Objective response rate (ORR) is the percentage of patients whose tumours shrink by at least 30%.
Objective response rate (ORR) is an endpoint recording the proportion of patients whose tumours shrink enough on scans to count as a response. Under RECIST 1.1 it combines complete and partial responses, and its aliases include overall response rate, confirmed responses and radiographic or radiological response. ORR is the basis for many accelerated approvals yet an imperfect surrogate for survival, which is why it appears in the bottleneck on trial design, endpoints and cost and in ideas on an independent programme to validate surrogate endpoints and on requiring a randomised phase 2 before any phase 3. The term is also used by Blinded independent central review (BICR), by the Sarcomas and EPCORE NHL-1 entries, and in the ASCENT, DeLLphi-301 and CodeBreaK 200 papers.
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.
Patients with high-risk bladder cancer confined to the lining whose disease has not responded to BCG now have a bladder-sparing option that clears the cancer in most cases, delivered through a simple outpatient procedure. It may allow many to avoid or defer cystectomy, a life-changing operation. Whether responses translate into avoided progression and cystectomy over the long term, and how it compares with cystectomy on survival, remain to be shown.
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.
IMerge validated telomerase as a drug target in cancer, decades after its discovery, and gave a second-line option for MDS patients whose anaemia no longer responds to erythropoietin or luspatercept. The hint of clonal reduction is what makes the drug interesting beyond transfusion counts. Cytopenias require close monitoring in the first cycles.
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.
An off-the-shelf alternative to CAR-T for repeatedly relapsed follicular lymphoma: no apheresis, no manufacturing wait, and a complete response rate in the same range, at the cost of continued treatment rather than a single infusion.
Patients with advanced synovial sarcoma, a rare cancer of young adults with few effective drugs, now have an approved cell therapy that produces responses lasting about a year in a substantial minority, if their tissue type and tumour antigen match. It proves that engineered T cells can work against a solid tumour when a good target is present, which had been elusive. It is not a cure for most, requires specialised centres, and only a minority of patients are eligible.
Revumenib proved that a transcriptional dependency, rather than a kinase, can be drugged in leukaemia, opening treatment for two genetic subgroups that together cover roughly a third of AML plus most infant ALL. It is now approved and is being combined with venetoclax-azacitidine and intensive chemotherapy in front-line trials. Single-agent remissions are often short without transplant.
Shares Require a randomised phase 2 before any phase 3, Blinded independent central review (BICR), Duration of response, Duration of response (DoR) and disease control rate (DCR).
Shares EPCORE NHL-1, CARTITUDE-1: cilta-cel, a BCMA CAR-T, in heavily pretreated myeloma, KarMMa-3: ide-cel CAR-T versus standard regimens in triple-class-exposed relapsed myeloma, JULIET: tisagenlecleucel for adults with relapsed or refractory diffuse large B-cell lymphoma.
Shares Slamon 2001: adding trastuzumab to chemotherapy for HER2-positive metastatic breast cancer, CheckMate 057: nivolumab beats docetaxel after chemotherapy in non-squamous lung cancer, An independent programme that validates surrogate endpoints, setting by setting, KEYNOTE-006 (Robert 2015): pembrolizumab versus ipilimumab in advanced melanoma.
Shares CARTITUDE-1: cilta-cel, a BCMA CAR-T, in heavily pretreated myeloma, JULIET: tisagenlecleucel for adults with relapsed or refractory diffuse large B-cell lymphoma, ZUMA-2: brexu-cel CAR-T for mantle cell lymphoma that has failed BTK inhibitors, Lisocabtagene maraleucel for patients with relapsed or refractory large B-cell lymphomas (TRANSCEND NHL 001): a multicentre seamless design study.
Shares NAVIGATE, Endpoint, Basket trial, Surrogate endpoint.
Shares ANNOUNCE, ATLANTIS, Surrogate endpoint, Surrogate endpoint validation: which stand-ins have earned trust.
Shares CARTITUDE-1: cilta-cel, a BCMA CAR-T, in heavily pretreated myeloma, KarMMa-3: ide-cel CAR-T versus standard regimens in triple-class-exposed relapsed myeloma, JULIET: tisagenlecleucel for adults with relapsed or refractory diffuse large B-cell lymphoma, Safety and efficacy of odronextamab in patients with relapsed or refractory follicular lymphoma.
Shares ANNOUNCE, ATLANTIS, Surrogate endpoint, Single-arm trial.