Background: Targeting the epidermal growth factor receptor pathway remains controversial in pancreatic cancer. Afatinib is an oral irreversible ErbB family blocker approved in non-small-cell lung cancer. This open-label, multicenter, randomised phase II trial evaluated gemcitabine plus afatinib (Gem/afatinib) versus gemcitabine (Gem) alone as first-line treatment for metastatic pancreatic cancer., Patients and Methods: Patients were randomised in a 2:1 ratio to either Gem (1000 mg/m 2 weekly for three weeks followed by one week of rest, repeated every four weeks) and afatinib (40 mg orally once daily) or Gem alone. Overall survival (OS) was the primary study end-point. The novel BOTh©™ methodology was implemented to derive a quantitative estimate for the 'Burden of Therapy/Toxicity' (BOTh) for each patient on every day during the clinical study., Results: One hundred nineteen patients from 25 centres were randomised, 79 patients for Gem/afatinib and 40 for Gem. Median OS was 7.3 months in the Gem/afatinib arm versus 7.4 months in the Gem-alone arm (hazard ratio [HR]: 1.06, p = 0.80). Median progression-free survival was identical in both arms (3.9 months versus 3.9 months, HR: 0.85, p = 0.43). Adverse events were more frequent in the Gem/afatinib arm, especially diarrhoea (71% vs. 13%) and skin rash (65% vs. 5%). The BOTh©™ analysis revealed a significantly higher burden of toxicity in the combination arm (p = 0.0005)., Conclusion: The addition of afatinib to Gem did not improve treatment efficacy and was more toxic. The BOTh©™ methodology allowed a detailed insight into the course of treatment-related adverse events over the study period. The trial was registered at clinicaltrials.gov (NCT01728818) and Eudra-CT (2011-004063-77)., Competing Interests: Conflict of interest statement M.H. reports receiving research funding from Boehringer Ingelheim. A.A.-A. reports serving as consulting or advisory role for Roche UK; R.S. reports receiving employment from Astellas Pharma. D.T.W. reports receiving Speakers' Bureau from AstraZeneca, Bayer, Bristol-Myers Squibb, Celgene, Eisai Europe, Falk Pharma, Ipsen, Novartis, Roche, SERVIER, Shire, Sirtex Medical; reports receiving travel accommodations and expenses from Bayer, Celgene, Ipsen, Novartis, Sirtex Medical. M.S. reports receiving honoraria from Amgen, Celgene, Lilly, Merck Serono, MSD, Pfizer, Sanofi, SERVIER; reports serving as consulting or advisory role for Bristol-Myers Squibb, Lilly, MSD, Shire; reports receiving travel fees, accommodations and expenses from Amgen, Bristol-Myers Squibb, Merck Serono, MSD. A.R.-S. reports receiving honoraria from Amgen, AstraZeneca, Aurikamed, Baxalta, BOVita, Bristol-Myers Sqibb, Celgene, iomedico, Lilly, MCI Global, med public, Merck Serono, MSD, Pfizer, promedicis, Roche, Sanofi/Aventis, SERVIER, Shire; reports serving as consulting or advisory role for Amgen, AstraZeneca, Baxalta, Bristol-Myers Sqibb, Celgene, Merck Serono, MSD, onkowissen.de, Pfizer, Pierre Fabre, Roche, Sanofi/Aventis, SERVIER; reports receiving research funding from Agricola, AIO Studien gGmbH, Alexion, Amgen, AstraZeneca, Celgene, Ipsen, Lilly, Mologen Berlin, Pharma Consulting Group AB Sweden, PPD Global Limited, Roche, SERVIER, Syneed medidata GmbH, Universität Erlangen, Universität Köln, Universität München; reports receiving travel, accommodations and expenses from Amgen, AstraZeneca, Celgene, Ipsen, MCI Global, Merck Serono, MSD, onkowissen.de, Pierre Fabre, Roche, SERVIER. N.F. reports receiving research funding from Bristol-Myers Squibb, MSD Oncology, Roche. T.S reports receiving honoraria from Amgen, Baxalta, Bayer, Celgene, Falk Foundation, Halozyme, Merck Serono, Roche, Sanofi, SERVIER; reports receiving consulting or advisory role for Baxalta, Bayer, Celgene, Halozyme, Merck Serono, Roche/Genentech, Shire; reports research funding from Celgene, Sanofi; reports receiving travel, accommodations, and expenses from Celgene, Merck Serono, Roche, Sanofi, SERVIER. R.M reports receiving honoraria from Amgen, Novartis, Roche; reports receiving travel, accommodations and expenses from Amgen, Merck, Pfizer. P.M.reports serving as consulting of advisory role for Bayer, Danone, Mayoly-Spindler; reports receiving speakers' bureau from Alfasigma, Bayer, Falk Foundation, Phantom Pharmaceuticals, Takeda. S.K.reports receiving honoraria from Amgen, Bayer, Roche, Sanofi; reports wserving as consulting or advisory role for Amgen, Bayer, Roche, Sanofi; reports receiving travel, accommodations and expenses from Amgen, Bayer, Roche, Sanofi. S.B. reports receiving honoraria from Celgene, SERVIER. M.v.B.-B. reports receiving honoraria, speakers' bureau, research funding, travel, accommodations and expenses from Astellas Pharma, Bristol-Myers Squibb, Kite Gilead, Miltenyi Biotec, MOLOGEN, MSD, Novartis, Roche. V.H. reports receiving honoraria from Amgen, Baxalta, Boehringer Ingelheim, Celgene, Lilly, Merck, Roche, Sanofi, SERVIER, Sirtex Medical, Taiho Pharmaceutical; reports serving as consulting or advisory role for Amgen, Baxalta, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Halozyme, Merck, MSD, Roche, Sanofi, SERVIER, Sirtex Medical; reports receiving research funding from Amgen, Boehringer Ingelheim, Celgene, Merck, Roche, SERVIER, Shire, Sirtex Medical; reports receiving travel, accommodations and expenses from Amgen, Bristol-Myers Squibb, Merck, MSD, SERVIER, Shire, Sirtex Medical. All other authors declare that they have no conflicts of interest., (Copyright © 2021 Elsevier Ltd. All rights reserved.)