OnCo
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Lines of therapy

First-line is the first treatment for advanced cancer; second-line is what comes after it fails, and so on.

Drugs are typically approved first in later lines (where control arms are weak) then move earlier. Each shift to an earlier line reshapes the entire sequence, as with ADCs in TNBC in 2026.

Clinical: what this kind of term is about · animated schematic, not to scale
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Clinical

Key papers

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rctNew England Journal of Medicine 2025changed practice
BREAKWATER: encorafenib plus cetuximab with chemotherapy as first treatment for BRAF V600E-mutated colorectal cancer

Patients with newly diagnosed metastatic colorectal cancer whose tumour carries a BRAF V600E mutation, which is about 8-12% of cases, should now be offered encorafenib and cetuximab together with FOLFOX from the start rather than after chemotherapy fails; median survival has roughly doubled to about two and a half years. BRAF testing at diagnosis is therefore essential, alongside RAS and mismatch repair testing. The regimen is more toxic than chemotherapy alone.

rctThe Lancet 2025
HARMONi-2: ivonescimab, a PD-1 x VEGF bispecific, beats pembrolizumab head-to-head in PD-L1-positive lung cancer

For the first time a new drug has beaten pembrolizumab, the global first-line standard, in a randomised lung cancer trial, and it did so by combining checkpoint blockade with anti-angiogenesis in one molecule. For patients outside China nothing changes yet: the drug is not approved in the West, the trial was single-country, and survival benefit has not been shown. If confirmed in the global HARMONi-3 and HARMONi-7 trials, PD-1 x VEGF bispecifics could replace PD-1 antibodies as the immunotherapy backbone.

rctNew England Journal of Medicine 2024changed practice
DESTINY-Breast06: trastuzumab deruxtecan before any chemotherapy in hormone-receptor-positive, HER2-low or ultralow breast cancer

Patients with hormone-receptor-positive metastatic breast cancer that has stopped responding to endocrine therapy can be offered trastuzumab deruxtecan as their first chemotherapy-type treatment if the tumour shows any HER2 staining, rather than waiting until after conventional chemotherapy. Whether to use it before or after chemotherapy is now a choice, since overall survival was not shown to differ and the drug carries a risk of lung inflammation.

rctNew England Journal of Medicine 2024changed practice
EV-302: enfortumab vedotin plus pembrolizumab replaces chemotherapy as first treatment for advanced bladder cancer

Almost every patient newly diagnosed with advanced bladder or urothelial cancer should now be offered enfortumab vedotin plus pembrolizumab rather than chemotherapy, with median survival extended from about 16 months to over two and a half years. Neuropathy and skin toxicity need monitoring and dose adjustment, and patients with severe diabetes or pre-existing neuropathy need care. Platinum chemotherapy remains an option for those who cannot receive the combination.

rctNew England Journal of Medicine 2024changed practice
MARIPOSA: amivantamab plus lazertinib versus osimertinib as first treatment for EGFR-mutated lung cancer

Patients newly diagnosed with EGFR-mutated advanced lung cancer now have a first-line option that improves survival over osimertinib, particularly if they have high-risk features. The trade-off is intravenous (now subcutaneous) infusions and considerably more skin, nail and clotting toxicity, so osimertinib alone remains reasonable for those who prioritise convenience and tolerability. Both this regimen and osimertinib plus chemotherapy (FLAURA2) are approved; there is no direct comparison.

rctThe Lancet 2024changed practice
NETTER-2: lutetium-177 dotatate as first treatment for higher-grade gastroenteropancreatic neuroendocrine tumours

Patients newly diagnosed with an advanced grade 2 or 3 neuroendocrine tumour of the gut or pancreas that shows somatostatin receptors on imaging can now receive lutetium dotatate as their first treatment, gaining more than a year of additional disease control and a much higher chance of tumour shrinkage. It does not settle whether radioligand therapy is better than other first-line options such as capecitabine-temozolomide or everolimus, and long-term marrow safety with earlier use needs surveillance.

rctThe Lancet 2023changed practice
NAPOLI-3: NALIRIFOX versus gemcitabine plus nab-paclitaxel as first treatment for metastatic pancreatic cancer

For fit patients with newly diagnosed metastatic pancreatic cancer, a FOLFIRINOX-type regimen is now proven to be better than gemcitabine plus nab-paclitaxel, settling a long-standing debate. The absolute gain is about two months of median survival, and the regimen is more toxic for the gut. Whether liposomal irinotecan adds anything over conventional irinotecan (standard FOLFIRINOX) has never been tested head-to-head.

rctNew England Journal of Medicine 2023changed practice
RUBY: dostarlimab with chemotherapy for advanced or recurrent endometrial cancer

Women with newly diagnosed advanced or recurrent endometrial cancer should receive a PD-1 antibody (dostarlimab or pembrolizumab) with their chemotherapy, and mismatch repair testing is now essential because women with dMMR tumours gain a very large and durable benefit. The gain in mismatch-repair-proficient tumours is real but smaller, and molecular classification (POLE, p53, MMR) is increasingly used to decide who benefits most.

rctThe Lancet 2023changed practice
SPOTLIGHT: zolbetuximab, the first Claudin 18.2 antibody, added to chemotherapy in gastric cancer

Patients with newly diagnosed advanced stomach cancer should now have Claudin 18.2 tested alongside HER2, PD-L1 and mismatch repair, because roughly a third will be eligible for zolbetuximab, which adds about three months of median survival. The main practical problem is nausea and vomiting during infusions, which needs aggressive prophylaxis. How to sequence or combine it with immunotherapy in PD-L1-positive tumours is unresolved.

rctNew England Journal of Medicine 2022changed practice
RELATIVITY-047: relatlimab plus nivolumab, the first LAG-3 checkpoint combination, in untreated advanced melanoma

Patients with newly diagnosed advanced melanoma have a dual-checkpoint option that improves on nivolumab alone with only a modest increase in serious side effects, making it attractive for those unable to tolerate or unwilling to risk the toxicity of ipilimumab. It did not prove superior survival, and it has not been compared with nivolumab plus ipilimumab, which remains preferred for patients with brain metastases or other high-risk features. LAG-3 is now an established target under study in many other cancers.

rctThe Lancet 2021changed practice
CheckMate 649: nivolumab plus chemotherapy as first treatment for advanced gastric, gastro-oesophageal junction and oesophageal adenocarcinoma

Patients with newly diagnosed advanced stomach or oesophageal adenocarcinoma whose tumour is HER2-negative and PD-L1 positive (CPS 5 or more, or at least 1 in some regions) should receive chemotherapy with nivolumab (or pembrolizumab, from KEYNOTE-859), which adds about three months of median survival and doubles the chance of being alive at three years. The benefit in PD-L1-negative tumours is doubtful, and these patients may be better served by chemotherapy alone or by trials.

rctNew England Journal of Medicine 2021changed practice
CLEAR: lenvatinib plus pembrolizumab versus sunitinib as first treatment for advanced kidney cancer

Patients with newly diagnosed advanced clear-cell kidney cancer should receive an immunotherapy-based combination; lenvatinib plus pembrolizumab gives the highest response rate and longest PFS of the available options, at the cost of more side effects requiring dose adjustment. Sunitinib alone is no longer an appropriate standard. Choosing among the combinations depends on risk group, symptoms, comorbidity and the value placed on treatment-free survival, which favours nivolumab plus ipilimumab in intermediate and poor risk.

rctNew England Journal of Medicine 2020changed practice
IMbrave150: atezolizumab plus bevacizumab replaces sorafenib as first treatment for advanced liver cancer

Patients with advanced liver cancer and good liver function should be offered atezolizumab plus bevacizumab (or durvalumab plus tremelimumab) rather than sorafenib as first treatment; median survival is now around 19 months and about a quarter of patients respond. Endoscopy to treat varices before starting bevacizumab is essential because of bleeding risk. Patients with poorer liver function (Child-Pugh B) or autoimmune disease or transplants were not studied.

rctNew England Journal of Medicine 2020changed practice
KEYNOTE-177: pembrolizumab instead of chemotherapy as first treatment for mismatch-repair-deficient metastatic colorectal cancer

Every colorectal cancer should be tested for mismatch repair deficiency, because patients whose metastatic tumour is dMMR should receive pembrolizumab rather than chemotherapy as first treatment, gaining a much better chance of durable remission with fewer side effects. About a third of dMMR tumours do not respond initially, so early scans are essential and chemotherapy remains available. The trial does not apply to the 95% of colorectal cancers that are mismatch-repair proficient.

rctThe Lancet 2019changed practice
KEYNOTE-048: pembrolizumab, alone or with chemotherapy, as first treatment for recurrent or metastatic head and neck cancer

Patients with head and neck squamous cell cancer that has recurred or spread should be treated first with pembrolizumab: alone if their tumour is strongly PD-L1 positive and they can wait for a slower response, or with chemotherapy if the tumour is bulky or PD-L1 low. Cetuximab-based chemotherapy is no longer the default. Long-term follow-up shows a small but real group of patients alive at four to five years, which was almost unheard of before.

rctNew England Journal of Medicine 2018changed practice
FLAURA: osimertinib as first treatment for EGFR-mutated lung cancer

Anyone diagnosed with advanced lung cancer should have EGFR testing before treatment, because osimertinib as the first drug gives the longest disease control, protects the brain, and is well tolerated. Chemotherapy is not the first step for these patients. The remaining questions are whether to intensify upfront (adding chemotherapy or amivantamab) and how to treat resistance when it develops.

rctNew England Journal of Medicine 2018changed practice
KEYNOTE-189: pembrolizumab plus chemotherapy as first treatment for non-squamous lung cancer without a driver mutation

Most patients with newly diagnosed advanced non-squamous lung cancer that lacks a targetable mutation should receive chemotherapy plus pembrolizumab; those with PD-L1 of 50% or more may reasonably receive pembrolizumab alone. About one in five patients is alive at five years, compared with roughly one in ten with chemotherapy alone. Patients with EGFR or ALK alterations were excluded and should have targeted therapy first.

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key papers

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BREAKWATER: encorafenib plus cetuximab with chemotherapy as first treatment for BRAF V600E-mutated colorectal cancerCheckMate 649: nivolumab plus chemotherapy as first treatment for advanced gastric, gastro-oesophageal junction and oesophageal adenocarcinomaCLEAR: lenvatinib plus pembrolizumab versus sunitinib as first treatment for advanced kidney cancerDESTINY-Breast06: trastuzumab deruxtecan before any chemotherapy in hormone-receptor-positive, HER2-low or ultralow breast cancerEV-302: enfortumab vedotin plus pembrolizumab replaces chemotherapy as first treatment for advanced bladder cancerFLAURA: osimertinib as first treatment for EGFR-mutated lung cancerHARMONi-2: ivonescimab, a PD-1 x VEGF bispecific, beats pembrolizumab head-to-head in PD-L1-positive lung cancerIMbrave150: atezolizumab plus bevacizumab replaces sorafenib as first treatment for advanced liver cancerKEYNOTE-048: pembrolizumab, alone or with chemotherapy, as first treatment for recurrent or metastatic head and neck cancerKEYNOTE-177: pembrolizumab instead of chemotherapy as first treatment for mismatch-repair-deficient metastatic colorectal cancerKEYNOTE-189: pembrolizumab plus chemotherapy as first treatment for non-squamous lung cancer without a driver mutationMARIPOSA: amivantamab plus lazertinib versus osimertinib as first treatment for EGFR-mutated lung cancerNAPOLI-3: NALIRIFOX versus gemcitabine plus nab-paclitaxel as first treatment for metastatic pancreatic cancerNETTER-2: lutetium-177 dotatate as first treatment for higher-grade gastroenteropancreatic neuroendocrine tumoursRELATIVITY-047: relatlimab plus nivolumab, the first LAG-3 checkpoint combination, in untreated advanced melanomaRUBY: dostarlimab with chemotherapy for advanced or recurrent endometrial cancerSPOTLIGHT: zolbetuximab, the first Claudin 18.2 antibody, added to chemotherapy in gastric cancer