Anthony Nolan Trust (ANT) gave details of the history of their organisation and of the different types of stem cell transplants. They said the mailing was sent only to people who were already on their donor register. Those recipients would have received information before joining the register and would therefore be fully aware that, if they joined the register, they might never be called on to donate and that there would be no guarantee that the recipient of any transplant would recover. ANT believed the mailing did not misleadingly suggest to the target audience that if they were a match, the recipient of the donation was guaranteed to make a full recovery or that lives could routinely be saved without potential complications or difficulties. They said the average consumer, and particularly those on the register, would be aware that such procedures were never routine or guaranteed to be successful. They believed the mailing would be understood by recipients to mean that for each additional person who could be persuaded to become a donor, an additional potential match, or “the hope of life”, would be provided for patients who would otherwise die. They said a matching donor could save a life and the claims in the mailing were entirely true, proportionate and substantiated. They were supported by medical opinion and the position of governments around the world.

ANT said the number of transplants, including from donors’ stem cells had increased dramatically over the past 30 years, which would not have happened if there was no evidence of survival or patient benefit. They said the procedure for haematopoietic stem cell transplantation (HSCT), which was the transplantation of stem cells derived from bone marrow or blood, was risky and there were many possible complications. Without a transplant, however, most of the recipients of the treatment, which was, generally, reserved for patients with life-threatening conditions who would not benefit from prolonged treatment or who were already resistant to chemotherapy, would die. ANT said for allogeneic transplants, which were mandatory for some patients and had to come from a person with the same tissue type, 70% of patients were currently dependent on donors who were not relatives.

Between 1980 and 2010 there had been a significant increase in the proportion of unrelated donors providing stem cells, and as family sizes decreased, the availability of sibling donors would also decrease and the proportion of unrelated donors would increase accordingly. They said the leading experts agreed that non-sibling transplants provided a highly effective treatment for children and adults who had high-risk leukaemia and other haematological disorders but did not have a sibling donor. If those patients were given the opportunity of a non-sibling transplant, they would have more than a fighting chance of survival. The latest results showed that non-sibling transplants had approximately the same success levels as transplants from sibling donors, which meant the chances of survival increased from virtually zero to around 54%, and the proportion of positive outcomes continued to increase. They said those who were in need but did not receive a transplant had very little chance of survival. ANT said no clinician would consider HCST if it decreased, rather than increased, patients’ chances of survival.

They said although increasing numbers of patients were undergoing allogeneic stem cell transplantations, there were still many for whom no match was found. They estimated that for every patient they matched through their register there was another they could not, which was why they wanted to encourage more people to join the register. They said the prognosis for HSCT transplant patients varied depending on the disease type, stage, stem cell source, the matching status and conditioning regimen. A transplant, however, offered a chance for a cure, or for long-term remission, if certain complications were avoided. In recent years, survival rates had been gradually improving across almost all populations and sub-populations who received transplants. They submitted data related to survival rates and said allogeneic HSCT was a potentially curative procedure for many patients with haematological malignancies and some non-malignant diseases. Developments had also allowed the treatment to be extended to older, less fit and more heavily pre-treated patients. However, the procedure was still associated with significant mortality rates due to relapse or non-relapse causes; the latter were usually related to complications as a result of the transplantation procedure.

ANT said the estimation of overall survival and non-relapse mortality was of primary importance in assessing the risk/benefit ratio of HSCT and there were a number of mechanisms to predict transplantation tolerance and post-transplantation survival. They said the British Society of Blood and Bone Marrow Transplantation (BSBMT) estimated that in the UK, non-relapse mortality at five years after treatment was 31% for allogeneic transplants. In the past 30 years there had been a significant decrease in non-relapse mortality at one year, particularly in the case of allogeneic transplants. They also said overall survival rates between 1980 and 2010 had significantly increased. Median overall survival in that period for allogeneic transplants was three years and median progression free survival (the percentage of individuals in a group whose disease was likely to remain stable after a specified duration of time) was one year.

ANT said non-sibling transplants were usually undertaken when there was no matching sibling available. Patients therefore did not have a choice between sibling donor transplant or unrelated donor transplant, or no transplant. They said there was often a delay in finding a matching donor, due to the current size of the donor registry list, which could have a negative impact on the prognosis of the individual patient whereas that would not be the case for those who had quickly found a matched sibling donor. They said such treatment was often a ‘last chance’ for patients, who might also have become weaker by the time a match was found resulting in an increased likelihood of mortality through infection or complications. Those patients were not in the same position as a patient in relatively good health, for whom a clinician had recommended transplant at that stage of treatment or as a patient for whom a match was found quickly and whose doctor could choose an optimum time in the cycle of the condition to perform the transplant.

They said statistical outcomes for such disparate groups therefore could not be compared as though they were a single population. They said, for example, if transplants were refused to the patients whose prognosis was weakest, the statistical outcome would be an improvement in the rates of survival five years after the transplant. They said that might result in a better success level overall for the transplant procedure but would reduce accordingly the five-year survival rates to zero, or near to zero, for those who had therefore lost the option of transplant. They said the treatment was accepted and common in every Western country. It had increased rapidly since it was introduced and although it was traditionally reserved for patients with life-threatening conditions, based on clinical decisions, thousands of people were alive today due to the kindness of unrelated donors.

They said research had consistently shown that where a matched sibling was not available, a well-matched unrelated donor could and should be used. They said survival rates were higher for donations from siblings but were on average less than 10% better than those from unrelated donors. Some studies on specific diseases suggested that donations from well-matched unrelated donors gave better outcomes than those from siblings. ANT submitted details of those studies as well as a study comparing related and unrelated donor transplants in adults with acute myeloid leukaemia in first remission and a paper on 20 years of unrelated donor transplants facilitated by the National Marrow Donor Programme in America. They also submitted several other studies and the UK Stem Cell Strategic Forum report on the future of unrelated donor cell transplants in the UK, along with letters from the American Society for Blood and Marrow Transplantation (ASBMT) and the European Group for Blood and Marrow Transplantation (EBMT). They said for the past 35 years they had been the best chance for thousands of people who urgently needed stem cell transplants but knew that for every person they helped, there was another who missed the chance and they therefore aimed to expand their register.