Autologous hematopoietic stem cell transplantation for multiple sclerosis: A current perspective.

The most effective treatment at halting inflammation in patients with highly active multiple sclerosis (MS) is immune ablation followed by autologous hematopoietic stem cell transplantation (AHSCT). Better patient selection and supportive management, as well as advances in conditioning regimens have resulted in improved safety with AHSCT. However, which comorbidities or prior therapies increase the risks associated with AHSCT still need to be determined. In addition, there is still debate as to which AHSCT conditioning regimen offers the best balance of long-term efficacy and safety. New studies comparing AHSCT with highly effective disease-modifying therapies will help to inform on the ideal placement of AHSCT in the treatment algorithm. Currently, many centers are experienced and use AHSCT to treat select patients with MS, contributing to ongoing registries and clinical trials which will help answer these questions.

Does Resetting the Immune System Fix Multiple Sclerosis?

Multiple sclerosis is the leading non-traumatic cause of disability in young adults, affecting up to 100,000 Canadians. This chronic inflammatory and neurodegenerative disease of the central nervous system leads to irreversible neurologic disability if inadequately controlled. Though many current medications are available that reduce inflammatory damage, most patients continue to show some evidence of disease activity and accrue disability. In this review, we discuss the role of immune ablation followed by autologous hematopoietic stem cell transplantation (AHSCT), a therapeutic option for select patients with a more aggressive disease course. By "resetting" the immune system with a variety of ablative conditioning regimens, followed by immune reconstitution, this therapy has shown a durable response in halting evidence of inflammatory activity in most patients, without the need for continued disease-modifying therapies (DMT). Since the introduction of this therapy, there have been advances in patient selection and supportive care, such that morbidity has significantly declined and treatment-related mortality is minimized. Recent phase-II trials have shown excellent results in efficacy and safety of AHSCT; however, challenges exist which require ongoing study. The future challenges include comparing the variety of AHSCT conditioning regimens with each other as well as with existing highly effective DMT; identifying patients with an aggressive disease course through novel biomarkers who may benefit the most from AHSCT; and surveillance of long-term outcomes of different treatment protocols. In select patients, replacing the immune system with AHSCT holds promise of fundamentally altering the trajectory of their aggressive disease course.

Est-ce que le fait de réinitialiser le système immunitaire permet de guérir de la sclérose en plaques? La sclérose en plaques (SP) demeure la principale cause non-traumatique d'invalidité chez les jeunes adultes et affecte jusqu'à 100 000 Canadiens. Cette maladie chronique neuro-dégénérative inflammatoire du système nerveux central entraîne une incapacité neurologique irréversible si elle n'est pas adéquatement contrôlée. Bien que de nombreux traitements médicaux permettent de réduire les dommages inflammatoires de la SP, on continue à observer chez la plupart des patients des signes d'activité de la maladie et une invalidité qui va en croissant. Dans cette étude, nous voulons discuter du rôle de la suppression immunitaire (immune ablation) suivie d'une greffe autologue de moelle osseuse (autologous hematopoietic stem cell transplantation ou AHSCT). Il s'agit ainsi d'une option thérapeutique pour certains patients dont l'évolution de la SP est davantage fulgurante. En « remettant à zéro ¼ le système immunitaire des patients atteints de SP à l'aide de régimes de suppression de la réponse immunitaire, lesquels sont suivis ensuite par une reconstitution immunitaire, cette thérapie a pour effet de stopper l'activité inflammatoire chez la plupart d'entre eux sans qu'ils n'aient eu à entamer des thérapies continues modifiant le cours de la SP. À notre avis, cela constitue une réponse durable. Depuis l'introduction de cette thérapie, on a noté des avancées en ce qui regarde la sélection des patients et les soins prodigués, de sorte que les taux de morbidité ont diminué de façon notable et que la mortalité reliée aux traitements a été minimisée. De récents essais cliniques de phase II ont par ailleurs montré d'excellents résultats en matière d'efficacité et de sécurité. Cela dit, certains défis exigent des études supplémentaires : songeons, par exemple, à une comparaison entre les divers régimes de suppression de la réponse immunitaire et de greffe de moelle osseuse; au fait de comparer ces mêmes régimes à d'autres thérapies modificatrices de la maladie qu'on estime à l'heure actuelle très efficaces; à l'identification, au moyen de biomarqueurs novateurs, de patients dont l'évolution de la SP est davantage accélérée, patients qui pourraient le plus bénéficier d'une greffe de la moelle osseuse ; à la nécessité d'un suivi à long terme des différents protocoles de traitement et de leurs résultats. En somme, le fait de réinitialiser le système immunitaire de certains patients au moyen d'une greffe de moelle osseuse laisse entrevoir la possibilité de pouvoir modifier fondamentalement la trajectoire fulgurante de cette maladie.

Autologous Hematopoietic Cell Transplantation for Treatment-Refractory Relapsing Multiple Sclerosis: Position Statement from the American Society for Blood and Marrow Transplantation.

Multiple sclerosis (MS) is a chronic, disabling, immune-mediated, demyelinating and degenerative disease of the central nervous system. Approved disease-modifying therapies may be incompletely effective in some patients with highly active relapsing disease and high risk of disability. The use of immunoablative or myeloablative therapy followed by autologous hematopoietic cell transplantation (AHCT) has been investigated in retrospective studies, clinical trials, and meta-analyses/systematic reviews as an approach to address this unmet clinical need. On behalf of the American Society for Blood and Bone Marrow Transplantation (ASBMT), a panel of experts in AHCT and MS convened to review available evidence and make recommendations on MS as an indication for AHCT. A review of recent literature identified 8 retrospective studies, 8 clinical trials, and 3 meta-analyses/systematic reviews. In aggregate, these studies indicate that AHCT is an efficacious and safe treatment for active relapsing forms of MS to prevent clinical relapse, magnetic resonance imaging-detectable lesion activity, and worsening disability and to reverse disability without unexpected adverse events. Based on the available evidence, the ASBMT recommends that treatment-refractory relapsing MS with high risk of future disability be considered a "standard of care, clinical evidence available" indication for AHCT. Collaboration of neurologists with expertise in treating MS and transplantation physicians with experience performing AHCT for autoimmune disease is crucial for ensuring appropriate patient selection and optimizing transplantation procedures to improve patient outcomes. Transplantation centers in the United States and Canada are strongly encouraged to report baseline and outcomes data on patients receiving AHCT for multiple sclerosis to the Center for International Blood and Marrow Transplant Research.

Autologous hematopoietic stem cell transplantation improves fatigue in multiple sclerosis.

BACKGROUND: Fatigue is a common problem in multiple sclerosis (MS) affecting as many as 90% of patients. The Fatigue Impact Scale (FIS) is a validated measure of fatigue in MS patients. The cause of fatigue in MS is likely multifactorial, with some evidence that ongoing central nervous system (CNS) inflammation is a contributing factor. Immunoablation and autologous hematopoietic stem cell transplantation (aHSCT) have been shown to halt ongoing CNS inflammation. OBJECTIVE: To investigate whether halting all ongoing inflammation with aHSCT impacts FIS scores in patients with severe MS. METHODS: In the Canadian aHSCT study ( ClinicalTrials.gov , NCT01099930), 23 patients underwent aHSCT and had FIS prospectively collected every 6 months for 36 months of follow-up. Change in FIS was analysed by repeated-measures analysis of variance (RMANOVA) with multiple linear regression to determine independent predictors. RESULTS: The median FIS score decreased 36%, from 36 to 23 (p = 0.001), and four patients had 100% reduction. Improvement in FIS correlated with lower age and Expanded Disability Status Scale at baseline, as well as increased independence as evidenced by a return to gainful employment and even driving. CONCLUSION: Patients had significantly less fatigue on average after aHSCT. This may serve to better understand the contribution of ongoing CNS inflammation to fatigue peculiar to MS.

Impact of immunoablation and autologous hematopoietic stem cell transplantation on gray and white matter atrophy in multiple sclerosis.

BACKGROUND: Immunoablation and autologous hematopoietic stem cell transplantation (IA/aHSCT) halts relapses, white matter (WM) lesion formation, and pathological whole-brain (WB) atrophy in multiple sclerosis (MS) patients. Whether the latter was due to effects on gray matter (GM) or WM warranted further exploration. OBJECTIVE: To model GM and WM volume changes after IA/aHSCT to further understand the effects seen on WB atrophy. METHODS: GM and WM volume changes were calculated from serial baseline and follow-up magnetic resonance imaging (MRI) ranging from 1.5 to 10.5 years in 19 MS patients treated with IA/aHSCT. A mixed-effects model with two predictors (total busulfan dose and baseline T1-weighted WM lesion volume "T1LV") characterized the time-courses after IA/aHSCT. RESULTS: Accelerated short-term atrophy of 2.1% and 3.2% occurred in GM and WM, respectively, on average. Both busulfan dose and T1LV were significant predictors of WM atrophy, whereas only busulfan was a significant predictor of GM atrophy. Compared to baseline, a significant reduction in GM atrophy, not WM atrophy, was found. The average rates of long-term GM and WM atrophy were -0.18%/year (standard error (SE): 0.083) and -0.07%/year (SE: 0.14), respectively. CONCLUSION: Chemotherapy-related toxicity affected both GM and WM. WM was further affected by focal T1-weighted lesion-related pathologies. Long-term rates of GM and WM atrophy were comparable to those of normal-aging.

Immunoablation and autologous haemopoietic stem-cell transplantation for aggressive multiple sclerosis: a multicentre single-group phase 2 trial.

BACKGROUND: Strong immunosuppression, including chemotherapy and immune-depleting antibodies followed by autologous haemopoietic stem-cell transplantation (aHSCT), has been used to treat patients with multiple sclerosis, improving control of relapsing disease. We addressed whether near-complete immunoablation followed by immune cell depleted aHSCT would result in long-term control of multiple sclerosis. METHODS: We did this phase 2 single-arm trial at three hospitals in Canada. We enrolled patients with multiple sclerosis, aged 18-50 years with poor prognosis, ongoing disease activity, and an Expanded Disability Status Scale of 3.0-6.0. Autologous CD34 selected haemopoietic stem-cell grafts were collected after mobilisation with cyclophosphamide and filgrastim. Immunoablation with busulfan, cyclophosphamide, and rabbit anti-thymocyte globulin was followed by aHSCT. The primary outcome was multiple sclerosis activity-free survival (events were clinical relapse, appearance of a new or Gd-enhancing lesion on MRI, and sustained progression of Expanded Disability Status Scale score). This study was registered at ClinicalTrials.gov, NCT01099930. FINDINGS: Between diagnosis and aHSCT, 24 patients had 167 clinical relapses over 140 patient-years with 188 Gd-enhancing lesions on 48 pre-aHSCT MRI scans. Median follow-up was 6.7 years (range 3.9-12.7). The primary outcome, multiple sclerosis activity-free survival at 3 years after transplantation was 69.6% (95% CI 46.6-84.2). With up to 13 years of follow-up after aHSCT, no relapses occurred and no Gd enhancing lesions or new T2 lesions were seen on 314 MRI sequential scans. The rate of brain atrophy decreased to that expected for healthy controls. One of 24 patients died of transplantation-related complications. 35% of patients had a sustained improvement in their Expanded Disability Status Scale score. INTERPRETATION: We describe the first treatment to fully halt all detectable CNS inflammatory activity in patients with multiple sclerosis for a prolonged period in the absence of any ongoing disease-modifying drugs. Furthermore, many of the patients had substantial recovery of neurological function despite their disease's aggressive nature. FUNDING: Multiple Sclerosis Scientific Research Foundation.

Brain atrophy after bone marrow transplantation for treatment of multiple sclerosis.

BACKGROUND: A cohort of patients with poor-prognosis multiple sclerosis (MS) underwent chemotherapy-based immune ablation followed by immune reconstitution with an autologous hematopoietic stem cell transplant (IA/aHSCT). This eliminated new focal inflammatory activity, but resulted in early acceleration of brain atrophy. OBJECTIVE: We modeled the time course of whole-brain volume in 19 patients to identify the baseline predictors of atrophy and to estimate the average rate of atrophy after IA/aHSCT. METHODS: Percentage whole-brain volume changes were calculated between the baseline and follow-up magnetic resonance imaging (MRI; mean duration: 5 years). A mixed-effects model was applied using two predictors: total busulfan dose and baseline volume of T1-weighted white-matter lesions. RESULTS: Treatment was followed by accelerated whole-brain volume loss averaging 3.3%. Both the busulfan dose and the baseline lesion volume were significant predictors. The atrophy slowed progressively over approximately 2.5 years. There was no evidence that resolution of edema contributed to volume loss. The mean rate of long-term atrophy was -0.23% per year, consistent with the rate expected from normal aging. CONCLUSION: Following IA/aHSCT, MS patients showed accelerated whole-brain atrophy that was likely associated with treatment-related toxicity and degeneration of "committed" tissues. Atrophy eventually slowed to that expected from normal aging, suggesting that stopping inflammatory activity in MS can reduce secondary degeneration and atrophy.

ORFV: a novel oncolytic and immune stimulating parapoxvirus therapeutic.

Replicating viruses for the treatment of cancer have a number of advantages over traditional therapeutic modalities. They are highly targeted, self-amplifying, and have the added potential to act as both gene-therapy delivery vehicles and oncolytic agents. Parapoxvirus ovis or Orf virus (ORFV) is the prototypic species of the Parapoxvirus genus, causing a benign disease in its natural ungulate host. ORFV possesses a number of unique properties that make it an ideal viral backbone for the development of a cancer therapeutic: it is safe in humans, has the ability to cause repeat infections even in the presence of antibody, and it induces a potent T(h)-1-dominated immune response. Here, we show that live replicating ORFV induces an antitumor immune response in multiple syngeneic mouse models of cancer that is mediated largely by the potent activation of both cytokine-secreting, and tumoricidal natural killer (NK) cells. We have also highlighted the clinical potential of the virus by demonstration of human cancer cell oncolysis including efficacy in an A549 xenograft model of cancer.

Harnessing oncolytic virus-mediated antitumor immunity in an infected cell vaccine.

Treatment of permissive tumors with the oncolytic virus (OV) VSV-Δ51 leads to a robust antitumor T-cell response, which contributes to efficacy; however, many tumors are not permissive to in vivo treatment with VSV-Δ51. In an attempt to channel the immune stimulatory properties of VSV-Δ51 and broaden the scope of tumors that can be treated by an OV, we have developed a potent oncolytic vaccine platform, consisting of tumor cells infected with VSV-Δ51. We demonstrate that prophylactic immunization with this infected cell vaccine (ICV) protected mice from subsequent tumor challenge, and expression of granulocyte-monocyte colony stimulating factor (GM-CSF) by the virus (VSVgm-ICV) increased efficacy. Immunization with VSVgm-ICV in the VSV-resistant B16-F10 model induced maturation of dendritic and natural killer (NK) cell populations. The challenge tumor is rapidly infiltrated by a large number of interferon γ (IFNγ)-producing T and NK cells. Finally, we demonstrate that this approach is robust enough to control the growth of established tumors. This strategy is broadly applicable because of VSV's extremely broad tropism, allowing nearly all cell types to be infected at high multiplicities of infection in vitro, where the virus replication kinetics outpace the cellular IFN response. It is also personalized to the unique tumor antigen(s) displayed by the cancer cell.

CLIPPERS Responsive to Cladribine as a Durable Steroid-Sparing Agent.

OBJECTIVE: We report a case of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) who achieved durable and steroid-free remission after IV cladribine. METHODS: A 25 year-old man presented with progressively worsening headaches, polydipsia, dysarthria, diplopia and vertigo, and obtundation requiring respiratory support. CSF revealed lymphocytosis, and MRI revealed a perivascular pattern of punctate enhancement involving the pons. An extensive workup for inflammatory, autoimmune, infective, and malignant explanations was unrevealing. He responded dramatically to steroids, compatible with CLIPPERS as a diagnosis of exclusion. Attempts to wean prednisone over the ensuing year resulted in 2 clinical relapses and persistent punctate enhancement. Given significant steroid side effects, steroid-sparing agents were considered. RESULTS: IV cladribine IV (0.0875 mg/kg adjusted body weight daily × 4 days at 0, 4, 8, and 16 months) was selected, given its favorable side effect profile including lower risks of malignancy and infertility and the potential for long-lasting effects. The only side effect was short-term fatigue at the time of infusion. At 20 months after cladribine initiation, he was able to wean-off prednisone altogether. Now at 33 months, he remains in clinical and MRI remission. DISCUSSION: Cladribine is a rational candidate steroid-sparing treatment for presumed neurologic autoimmune conditions such as CLIPPERS. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that cladribine is a steroid-sparing treatment consideration in CLIPPERS.

Autologous hematopoietic stem cell transplantation for autoimmune disease--is it now ready for prime time?

Current systemic therapies are rarely curative for patients with severe life-threatening forms of autoimmune disease (AID). During the past 15 years, autologous hematopoietic stem cell transplantation (HCT) has been demonstrated to cure some patients with severe AID refractory to all other available therapies, and thus AID has become an emerging indication for cell therapy. The sustained clinical effects after autologous HCT are better explained by qualitative change in the reconstituted immune repertoire rather than transient depletion of immune cells. Since 1996, more than 1300 AID patients have been registered by the European Group for Blood and Marrow Transplantation (EBMT) and almost 500 patients by the Center for International Blood and Marrow Transplant Research (CIBMTR). Autologous HCT is most commonly performed for patients with multiple sclerosis (MS) or systemic sclerosis (SSc). Systemic lupus, Crohn's disease, type I diabetes, and juvenile idiopathic arthritis are other common indications. Allogeneic transplants are still considered too toxic for use in AID, except for cases of immune cytopenia. Although biologic therapies have been effective at controlling the manifestations of the disease, they require continuous administration, thus raising questions about their increasing costs, morbidity, and mortality related to prolonged therapy. Perhaps it is a reasonable time to ask, "Is autologous HCT for severe AID now ready for prime time?" Yet, the paucity of controlled studies, the short-term toxicities, and the upcoming availability of second-generation biologic and targeted immunotherapies argues that perhaps HCT for AID should be still limited to clinical trials. In this article, we focus on the results of autologous HCT for MS and SSc because these are the two most commonly transplanted diseases. The promising data that is emerging may establish these diseases as standard indications for HCT.

Transplantation for autoimmune diseases in north and South America: a report of the Center for International Blood and Marrow Transplant Research.

Hematopoietic cell transplantation (HCT) is an emerging therapy for patients with severe autoimmune diseases (AID). We report data on 368 patients with AID who underwent HCT in 64 North and South American transplantation centers reported to the Center for International Blood and Marrow Transplant Research between 1996 and 2009. Most of the HCTs involved autologous grafts (n = 339); allogeneic HCT (n = 29) was done mostly in children. The most common indications for HCT were multiple sclerosis, systemic sclerosis, and systemic lupus erythematosus. The median age at transplantation was 38 years for autologous HCT and 25 years for allogeneic HCT. The corresponding times from diagnosis to HCT were 35 months and 24 months. Three-year overall survival after autologous HCT was 86% (95% confidence interval [CI], 81%-91%). Median follow-up of survivors was 31 months (range, 1-144 months). The most common causes of death were AID progression, infections, and organ failure. On multivariate analysis, the risk of death was higher in patients at centers that performed fewer than 5 autologous HCTs (relative risk, 3.5; 95% CI, 1.1-11.1; P = .03) and those that performed 5 to 15 autologous HCTs for AID during the study period (relative risk, 4.2; 95% CI, 1.5-11.7; P = .006) compared with patients at centers that performed more than 15 autologous HCTs for AID during the study period. AID is an emerging indication for HCT in the region. Collaboration of hematologists and other disease specialists with an outcomes database is important to promote optimal patient selection, analysis of the impact of prognostic variables and long-term outcomes, and development of clinical trials.

Mesenchymal stem cell therapy and cognition in MS: Preliminary findings from a phase II clinical trial.

BACKGROUND: Mesenchymal stem cell (MSC) therapies are being evaluated in multiple sclerosis (MS) for possible neural repair. To date, the potential benefits on cognition have received little attention. The objective of the current study was to comprehensively evaluate cognition before and after MSC therapy in those with MS as part of a double-blind, phase II clinical trial. METHODS: Twenty-eight individuals with a confirmed diagnosis of MS were randomly assigned into two study arms. Cognition was evaluated using an expanded Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) battery. The battery was administered at Week 0, Week 24, and Week 48 and results were analysed at the group and individual level. RESULTS: No detectable effect of MSC-mediated neural repair was noted in the short-term with respect to cognition, although some cognitive stability or improvement was observed. Decline was noted in some cognitive areas immediately following the procedure at Week 24; though these were temporary with performance returning to baseline levels at Week 48. CONCLUSIONS: While MSC therapy does not lead to improvement in cognition, at least in the short-term, neither does the procedure have lasting deleterious effects. The current findings lend support to the safety and feasibility of MSC therapy as a potentially viable treatment option for individuals with MS.

Reciprocal Th1 and Th17 regulation by mesenchymal stem cells: Implication for multiple sclerosis.

Human mesenchymal stem cells (hMSCs) are being considered for clinical trials of multiple sclerosis (MS). We examined the effects of adult bone marrow-derived hMSCs on responses of primary human Th1, Th17, and Th1/17 double-expressing T-cell subsets, all implicated in MS. As expected, soluble products from hMSCs inhibited Th1 responses; however, Th17 responses were increased. Secretion of interleukin (IL)-10, considered anti-inflammatory, was decreased. Pretreating hMSCs with the proinflammatory cytokine IL-1ß accentuated these effects, and caused decreases in the Th1/17 subset. These findings underscore the importance of further preclinical work and immune-monitoring to define hMSC effects on disease-relevant immune responses under variable conditions.

Altered myocardial glucose utilization and the reverse mismatch pattern on rubidium-82 perfusion/F-18-FDG PET during the sub-acute phase following reperfusion of acute anterior myocardial infarction.

BACKGROUND: Reperfused myocardium post-acute myocardial infarction (AMI) may have altered metabolism with implications for therapy response and function recovery. We explored glucose utilization and the "reverse mismatch" (RMM) pattern (decreased F-18-fluorodeoxyglucose (FDG) uptake relative to perfusion) in patients who underwent mechanical reperfusion with percutaneous coronary intervention (PCI) for AMI. METHODS AND RESULTS: Thirty-one patients with anterior wall AMI treated with acute reperfusion, with left ventricular ejection fraction ≤45%, underwent rest rubidium-82 (Rb-82) and FDG PET 2-10 days post-AMI. Resting echocardiograms were used to assess wall motion abnormalities. Significant RMM occurred in 15 (48%) patients and was associated with a shorter time to PCI of 2.9 hours (2.2, 13.3 hours) compared to patients without significant RMM: 11.4 hours (3.9, 22.4 hours) (P = .03). Within the peri-infarct regions, segments with significant RMM were more likely to have wall motion abnormalities (OR = 2.3 (1.1, 4.7), P = .02) compared to segments without significant RMM. CONCLUSIONS: RMM is a common pattern on perfusion/FDG PET during the sub-acute phase following reperfusion of AMI and is associated with shorter times to PCI. Within the peri-infarct region, RMM occurs frequently and is more often associated with wall motion abnormalities than segments without RMM. Whether this represents a myocardial metabolic shift during the sub-acute phase of recovery warrants further study.

A real-world single-centre analysis of alemtuzumab and cladribine for multiple sclerosis.

BACKGROUND: Highly active MS may warrant higher efficacy treatments for disease control. However, these often confer more risk and have not been compared in head-to-head clinical trials, making relative efficacy and safety difficult to interpret. Alemtuzumab and cladribine are two high-efficacy treatments given as discrete courses separated by one year, followed by a durable response that potentially does not require ongoing treatment. Before the approval of oral cladribine, our centre had been treating patients with a bioequivalent intravenous (IV) regimen since 2010. The objective of this study is to report the safety and efficacy data of alemtuzumab and cladribine in a real-world, single centre setting. METHODS: We retrospectively reviewed all patients treated with alemtuzumab or cladribine at the Ottawa Hospital MS Clinic with 2 or more years of follow-up. Information on baseline demographic variables, previous treatment, and prior disease activity was collected. Outcomes investigated were "no evidence of disease activity" (NEDA) and its constituents: new clinical relapse, new MRI activity, and Expanded Disability Status Scale (EDSS) progression; as well as any adverse events or treatment discontinuation. We performed univariate and multiple logistic regression to determine differences in 2-year NEDA and time-to-event analyses with Cox regression models to determine factors associated with each outcome through the study period. RESULTS: Forty-six patients were treated with alemtuzumab and 65 with cladribine of whom 51 (78%) received the intravenous regimen, followed for a total of 420.1 person-years. The cladribine group was older (p=.0002), with higher baseline EDSS (p=.0015), and more likely secondary progressive (p<.0001). Alemtuzumab had a higher rate of 2-year NEDA than cladribine (OR 4.78, 95%CI: 1.57-14.50, p=.006), but beyond 2 years the difference was not statistically significant (HR 0.50, 95%CI: 0.25-1. 30, p=.061). More prior treatments were associated with lower likelihood of retaining NEDA (HR 1.26, 95%CI: 1.03-1.54, p=.027). Alemtuzumab had more infusion reactions (80% vs. 17%, p<.0001), shingles (22% vs. 2%, p=.005), and secondary autoimmunity (52% vs. 3%, p<.0001) than cladribine, but there was no difference in grade 3 or higher adverse events (21.7% vs. 18.5%, p=1.0). CONCLUSION: In our cohort alemtuzumab and cladribine achieved similar rates of NEDA in long-term follow-up, with overall less adverse events with cladribine. Patient registries would allow more robust comparisons, detection of adverse events, and assessment of a durable response.

Personalized oncology and BRAFK601N melanoma: model development, drug discovery, and clinical correlation.

PURPOSE: Mutations in BRAF are the most prominent activating mutations in melanoma and are increasingly recognized in other cancers. There is currently no accepted treatment regimen for patients with mutant BRAFK601N melanoma, and the study of melanoma driven by BRAF mutations at the 601 locus is lacking due to a paucity of cellular model systems. Therefore, we sought to better understand the treatment and clinical approach to patients with mutant BRAFK601N melanoma and subsequently develop a novel personalized oncology platform for rare or treatment-refractory cancers. METHODS: We developed and characterized the first patient-derived, naturally occurring BRAFK601N melanoma model, described herein as OHRI-MEL-13, and assessed efficacy using the Prestwick Chemical Library and select targeted therapeutics. RESULTS: OHRI-MEL-13 exhibits loss of heterozygosity of BRAF, closely mimics the original tumor's gene expression profile, is tumorigenic in immune-deficient murine models, and is available for public accession through American Type Culture Collection. We present in silico modeling data, which illustrates the therapeutic failure of BRAFV600E-targeted therapies in BRAFK601N mutants. Our platform elucidated a unique role for MEK inhibition with cobimetinib, which resulted in short-term clinical success by reducing the metastatic burden. CONCLUSION: Our model of BRAFK601N-activated melanoma was developed, thoroughly characterized, and made available for public accession. This model served to demonstrate the feasibility of a novel personalized oncology platform that could be optimized at an institutional level for rare variant or treatment-refractory cancers. We also demonstrate the clinical utility of monotherapy MEK inhibition in a case of BRAFK601N melanoma.