deliver drugs directly to tumours, minimising harm to healthy tissues [12]. These materials respond to specific tumor microenvironment triggers (pH, temperature, enzymes), ensuring drug release exclusively where needed, thereby overcoming drug resistance and tumor hypoxia. Organelle-targeted nano-materials deliver therapies to specific cellular compartments, boosting effectiveness and reducing required doses [14].

6.2 Immune System Modulation Through Biomaterials

Biomaterials carry and release immunotherapies including checkpoint inhibitors and CAR-T cells directly to tumours, improving immune cell targeting and reducing off-target effects. These materials modulate the tumor microenvironment to enhance immune responses through immune cell reprogramming and TME remodelling, reducing immune suppression [16].

6.3 Theragnostic and Advanced Approaches

Theragnostic biomaterials combine therapy and diagnostics, enabling real-time imaging of drug delivery and treatment response. Cell-inspired and metal-based biomaterials offer improved biocompatibility, immune evasion, and multifunctional capabilities including novel cancer cell death mechanisms [18].

7. CONVERGENCE OF IMMUNOTHERAPY AND TARGETED THERAPY

7.1 Rationale for Combination Strategies

Recent advances have demonstrated that combining immunotherapy and targeted therapy offers synergistic benefits superior to single-modality approaches [19]. Immunotherapy activates T cells to attack cancer cells by targeting immune checkpoints like PD-1/PD-L1 and CTLA-4, but can cause autoimmunity and delayed responses. Targeted therapies block cancer-driving mutations and show rapid responses but develop resistance within 6 months due to therapeutic escape mechanisms [21].

Combination approaches address these limitations by:

• Boosting immune activation through targeting immunosuppressive checkpoints
• Helping overcome resistance through simultaneous targeting of multiple pathways
• Enhancing tumor recognition by the immune system through antigen exposure and immune activation [22]

A critical challenge is the immunosuppressive tumor microenvironment that blocks immune responses. Contemporary research focuses on overcoming this barrier through combination treatments that modulate the tumor environment and improve immune-cell infiltration and function [23].

7.2 VEGF Inhibitors Combined with Immunotherapy

VEGF-A and its receptors (VEGFRs) are key drivers of tumor angiogenesis [24]. Drugs including bevacizumab, sorafenib, and sunitinib block this pathway and are approved for several cancers. High VEGF levels suppress the immune system by reducing T cell and dendritic cell activity while increasing immune checkpoint expression. VEGF inhibitors normalise tumor vasculature, improving immune cell infiltration [26].

Clinical studies demonstrate enhanced anti-tumor effects with combination therapy. Bevacizumab enhanced cancer vaccine responses in prostate cancer and improved ipilimumab (anti-CTLA-4) efficacy in melanoma. Bevacizumab combined with PD-L1 inhibitors benefited renal cancer patients. These combinations increase immune activation and clinical response rates. New targets including the angiopoietin/Tie2 pathway are under investigation for similar synergy [29].

7.3 MAPK-MEK Inhibitors Combined with Immunotherapy

The mitogen-activated protein kinase (MAPK) signalling axis is a critical driver of tumorigenesis [30]. Nearly half of all melanomas harbour BRAF V600E mutations, which are associated with immune escape and immunosuppressive tumor microenvironment. MAPK pathway inhibition using BRAF and MEK inhibitors counteracts immunosuppression, revealing synergy between targeted therapy and immunotherapy [32].

MAPK pathway inhibition increases melanoma differentiation antigen expression, priming antigen-specific T cells. MAPK inhibitors augment anti-tumor immunity by increasing intramural T cell infiltration and altering tumor microenvironment immune status, likely through blocking T cell exhaustion signals and down-regulating immunosuppressive factors [34].

Pharmacological MAPK inhibition augments immune checkpoint inhibitor effects. In BRAF V600E-driven melanoma models, BRAF inhibitor combined with engineered T cell transfer resulted in stronger anti-tumor responses than either therapy alone. Immune checkpoint blockade also augmented BRAF inhibitor effects against metastatic melanoma by activating tumor-infiltrating T cells. In metastatic colorectal cancer, the MEK inhibitor cobimetinib synergised with anti-PD-L1 antibody atezolizumab [37].

7.4 PI3K-AKT-mTOR Pathway Inhibitors Combined with Immunotherapy

The PI3K-AKT-mTOR pathway regulates both cancer progression and T cell function. Pathway over-activation (e.g., PTEN loss) links to increased PD-L1 expression and immune evasion in melanoma and glioblastoma [39]. Blocking PI3K signalling enhances T cell infiltration and improves immune checkpoint inhibitor efficacy. PI3K inhibition in regulatory T cells boosts anti-tumor immunity.

The PI3K inhibitor idelalisib shows promise combined with PD-1 blockers in clinical trials for leukaemia and lymphoma. While mTOR inhibitors are traditionally used for immunosuppression, they can enhance CD8+ T cell memory and response in cancer therapy. Rapamycin combined with cancer vaccines or CD40 antibodies increases T cell tumor infiltration in mouse models. These combinations offer strategies for overcoming immune resistance, with preclinical studies supporting synergy [41].

8. PRE-CLINICAL AND CLINICAL EVIDENCE

8.1 Pre-Clinical Studies

Numerous studies have demonstrated synergy in combined targeted therapy and immunotherapy regimens in mouse models. BMS908662 (BRAF inhibitor) enhanced CTLA-4 blockade by significantly promoting antigen-specific CD8+ T cell expansion. Similar antitumor responses were observed with BRAF inhibition combined with PD-1 blockade through increased tumor-infiltrating T cell number and function [25].

When PD-L1 expression increases with BRAF and MEK inhibition, triple combination blockade of PD-L1, BRAF, and MEK yields ideal antitumor effects [28]. Beyond immune checkpoint blockade, additional immune stimulatory agents should be considered to enhance response.

MEK inhibitor trametinib up-regulates TIM-3 expression, and TIM-3 blockade combination promotes tumor elimination [30]. Combined OVA TCR gene-engineered adoptive cell therapy plus vemurafenib significantly improved antitumor activity by enhancing intramural T cell effector function in melanoma models, providing strong theoretical support for targeted therapy combined with adoptive cell therapy [31].

8.2 Clinical Evidence

Clinical trials actively explore targeted therapy combined with immunotherapy for metastatic melanoma, particularly in BRAF-mutant patients. Most trials focus on combining BRAF/MEK inhibitors with immune checkpoint inhibitors (CTLA-4 or PD-1/PD-L1), cytokines (IL-2, IFN-α), vaccines, and adoptive T cell therapy [39].

Some combinations including vemurafenib with ipilimumab caused hepatotoxicity or skin toxicities, highlighting efficacy-safety balance challenges. PD-1/PD-L1 combinations appear safer and better tolerated. Trials testing optimal timing and sequencing of combinations are ongoing. Vemurafenib with high-dose IL-2 showed initial responses but also caused toxicity and potential resistance through regulatory T cell increases [33].

BRAF inhibitors combined with IFN-α restored IFN receptor expression, supporting this combination. Oncolytic virus T-VEC combined with targeted therapy showed clinical benefit in select patients, with trials continuing [41]. TIL therapy combined with vemurafenib showed promising response rates and safety, suggesting feasibility for resistant melanoma [60].

8.3 FDA-Approved Combination Therapies

Ten FDA-approved combination therapies for immunotherapy and targeted therapy include:

1. Nivolumab + ipilimumab
2. Pembrolizumab + trastuzumab + chemotherapy
3. Pembrolizumab + Lenvatinib
4. Atezolizumab + bevacizumab
5. Nivolumab + cabozantinib
6. Rituximab + brentuximab vedotin + lenalidomide
7. Avutometinib + defactinib
8. Tafasitamab + lenalidomide
9. Avelumab + axitinib
10. Durvalumab + tremelimumab + bevacizumab

9. CHALLENGES IN COMBINATION THERAPY

9.1 Key Challenges

Combining targeted and immunotherapy approaches presents significant challenges:

Optimal Sequencing and Timing: Determining proper therapy order and timing is difficult; immunomodulatory benefits of targeted agents require careful integration for maximum efficacy.

Patient Selection and Biomarkers: Identifying patients benefiting from combination therapy is complex due to evolving tumor resistance mechanisms and limited predictive biomarkers.

Efficacy Assessment: Traditional response criteria may be inadequate, as immunomodulating regimens cause atypical responses including pseudo progression, complicating response evaluation.

Molecular Mechanism Understanding: Complex interplay between targeted agents and the immune microenvironment may alter expected effects, with single-agent findings not always translating to combinations.

Logistical Trial Challenges: The vast number of potential combinations exceeds feasible testing capacity, necessitating new prioritisation and testing approaches.

Cumulative and Unpredictable Toxicity: Combination regimens may cause higher or unexpected toxicity including hepatotoxicity and immune-related adverse events, sometimes leading to trial termination.

9.2 Future Prospects

Personalised and Precision Approaches: Ongoing clinical trials evaluate individualized regimens including PD-1 inhibitors with mutation-specific targeted drugs. Such precision medicine approaches are expected to optimise efficacy while minimising toxicity.

Synergistic Efficacy: Preclinical and early clinical data suggest improved outcomes (longer progression-free and overall survival) combining immunotherapy with targeted agents, particularly for single-modality-resistant cancers.

Enhanced Tumor Microenvironment: Combination therapies modulate tumor immune landscapes, increasing cytotoxic T cell infiltration while reducing immunosuppressive cell populations, creating favourable long-term immune control conditions.

Expanding Clinical Applications: Ongoing studies will define which cancers and molecular subtypes derive greatest benefit from combinations, exploring integration with chemotherapy and radiation.

Long-Term Remissions: Some trials have achieved durable responses and rare long-term remissions in advanced or previously untreatable cancers.

10. CONCLUSION

Cancer treatment has been substantially improved through integration of immunotherapy, targeted therapy, and biomaterials. Immunotherapy enables the body's immune system to combat cancer through multiple mechanisms including checkpoint blockade and cell engineering. Targeted therapy focuses on specific cancer-driving molecules, reducing healthy tissue damage. Biomaterials including nanoparticles and hydrogels deliver treatments directly to tumours with reduced side effects and enhanced efficacy.

The convergence of immunotherapy and targeted therapy produces superior outcomes to single-modality approaches. These combinations improve treatment results, overcome resistance mechanisms, and offer hope for long-term recovery. However, challenges remain including cumulative toxicity, resistance development, and optimal patient selection. With continued research, mechanistic understanding, and personalised treatment strategies, these combined approaches represent a powerful advance in oncology, enabling patients to achieve longer survival and improved quality of life.

The future of cancer therapy lies in precision oncology approaches that integrate multiple therapeutic modalities—immunotherapy, targeted therapy, and optimised biomaterial platforms—tailored to individual patient tumor biology and immune status. Such personalised convergent strategies hold unprecedented promise for transforming cancer from a fatal to a manageable chronic disease.

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