The team

Professor John Gribben graduated from the University of Glasgow in 1980. He subsequently trained in Haematology at University College London and in Medical Oncology at the Dana-Farber Cancer Institute, Harvard Medical School, where he remained on the faculty for 17 years before returning to the UK. 

He specialises in haematological cancers including lymphomas, leukaemias and bone marrow transplantation and immunotherapy approaches including CAR-T cells.

He holds the Hamilton Fairley Chair of Medical Oncology at Barts and the London School of Medicine and Dentistry and his NHS post is as Honorary Consultant Haematologist and Medical Oncologist Barts and The London NHS Trust.

He is the author of more than 500 articles and chapters in peer-reviewed publications and has a global reputation for his work in researching new drugs and forms of cancer treatment. He has grant funding from The National Cancer Institute and Cancer Research UK for pioneering studies in leukaemia and lymphoma.

He took up his role as President of the European Hematology Association (EHA) for two years from June 2019, and serves on the EHA Executive Board. 

He is Chair of the international workshop for non-Hodgkin’s lymphoma (iwNHL) and co-chair of the international workshop for CAR T cells (iwCART). He was an Editor of Blood from 2007-2014. He is a Trustee of the London Clinic.

Make an appointment with Professor Gribben

Dr Richard Kaczmarski graduated from King’s College Hospital Medical School, University of London in 1984. He trained in internal medicine at St Bartholomew’s Hospital and haematology training at King’s College Hospital where he held research posts funded by the Wellcome Trust and Medical Research Council. He completed specialist haematology training at Hammersmith Hospital.

He is currently Consultant Haematologist and Clinical Lead at Hillingdon Hospital in London, Honorary Senior Lecturer at Imperial College and Specialty Lead for Cancer in the North West London Clinical Research Network.

His main interests are the diagnosis and treatment of patients with haematological malignancies (including acute and chronic leukaemias, myelodysplastic syndromes, lymphomas, myeloma and myeloproliferative disorders).

He is also involved with the investigation and management of:

• anaemias
• red cell disorders
• coagulation and thrombotic problems
• blood transfusion. 

He actively participates in NIHR, commercial and academic clinical trials and research. He has published peer reviewed papers, articles and chapters. He is an Examiner for the Royal College of Pathologists.

At The London Clinic he is Director of the Stem Cell Laboratory and chairs the Hospital Transfusion Committee.

Dr Kaczmarski consults at The London Clinic on Thursdays, 10am – 5pm

Make an appointment with Dr Kaczmarski

Dr Jan-Mohamed qualified as a doctor in 1981 at the Middlesex Hospital Medical School, London. He trained in clinical haematology at King’s College Hospital London. He was a Consultant Haematologist, head of department and Clinical Director at The Hillingdon Hospital. He was also Honorary Senior Lecturer at The Royal Free Hospital and Imperial College and a Clinical Tutor for the Royal College of Pathologists. 

He is an author of many peer review publications in the field of lymphoma, neutropenia, sepsis and haemato-oncology. He has recently retired from his NHS practice to concentrate working at The London Clinic.

He will facilitate the collections of stem cells from bone marrow and peripheral blood from normal volunteer donors so that unrelated patients with blood disorders may undergo allogeneic bone marrow transplantation. In addition, these cells and lymphocytes, in the future, may be used for research and development in the field of medical therapy including gene therapy, which may involve the development and manufacture of biological therapeutic products for patients.

Outside interests: cricket, classical Russian literature, art and theatre.

Make an appointment with Dr Jan-Mohammed

Dr Mike Potter works at The London Clinic, the Royal Marsden Hospital and Mount Alvernia Hospital, Guildford.  He qualified in Medicine from Cambridge and London Universities.   He trained in Internal Medicine and Haematology and has been a Consultant Haematologist for 25 years including the Royal Free Hospital  (8 years)  and the Royal Marsden Hospital (15 years).  

At the Royal Marsden Hospital he is the Programme Director for the Stem Cell Transplant Programme, one of the the largest in the UK.

Although predominantly a clinician he has also been active in management (Department Head for 4 years and Associate Medical Director for 3 years), research and teaching.  He currently hold a silver merit award and has published around 170 research articles.

His main interests are in the diagnosis and treatment of patients with haematological disorders including leukaemias, lymphomas, myeloma, myelodysplasia and myeloproliferative disorders.  This includes the application of stem cell transplantation in treatment of these diseases.

He is the Programme Director of the Stem Cell Transplant programme at The London Clinic. This  is the only independent hospital to have a fully JACIE accredited unit in the UK. The stem cell collection unit is one of  the largest in Europe: approximately 800 donor collections are performed annually.

He also treats patients with chemotherapy and biological targeted therapies such as antibodies, small molecules (often tablets) and immune active T - cells such as CAR-T cells which are now clinically available for patients with ALL and non Hodgkins Lymphoma at The London Clinic.

Dr Potter also sees more general haematology referrals at The London Clinic, both for diagnosis and treatment.  This includes patients with anaemias, polycythaemia, low/high white cell and/or platelet counts, high ferritin and lymph gland swelling.

He also is happy to provide second opinions if requested. He works with a talented team of clinicians, pathologists and radiologists to provide the very best advice in terms of diagnosis and treatment. His personal feedback is excellent with patients particularly emphasising his friendly and positive outlook and clear explanation of the issues involved. 

Dr Mike Potter consults at The London Clinic by appointment.