Publications

2013

Djulbegovic, Benjamin, Ambuj Kumar, Branko Miladinovic, Tea Reljic, Sanja Galeb, Asmita Mhaskar, Rahul Mhaskar, et al. (2013) 2013. “Treatment Success in Cancer: Industry Compared to Publicly Sponsored Randomized Controlled Trials.”. PloS One 8 (3): e58711. https://doi.org/10.1371/journal.pone.0058711.

OBJECTIVE: To assess if commercially sponsored trials are associated with higher success rates than publicly-sponsored trials.

STUDY DESIGN AND SETTINGS: We undertook a systematic review of all consecutive, published and unpublished phase III cancer randomized controlled trials (RCTs) conducted by GlaxoSmithKline (GSK) and the NCIC Clinical Trials Group (CTG). We included all phase III cancer RCTs assessing treatment superiority from 1980 to 2010. Three metrics were assessed to determine treatment successes: (1) the proportion of statistically significant trials favouring the experimental treatment, (2) the proportion of the trials in which new treatments were considered superior according to the investigators, and (3) quantitative synthesis of data for primary outcomes as defined in each trial.

RESULTS: GSK conducted 40 cancer RCTs accruing 19,889 patients and CTG conducted 77 trials enrolling 33,260 patients. 42% (99%CI 24 to 60) of the results were statistically significant favouring experimental treatments in GSK compared to 25% (99%CI 13 to 37) in the CTG cohort (RR = 1.68; p = 0.04). Investigators concluded that new treatments were superior to standard treatments in 80% of GSK compared to 44% of CTG trials (RR = 1.81; p<0.001). Meta-analysis of the primary outcome indicated larger effects in GSK trials (odds ratio = 0.61 [99%CI 0.47-0.78] compared to 0.86 [0.74-1.00]; p = 0.003). However, testing for the effect of treatment over time indicated that treatment success has become comparable in the last decade.

CONCLUSIONS: While overall industry sponsorship is associated with higher success rates than publicly-sponsored trials, the difference seems to have disappeared over time.

Kharfan-Dabaja, Mohamed A, Mehdi Hamadani, Tea Reljic, Taiga Nishihori, William Bensinger, Benjamin Djulbegovic, and Ambuj Kumar. (2013) 2013. “Comparative Efficacy of Tandem Autologous versus Autologous Followed by Allogeneic Hematopoietic Cell Transplantation in Patients With Newly Diagnosed Multiple Myeloma: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.”. Journal of Hematology & Oncology 6: 2. https://doi.org/10.1186/1756-8722-6-2.

BACKGROUND: Despite advances in understanding of clinical, genetic, and molecular aspects of multiple myeloma (MM) and availability of more effective therapies, MM remains incurable. The autologous-allogeneic (auto-allo) hematopoietic cell transplantation (HCT) strategy is based on combining cytoreduction from high-dose (chemo- or chemoradio)-therapy with adoptive immunotherapy. However, conflicting results have been reported when an auto-allo HCT approach is compared to tandem autologous (auto-auto) HCT. A previously published meta-analysis has been reported; however, it suffers from serious methodological flaws.

METHODS: A systematic search identified 152 publications, of which five studies (enrolling 1538 patients) met inclusion criteria. All studies eligible for inclusion utilized biologic randomization.

RESULTS: Assessing response rates by achievement of at least a very good partial response did not differ among the treatment arms [risk ratio (RR) (95% CI) = 0.97 (0.87-1.09), p = 0.66]; but complete remission was higher in the auto-allo HCT arm [RR = 1.65 (1.25-2.19), p = 0.0005]. Event-free survival did not differ between auto-allo HCT group versus auto-auto HCT group using per-protocol analysis [hazard ratio (HR) = 0.78 (0.58-1.05)), p = 0.11] or using intention-to-treat analysis [HR = 0.83 (0.60-1.15), p = 0.26]. Overall survival (OS) did not differ among these treatment arms whether analyzed on per-protocol [HR = 0.88 (0.33-2.35), p = 0.79], or by intention-to-treat [HR = 0.80 (0.48-1.32), p = 0.39] analysis. Non-relapse mortality (NRM) was significantly worse with auto-allo HCT [RR (95%CI) = 3.55 (2.17-5.80), p < 0.00001].

CONCLUSION: Despite higher complete remission rates, there is no improvement in OS with auto-allo HCT; but this approach results in higher NRM in patients with newly diagnosed MM. At present, totality of evidence suggests that an auto-allo HCT approach for patients with newly diagnosed myeloma should not be offered outside the setting of a clinical trial.

Kharfan-Dabaja, Mohamed A, Mehdi Hamadani, Tea Reljic, Rachel Pyngolil, Rami S Komrokji, Jeffrey E Lancet, Hugo F Fernandez, Benjamin Djulbegovic, and Ambuj Kumar. (2013) 2013. “Gemtuzumab Ozogamicin for Treatment of Newly Diagnosed Acute Myeloid Leukaemia: A Systematic Review and Meta-Analysis.”. British Journal of Haematology 163 (3): 315-25. https://doi.org/10.1111/bjh.12528.

Evidence regarding the efficacy of gemtuzumab ozogamicin (GO) addition to standard induction chemotherapy in newly diagnosed acute myeloid leukaemia (AML) is conflicting. This systematic review aimed to identify and summarize all evidence regarding the benefits and harms of adding GO to conventional chemotherapy for induction treatment of AML. A comprehensive literature search of two databases (PUBMED and Cochrane) from inception up to November 22, 2012, and 4 years of proceedings from four major haematology/oncology conferences was undertaken. Endpoints included benefits (complete remission, relapse-free, event-free, and overall survival), and harms (early mortality and incidence of hepatic veno-occlusive disease/sinusoidal obstructive syndrome). Seven trials (3942 patients) met all inclusion criteria. Addition of GO showed improved relapse-free [Hazard Ratio (HR) = 0·84 (95% confidence interval (CI) 0·71-0·99)] and event-free survival [HR = 0·59 (95%CI 0·48-0·74)] but not overall survival [HR = 0·95 (95%CI 0·83-1·08)]. Addition of GO resulted in higher rate of early mortality [Risk Ratio = 1·60 (95%CI 1·07-2·39)]. Improved overall survival was observed in studies using a lower cumulative GO dose (<6 mg/m(2) ) [HR = 0·89 (95%CI 0·81-0·99)]. Addition of GO to conventional chemotherapy as induction therapy may improve relapse-free and event-free survival, but does not impact overall survival and significantly increases early mortality in AML.

El-Jurdi, Najla, Tea Reljic, Ambuj Kumar, Joseph Pidala, Ali Bazarbachi, Benjamin Djulbegovic, and Mohamed A Kharfan-Dabaja. (2013) 2013. “Efficacy of Adoptive Immunotherapy With Donor Lymphocyte Infusion in Relapsed Lymphoid Malignancies.”. Immunotherapy 5 (5): 457-66. https://doi.org/10.2217/imt.13.31.

AIMS: There is a perceived benefit associated with the administration of donor lymphocyte infusion (DLI) in patients with lymphoid malignancies relapsing after allogeneic hematopoietic cell transplantation. However, it is unclear if and how this benefit varies according to specific diseases. Because administration of DLI is not universally effective and could be associated with significant toxicities resulting in morbidity and mortality, it is imperative to identify cases where benefits outweigh harms of the procedure.

MATERIALS & METHODS: We conducted a systematic review of the published literature and extracted and pooled data independently for each disease cohort: acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), multiple myeloma (MM), non-Hodgkin's lymphoma (NHL) and Hodgkin's lymphoma (HL).

RESULTS: In summary, 39 studies met inclusion criteria. The pooled proportion (95% CI) for complete response was 27% (16-40) in ALL, 55% (15-92) in CLL, 26% (19-33) in MM, 52% (33-71) in NHL and 37% (20-56) in HL.

CONCLUSION: Complete response rates appear higher when DLI is used for relapsed CLL and lymphomas (NHL and HL), and less pronounced in ALL or MM. Absence of data pertaining to disease-specific prognostic determinants, such as adverse genetic or molecular abnormalities, or quantitative disease burden when applicable, limit our ability to identify cases in whom benefits from DLI outweigh risks associated with the procedure within a particular disease.

2012

Gulati, Gavish, Krutika Satish Gaonkar, Balu Kamraj, Ambuj Kumar, and Rituraj Purohit. (2012) 2012. “Structure Based Energy Calculation to Determine the Regulation of G Protein Signalling by RGS and RGS-G Protein Interaction Specificity.”. Interdisciplinary Sciences, Computational Life Sciences 4 (3): 173-82. https://doi.org/10.1007/s12539-012-0130-0.

The RGS proteins act as GTPase activating proteins and therefore regulate the lifespan of the active G alpha-GTP by accelerating the GTP hydrolysis. Modulatory residues in the RGS protein are present at the periphery of the RGS domain-G protein interface which is essential to fine-tune the G protein recognition and interaction. The docking energies of the mutant complex and the native complex were compared to see the effects of the mutations in the Modulatory regions. Mutations of Modulatory residues in high-activity RGS proteins lead to loss of function, whereas multiple mutations in the low-activity RGS proteins in critical Modulatory positions lead to complete gain of function. In the RGS proteins the Significant and Conserved core residues with peripheral Modulatory residues selectively optimize G protein recognition and inactivation. The flexibility of the structures of the mutant complexes were seen to be higher and the accessible surface area for the complexes increased after the mutations in the Modulatory residues. Through this approach we analyzed the interaction specificity among the RGS and the G alpha protein, the approach can also be applied to other protein families to find the residues which along with the core binding domain, fine tune the protein recognition and are crucial in the loss or gain of function.

Kumar, Ambuj, and Rituraj Purohit. (2012) 2012. “Computational Screening and Molecular Dynamics Simulation of Disease Associated NsSNPs in CENP-E.”. Mutation Research 738-739: 28-37. https://doi.org/10.1016/j.mrfmmm.2012.08.005.

Aneuploidy and chromosomal instability (CIN) are hallmarks of most solid tumors. Mutations in centroemere proteins have been observed in promoting aneuploidy and tumorigenesis. Recent studies reported that Centromere-associated protein-E (CENP-E) is involved in inducing cancers. In this study we investigated the pathogenic effect of 132 nsSNPs reported in CENP-E using computational platform. Y63H point mutation found to be associated with cancer using SIFT, Polyphen, PhD-SNP, MutPred, CanPredict and Dr. Cancer tools. Further we investigated the binding affinity of ATP molecule to the CENP-E motor domain. Complementarity scores obtained from docking studies showed significant loss in ATP binding affinity of mutant structure. Molecular dynamics simulation was carried to examine the structural consequences of Y63H mutation. Root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration (R(g)), solvent accessibility surface area (SASA), energy value, hydrogen bond (NH Bond), eigenvector projection, trace of covariance matrix and atom density analysis results showed notable loss in stability for mutant structure. Y63H mutation was also shown to disrupt the native conformation of ATP binding region in CENP-E motor domain. Docking studies for remaining 18 mutations at 63rd residue position as well as other two computationally predicted disease associated mutations S22L and P69S were also carried to investigate their affect on ATP binding affinity of CENP-E motor domain. Our study provided a promising computational methodology to study the tumorigenic consequences of nsSNPs that have not been characterized and clear clue to the wet lab scientist.

Kumar, Ambuj, and Rituraj Purohit. (2012) 2012. “Computational Centrosomics: An Approach to Understand the Dynamic Behaviour of Centrosome.”. Gene 511 (1): 125-6. https://doi.org/10.1016/j.gene.2012.09.040.

Centrosomes are the key regulating element of cell cycle progression. Aberrations in their functional mechanism leads to several cancer related disorders. Although genomic studies in the field of centrosome have been extensively carried out, with the lack of structural conformation, the proteomic analysis of pathological genetic mutation is still a challenging task. Several computational algorithms and high range force fields are used to design the 3D structure conformation of proteins, which has now become the leading platform for in-silico drug discovery approaches. Application of these highly efficient platforms in centrosomics studies will be a novel approach to develop an efficient drug therapy for the treatment of their dysfunction disorders.

Miladinovic, Branko, Ambuj Kumar, Rahul Mhaskar, Sehwan Kim, Ronald Schonwetter, and Benjamin Djulbegovic. (2012) 2012. “A Flexible Alternative to the Cox Proportional Hazards Model for Assessing the Prognostic Accuracy of Hospice Patient Survival.”. PloS One 7 (10): e47804. https://doi.org/10.1371/journal.pone.0047804.

Prognostic models are often used to estimate the length of patient survival. The Cox proportional hazards model has traditionally been applied to assess the accuracy of prognostic models. However, it may be suboptimal due to the inflexibility to model the baseline survival function and when the proportional hazards assumption is violated. The aim of this study was to use internal validation to compare the predictive power of a flexible Royston-Parmar family of survival functions with the Cox proportional hazards model. We applied the Palliative Performance Scale on a dataset of 590 hospice patients at the time of hospice admission. The retrospective data were obtained from the Lifepath Hospice and Palliative Care center in Hillsborough County, Florida, USA. The criteria used to evaluate and compare the models' predictive performance were the explained variation statistic R(2), scaled Brier score, and the discrimination slope. The explained variation statistic demonstrated that overall the Royston-Parmar family of survival functions provided a better fit (R(2) =0.298; 95% CI: 0.236-0.358) than the Cox model (R(2) =0.156; 95% CI: 0.111-0.203). The scaled Brier scores and discrimination slopes were consistently higher under the Royston-Parmar model. Researchers involved in prognosticating patient survival are encouraged to consider the Royston-Parmar model as an alternative to Cox.

Kumar, Ambuj, Vidya Rajendran, Rao Sethumadhavan, and Rituraj Purohit. (2012) 2012. “In Silico Prediction of a Disease-Associated STIL Mutant and Its Affect on the Recruitment of Centromere Protein J (CENPJ).”. FEBS Open Bio 2: 285-93. https://doi.org/10.1016/j.fob.2012.09.003.

Human STIL (SCL/TAL1 interrupting locus) protein maintains centriole stability and spindle pole localisation. It helps in recruitment of CENPJ (Centromere protein J)/CPAP (centrosomal P4.1-associated protein) and other centrosomal proteins. Mutations in STIL protein are reported in several disorders, especially in deregulation of cell cycle cascades. In this work, we examined the non-synonymous single nucleotide polymorphisms (nsSNPs) reported in STIL protein for their disease association. Different SNP prediction tools were used to predict disease-associated nsSNPs. Our evaluation technique predicted rs147744459 (R242C) as a highly deleterious disease-associated nsSNP and its interaction behaviour with CENPJ protein. Molecular modelling, docking and molecular dynamics simulation were conducted to examine the structural consequences of the predicted disease-associated mutation. By molecular dynamic simulation we observed structural consequences of R242C mutation which affects interaction of STIL and CENPJ functional domains. The result obtained in this study will provide a biophysical insight into future investigations of pathological nsSNPs using a computational platform.

Wells, Kristen J, Charles Preuss, Yashwant Pathak, J K Kosambiya, and Ambuj Kumar. (2012) 2012. “ENGAGING THE COMMUNITY IN HEALTH RESEARCH IN INDIA.”. Technology and Innovation 13 (4). https://doi.org/10.3727/194982412X13292321140886.

Community-engaged research approaches involve members of the community in various aspects of a research endeavor to improve the health of populations. Engaging the community in research is important in the development, dissemination, and evaluation of new interventions, technologies, and other medical advancements to improve population health globally. A review of published community-engaged research studies conducted in India was performed. Fifteen published studies were identified and reviewed to evaluate the state of community-engaged research in India. The review indicated that community-engaged research in India is limited. Most published community-engaged research focused on health promotion, especially in the prevention or management of HIV/AIDS and other STIs. Community members were involved in a variety of aspects of the research, but there was not one published article indicating that community members had defined the disease of focus. Community-engaged research often led to valuable insights into the views, experiences, and behaviors of community members and also led to increased community participation in health initiatives. It is anticipated that future community-engaged research will lead to improvements in global health through increased empowerment of communities and a better ability to implement new and innovative medical advances, technologies, and interventions.