Tecentriq (Atezolizumab)
atezolizumab — humanised IgG1 anti-PD-L1 monoclonal antibody
Indications
Atezolizumab is the first FDA-approved PD-L1-targeting checkpoint inhibitor, receiving initial clearance for urothelial carcinoma in May 2016. The current label (March 2026) reflects several indication expansions and notable withdrawals. The following table summarises all currently approved indications; previously held urothelial carcinoma and triple-negative breast cancer indications were voluntarily withdrawn in 2021–2022 after confirmatory trials did not meet their primary endpoints.
| Indication | Approved Population | Therapy Type | Status |
|---|---|---|---|
| Adjuvant NSCLC (Stage II–IIIA) | Adults (PD-L1 ≥1% TC, post-resection + platinum chemo) | Monotherapy | FDA Approved |
| Metastatic NSCLC — first-line monotherapy | Adults (high PD-L1: TC ≥50% or IC ≥10%, no EGFR/ALK) | Monotherapy | FDA Approved |
| Metastatic non-squamous NSCLC — first-line | Adults (no EGFR/ALK) | + bevacizumab + paclitaxel + carboplatin | FDA Approved |
| Metastatic non-squamous NSCLC — first-line | Adults (no EGFR/ALK) | + nab-paclitaxel + carboplatin | FDA Approved |
| Metastatic NSCLC — second-line or later | Adults (post-platinum; EGFR/ALK must have progressed on approved therapy) | Monotherapy | FDA Approved |
| ES-SCLC — first-line induction | Adults | + carboplatin + etoposide | FDA Approved |
| ES-SCLC — maintenance | Adults (no progression after 1L induction with atezolizumab + carbo/etop) | + lurbinectedin | FDA Approved |
| Unresectable / metastatic HCC — first-line | Adults (no prior systemic therapy) | + bevacizumab | FDA Approved |
| BRAF V600+ unresectable / metastatic melanoma | Adults (BRAF V600 mutation confirmed) | + cobimetinib + vemurafenib | FDA Approved |
| Alveolar soft part sarcoma (ASPS) | Adults and paediatric ≥2 yr | Monotherapy | FDA Approved |
Atezolizumab’s clinical utility spans lung cancers (both NSCLC and SCLC), hepatocellular carcinoma, BRAF-mutant melanoma, and the rare soft-tissue sarcoma ASPS. Notably, it is the only PD-1/PD-L1 inhibitor with an approved maintenance regimen combining a checkpoint inhibitor with lurbinectedin for ES-SCLC (approved October 2025). A subcutaneous formulation (Tecentriq Hybreza, containing 1875 mg atezolizumab with 30,000 units of hyaluronidase) was approved in 2024 for all adult IV indications.
Triple-negative breast cancer (TNBC): Atezolizumab + nab-paclitaxel was formerly approved for PD-L1-positive metastatic TNBC but voluntarily withdrawn in August 2021 after IMpassion131 did not confirm benefit. Some institutions still consider it in selected PD-L1-positive patients based on IMpassion130 data. Evidence quality: moderate.
Urothelial carcinoma: Both first-line (cisplatin-ineligible) and second-line (post-platinum) UC indications were voluntarily withdrawn (March 2021 and November 2022, respectively). Evidence quality: low (confirmatory trials did not meet primary endpoints).
Dosing
Atezolizumab uses a uniquely flexible flat-dose schedule across nearly all indications: clinicians may choose 840 mg every 2 weeks, 1200 mg every 3 weeks, or 1680 mg every 4 weeks, with pharmacokinetic modelling confirming equivalent exposure across regimens. No dose reductions are recommended. The first IV infusion is given over 60 minutes; subsequent infusions may be shortened to 30 minutes if tolerated.
Monotherapy Indications
| Clinical Scenario | Starting Dose | Maintenance Dose | Maximum Dose | Notes |
|---|---|---|---|---|
| Adjuvant NSCLC (Stage II–IIIA, PD-L1 ≥1% TC) | 840 mg Q2W, 1200 mg Q3W, or 1680 mg Q4W | Same | 1680 mg Q4W | Maximum duration: 1 year. Post-resection and up to 4 cycles platinum-based chemo. PD-L1 testing by FDA-approved companion diagnostic required |
| Metastatic NSCLC first-line monotherapy (high PD-L1) | 840 mg Q2W, 1200 mg Q3W, or 1680 mg Q4W | Same | 1680 mg Q4W | Continue until progression or unacceptable toxicity. No EGFR/ALK aberrations. TC ≥50% or IC ≥10% by SP142 assay |
| Metastatic NSCLC second-line+ (post-platinum) | 840 mg Q2W, 1200 mg Q3W, or 1680 mg Q4W | Same | 1680 mg Q4W | Continue until progression or unacceptable toxicity. Any histology. |
| ASPS (adults) | 840 mg Q2W, 1200 mg Q3W, or 1680 mg Q4W | Same | 1680 mg Q4W | Continue until progression or unacceptable toxicity. |
| ASPS (paediatric ≥2 years) | 15 mg/kg Q3W (max 1200 mg) | Same | 1200 mg Q3W | Weight-based dosing. Continue until progression or unacceptable toxicity. |
Combination Regimens
| Clinical Scenario | Starting Dose | Maintenance Dose | Maximum Dose | Notes |
|---|---|---|---|---|
| NSCLC 1L + bevacizumab + paclitaxel + carboplatin | 840 mg Q2W, 1200 mg Q3W, or 1680 mg Q4W | Same (± bev after chemo completion) | 1680 mg Q4W | Chemo for 4–6 cycles; atezolizumab ± bevacizumab continues. Give atezolizumab before chemo/bev on same day. 1200 mg Q3W aligns with standard Q3W chemo cycles |
| NSCLC 1L + nab-paclitaxel + carboplatin | 840 mg Q2W, 1200 mg Q3W, or 1680 mg Q4W | Same | 1680 mg Q4W | Chemo for 4–6 cycles; atezolizumab continues as monotherapy maintenance. 1200 mg Q3W aligns with standard Q3W chemo cycles |
| ES-SCLC first-line induction + carboplatin + etoposide | 840 mg Q2W, 1200 mg Q3W, or 1680 mg Q4W | Same | 1680 mg Q4W | Chemo for 4 induction cycles; atezolizumab continues as maintenance. Give atezolizumab before chemo on same day. 1200 mg Q3W used in pivotal IMpower133 trial |
| ES-SCLC maintenance + lurbinectedin | 840 mg Q2W, 1200 mg Q3W, or 1680 mg Q4W + lurbinectedin | Same | 1680 mg Q4W | Only for patients with no progression after 1L induction with atezolizumab + carbo/etop. |
| HCC first-line + bevacizumab | 840 mg Q2W, 1200 mg Q3W, or 1680 mg Q4W + bev 15 mg/kg Q3W | Same | 1680 mg Q4W | Give atezolizumab before bevacizumab on same day. Continue until progression or toxicity. No prior systemic therapy. |
| Melanoma BRAF V600+ + cobimetinib + vemurafenib | 840 mg Q2W, 1200 mg Q3W, or 1680 mg Q4W + cobi 60 mg PO daily (21/7) + vemu 720 mg PO BID | Same | 1680 mg Q4W | 28-day run-in cycle with cobi + vemu (vemu 960 mg BID days 1–21, then 720 mg BID days 22–28) before adding atezolizumab. |
Atezolizumab’s three interchangeable dosing schedules (Q2W, Q3W, Q4W) were established through population pharmacokinetic simulations, which demonstrated equivalent overall exposure across regimens. The Q4W schedule reduces clinic visits, while Q2W may align better with combination chemotherapy cycles. All three schedules maintain trough concentrations well above the 6 µg/mL target for PD-L1 receptor occupancy. The subcutaneous formulation (Tecentriq Hybreza, 1875 mg Q3W) provides a further option for reducing infusion burden.
Pharmacology
Mechanism of Action
Atezolizumab is a humanised immunoglobulin G1 (IgG1) monoclonal antibody that directly targets PD-L1, the ligand for the PD-1 receptor. Unlike PD-1 inhibitors such as nivolumab and pembrolizumab, atezolizumab blocks PD-L1 from binding to both PD-1 and B7.1 (CD80), thereby restoring anti-tumour T-cell activity through two complementary pathways. Its Fc region is engineered with a substitution that eliminates antibody-dependent cellular cytotoxicity (ADCC), preventing atezolizumab from depleting the PD-L1-expressing activated T cells it is designed to unleash.
By blocking PD-L1 on tumour cells and tumour-infiltrating immune cells, atezolizumab lifts the immunosuppressive brake that tumours exploit to evade cytotoxic T-cell recognition. The additional blockade of the PD-L1/B7.1 interaction may further enhance T-cell priming, a mechanistic distinction from anti-PD-1 agents.
ADME Profile
| Parameter | Value | Clinical Implication |
|---|---|---|
| Absorption | IV route: 100% bioavailability. SC (Hybreza): mean absolute bioavailability 72% (CV 83%); Tmax ~4.5 days. Cavg at steady state comparable to IV 1200 mg Q3W. | SC formulation achieves comparable steady-state exposure despite 72% bioavailability because of the higher administered dose (1875 mg vs 1200 mg). Linear PK across 1–20 mg/kg. |
| Distribution | Vdss = 6.9 L. Limited extravascular distribution consistent with IgG1 molecular weight (~145 kDa). | Small Vd indicates primarily intravascular and interstitial distribution. Body weight has modest effect but is not clinically meaningful. |
| Metabolism | Catabolised by non-specific proteolytic pathways. No CYP involvement. FcRn recycling prolongs circulating half-life. | No hepatic CYP drug interactions. No dose adjustment for mild hepatic impairment. Engineered Fc retains FcRn binding for normal IgG recycling. |
| Elimination | Terminal t½ = 27 days; CL = 0.200 L/day (8.3 mL/h). Time-varying clearance decreases over treatment (tumour burden reduction). | Long half-life supports Q2W, Q3W, or Q4W flat dosing. Steady state by 6–9 weeks (2–3 cycles at Q3W). Anti-drug antibodies (ADA) detected in ~30–55% but without clinically meaningful impact on PK. |
Side Effects
Atezolizumab’s toxicity profile is defined by immune-mediated adverse reactions (irAEs) common to all PD-1/PD-L1 inhibitors, alongside conventional side effects that vary by combination partner. Incidence data below are primarily from pooled monotherapy analyses (n=2616) and pivotal combination trials as reported in the FDA prescribing information. The melanoma triple combination (+ cobimetinib + vemurafenib) carries distinctly higher toxicity rates than other regimens.
| Adverse Effect | Incidence | Clinical Note |
|---|---|---|
| Fatigue / asthenia | 48–51% | Most common across all settings. Exclude thyroid dysfunction and adrenal insufficiency. Higher (51%) with melanoma triple therapy. |
| Nausea | 24–38% | 24% monotherapy; up to 38% with platinum-based chemotherapy combinations. |
| Decreased appetite | 25–27% | Monitor weight; distinguish from endocrine causes such as adrenal insufficiency. |
| Cough | 22% | Evaluate persistent or worsening cough to exclude immune-mediated pneumonitis. |
| Dyspnoea | 22% | Requires imaging if new or progressive to rule out pneumonitis or disease progression. |
| Alopecia | 35% | Primarily with chemotherapy combinations (IMpower130/133); not typical of monotherapy. |
| Constipation | 29% | With chemotherapy combinations. Manageable with standard bowel regimens. |
| Diarrhoea | 18–28% | Distinguish from immune-mediated colitis which requires corticosteroids. Higher with chemotherapy combinations. |
| Rash | 15–75% | 15% monotherapy; up to 75% with cobimetinib + vemurafenib (melanoma). Includes maculopapular, photosensitivity reactions. |
| Hypothyroidism | 4.9–26% | 4.9% monotherapy pooled; 11% with chemo; 17% adjuvant NSCLC (IMpower010); 26% with cobi/vemu. Mostly permanent; requires levothyroxine. |
| Adverse Effect | Incidence | Clinical Note |
|---|---|---|
| Hyperthyroidism | 0.8–19% | 0.8% monotherapy pooled; 6% adjuvant NSCLC; 19% with cobi/vemu. Often transient thyroiditis preceding hypothyroidism. |
| Immune-mediated pneumonitis | 3–13% | 3% monotherapy; 3.8% adjuvant NSCLC; 13% with cobi/vemu. Higher in patients with prior thoracic radiation. |
| Immune-mediated hepatitis | 1.8–6.1% | 1.8% monotherapy; 6.1% with cobi/vemu (melanoma). Monitor LFTs each cycle. |
| Immune-mediated colitis | 1% | Monotherapy pooled; can present with diarrhoea, abdominal pain, or GI bleeding. |
| Infusion-related reactions | 1.3% | Grade 3 in 0.2%. Consider premedication for subsequent doses if Grade 1–2 reaction occurs. |
| Elevated creatinine / nephritis | <0.1–1.3% | Very rare with monotherapy (<0.1%); 1.3% with cobi/vemu. Monitor renal function each cycle. |
| Adrenal insufficiency | 0.4–1.2% | 0.4% pooled monotherapy; 1.2% adjuvant NSCLC. May require lifelong hormone replacement. |
| Adverse Effect | Estimated Frequency | Typical Onset | Required Action |
|---|---|---|---|
| Immune-mediated pneumonitis | 3% (mono); 13% (+ cobi/vemu) | 2–24 months | Withhold for Grade 2; permanently discontinue for Grade 3–4. High-dose corticosteroids (1–2 mg/kg/day prednisone). |
| Immune-mediated hepatitis | 1.8% (mono); fatal <0.1% | 1–6 months | Withhold for AST/ALT >3–8× ULN; permanently discontinue for >8× ULN. Systemic corticosteroids. |
| Immune-mediated colitis | 1% | 1–10 months | Withhold for Grade 2–3; permanently discontinue for Grade 4. CMV testing for steroid-refractory cases. |
| Immune-mediated myocarditis / pericarditis | Rare (<1%); potentially fatal | First 1–3 cycles | Permanently discontinue for Grade 2–4. Immediate high-dose corticosteroids. Cardiology consultation. |
| Immune-mediated nephritis | <0.1% (mono); 1.3% (+ cobi/vemu) | Variable | Withhold for Grade 2–3; permanently discontinue for Grade 4. Corticosteroids; consider renal biopsy. |
| Severe dermatologic reactions (SJS, TEN, DRESS) | Rare (<1%) | Days to weeks | Withhold for suspected; permanently discontinue if confirmed. Dermatology consultation. |
| Type 1 diabetes mellitus (may present as DKA) | 0.3% | Variable | Initiate insulin immediately. Long-term insulin therapy required. Withhold atezolizumab depending on severity. |
| Neurological toxicity (encephalitis, Guillain-Barré, myasthenia gravis) | Rare (<1%) | Variable | Withhold for Grade 2; permanently discontinue for Grade 3–4. High-dose corticosteroids; IVIG as indicated. |
The management principles for atezolizumab-related irAEs follow the class-wide approach: withhold for Grade 3, permanently discontinue for Grade 4 or recurrent Grade 3 requiring systemic immunosuppression. Initiate corticosteroids at 1–2 mg/kg/day prednisone equivalent for significant irAEs and taper over at least 4 weeks once the event resolves to Grade 0–1. The melanoma triple combination warrants heightened vigilance, particularly for pneumonitis (13%) and hepatotoxicity (50%), which are substantially more common than with monotherapy.
Drug Interactions
No formal pharmacokinetic drug-drug interaction studies have been conducted with atezolizumab. As a monoclonal antibody eliminated by proteolytic catabolism, it does not interact with cytochrome P450 enzymes. Interactions are predominantly pharmacodynamic, involving effects on immune regulation.
Monitoring
- Liver Function (AST, ALT, bilirubin)Baseline, then before each cycle
RoutineWithholding thresholds differ for patients with versus without hepatic tumour involvement. The melanoma triple combination warrants heightened monitoring given 50% hepatotoxicity rate. - Renal Function (creatinine)Baseline, then before each cycle
RoutineImmune-mediated nephritis is rare with monotherapy but more common with the cobi/vemu combination (1.3%). - Thyroid Function (TSH, free T4)Baseline, then every 4–6 weeks
RoutineHypothyroidism occurs in 5–26% depending on regimen. Particularly high in adjuvant NSCLC and melanoma triple therapy. Most cases require permanent levothyroxine replacement. - Blood Glucose / HbA1cBaseline, then periodically
Trigger-basedNew-onset type 1 diabetes occurs in 0.3%; may present acutely as DKA. High index of suspicion for new hyperglycaemia. - Pulmonary AssessmentBaseline CT; re-image if respiratory symptoms develop
Trigger-basedPneumonitis is higher with prior thoracic radiation and with the melanoma triple combination (13%). Prompt CT chest for new dyspnoea or cough. - Blood PressureEach visit when co-administered with bevacizumab
RoutineHypertension is the most common adverse reaction in the HCC regimen (atezolizumab + bevacizumab). Manage with standard antihypertensives. - Cardiac Biomarkers (troponin)If cardiac symptoms develop
Trigger-basedMyocarditis is rare but potentially fatal. Obtain troponin and ECG for chest pain, dyspnoea, or new arrhythmia. - Complete Blood CountBefore each cycle (especially with chemo)
RoutineEssential when combined with platinum-based chemotherapy. Immune-mediated haemolytic anaemia and thrombocytopenia are rare but reported.
Contraindications & Cautions
Absolute Contraindications
The IV formulation (Tecentriq) lists no absolute contraindications. The subcutaneous formulation (Tecentriq Hybreza) is contraindicated in patients with known hypersensitivity to hyaluronidase or any of its components.
Relative Contraindications (Specialist Input Recommended)
- Active, severe autoimmune disease requiring systemic immunosuppression: risk of life-threatening flare with PD-L1 blockade.
- Prior organ transplantation: PD-L1 blockade may precipitate acute allograft rejection.
- Prior life-threatening irAE from any PD-1/PD-L1 inhibitor: rechallenge with a different checkpoint inhibitor carries residual risk.
- Pregnancy or planned pregnancy: atezolizumab can cause fetal harm. Effective contraception required during treatment and for 5 months after last dose.
Use with Caution
- Controlled autoimmune conditions (e.g., stable rheumatoid arthritis, psoriasis): elevated flare risk; close monitoring required.
- Pre-existing interstitial lung disease or prior thoracic radiation: higher baseline pneumonitis risk.
- Moderate-to-severe hepatic impairment: not formally studied; heightened LFT monitoring recommended.
- HCC patients with esophageal/gastric varices: when used with bevacizumab, endoscopic evaluation recommended within 6 months before starting treatment due to bleeding risk.
Atezolizumab can cause severe and fatal immune-mediated adverse reactions in any organ system, including pneumonitis, colitis, hepatitis, endocrinopathies, nephritis, dermatologic reactions, myocarditis, and neurological toxicities. These may occur during or after treatment discontinuation. Early identification with laboratory monitoring and prompt corticosteroid therapy are essential. Complications of allogeneic HSCT can occur in patients treated with PD-1/PD-L1 blocking antibodies before or after transplant.
Patient Counselling
Purpose of Therapy
Atezolizumab helps the immune system recognise and attack cancer cells by blocking a protein called PD-L1 that tumours use to hide from immune detection. Unlike traditional chemotherapy, it works by releasing the body’s own immune defences rather than directly killing cancer cells. It is given by intravenous infusion or subcutaneous injection on a regular schedule.
How to Take
The first IV infusion takes about 60 minutes. If tolerated, subsequent infusions may be shortened to 30 minutes. For patients receiving the subcutaneous formulation (Tecentriq Hybreza), the injection takes approximately 7 minutes and is given in the thigh at the clinic. When combined with chemotherapy or other agents, atezolizumab is always given first on the same day.
Sources
- Genentech, Inc. TECENTRIQ (atezolizumab) injection, for intravenous use. Full Prescribing Information. Revised 03/2026. gene.comPrimary source for all dosing, indications, adverse reactions, and warnings in this monograph.
- Genentech, Inc. TECENTRIQ HYBREZA (atezolizumab and hyaluronidase-tqjs) injection, for subcutaneous use. Full Prescribing Information. 2025. FDA.govPrescribing information for the subcutaneous formulation, including IMscin001 clinical data.
- Horn L, Mansfield AS, Szczęsna A, et al. First-line atezolizumab plus chemotherapy in extensive-stage small-cell lung cancer. N Engl J Med. 2018;379(23):2220–2229. doi:10.1056/NEJMoa1809064IMpower133: established atezolizumab + carboplatin/etoposide as first-line standard for ES-SCLC.
- Finn RS, Qin S, Ikeda M, et al. Atezolizumab plus bevacizumab in unresectable hepatocellular carcinoma. N Engl J Med. 2020;382(20):1894–1905. doi:10.1056/NEJMoa1915745IMbrave150: established atezolizumab + bevacizumab as first-line standard for unresectable HCC.
- Socinski MA, Jotte RM, Cappuzzo F, et al. Atezolizumab for first-line treatment of metastatic nonsquamous NSCLC. N Engl J Med. 2018;378(24):2288–2301. doi:10.1056/NEJMoa1716948IMpower150: basis for the ABCP regimen (atezolizumab + bevacizumab + paclitaxel + carboplatin) in non-squamous NSCLC.
- Felip E, Altorki N, Zhou C, et al. Adjuvant atezolizumab after adjuvant chemotherapy in resected stage IB–IIIA NSCLC (IMpower010). Lancet. 2021;398(10308):1344–1357. doi:10.1016/S0140-6736(21)02098-5IMpower010: basis for adjuvant atezolizumab in PD-L1-positive resected NSCLC.
- Herbst RS, Giaccone G, de Marinis F, et al. Atezolizumab for first-line treatment of PD-L1-selected patients with NSCLC. N Engl J Med. 2020;383(14):1328–1339. doi:10.1056/NEJMoa1917346IMpower110: basis for atezolizumab monotherapy in high PD-L1-expressing metastatic NSCLC.
- West H, McCleod M, Hussein M, et al. Atezolizumab in combination with carboplatin plus nab-paclitaxel in first-line metastatic non-squamous NSCLC. J Clin Oncol. 2019;37(11):849–858. doi:10.1200/JCO.18.00824IMpower130: basis for the atezolizumab + nab-paclitaxel + carboplatin combination in non-squamous NSCLC.
- Gutzmer R, Stroyakovskiy D, Gogas H, et al. Atezolizumab, vemurafenib, and cobimetinib as first-line treatment for unresectable BRAF V600 mutation-positive melanoma (IMspire150). Lancet. 2020;395(10240):1835–1844. doi:10.1016/S0140-6736(20)30934-XIMspire150: basis for the atezolizumab + cobimetinib + vemurafenib triple combination in BRAF V600+ melanoma.
- Paz-Ares L, Borghaei H, Liu SV, et al. First-line maintenance therapy with lurbinectedin plus atezolizumab in extensive-stage small-cell lung cancer (IMforte). Lancet. 2025;405(10495):2129–2143. doi:10.1016/S0140-6736(25)00669-4IMforte: basis for the lurbinectedin + atezolizumab maintenance indication in ES-SCLC (approved October 2025).
- NCCN Clinical Practice Guidelines in Oncology. Non-Small Cell Lung Cancer. Version 4.2026. NCCN.orgIncorporates atezolizumab-based regimens as preferred options in adjuvant, first-line metastatic, and second-line NSCLC.
- Brahmer JR, Abu-Sbeih H, Ascierto PA, et al. Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immune checkpoint inhibitor-related adverse events. J Immunother Cancer. 2021;9(6):e002435. doi:10.1136/jitc-2021-002435Comprehensive irAE management guidelines applicable across PD-1/PD-L1 inhibitor classes.
- Stroh M, Winter H, Marchand M, et al. Clinical pharmacokinetics and pharmacodynamics of atezolizumab in metastatic urothelial carcinoma. Clin Pharmacol Ther. 2017;102(2):305–312. doi:10.1002/cpt.587Definitive population PK analysis establishing clearance (0.200 L/day), Vd (6.91 L), and t½ (27 days) of atezolizumab.