Dr. L.T. (Lourens) Bloem

Assistant Professor
Pharmacoepi. and Clinical Pharmacol.
l.t.bloem@uu.nl

Selection of key publications

  • Brinkhuis, F., Goettsch, W. G., Mantel - Teeuwisse, A., & Bloem, L. T. (2024). Added benefit and revenues of oncology drugs approved by the European Medicines Agency between 1995 and 2020: retrospective cohort study. The BMJ, 384, e077391. https://doi.org/10.1136/bmj-2023-077391
  • Brinkhuis, F., Goettsch, W. G., Mantel - Teeuwisse, A., & Bloem, L. T. (2024). High cost oncology drugs without proof of added benefit are burdening health systems. The BMJ, 384, q511. https://doi.org/10.1136/bmj.q511
  • Gort, J., van Hattem, C. C., Bloem, L. T., & ten Ham, R. M. T. (2023). Geneesmiddelen voor Geavanceerde Therapie (ATMP’s) in Nederland: Veldverkenning, Knelpuntanalyse en Activiteitenkaart. Utrecht University. https://doi.org/10.33540/1874/433501
    Note: Report in Dutch; translated title: ‘Advanced Therapy Medicinal Products (ATMPs) in the Netherlands: Field Map, Bottleneck Analysis, and Activity Map’

Book chapters

  • Bloem, L.T., Van der Elst, M.E., Klungel, O.H. Principles of Pharmacovigilance and Drug Regulation. In: Jose, J., Cox, A.R., Paudyal, V., editors. Principles and Practice of Pharmacovigilance and Drug Safety. 1st ed. Cham: Springer; 2024. p. 135-161. https://doi.org/10.1007/978-3-031-51089-2_6

Publications

2025

Scholarly publications

de Haart, K., Asao, K., Ataher, Q., Geier, J., Hillen, J., Huang, K., Mol, P. G. M., Rivera, D., Wang, H., Yang, H., Zhan, S., Hoogendoorn, W. E., & Bloem, L. T. (2025). Long-term follow-up after authorization of gene therapy: leveraging real-world data. Drug Discovery Today, 104337. Advance online publication. https://doi.org/10.1016/j.drudis.2025.104337
MOLecular Evaluation of Melanocytic Ambiguous Tumours (MOLEMAT) Investigators (2025). Clinical outcomes and genomic profiles of MAP2K1-mutated primary cutaneous melanocytic tumours. EBioMedicine, 114, 105643. Advance online publication. https://doi.org/10.1016/j.ebiom.2025.105643
Verschueren, M. V., Tassopoulou, V. P., Visscher, R., Schuurkamp, J., Peters, B. J. M., Koopman, M., van de Garde, E. M. W., Egberts, A. C. G., & Bloem, L. T. (2025). Definitions, measurement, and reporting of progression-free survival in randomized clinical trials and observational studies of patients with advanced non-small-cell lung cancer treated with immunotherapy: a scoping review. ESMO Real World Data and Digital Oncology, 7, Article 100118. https://doi.org/10.1016/j.esmorw.2025.100118
https://research-portal.uu.nl/ws/files/258838270/PIIS2949820125000074.pdf
Bloem, L. T., Leufkens, H. G. M., Berends, S. E., Vreman, R. A., Hollak, C. E. M., van Weely, S., de Lannoy, L. M., Bertens, P. J. A., & Pasmooij, A. M. G. (2025). Stimulating development of innovative medicines in the European Union: does a new definition for unmet medical need add value? Drug Discovery Today, 30(1), Article 104251. https://doi.org/10.1016/j.drudis.2024.104251
https://research-portal.uu.nl/ws/files/250603392/1-s2.0-S1359644624003763-main.pdf
Hogervorst, M. A., Soman, K. V., Gardarsdottir, H., Goettsch, W. G., & Bloem, L. T. (2025). Analytical Methods for Comparing Uncontrolled Trials with External Controls from Real-World Data: a Systematic Literature Review and Comparison to European Regulatory and Health Technology Assessment Practice. Value in Health, 28(1), 161-174. https://doi.org/10.1016/j.jval.2024.08.002
https://research-portal.uu.nl/ws/files/251712637/1-s2.0-S1098301524028420-main_1_.pdf

2024

Scholarly publications

Taams, A. C., Herberts, C. A., Egberts, A. C. G., Zafiropoulos, N., Pignatti, F., & Bloem, L. T. (2024). Uncertainties about the benefit-risk balance of oncology medicines assessed by the European Medicines Agency. ESMO Open, 9(12), Article 103991. https://doi.org/10.1016/j.esmoop.2024.103991
https://research-portal.uu.nl/ws/files/248502550/PIIS2059702924017617.pdf
van Hattem, C. C., de Jong, A. J., de Groot, J. S., Hoekman, J., Broekman, K. E., Sonke, G. S., van Hennik, P. B., & Bloem, L. T. (2024). Factors affecting the feasibility of post-authorisation RCTs for conditionally authorised anticancer medicines: a multistakeholder perspective from a qualitative focus group study. BMJ Open, 14(11), Article e084483. https://doi.org/10.1136/bmjopen-2024-084483
https://research-portal.uu.nl/ws/files/244648426/e084483.full.pdf
Zinken, J. F., Pasmooij, A. M. G., Ederveen, A. G. H., Hoekman, J., & Bloem, L. T. (2024). Environmental risk assessment in the EU regulation of medicines for human use: an analysis of stakeholder perspectives on its current and future role. Drug Discovery Today, 29(12), Article 104213. https://doi.org/10.1016/j.drudis.2024.104213
https://research-portal.uu.nl/ws/files/245368211/1-s2.0-S1359644624003386-main.pdf
Stoelinga, J., Bloem, L. T., Russo, M., Kesselheim, A. S., & Feldman, W. B. (2024). Comparing supplemental indications for cancer drugs approved in the US and EU. European Journal of Cancer, 212, Article 114330. https://doi.org/10.1016/j.ejca.2024.114330
https://research-portal.uu.nl/ws/files/241659817/1-s2.0-S0959804924009869-main.pdf
Verschueren, M. V., Abedian Kalkhoran, H., Deenen, M., van den Borne, B. E. E. M., Zwaveling, J., Visser, L. E., Bloem, L. T., Peters, B. J. M., & van de Garde, E. M. W. (2024). Development and Portability of a Text Mining Algorithm for Capturing Disease Progression in Electronic Health Records of Patients With Stage IV Non-Small Cell Lung Cancer. JCO clinical cancer informatics, 8, Article e2400053. https://doi.org/10.1200/CCI.24.00053
https://research-portal.uu.nl/ws/files/241659755/verschueren-et-al-2024-development-and-portability-of-a-text-mining-algorithm-for-capturing-disease-progression-in.pdf
Ogar, C. K., Gilbert, H. N., Bloem, L. T., Leopold, C., Bassi, P. U., Katagum, Y. M., Osakwe, A. I., Opadeyi, A. O., Oreagba, I., Mbo, D. N. D., Mantel-Teeuwisse, A. K., & De Bruin, M. L. (2024). Patient-reported outcomes of adverse events after COVID-19 vaccination in Nigeria: A mixed methods study. Vaccine, 42(23), Article 126196. https://doi.org/10.1016/j.vaccine.2024.126196
https://research-portal.uu.nl/ws/files/237158613/1-s2.0-S0264410X24008764-main.pdf
Bloem, L. T., Van der Elst, M. E., & Klungel, O. H. (2024). Principles of Pharmacovigilance and Drug Regulation. In J. Jose, A. R. Cox, & V. Paudyal (Eds.), Principles and Practice of Pharmacovigilance and Drug Safety (pp. 135-161). Springer. https://doi.org/10.1007/978-3-031-51089-2_6
https://research-portal.uu.nl/ws/files/235298977/978-3-031-51089-2_6.pdf
Jadoenathmisier, K. D., Stoyanova-Beninska, V., Soons, I. M., Leufkens, H. G., Bloem, L. T., & Pasmooij, A. M. (2024). Feasibility of disease terminology systems for mapping orphan conditions and therapeutic indications of designated orphan medicines in the European Union. European Journal of Pharmaceutical Sciences, 202, Article 106871. https://doi.org/10.1016/j.ejps.2024.106871
https://research-portal.uu.nl/ws/files/239243465/1-s2.0-S0928098724001830-main.pdf
Sadreghaemy, M., Gamba, M. A., Bloem, L. T., & Egberts, T. C. G. (2024). Leftover of Amoxicillin Suspension After Use by Children in the Netherlands. Pharmacoepidemiology and Drug Safety, 33(8), Article e5868. https://doi.org/10.1002/pds.5868
https://research-portal.uu.nl/ws/files/234642151/Pharmacoepidemiology_and_Drug_-_2024_-_Sadreghaemy_-_Leftover_of_Amoxicillin_Suspension_After_Use_by_Children_in_the.pdf
van de Voort, T., Moors, E., Hoekman, J., & Bloem, L. T. (2024). Understanding the transformative nature of initiatives challenging the traditional pharmaceutical model in the gene and cell therapy field. Abstract from EASST-4S 2024 Conference, Amsterdam, Netherlands.
Maksimova, M. V., van Thiel, G. J. M. W., Tromp, Y., Lechner, R., van Delden, J. J. M., & Bloem, L. T. (2024). Balancing ethical norms and duties for the introduction of new medicines through conditional marketing authorization: a research agenda. Frontiers in Medicine, 11, Article 1408553. https://doi.org/10.3389/fmed.2024.1408553
https://research-portal.uu.nl/ws/files/232540384/fmed-11-1408553.pdf
Hogervorst, M. A., van Hattem, C. C., Sonke, G. S., Mantel-Teeuwisse, A. K., Goettsch, W. G., & Bloem, L. T. (2024). Healthcare decision-making for tumour-agnostic therapies in Europe: lessons learned. Drug Discovery Today, 29(7), Article 104031. https://doi.org/10.1016/j.drudis.2024.104031
https://dspace.library.uu.nl/bitstream/handle/1874/452776/1-s2.0-S1359644624001569-main.pdf?sequence=1
Madrid Paredes, J., Versteeg, J.-W., Vreman, R. A., & Bloem, L. T. (2024). Agreement about Availability of Alternative Treatments for Innovative Drugs Assessed by the EMA and HTA Organizations. Clinical Pharmacology and Therapeutics, 116(1), 136-146. https://doi.org/10.1002/cpt.3252
https://research-portal.uu.nl/ws/files/228030707/Clin_Pharma_and_Therapeutics_-_2024_-_Madrid_Paredes_-_Agreement_about_Availability_of_Alternative_Treatments_for.pdf
Brinkhuis, F., Goettsch, W. G., Mantel - Teeuwisse, A., & Bloem, L. T. (2024). High cost oncology drugs without proof of added benefit are burdening health systems. The BMJ, 384, Article q511. https://doi.org/10.1136/bmj.q511
https://dspace.library.uu.nl/bitstream/handle/1874/437614/bmj.q511.full.pdf?sequence=1
Brinkhuis, F., Goettsch, W. G., Mantel - Teeuwisse, A., & Bloem, L. T. (2024). Added benefit and revenues of oncology drugs approved by the European Medicines Agency between 1995 and 2020: retrospective cohort study. The BMJ, 384, Article e077391. https://doi.org/10.1136/bmj-2023-077391
https://dspace.library.uu.nl/bitstream/handle/1874/437211/bmj-2023-077391.full.pdf?sequence=1
Verweij, S., Haverhoek, V., Bergman, E., Westman, G., & Bloem, L. T. (2024). A Natural Language Processing Approach towards Harmonized Communication of Uncertainties Identified during the European Medicine Authorization Process. Clinical Pharmacology and Therapeutics, 115(4), 871-880. https://doi.org/10.1002/cpt.3195
https://dspace.library.uu.nl/bitstream/handle/1874/437524/Clin_Pharma_and_Therapeutics_-_2024_-_Verweij_-_A_Natural_Language_Processing_Approach_Towards_Harmonized_Communication_of.pdf?sequence=1
Verschueren, M. V., Peters, B. J., Bloem, L. T., Kruik, V. R., Uitvlugt, E. B., Bijsmans, A. R., Egberts, A. C., & van de Garde, E. M. (2024). Pembrolizumab Plus Chemotherapy Per PD-L1 Stratum In Patients With Metastatic Non-Small Cell Lung Cancer: Real-World Effectiveness Versus Trial Efficacy. Clinical Lung Cancer, 25(2), 119-127.e1. https://doi.org/10.1016/j.cllc.2023.12.011
https://dspace.library.uu.nl/bitstream/handle/1874/437933/1-s2.0-S1525730423002681-main.pdf?sequence=1

Professional publications

Hoek, J. M., Warmerdam, D. O., Berends, S. E., Vingerhoed-van Aken, B. E., Driessens, M. H. E., Fabriek, B. O., Hernandez, J. F., Meij, P., van Oers, C. C. M., Stolk, P., ten Ham, R., & Bloem, L. T. (2024). Shaping the potential of a Dutch ATMP network: Report of the RSNN SIG Advanced Therapies and FAST workshop on 11 June 2024. Utrecht University. https://doi.org/10.33540/UU2
https://research-portal.uu.nl/ws/files/249222866/RSNN_SIG_FAST_-_Shaping_the_potential_of_a_Dutch_ATMP_network_2024_.pdf

2023

Scholarly publications

van den Berg, R. B., Laarman, A. R. C., Bloem, L. T., Dijkstra, J. A., Veldkamp, A. I., Allegaert, K., Swart, E. L., & van Weissenbruch, M. M. (2023). Neonatal pain score after use of paracetamol: Is there a relationship with serum trough concentration at steady state in preterm and term neonates? International Journal of Clinical Pharmacology and Therapeutics, 61(8), 354 - 362. https://doi.org/10.5414/CP204431
Verschueren, M. V., Dijs, T., Gulikers, J. L., Veelen, A. V., Croes, S., Hendriks, L. E., Smit, A. A., Bloem, L. T., Egberts, A. C., van de Garde, E. M., & Peters, B. J. (2023). Durvalumab after chemoradiotherapy in patients with stage III non-small-cell lung cancer: real-world outcomes versus clinical trial results. Immunotherapy, 15(11), 839-851. https://doi.org/10.2217/imt-2023-0002
https://dspace.library.uu.nl/bitstream/handle/1874/430176/imt-2023-0002.pdf?sequence=1
Bloem, L. T., Schelhaas, J., López-Anglada, L., Herberts, C., van Hennik, P. B., & Tenhunen, O. (2023). European Conditional Marketing Authorization in a Rapidly Evolving Treatment Landscape: A Comprehensive Study of Anticancer Medicinal Products in 2006-2020. Clinical Pharmacology and Therapeutics, 114(1), 148-160. https://doi.org/10.1002/cpt.2906
https://dspace.library.uu.nl/bitstream/handle/1874/429487/Clin_Pharma_and_Therapeutics_-_2023_-_Bloem_-_European_Conditional_Marketing_Authorization_in_a_Rapidly_Evolving_Treatment.pdf?sequence=1

Professional publications

Gort, J., van Hattem, C. C., Bloem, L. T., & ten Ham, R. M. T. (2023). Geneesmiddelen voor Geavanceerde Therapie (ATMP’s) in Nederland: Veldverkenning, Knelpuntanalyse en Activiteitenkaart. Utrecht University. https://doi.org/10.33540/1874/433501
https://research-portal.uu.nl/ws/files/205439760/UU_UMCU_-_Geneesmiddelen_voor_Geavanceerde_Therapie_ATMP_s_in_Nederland_-_Dec2023.pdf
European Commission, Directorate-General for Health and Food Safety, Mantel - Teeuwisse, A., Bloem, L. T., Boon, W., De Bruin, M. L., Hoekman, J., Klein, K., Stolk, P., & Vreman, R. (2023). Study in support of the evaluation and impact assessment of the EU general pharmaceuticals legislation: Analytical Report. Publications Office of the European Union. https://doi.org/10.2875/780874
https://dspace.library.uu.nl/bitstream/handle/1874/436130/study_in_support_of_the_evaluation_and_impact_assessment_EW0423300ENN.pdf?sequence=1
European Commission, Directorate-General for Health and Food Safety, Mantel - Teeuwisse, A., Bloem, L. T., Boon, W., De Bruin, M. L., Hoekman, J., Klein, K., Stolk, P., & Vreman, R. (2023). Study in support of the evaluation and impact assessment of the EU general pharmaceuticals legislation: Evaluation Report. Publications Office of the European Union. https://doi.org/10.2875/62709
https://dspace.library.uu.nl/bitstream/handle/1874/436129/study_in_support_of_the_evaluation_and_impact_assessment_EW0423299ENN.pdf?sequence=1

Other output

Hoogendoorn, M., Fabriek, B., & Bloem, L. T. (2023). Regulatory and health technology assessment of cell and gene therapies in Europe: Convergence or divergence? Pharmacoepidemiology and Drug Safety, 32, 16-16.
Eskola, S. M., Jokinen, S., Bloem, L. T., Brouwer, E., Brown, D. A., Camarero, J., De Bruin, M. L. L., Gardarsdottir, H., & Hakkarainen, K. M. (2023). Systematic review of externally controlled (EC) trials, data used in them, and their role in regulatory decision-making. Pharmacoepidemiology and Drug Safety, 32(supplement 1), 260-261. Article 260.
van Hattem, C. C., de Jong, A., de Groot, J. S., & Bloem, L. T. (2023). Feasibility of post-authorization randomized controlled trials for conditionally authorized anticancer medicines-A multistakeholder perspective. Pharmacoepidemiology and Drug Safety, 32, 623-623.
Verschueren, M., Kruik, V., Peters, B., Bloem, L., Bijsmans, A. R., Egberts, T., & van de Garde, E. (2023). Real-world versus clinical trial outcomes of pembrolizumab plus chemotherapy in patients with stage IV non-squamous non-small cell lung cancer. Journal of Thoracic Oncology, 18(4), S72-S72.

2022

Scholarly publications

Ebbelaar, C. F., Schrader, A. M. R., van Dijk, M., Meijers, R. W. J., de Leng, W. W. J., Bloem, L. T., Jansen, A. M. L., Blokx, W. A. M., & on behalf of the MOLecular Evaluation of Melanocytic Ambiguous Tumors (MOLEMAT) investigators (2022). Towards diagnostic criteria for malignant deep penetrating melanocytic tumors using single nucleotide polymorphism array and next-generation sequencing. Modern Pathology, 35(8), 1110-1120. https://doi.org/10.1038/s41379-022-01026-6
https://dspace.library.uu.nl/bitstream/handle/1874/424328/s41379_022_01026_6.pdf?sequence=1
Bloem, L. T., Bot, R. E., Mantel-Teeuwisse, A. K., van der Elst, M. E., Sonke, G. S., Klungel, O. H., Leufkens, H. G. M., & Hoekman, J. (2022). Pre-approval and post-approval availability of evidence and clinical benefit of conditionally approved cancer drugs in Europe: a comparison with standard approved cancer drugs. British Journal of Clinical Pharmacology, 88(5), 2169-2179. https://doi.org/10.1111/bcp.15141
https://dspace.library.uu.nl/bitstream/handle/1874/425060/Brit_J_Clinical_Pharma_2021_Bloem_Pre_approval_and_post_approval_availability_of_evidence_and_clinical_benefit_of.pdf?sequence=1
Vreman, R. A., Bloem, L. T., van Oirschot, S., Hoekman, J., van der Elst, M. E., Leufkens, H. G., Klungel, O. H., Goettsch, W. G., & Mantel-Teeuwisse, A. K. (2022). The Role of Regulator-Imposed Post-Approval Studies in Health Technology Assessments for Conditionally Approved Drugs. International Journal of Health Policy and Management, 11(5), 642-650. https://doi.org/10.34172/ijhpm.2020.198
https://dspace.library.uu.nl/bitstream/handle/1874/420563/IJHPM_Volume_11_Issue_5_Pages_642_650.pdf?sequence=1

Other output

Hogervorst, M., Goettsch, W., Mantel-Teeuwisse, A. K., Bloem, L., & Vreman, R. A. (2022). Uncertainties Around Tumour Agnostic Therapies in Europe: Barriers and Facilitators of Patient Access. Value in Health, 25(12), S266-S266.

2021

Scholarly publications

Ebbelaar, C. F., Jansen, A. M. L., Bloem, L. T., & Blokx, W. A. M. (2021). Genome-wide copy number variations as molecular diagnostic tool for cutaneous intermediate melanocytic lesions: a systematic review and individual patient data meta-analysis. Virchows Archiv, 479(4), 773-783. https://doi.org/10.1007/s00428-021-03095-5
https://dspace.library.uu.nl/bitstream/handle/1874/413903/Ebbelaar2021_Article_Genome_wideCopyNumberVariation.pdf?sequence=1
Bloem, L. T. (2021). Evidence generation on benefits and risks of medicines and its impact on regulatory and downstream decision-making. [Doctoral thesis 1 (Research UU / Graduation UU), Universiteit Utrecht]. Utrecht University. https://doi.org/10.33540/888
https://research-portal.uu.nl/ws/files/106128997/phdthesis-bloemlourens-evidencegeneration-uu%20-%2061784f3b3f737.pdf
Bloem, L. T., Karomi, M., Hoekman, J., van der Elst, M. E., Leufkens, H. G. M., Klungel, O. H., & Mantel-Teeuwisse, A. K. (2021). Comprehensive evaluation of post-approval regulatory actions during the drug lifecycle–a focus on benefits and risks. Expert Opinion on Drug Safety, 20(11), 1433-1442. https://doi.org/10.1080/14740338.2021.1952981
https://dspace.library.uu.nl/bitstream/handle/1874/413000/14740338.2021.pdf?sequence=1
Bloem, L. T., Vreman, R. A., Peeters, N. W. L., Hoekman, J., van der Elst, M. E., Leufkens, H. G. M., Klungel, O. H., Goettsch, W. G., & Mantel-Teeuwisse, A. K. (2021). Associations between uncertainties identified by the European Medicines Agency and national decision making on reimbursement by HTA agencies. Clinical and Translational Science, 14(4), 1566-1577. https://doi.org/10.1111/cts.13027
https://dspace.library.uu.nl/bitstream/handle/1874/412025/cts.13027.pdf?sequence=1

2019

Scholarly publications

Vreman, R. A., Bouvy, J. C., Bloem, L. T., Hövels, A. M., Mantel-Teeuwisse, A. K., Leufkens, H. G. M., & Goettsch, W. G. (2019). Weighing of Evidence by Health Technology Assessment Bodies: Retrospective Study of Reimbursement Recommendations for Conditionally Approved Drugs. Clinical Pharmacology and Therapeutics, 105(3), 684-691. https://doi.org/10.1002/cpt.1251
https://dspace.library.uu.nl/bitstream/handle/1874/390145/Vreman_et_al_2019_Clinical_Pharmacology_Therapeutics.pdf?sequence=1
Bloem, L. T., Mantel-Teeuwisse, A. K., Leufkens, H. G. M., De Bruin, M. L., Klungel, O. H., & Hoekman, J. (2019). Postauthorization Changes to Specific Obligations of Conditionally Authorized Medicines in the European Union: A Retrospective Cohort Study. Clinical Pharmacology and Therapeutics, 105(2), 426-435. https://doi.org/10.1002/cpt.1169
https://dspace.library.uu.nl/bitstream/handle/1874/378208/Postauthorization.pdf?sequence=1

2017

Other output

Shakir, S., Bloem, L., Bruin, M. L. D., Hoekman, J., Leufkens, H., & Ryan, P. (2017). Practical Points to Address Uncertainties in Risk Management Planning.
Bloem, L. T., Mantel-Teeuwisse, A. K., Leufkens, H. G. M., De Bruin, M. L., Klungel, O. H., & Hoekman, J. (2017). Risk factors associated with post-marketing changes in specific obligations of conditionally authorised products in the EU. Pharmacoepidemiology and Drug Safety, 26, 605. https://doi.org/10.1002/pds.4275

2016

Scholarly publications

Bloem, L. T., De Abreu Lourenco, R., Chin, M., Ly, B., & Haas, M. (2016). Factors impacting treatment choice in the first-line treatment of colorectal cancer. Oncology and Therapy, 4(1), 103–116. https://doi.org/10.1007/s40487-016-0020-4
https://dspace.library.uu.nl/bitstream/handle/1874/336975/Bloem_2016_Factors_Impacting_Treatment_Choice_in_the_First_Line_Treatment_of_Colorectal_Cancer_Oncology_and_Therapy.pdf?sequence=1