Treatment of Non-infectious Disease — Pharmacological, Surgical, Lifestyle and Emerging Therapies
Treating non-infectious disease means understanding what is broken at the molecular, cellular, or organ level — and finding the most precise, effective, and safe way to fix it. Every treatment approach in this lesson traces directly back to the disease mechanisms you studied in IQ2.
Practise this lesson
Four printable worksheets that build from the foundations up to exam-style questions — start at whatever level suits you.
Treatment of non-infectious disease applies the IQ2 mechanism knowledge you have built
Cystic fibrosis was first described in 1938. The CFTR gene was identified in 1989. Despite knowing the exact genetic cause for 35 years, a truly effective treatment (Trikafta — a CFTR modulator) only reached Australian patients in 2022. The mechanism was understood decades before the treatment existed.
Type 2 diabetes, by contrast, can be dramatically improved by lifestyle modification — weight loss, dietary change, and physical activity — without any drug, simply by reducing the metabolic overload that drives insulin resistance. The treatment in this case requires no molecular knowledge of insulin signalling, just intervention at the behavioural level.
Before reading on:
Q1: What does the cystic fibrosis story suggest about the relationship between understanding a disease mechanism and being able to treat it? What types of treatment can work at the molecular level?
Q2: For a disease like Type 2 diabetes, which has both genetic and lifestyle causes, what are the advantages and disadvantages of treating it with: (a) a drug; (b) lifestyle modification?
Know
- The four main categories of treatment: pharmacological, surgical, lifestyle, and emerging therapies
- Specific examples of each treatment type for diseases studied in IQ2
- How CFTR modulators treat cystic fibrosis at the molecular level
- How lifestyle modification can achieve T2D remission
Understand
- Why understanding disease mechanism directly enables rational drug design
- Why targeted therapies have fewer side effects than cytotoxic chemotherapy
- How immunotherapy works differently from conventional cancer treatment
- Why lifestyle modification is mechanistically the most direct treatment for T2D
Can Do
- Match treatments to specific diseases and explain the mechanism of each
- Evaluate the advantages and limitations of different treatment approaches
- Connect treatment mechanisms back to the disease mechanisms studied in IQ2
- Distinguish between treating symptoms, managing progression, and addressing root cause
Core Content
Treatments differ in whether they address the root cause, slow progression, or manage symptoms — and understanding this distinction is fundamental to evaluating any therapy
Every treatment for non-infectious disease can be categorised by where it intervenes in the disease pathway. Some treatments address the root cause directly (CFTR modulators fix the dysfunctional protein in CF). Some slow disease progression (statins slow atherosclerosis). Some manage symptoms without altering the underlying process (pain relief for cancer). The most desirable treatments address root causes — but they are often the hardest to develop.
Treatment approaches for non-infectious disease
Treatment hierarchy from prevention to cure
| Level of intervention | What it does | Example | Limitation |
|---|---|---|---|
| Root cause | Corrects the fundamental molecular or cellular defect driving disease | CFTR modulators in CF — restore CFTR protein function | Requires detailed molecular knowledge; technically difficult; not always possible |
| Mechanism | Interrupts a key step in the disease pathway without correcting the root cause | Insulin therapy in T1D — replaces missing insulin; BRAF inhibitors in melanoma — inhibit the oncogenic protein | Does not cure the underlying condition; long-term management required |
| Progression | Slows the rate at which disease worsens | Statins reducing LDL to slow atherosclerosis; ACE inhibitors reducing blood pressure to slow kidney damage in diabetes | Disease continues to progress, just more slowly; patient still needs ongoing treatment |
| Symptoms | Relieves symptoms without affecting the disease process | Analgesics for cancer pain; bronchodilators for COPD symptoms | No impact on disease trajectory — disease continues unchecked |
What to write in your book
- Four levels of intervention: root cause → mechanism → progression → symptoms.
- Root cause (CFTR modulators) is most desirable but hardest to develop.
- Mechanism (insulin, BRAF inhibitors) interrupts a key step but doesn't cure.
- Always trace: target → how the treatment modifies it → downstream effect.
Which treatment best addresses the ROOT CAUSE of its disease?
From replacing missing molecules to blocking overactive pathways — six key examples directly connected to IQ2 diseases
Pharmacological treatments work by interacting with specific molecular targets — receptors, enzymes, ion channels, or signalling proteins — to either restore a function that is lost or inhibit a process that is overactive. The more precisely a drug targets the disease-causing mechanism, the fewer off-target side effects it produces.
Insulin therapy — Type 1 diabetes (connecting to L07)
In Type 1 diabetes, autoimmune destruction of beta cells eliminates insulin production. The treatment replaces what is missing: exogenous insulin is injected or delivered via a continuous subcutaneous pump. Modern insulins are recombinant human insulin (produced by genetically modified bacteria — a biotechnology application you will revisit in L17). Rapid-acting analogues (lispro, aspart) are taken with meals to manage post-meal glucose spikes; long-acting analogues (glargine, detemir) provide background insulin coverage. Closed-loop insulin pump systems now use continuous glucose monitoring to automatically adjust insulin delivery — approaching artificial pancreas function.
Statins — cardiovascular disease (connecting to L09)
Statins (e.g. atorvastatin, rosuvastatin) inhibit HMG-CoA reductase — the rate-limiting enzyme in the liver's cholesterol synthesis pathway. Blocking this enzyme reduces hepatic cholesterol production → liver upregulates LDL receptors to capture more LDL from the blood → blood LDL concentration falls → less LDL available to infiltrate arterial walls → slower atherosclerotic plaque formation. This is mechanism-level intervention: statins do not reverse existing plaques, but reduce the rate of new plaque formation. They also have anti-inflammatory effects in arterial walls independent of their LDL-lowering action.
CFTR modulators — cystic fibrosis (connecting to L07)
CFTR modulators are the first treatments to target the root cause of cystic fibrosis at the molecular level. There are two classes: correctors (e.g. elexacaftor, lumacaftor) help the misfolded F508del CFTR protein fold correctly and reach the cell membrane; potentiators (e.g. ivacaftor) hold the CFTR channel open for longer once it reaches the membrane. Trikafta (elexacaftor-tezacaftor-ivacaftor — two correctors plus a potentiator) is effective in ~90% of CF patients with the F508del mutation. Clinical impact: lung function improved by 10–14 percentage points; hospitalisation rates fell dramatically; life expectancy is expected to increase by decades. This is the clearest example of mechanistic understanding of a genetic disease directly producing a transformative treatment.
Targeted therapy in cancer — BRAF inhibitors (connecting to L10)
Approximately 50% of melanomas carry the BRAF V600E oncogene mutation (a constitutively active BRAF kinase). BRAF inhibitors (vemurafenib, dabrafenib) specifically bind and inhibit the mutant BRAF V600E protein — blocking the constitutive proliferation signal it generates. Because the drug targets a cancer-specific mutation rather than a normal cellular process, it preferentially kills BRAF V600E-mutant cancer cells while sparing most normal cells. Contrast with conventional chemotherapy (cytotoxic drugs that kill all rapidly dividing cells — cancer and healthy alike, producing the characteristic side effects of hair loss, nausea, immunosuppression).
Immune checkpoint inhibitors (connecting to L10)
Advanced cancers often evade immune attack by expressing PD-L1 on their surface, which binds the PD-1 receptor on cytotoxic T cells and switches them off. Pembrolizumab and nivolumab are antibodies that block this PD-1/PD-L1 interaction — releasing the immune system's brake on T cell activity. With PD-1 blocked, T cells can recognise and kill cancer cells that were previously invisible to immune surveillance. Unlike chemotherapy (which kills rapidly dividing cells directly), immunotherapy works by restoring immune function — the immune system then kills the cancer. This produces durable responses in some patients because the immune system can establish memory and maintain long-term surveillance.
ACE inhibitors and ARBs — cardiovascular disease and diabetic nephropathy
ACE inhibitors (e.g. ramipril, perindopril) block angiotensin-converting enzyme, preventing the production of angiotensin II — the vasoconstrictor that drives blood pressure up via the RAAS pathway (covered in L04). Lower angiotensin II → less vasoconstriction → lower blood pressure → reduced mechanical stress on arterial walls (slowing atherosclerosis) and reduced pressure in glomerular capillaries (protecting kidneys from diabetic nephropathy). These drugs treat multiple mechanisms simultaneously: hypertension, heart failure, and kidney protection in diabetes.
What to write in your book
- Insulin: replaces missing insulin in T1D (mechanism-level). Statins: inhibit HMG-CoA reductase → ↓LDL.
- CFTR modulators: correctors (fold protein) + potentiators (open channel) — root cause.
- BRAF inhibitors: block mutant BRAF V600E kinase (targeted, fewer side effects than chemo).
- PD-1 inhibitors: block immune evasion → T cells kill cancer. ACE inhibitors: block angiotensin II → ↓BP, kidney protection.
Statins lower LDL cholesterol by acting on which molecular target?
When pharmacology is insufficient — surgical correction of structural disease, and lifestyle as the most powerful intervention for metabolic disease
Some non-infectious diseases require structural correction that drugs cannot provide. Others — particularly Type 2 diabetes and cardiovascular disease — respond more powerfully to lifestyle modification than to any single drug, because lifestyle addresses the primary metabolic drivers of the disease rather than compensating for their effects.
Surgical interventions for cardiovascular disease
Coronary angioplasty and stenting: A catheter with an inflatable balloon is inserted into a blocked coronary artery via the femoral artery. The balloon is inflated to compress the atherosclerotic plaque and widen the lumen. A metal mesh stent is then deployed to hold the artery open permanently. This restores blood flow to ischaemic heart muscle. Drug-eluting stents (coated with anti-proliferative drugs) reduce restenosis — scar tissue re-narrowing the stent — by inhibiting smooth muscle cell proliferation at the stent site.
Coronary artery bypass grafting (CABG): In severe multi-vessel disease where angioplasty is insufficient, a surgeon grafts a section of vein (usually from the leg) or artery (internal mammary) around the blocked coronary segment, creating a new route for blood to reach the heart muscle. This is major open-heart surgery — reserved for patients with extensive blockages or failed angioplasty.
Lifestyle modification — Type 2 diabetes remission
Type 2 diabetes can enter full remission (blood glucose returning to the non-diabetic range without medication) in patients who achieve significant weight loss — typically 10–15 kg. The mechanism: excess visceral adipose tissue produces inflammatory cytokines (adipokines) that impair insulin receptor signalling in liver, muscle, and fat cells. Weight loss reduces visceral fat → inflammatory signalling falls → insulin receptor sensitivity is restored → beta cells, which were not destroyed (unlike T1D) but were overworked and functionally exhausted, can recover their normal secretory capacity.
The DiRECT trial (UK, 2018) demonstrated that structured dietary weight management achieved remission in 46% of patients at 12 months. At 2 years, 36% remained in remission. This is the most powerful treatment for T2D in patients who can achieve sufficient weight loss — more effective per kilogram lost than any currently approved drug. However, remission is not a cure — the underlying genetic predisposition remains, and disease recurs with weight regain.
Physical activity as treatment
Regular moderate-intensity physical activity independently improves insulin sensitivity in skeletal muscle (through GLUT4 transporter upregulation — contracting muscle can take up glucose via an insulin-independent pathway), reduces cardiovascular risk (lowering blood pressure, improving lipid profile, reducing inflammatory markers), and has neuroprotective effects relevant to dementia prevention. Exercise is classified as a 'polypharmacy equivalent' in some guidelines — it benefits cardiovascular disease, Type 2 diabetes, depression, osteoporosis, and cancer risk simultaneously through multiple mechanisms.
What to write in your book
- Angioplasty + stent: compress plaque, hold lumen open; CABG: bypass blocked coronary artery.
- T2D remission: weight loss → ↓visceral fat → ↓adipokine inflammation → insulin sensitivity restored → beta cell recovery.
- DiRECT trial: 46% remission at 12 months with dietary management (vs 4% standard care).
- Exercise: GLUT4 upregulation → insulin-independent glucose uptake; multi-disease benefit.
Type 2 diabetes remission through weight loss is a permanent cure — the disease cannot return.
Pharmacological treatments for non-infectious diseases include medications that target specific molecular pathways, such as statins for cholesterol reduction.
Lifestyle modifications, such as diet and exercise, have no effect on the progression of non-infectious diseases like type 2 diabetes.
Technologies that are transforming treatment or have potential to do so in the near future — all directly linked to disease mechanisms studied in IQ2
Emerging therapies represent the direct application of molecular biology and genetic knowledge to disease treatment — the logical endpoint of the IQ2 content you have already studied. Understanding these therapies requires connecting what you know about gene mutations, protein function, and cell biology to specific therapeutic strategies.
CAR-T Cell Therapy (Cancer)
A patient's own T cells are extracted and genetically engineered in the laboratory to express a Chimeric Antigen Receptor (CAR) — an artificial receptor designed to recognise a specific protein on the surface of cancer cells (e.g. CD19 on B-cell leukaemia). The modified cells are expanded in culture and reinfused. The engineered T cells seek out and kill cancer cells expressing the target antigen. CAR-T has produced durable complete remissions in patients with relapsed/refractory leukaemia and lymphoma who had no other options. Approved in Australia for certain blood cancers.
Antisense Oligonucleotides (Huntington's Disease)
Antisense oligonucleotides (ASOs) are short synthetic DNA/RNA strands that bind to the mutant HTT mRNA and trigger its degradation — reducing the production of toxic polyQ huntingtin protein before it can accumulate in neurons. Clinical trials (IONIS-HTTRx, now tominersen) demonstrated significant reductions in mutant huntingtin in cerebrospinal fluid. This approach targets the disease at the mRNA level — downstream of the gene mutation but upstream of the toxic protein. Currently in Phase 3 trials for Huntington's disease.
CRISPR Gene Editing (CF, Sickle Cell, Cancer)
CRISPR-Cas9 allows precise editing of DNA sequences — in principle, correcting the F508del mutation in CFTR or other disease-causing mutations at the source. In 2023, Casgevy — the world's first approved CRISPR therapy — was approved for sickle cell disease and beta-thalassaemia. For CF, CRISPR editing of lung stem cells to correct CFTR mutations is in early development. For cancer, CRISPR is being used to engineer tumour-infiltrating lymphocytes with enhanced cancer-killing activity. This technology will be covered in more detail in L16 (IQ4 — Prevention).
GLP-1 Receptor Agonists (T2D and Obesity)
GLP-1 agonists (semaglutide — brand name Ozempic/Wegovy; liraglutide — Victoza/Saxenda) mimic the gut hormone glucagon-like peptide-1, which stimulates insulin secretion from beta cells in a glucose-dependent manner, suppresses glucagon, delays gastric emptying, and reduces appetite centrally. Originally developed for Type 2 diabetes, semaglutide also produces 15–17% body weight reduction in trials — the most effective non-surgical weight loss treatment ever approved — leading to its use in obesity treatment and driving T2D remission through weight loss. As of 2024, trials also show cardiovascular mortality benefit independent of glucose lowering.
What to write in your book
- CAR-T: engineer patient's T cells to target cancer surface antigens (e.g. CD19).
- ASOs: bind mutant HTT mRNA → degrade it → less toxic huntingtin (Huntington's).
- CRISPR: correct DNA mutations at source (Casgevy approved 2023 for sickle cell/β-thalassaemia).
- GLP-1 agonists (semaglutide): insulin secretion + appetite suppression + weight loss for T2D/obesity.
The gene-editing technology that can correct a disease-causing mutation directly in the DNA sequence is called _____ (Cas9).
Treatment Mechanism Matching
For each treatment, identify the disease it primarily treats, state the molecular or physiological target, and explain the mechanism of action. Connect each treatment back to the disease mechanism studied in IQ2.
- Ivacaftor (a CFTR potentiator) — a drug that binds to the CFTR protein and increases the probability and duration of the channel being in its open state.
- Pembrolizumab (anti-PD-1 antibody) — an antibody that binds to the PD-1 receptor on cytotoxic T cells.
- Ramipril (an ACE inhibitor) prescribed to a patient with Type 2 diabetes and early kidney disease.
- Compare cytotoxic chemotherapy with BRAF inhibitor (vemurafenib) therapy for melanoma. For each: state the mechanism of action, the target (specific or general), and one advantage and one disadvantage.
Evaluating Treatment Options
Read each scenario and answer all parts, connecting treatments to mechanisms and evaluating their appropriateness.
- A 48-year-old patient with Type 2 diabetes is offered two treatment options: (A) metformin (reduces hepatic glucose production and improves insulin sensitivity) taken daily; or (B) a structured 12-week dietary intervention targeting 15 kg weight loss. The patient is currently 35 kg overweight. Discuss the mechanism of each treatment, evaluate their respective advantages and limitations, and recommend which approach you would consider most appropriate for this patient, with justification.
- An 8-year-old child is newly diagnosed with cystic fibrosis (homozygous F508del mutation). Their parents ask: "What treatments are available? Will they be on medication forever? Is there a cure?" Answer all three questions, distinguishing clearly between symptom management, mechanism-level treatment, and potential future root-cause treatment (CRISPR).
For most of the 20th century, treatment for cystic fibrosis was purely symptomatic — physiotherapy to clear mucus, antibiotics for infections, nutritional supplementation for malabsorption. Life expectancy for CF patients was measured in years to early decades. None of these treatments addressed the root cause: the dysfunctional CFTR protein.
The identification of the CFTR gene in 1989 began a 30-year journey toward targeting the protein directly. The first CFTR potentiator, ivacaftor (Kalydeco), was approved in 2012 — but it only worked for the rare G551D mutation (~4% of CF patients), not for the common F508del mutation (~70%). The challenge with F508del was that the protein misfolded before reaching the membrane — a corrector was needed to stabilise its folding, plus a potentiator to keep the channel open once it arrived.
Trikafta — combining two correctors (elexacaftor and tezacaftor) with the potentiator ivacaftor — was approved by the US FDA in 2019. In clinical trials, it improved lung function by approximately 14 percentage points (a massive improvement for a lung disease measured in single-digit annual declines), reduced pulmonary exacerbations by 63%, and transformed quality of life. The TGA approved it in Australia in 2021 and the PBS listed it in 2022. The CF community described the day of PBS listing as a turning point in the history of the disease. Children starting Trikafta today may never need a lung transplant — something that would have been unimaginable for most CF patients 10 years ago.
Pharmacological Examples
- Insulin: replaces missing insulin in T1D
- Statins: inhibit HMG-CoA reductase → lower LDL → slower atherosclerosis
- CFTR modulators: correctors (fold) + potentiators (open channel)
- BRAF inhibitors: block mutant BRAF V600E; PD-1 inhibitors: release immune brake; ACE inhibitors: block angiotensin II
Surgical
- Angioplasty + stent: compress plaque, hold lumen open
- CABG: bypass blocked coronary artery with graft
- Targets structural disease that drugs cannot reverse
Lifestyle
- T2D remission: weight loss → ↓visceral fat → insulin resistance reversed → beta cell recovery
- DiRECT trial: 46% remission at 12 months
- Exercise: GLUT4 upregulation → insulin-independent glucose uptake
Emerging Therapies
- CAR-T: engineered T cells → target cancer surface antigens
- ASOs: silence mutant HTT mRNA → less toxic huntingtin (HD)
- CRISPR: correct DNA mutations at source (CF, sickle cell)
- GLP-1 agonists (semaglutide): insulin + satiety + weight loss for T2D/obesity
A fresh set drawn from this lesson's question bank — feedback shown immediately. +5 XP per correct · +25 XP all correct
Pick your answer, then rate your confidence — that tells the system what to drill next.
ApplyBand 4(4 marks) 1. Explain how immune checkpoint inhibitors (such as pembrolizumab) treat cancer. Describe the normal function of the PD-1/PD-L1 pathway, how cancer cells exploit it to evade immune attack, and how the drug disrupts this evasion mechanism.
AnalyseBand 4–5(5 marks) 2. Compare pharmacological treatment (insulin therapy) and lifestyle modification for managing Type 2 diabetes. For each approach, describe the mechanism of action, the level of intervention (root cause / mechanism / progression / symptom), and one advantage and one limitation. Conclude by explaining why the two approaches are often used together rather than as alternatives.
EvaluateBand 5–6(6 marks) 3. "The development of CFTR modulators like Trikafta demonstrates that understanding a disease mechanism at the molecular level is sufficient to develop an effective treatment." Evaluate this claim using the history of CF treatment and considering whether the same approach could work for all genetic diseases.
Show all answers
Multiple choice
MC answers and full explanations are shown inline as you complete each question. Use the retry button to attempt a fresh set from the lesson bank.
Activity 1 — Treatment Mechanism Matching
1. Ivacaftor — cystic fibrosis. Target: the CFTR chloride channel in the apical membrane of epithelial cells. Mechanism: ivacaftor binds CFTR and increases the probability/duration the channel is open → more Cl⁻ flows into the lumen → water follows by osmosis → mucus is hydrated → mucociliary clearance restored. IQ2 (L07): the root defect is CFTR mutation → dysfunctional Cl⁻ channel → thick mucus. Ivacaftor maximises the function of CFTR protein that reaches the membrane (it does not correct folding — that needs correctors).
2. Pembrolizumab — cancer (melanoma, lung, etc.). Target: PD-1 on cytotoxic T cells. Mechanism: blocks PD-1's interaction with tumour PD-L1, so the tumour cannot deliver the inhibitory signal that switches off T cells → T cells remain active → recognise and kill cancer cells. IQ2 (L10): cancers evade immune surveillance by overexpressing PD-L1; pembrolizumab disrupts this evasion.
3. Ramipril (ACE inhibitor) for T2D nephropathy. Mechanism: blocks ACE → less angiotensin II → preferential dilation of the efferent arteriole → reduced intraglomerular pressure → reduced mechanical stress on the glomerular filtration barrier → slower progression of proteinuria/glomerulosclerosis (plus lower systemic BP slows atherosclerosis). IQ2 + L04: the RAAS pathway raises BP via renin→angiotensin I→ACE→angiotensin II→aldosterone; ACE inhibitors interrupt this, making them specifically nephroprotective where glomerular hypertension drives kidney damage.
4. Chemotherapy vs BRAF inhibitor. Chemo: mechanism — DNA damage/mitotic disruption in all rapidly dividing cells; target — non-specific; advantage — works across many cancer types regardless of mutation; disadvantage — off-target toxicity (hair loss, nausea, immunosuppression). BRAF inhibitor (vemurafenib): mechanism — inhibits the mutant BRAF V600E kinase blocking its proliferation signal; target — specific (BRAF V600E-mutant cells); advantage — far fewer side effects; disadvantage — only works in ~50% of melanomas (V600E-positive) and resistance commonly develops within 6–18 months.
Activity 2 — Treatment Evaluation
1. T2D treatment comparison. Metformin: reduces hepatic glucose production (inhibits mitochondrial complex I in liver) and improves muscle insulin sensitivity; level = mechanism (compensates without fixing visceral fat); advantage = well-tolerated, effective, inexpensive, cardiovascular benefit; limitation = doesn't address root cause, disease progresses, no remission. Dietary intervention: weight loss → ↓visceral fat → ↓adipokine inflammation → insulin sensitivity restored → exhausted beta cells recover → remission; level = root cause; advantage = can achieve remission (46% at 12 months, DiRECT), broad metabolic benefit; limitation = requires sustained 10–15 kg loss, hard to maintain, recurs with weight regain. Recommendation: prioritise the dietary intervention for this newly diagnosed, 35 kg-overweight patient (best chance of remission per DiRECT), with metformin as a bridge and weaned if remission is achieved — the two are complementary.
2. CF treatment questions. Available: (1) symptomatic — physiotherapy, antibiotics, pancreatic enzyme replacement, fat-soluble vitamins; (2) mechanism-level — Trikafta (elexacaftor-tezacaftor-ivacaftor): correctors fold the F508del protein and traffic it to the membrane; the potentiator holds the channel open → restored Cl⁻/water secretion → hydrated mucus; (3) emerging — CRISPR editing of lung stem cells to correct F508del (early development). Forever on medication: yes — Trikafta manages but does not cure; the gene mutation persists in every cell, so stopping the drug returns the disease, unless gene therapy/CRISPR eventually corrects the mutation. Is there a cure? Not yet — Trikafta is transformative but not curative; CRISPR is the theoretical path to cure.
Short Answer Model Answers
SA1 (4 marks): Normal PD-1/PD-L1: PD-1 is on cytotoxic T cells; when PD-L1 (on healthy cells or activated T cells) binds it, an inhibitory signal suppresses T cell activity — preventing autoimmunity and limiting tissue damage [1]. Cancer exploitation: tumour cells upregulate PD-L1; tumour PD-L1 binding T cell PD-1 switches the T cell off, making the cancer invisible to immune attack despite being recognised as abnormal [1]. Drug mechanism: pembrolizumab is a monoclonal antibody that binds PD-1, blocking the PD-L1/PD-1 interaction; the tumour can no longer switch off the T cells, so they mount a cytotoxic response and kill the cancer [1]. Unlike chemotherapy (which kills dividing cells), it restores immune function — producing durable responses as the immune system establishes ongoing surveillance [1].
SA2 (5 marks): Insulin therapy: exogenous insulin compensates for insufficient endogenous insulin (advanced T2D) → binds insulin receptors → GLUT4 mobilises → glucose uptake → blood glucose falls; level = mechanism (compensates, doesn't fix resistance); advantage = reliable, precise control; limitation = doesn't address root cause, causes weight gain, hypoglycaemia risk [2]. Lifestyle modification: weight loss → ↓visceral fat → ↓inflammatory adipokines → insulin receptor sensitivity restored → exhausted beta cells recover secretory capacity → glucose normalises without medication; level = root cause; advantage = can achieve remission and broad metabolic benefit; limitation = requires sustained major weight loss, not achievable for all, recurs with regain [2]. Used together: in patients with both beta-cell failure and resistance, insulin controls dangerous hyperglycaemia immediately while lifestyle works on resistance over months; as sensitivity improves, insulin doses can be reduced or stopped [1].
SA3 (6 marks): Support: Trikafta is the clearest example of mechanistic understanding producing a transformative treatment — F508del was identified in 1989, the folding/trafficking defect was understood, and this directly guided design of correctors (stabilise folding, enable membrane trafficking) and a potentiator (maximise open probability), improving lung function by ~14 percentage points [2]. Qualification — 'sufficient' overstates: it took 30 years because designing cell-penetrant small molecules that interact with CFTR required extensive medicinal chemistry, structural resolution of CFTR, preclinical and Phase 1–3 trials, regulatory approval, and funding/access (PBS 2022). Mechanistic understanding initiates rational design — it does not automatically deliver a treatment [2]. Other genetic diseases: CF was unusually tractable because its defect is correctable by small molecules; Huntington's (gain-of-function toxin) needs ASOs/CRISPR not folding correction; PKU is managed dietarily; structural-protein diseases (e.g. Duchenne — dystrophin) and transcription-factor defects are far harder to target. The CF approach is not universally applicable — each disease needs an approach suited to its molecular defect. Conclusion: molecular understanding is necessary and enables rational treatment design, but it is not sufficient — technical tractability, time and funding are also required [2].
Five timed questions on pharmacological, surgical, lifestyle and emerging therapies. Beat the boss to bank a tier — gold (perfect + fast), silver (80%+), or bronze (cleared).
⚔ Enter the arenaAnswer questions on drugs, surgery, lifestyle and emerging therapies — matching each to its mechanism. Pool: lessons 1–14.
Return to your Think First responses at the start of this lesson.
- Q1 — mechanism and treatment: The CF story shows understanding mechanism is necessary but not sufficient — 30 years elapsed between identifying the gene and developing an effective molecular treatment. The key is whether the molecular defect is technically 'druggable'.
- Q2 — drug vs lifestyle for T2D: Drugs manage glucose without addressing the root cause (insulin resistance) and must be taken indefinitely; lifestyle modification addresses the root cause (weight loss reverses insulin resistance) and can achieve remission — but requires sustained effort. Both have roles; DiRECT supports lifestyle first for newly diagnosed patients who can lose weight.
- Name one treatment for each of CF, melanoma, T2D, and CVD — and for each, state whether it addresses root cause, mechanism, progression, or symptoms.