In the past 10 years we at Occams have have been privileged to be able to make a significant contribution to paediatric drug development through published research, including work on scaling adult pharmacokinetic/pharmacodynamic models to predict drug effects in children, minimizing the need for dose-finding clinical trials in paediatric patients. We're delighted that some of our most recent work on this important topic has been included in the recent special issue of Clinical Pharmacology & Therapeutics: Pharmacometrics & Systems Biology on Paediatric Rare Diseases.

In our most recent publication, a collaboration between Dan Liu at Eli Lilly & Co. and our own Jan-Stefan van der Walt, we propose a dosing regimen of selpercatinib in children with RET alterations, including thyroid cancer and other solid tumors, to achieve adult-equivalent exposure and to support accelerated FDA approval in children as young as 2 years old. We're very proud of this work, which showcases how cutting-edge pharmacometrics can be leveraged to bring effective treatments swiftly to those who need them the most.

Ten years ago today, three of us sat around a table in Amsterdam and signed the founding documents for Occams Coöperatie U.A. What started as a shared vision to do pharmacometrics with integrity and excellence has grown into something we're incredibly proud of, though "grown" might not be quite the right word.

We've intentionally stayed small, focusing on leveraging our collective skills and experience to deliver high-quality work while maintaining the work-life balance that's become central to how we collaborate with one another and serve our clients. A decade in, we've proven that doing excellent work doesn't require sacrificing everything else.

Thank you to our clients, and to our team - Rik Schoemaker, Jan-Stefan van der Walt, Justin Wilkins, Julia Winkler, and our emeritus heart and soul, Janet Wade.

Here's to the next ten years!

A new publication with Rik Schoemaker as Occams co-author has just been released: Pharmacokinetics and tolerability of single-dose Staccato® alprazolam in adolescents with epilepsy, and population pharmacokinetic analysis to support dose selection in adolescents, published in Epilepsia! The paper is Open Access and is therefore available as a free download.

Occams is a proud sponsor of both the Digital Health Africa conference from 3-4 September 2025, and the PMx Africa conference on 5 September 2025 both to be held in Kampala, Uganda, and online. Prior to the Digital Health Africa conference Rik Schoemaker and Justin Wilkins will be tutors in an nlmixr2 course on 2 September 2025. nlmixr2 is an open-source R-package that allows high quality nonlinear mixed-effect modelling for free, and Occams has been involved in its development from its inception. Course material can be obtained freely from the nlmixr2 blog!

A new publication with Jan-Stefan van der Walt and Justin Wilkins as Occams first and second author has just been released: Interplay between pharmacokinetics and immunogenicity of therapeutic proteins: stepwise development of a bidirectional joint pharmacokinetics-anti-drug antibodies model, published in the Journal of Pharmacolinetics and Pharmacodynamics! The paper is Open Access and is therefore available as a free download.

A new publication with Justin Wilkins as Occams co-author has just been released: Ethnic Sensitivity Assessment of MosunetuzumabPharmacokinetics and Pharmacodynamics in ChinesePatients With Relapsed or Refractory Follicular Lymphoma, published in Clinical and Translational Science! The paper is Open Access and is therefore available as a free download.

A new publication with Jan-Stefan van der Walt, Julia Winkler, and Rik Schoemaker as Occams co-authors has just been released: Population Pharmacokinetics and Pharmacodynamics of Fepixnebart (LY3016859) and Epiregulin in Patients with Chronic Pain, published in Clinical Pharmacokinetics! The paper is Open Access and is therefore available as a free download.

A new publication with Justin Wilkins as Occams co-author has just been released: A Novel Step-Up Dosage Regimen for Enhancing the Benefit-to-Risk Ratio of Mosunetuzumab in Relapsed or Refractory Follicular Lymphoma! The paper is Open Access and is therefore available as a free download.

A new publication with Rik Schoemaker as Occams co-author has just been released: Model-based comparisons of post-treatment free IgE and FEV1 between omalizumab asthma dosing tables in the United States and European Union! The paper is Open Access and is therefore available as a free download.

We are extremely proud to announce that Rik Schoemaker delivered his oral presentation at the PAGE meeting in Rome on 27 June 2024 on Quantification of the analgesic effect of intranasal coadministration of ketamine and sufentanil in adults to support the development of a pain relief treatment (CT001) in children with wonderful feedback from the audience! The pdf of the presentation can be downloaded here or from the PAGE website, and a pre-recorded presentation with audio can be downloaded here.

Occams is proud to sponsor the PAGE meeting in Rome from 25-28 June, and we hope to see many of you there!

Rik Schoemaker will be presenting at the SUP meeting in Stockholm on 11 April 2024 on Paediatric Posology and the EMA-endorsed graphical dose justification. The code for generating these graphs is available for download from github.com/GitOccams.

A new publication with Julia Winkler as Occams co-author has just been released: Systemic exposure to aflibercept after intravitreal injection in premature neonates with retinopathy of prematurity: results from the FIREFLEYE randomized phase 3 study! The paper is available as a free download.

A new publication with Justin Wilkins and Janet Wade as Occams co-authors has just been released: Covariate modeling in pharmacometrics: General points for consideration! The paper is available as a free download.

A new publication with Rik Schoemaker as Occams primary author has just been released: Brivaracetam exposure-response predictions in pediatric patients from age 1 month: Extrapolation of levetiracetam adult-pediatric scaling to brivaracetam! The paper is available for a limited time free download here.

The nlmixr2 team is delighted to announce that it will be running another nlmixr2 workshop prior to PAGE in Rome on Tuesday 25 June 2024 (13:00-17:00, at the PAGE conference hotel) hosted by Occams. The course will consist of a mixture of lectures and hands-on exercises. nlmixr2 and its satellite packages (including rxode2 and a range of tools facilitating seamless interaction with other industry-standard tools like NONMEM and Monolix) are undergoing continuous and intensive development, and are intended to provide a complete suite of packages for pharmacometric data analysis as free, open-source software. nlmixr2 is based in R and provides robust support for parameter estimation (primarily through the SAEM and FOCEi estimation methods) and simulation. Places are limited and can be reserved here.

A new publication with Justin Wilkins as Occams co-author just been released: Semi-mechanistic population pharmacokinetic/pharmacodynamic modeling of a Plasmodium elongation factor 2 inhibitor cabamiquine for prevention and cure of malaria! The paper is available for free download here.

Occams has once again co-authored a publication: Training the next generation of pharmacometric modelers: a multisector perspective with Justin Wilkins as Occams co-author!

Occams has co-authored yet another publication available for a 50-days free download: Causal chemoprophylactic activity of cabamiquine against Plasmodium falciparum in a controlled human malaria infection: a randomised, double-blind, placebo-controlled study in the Netherlands with Justin Wilkins as Occams co-author!

nlmixr2/rxode2 will be the centerpiece of a two days symposium, hosted by the PopSim Board (Danish Pharmaceutical Society) and the University of Copenhagen Drug Research Academy (DRA). Beginners and more advanced modellers will have the opportunity to work with nlmixr2/rxode2 during two workshops on the 15th and 16th of June. Having access to open source software like nlmixr2/rxode2 is a great opportunity for introducing population pharmacokinetic modeling and simulation to interested scientist who may otherwise not have had access. The advanced course on the afternoon of 16 June will be presented by Rik Schoemaker and Theodoros Papathanasiou, and course material is available from the nlmixr2 blog.

Occams is proud to sponsor the PAGE meeting in A Coruña from 27-30 June, and we hope to see many of you there!

Occams has co-authored yet another open-access publication available for free download: Characterization of exposure-response relationships of ipatasertib in patients with metastatic castration-resistant prostate cancer in the IPATential150 study with Justin Wilkins and Janet Wade as Occams co-authors!

Occams is proud to sponsor the PAGE meeting in Ljubljana from 28 June-1 July, and we'll all be there in person!

Rik Schoemaker and Justin Wilkins will be co-organizing an nlmixr2 course on 28 June - we hope to see many of you there!

Occams is proud to sponsor the QSPC2022 meeting in Leiden from 20-22 April, and Rik Schoemaker will be attending; looking forward to finally catching up with old and new friends again!

Occams is proud to have sponsored the WCoP2022 meeting in Cape Town from 29 March-1 April. Julia Winkler, Justin Wilkins , and Rik Schoemaker attended, and were witness to an amazing conference and the finest opportunity to connect to real people again!

Occams has co-authored another publication: Pharmacokinetics and exposure-efficacy relationships of omalizumab in patients with nasal polyps with Justin Wilkins and Rik Schoemaker as Occams authors. It is open access so you can directly download your copy!

Occams has co-authored yet another publication: Population Pharmacokinetics of Ipatasertib and Its Metabolite in Cancer Patients with Justin Wilkins, Julia Winkler and Janet Wade as Occams co-authors!

We are delighted that our recent open access paper Time-varying clearance and impact of disease state on the pharmacokinetics of avelumab in Merkel cell carcinoma and urothelial carcinoma by Justin Wilkins and Janet Wade has been recognized as a top-cited article in CPT:PSP!

From Wikipedia, on this day in 1328: English friar William of Ockham, who popularised the methodological principle known as Occam's razor, secretly left Avignon under threat from Pope John XXII.

Occams has co-authored another publication: Selection of the Recommended Phase 2 Dose for Bintrafusp Alfa, a Bifunctional Fusion Protein Targeting TGF-β and PD-L1 with Justin Wilkins as Occams author. It is open access so you can directly download your copy!

As past president of ISoP, Justin Wilkins delivered the keynote speech at the Pharmacometrics Japan Conference 2020 conference on 22 January!

Occams is extremely proud to be part of the nlmixr team that has just published a landmark comparison paper between the nlmixr/FOCEI and NONMEM/FOCEI algorithms, and between the nlmixr/SAEM and Monolix/SAEM algorithms. nlmixr is a free and open-source R-package that implements non-linear mixed effect modelling, and this publication now demonstrates that in both sparse and rich data situations, nlmixr can provide parameter estimates that match those obtained from the industry standards. The paper has been published in CPT:PSP and is now available in early view: Performance of the SAEM and FOCEI Algorithms in the Open-Source, Nonlinear Mixed Effect Modeling Tool nlmixr with Rik Schoemaker as first author, and Justin Wilkins as one of the co-authors.

Occams has co-authored another publication: Population pharmacokinetics and covariate analysis of Sym004, an antibody mixture against the epidermal growth factor receptor, in subjects with metastatic colorectal cancer and other solid tumors with Janet Wade and Rik Schoemaker as Occams authors. Contact us if you would like a copy!

Occams has co-authored the just-released ground breaking nlmixr tutorial in CPT:PSP, and as it is open access, we can provide a direct download: Nonlinear Mixed-Effects Model Development and Simulation Using nlmixr and Related R Open-Source Packages with Justin Wilkins and Rik Schoemaker as Occams authors.

Rik Schoemaker will be presenting an nlmixr course in the form of the Intermediate Population Approach workshop as part of the ASCEPT-PAGANZ joint meeting in Queenstown, New Zealand on 25 November 2019. More information can be found here, and full course materials can be downloaded here.

We have finally been able to publish the paper associated with the PAGE presentation by Lutz Harnisch in 2016(!) and as authors we can provide a free download: Modeling and simulation of the modified Rankin Scale and National Institutes of Health Stroke Scale neurological endpoints in intracerebral hemorrhage with Rik Schoemaker as first author, in Journal of Pharmacokinetics and Pharmacodynamics.

Occams has co-authored another publication: Population Pharmacokinetic Analysis of Bintrafusp Alfa in Different Cancer Types with Justin Wilkins as first author, in Advances in Therapy.

Occams has co-authored another publication, and as it is open access, we can provide a direct download: Systemic pharmacokinetic/pharmacodynamic analysis of intravitreal aflibercept injection in patients with retinal diseases with Julia Winkler as Occams author, in BMJ Open Opthalmology.

Occams has authored another publication, and as it is open access, we can provide a direct download: Time-varying clearance and impact of disease state on the pharmacokinetics of avelumab in Merkel cell carcinoma and urothelial carcinoma with Justin Wilkins and Janet Wade as Occams authors, in CPT:PSP.

The nlmixr team is delighted to announce that it will be running another nlmixr workshop at PAGE in Stockholm on Tuesday 11 June 2019. Recent updates incorporating a solid FOCE-I algorithm greatly enhance the applicability of the R-based free and open-source package for non-linear mixed effect modelling! Places are limited and can be reserved here.

To commemorate the 20th anniversary of PAGANZ, Janet Wade -as one of the original speakers at the founding conference- was invited to PAGANZ 2019 in Auckland to revisit her talk on simultaneous estimation of PK and PD. You can find her presentation here.

We are pretty proud to see our work being used in an EMA recommendation on How should results/predictions of pharmacokinetic analyses be presented to facilitate decision making about the adequacy of the proposed dosing regimen in paediatric patients? referencing Brivaracetam population pharmacokinetics in children with epilepsy aged 1 month to 16 years by Rik Schoemaker, Janet Wade and Armel Stockis, in the European Journal of Clinical Pharmacokinetics.

Julia Winkler, Rik Schoemaker, and Armel Stockis have authored another new publication! Population Pharmacokinetics of Adjunctive Lacosamide in Pediatric Patients With Epilepsy, in The Journal of Clinical Pharmacology.

Julia Winkler, Rik Schoemaker, and Armel Stockis have authored a new publication: Modeling and simulation for the evaluation of dose adaptation rules of intravenous lacosamide in children, in Epilepsy Research.

Justin, Janet and Rik will be attending ACoP9 in San Diego from 7 to 11 October 2018. We anticipate, with great pleasure and pride, to see Justin start his year as President of ISoP.

In addition, Justin and Rik will be assisting with the first ACoP-sponsored nlmixr tutorial on Thursday 11 October (8:00AM-12:00PM).

We look forward to seeing and talking to all our friends and colleagues!

Occams has just co-authored a new publication, with Justin Wilkins as final author: Data standards for model-informed drug development: an ISoP initiative, in Journal of Pharmacokinetics and Pharmacodynamics.

We are all attending PAGE in Montreux from 19 May to 1 June 2018! Justin and Rik will be assisting with the first European nlmixr workshop on 18 May, and we will be presenting two posters:

• I-59: Population pharmacokinetic analysis of M7824 (MSB0011359C) in different cancer types, by Justin and colleagues
• II-32: Drug-disease model describing the effect of intraarticular injected sprifermin on cartilage thickness measured by magnetic resonance imaging in osteoarthritis patients, by Julia, Rik and colleagues

On 20 April 2018 at 9:15 Marina Senek defended her PhD thesis New approaches for levodopa treatment in Parkinson’s Disease with aplomb at the Department of Neuroscience, Uppsala University. Janet Wade was on the board of examiners.

Rik Schoemaker will be presenting an overview of RxODE and nlmixr software developments at the 12th meeting of the Pharmacometrics Network Benelux in Groningen, the Netherlands on 29 March 2018. The slides can be found here.

The nlmixr team is delighted to announce that it will be running an nlmixr workshop at PAGE in Montreux on Tuesday 29 May 2018! Registration will open January 15th 2018. Mark your calendar; places are limited and can be reserved here.

Occams has just authored a new publication, and as it is open access, we can provide a direct download: Evaluation of brivaracetam efficacy as monotherapy in adult patients with focal seizures by Rik Schoemaker, Janet Wade Joseph D'Souza, and Armel Stockis, in Epilepsy Research.

The entire Occams team will be present at ACoP8 in Ft. Lauderdale, and we will be presenting three posters:

Rik will be presenting a poster on Tuesday on nlmixr: an open-source package for pharmacometric modeling in R (T-012). This poster will be part of the Poster Spotlight session to highlight the integration between statistics and pharmacometrics.

Justin will be presenting two posters on Wednesday on Clearance over time and effect of response in the pharmacokinetics of avelumab (W-079) and Population pharmacokinetic analysis of avelumab in different cancer types (W-080).

The oral presentation at PAGE 2016 on scaling brivaracetam effects from adults to children has now been published in Clinical Pharmacokinetics! It is open access, and so we can provide a direct download: Extrapolation of a Brivaracetam Exposure–Response Model from Adults to Children with Focal Seizures by Rik Schoemaker, Janet Wade and Armel Stockis.

As part of a series of articles to commemorate the retirement of pharmacometrics legend Meindert Danhof, Justin Wilkins collaborated with Mats Karlsson of Uppsala University, Daniela Conrado and Klaus Romero of the Critical Path Institute and Céline Sarr of Pharmetheus on an article discussing open innovation and sharing. We're delighted that it's now available online here!

We are all attending PAGE in Budapest from 6 to 9 June 2017! Come and see our posters:

• II-03: nlmixr: an open-source package for pharmacometric modelling in R, by Rik, Justin and colleagues
• II-49: Population PK analysis of Sym004 and the influence of variations in base model structure on covariate model building, by Janet, Rik and colleagues

The presenters will both be by their posters between 15:10 and 16:40 on Wednesday 7 June - come visit us!

In collaboration with DDMoRe, Justin Wilkins and colleagues have published a white paper describing the new Thoughtflow standard for facilitating provenance-based capture, storage, and reporting of knowledge, including assumptions and decisions, as well as supporting reproducibility in pharmacometrics.

Visit the Thoughtflow community group here!

Occams has just authored a new publication, and as it is open access, we can provide a direct download: Brivaracetam population pharmacokinetics in children with epilepsy aged 1 month to 16 years by Rik Schoemaker, Janet Wade and Armel Stockis, in the European Journal of Clinical Pharmacokinetics.

We have secured a new domain and Occams now sits maturely at Occams.com. Our email addresses will be updated shortly, but you will still be able to contact us using the occams.eu extension!

On 9 December 2016 at 9:15, Anne-Gaëlle Dosne defended her thesis with the title Improved methods for pharmacometric model-based decision making in clinical drug development brilliantly at Uppsala University, and Rik Schoemaker was her external examiner.

On 8 December at 15:15, Rik presented a seminar on nlmixr at Uppsala University (Biomedicinskt centrum, BMC in room C2:301) and the slides are available at this link.

Occams is very proud to be playing a supporting role in the release of nlmixr, an open source package for population PK and PKPD modelling developed by Wenping Wang and Yuan Xiong. nlmixr builds on Wenping's RxODE package for simulation of nonlinear mixed effect models using ordinary differential equations, by implementing parameter estimation algorithms like nlme, gnlmm and SAEM. nlmixr greatly expands the utility of existing packages (like nlme) by providing an efficient and versatile way to specify pharmacometric models and dosing scenarios, with rapid execution due to compilation to C++.

The source is now available at https://github.com/nlmixrdevelopment/nlmixr along with a vignette, and the models and datasets used in the nlmixr/nlme poster to be presented at ACoP (W-66): nlmixr: an open-source package for pharmacometric modelling in R on Wednesday, 26 October, 2016, 7:30-9:30 am. At this point, nlmixr is still very much in a testing stage and is under lively development. Get in touch, see us at ACoP to discuss ways you could contribute (Wenping Wang, Yuan Xiong, Justin Wilkins and Rik Schoemaker will all be there), or try it out for yourself, and experience the joy of a population modelling package within R! A live demo will be possible, so come see Rik if you are interested!

Occams will be represented at WCoP 2016 in Brisbane by Rik Schoemaker. Meet him there or come see his poster on nlmixr: an open-source package for pharmacometric modelling in R on Monday, 22 August, 2016, 12.15-1:15 pm. nlmixr is a highly exciting open-source development that allows non-linear mixed effect modelling using R and the nlme package, but implementing full dosing flexibility along with ordinary differential equations, and computational speed by compiling to C. A live demo will be possible, so come see Rik if you are interested!

At Occams we believe in providing academic output next to our consultancy work, and we are therefore happy to announce that we have co-authored two publications over the last months:

• Peter L. Bonate, Malidi Ahamadi, Nageshwar Budha, Amparo de la Peña, Justin C. Earp, Ying Hong, Mats O. Karlsson, Patanjali Ravva, Ana Ruiz-Garcia, Herbert Struemper, and Janet R. Wade. Methods and strategies for assessing uncontrolled drug–drug interactions in population pharmacokinetic analyses: results from the International Society of Pharmacometrics (ISOP) Working Group. J Pharmacokinet Pharmacodyn (2016) 43: 123.
• Rik Schoemaker, Janet R. Wade, and Armel Stockis. Brivaracetam Population Pharmacokinetics and Exposure-Response Modeling in Adult Subjects With Partial-Onset Seizures. Journal of Clinical Pharmacology (2016). doi: 10.1002/jcph.761.

We are extremely proud and honoured that Occams is has been granted two oral presentations at PAGE 2016! One will be presented by Lutz Harnisch (Pfizer) in a collaborative project with Pharmetheus, Occams and Pfizer with the title Modelling and simulation of neurological endpoints (modified Rankin Scale [mRS] and National Institute of Health Stroke Scale [NIHSS]) to aid clinical trial design in intracerebral hemorrhage (ICH), and one will be presented by Rik Schoemaker (Occams) with the title Extrapolation of a Brivaracetam Exposure-Response Model from Adults to Children on work performed while at Exprimo in collaboration with UCB.

The Bill & Melinda Gates Foundation is organising a Healthy Birth, Growth and Development Hackathon prior to PAGE, and Rik Schoemaker will be representing Occams. Will you join us? The networking reception from 6-9PM on Sunday 5 June is free for all! Sign up here.

Occams is committed to supporting global training, research and development in the field of pharmacometrics. Our consultants are variously associated with PAGE and the International Society of Pharmacometrics (ISoP), and in 2016 we are proud to be sponsors of PAGE (www.page-meeting.org), WCoP (wcop2016.org) and PMX Benelux !

We are extremely proud and happy to announce to the world that the Occams team has been extended with both Janet Wade and Justin Wilkins!

Occams will be represented at ACoP 2015 by Rik Schoemaker. Meet him there or come see his poster (T-50) on Modeling the Effect of Levetiracetam on Daily and Aggregated Seizure Counts in Adults and Children on Tuesday, October 6, 2015, 7.30-9.00 am.

Occams is live! Look for Rik Schoemaker at PAGE in Crete.