From birth to bite: the evolutionary ecology of India's medically most important snake venoms.

BACKGROUND: Snake venoms can exhibit remarkable inter- and intraspecific variation. While diverse ecological and environmental factors are theorised to explain this variation, only a handful of studies have attempted to unravel their precise roles. This knowledge gap not only impedes our understanding of venom evolution but may also have dire consequences on snakebite treatment. To address this shortcoming, we investigated the evolutionary ecology of venoms of Russell's viper (Daboia russelii) and spectacled cobra (Naja naja), India's two clinically most important snakes responsible for an alarming number of human deaths and disabilities. METHODOLOGY: Several individuals (n = 226) of D. russelii and N. naja belonging to multiple clutches (n = 9) and their mothers were maintained in captivity to source ontogenetic stage-specific venoms. Using various in vitro and in vivo assays, we assessed the significance of prey, ontogeny and sex in driving venom composition, function, and potency. RESULTS: Considerable ontogenetic shifts in venom profiles were observed in D. russelii, with the venoms of newborns being many times as potent as juveniles and adults against mammalian (2.3-2.5 ×) and reptilian (2-10 ×) prey. This is the first documentation of the ontogenetic shift in viperine snakes. In stark contrast, N. naja, which shares a biogeographic distribution similar to D. russelii, deployed identical biochemical cocktails across development. Furthermore, the binding kinetics of cobra venom toxins against synthetic target receptors from various prey and predators shed light on the evolutionary arms race. CONCLUSIONS: Our findings, therefore, provide fascinating insights into the roles of ecology and life history traits in shaping snake venoms.

The Royal Armoury: Venomics and antivenomics of king cobra (Ophiophagus hannah) from the Indian Western Ghats.

Despite being famous as 'the king' of the snake world, the king cobra (Ophiophagus hannah) has remained a mysterious species, particularly with respect to its venom ecology. In contrast, venom research has largely focussed on the 'big four' snakes that are greatly responsible for the burden of snakebite in the Indian subcontinent. This study aims to bridge the current void in our understanding of the O. hannah venom by investigating its proteomic, biochemical, pharmacological, and toxinological profiles via interdisciplinary approaches. Considering their physical resemblance, the king cobra is often compared to the spectacled cobra (Naja naja). Comparative venomics of O. hannah and N. naja in this study provided interesting insights into their venom compositions, activities, and potencies. Our findings suggest that the O. hannah venom, despite being relatively less complex than the N. naja venom, is equally potent. Finally, our in vitro and in vivo assays revealed that both Indian polyvalent and Thai Red Cross monovalent antivenoms completely fail to neutralise the O. hannah venom. Our findings provide guidelines for the management of bites from this clinically important yet neglected snake species in India.

Multilevel Comparison of Indian Naja Venoms and Their Cross-Reactivity with Indian Polyvalent Antivenoms.

Snake envenoming is caused by many biological species, rather than a single infectious agent, each with a multiplicity of toxins in their venom. Hence, developing effective treatments is challenging, especially in biodiverse and biogeographically complex countries such as India. The present study represents the first genus-wide proteomics analysis of venom composition across Naja species (N. naja, N. oxiana, and N. kaouthia) found in mainland India. Venom proteomes were consistent between individuals from the same localities in terms of the toxin families present, but not in the relative abundance of those in the venom. There appears to be more compositional variation among N. naja from different locations than among N. kaouthia. Immunoblotting and in vitro neutralization assays indicated cross-reactivity with Indian polyvalent antivenom, in which antibodies raised against N. naja are present. However, we observed ineffective neutralization of PLA2 activities of N. naja venoms from locations distant from the source of immunizing venoms. Antivenom immunoprofiling by antivenomics revealed differential antigenicity of venoms from N. kaouthia and N. oxiana, and poor reactivity towards 3FTxs and PLA2s. Moreover, there was considerable variation between antivenoms from different manufacturers. These data indicate that improvements to antivenom manufacturing in India are highly desirable.

Safety of an investigational formulation of budesonide (budesonide oral suspension) for eosinophilic oesophagitis: an integrated safety analysis of six phase 1-3 clinical trials.

BACKGROUND: Questions remain regarding the safety of swallowed topical corticosteroids in eosinophilic oesophagitis (EoE). AIM: To assess the safety of an investigational formulation of budesonide (budesonide oral suspension; BOS) from six trials. METHODS: Safety data were integrated from six trials (healthy adults: SHP621-101 [phase 1]; patients with EoE: MPI 101-01 and MPI 101-06 [phase 2]; SHP621-301, SHP621-302 and SHP621-303 [phase 3]) for participants who received ≥1 dose of study drug (BOS 2.0 mg twice daily [b.i.d.], BOS any dose [including BOS 2.0 mg b.i.d.] and placebo). Adverse events (AEs), laboratory testing, bone density and adrenal AEs were assessed. Exposure-adjusted incidence rates were calculated for AEs and AEs of special interest (AESIs). RESULTS: Overall, 514 unique participants were included (BOS 2.0 mg b.i.d., n = 292; BOS any dose, n = 448; placebo, n = 168). The BOS 2.0 mg b.i.d., BOS any dose and placebo groups totalled 93.7, 122.4 and 25.0 participant-years of exposure (PY), respectively. Proportions of treatment-emergent AEs (TEAEs) and AESIs (any) reported were higher for BOS than placebo; however, most were mild/moderate in severity. The most commonly reported AESIs (exposure-adjusted incidence rates [per 100 PY]) in the BOS 2.0 mg b.i.d., BOS any dose and placebo groups were infections (133.5, 154.4 and 136.2, respectively) and gastrointestinal AEs (84.3, 80.9 and 92.1, respectively). Adrenal AEs were more frequent with BOS 2.0 mg b.i.d. and BOS any dose than placebo (44.8, 34.3 and 24.0, respectively). TEAEs and AESIs related to study drug or leading to discontinuation were infrequent. CONCLUSIONS: BOS was well-tolerated; most TEAEs with BOS were mild/moderate in severity. GOV NUMBERS: SHP621-101 (no clinical trials registration number), MPI 101-01 (NCT00762073), MPI 101-06 (NCT01642212), SHP621-301 (NCT02605837), SHP621-302 (NCT02736409) and SHP621-303 (NCT03245840).

Revisiting the impact of serial therapeutic phlebotomy in polycythaemia on laboratory and clinical parameters using a fixed interval and fixed volume protocol.

OBJECTIVES: Therapeutic phlebotomy allows for a controlled and gradual decrease in red cell mass leading to improved blood flow and symptomatic relief in polycythaemia. The present study was aimed to determine the impact of serial fixed volume and fixed interval therapeutic phlebotomy protocol on the laboratory and clinical parameters in patients of polycythaemia. MATERIAL AND METHODS: This prospective longitudinal study was conducted over 18 months. The desired haematocrit for polycythemia vera and secondary polycythemia was 45% and 52% respectively. A fixed volume of 350 ml phlebotomy was performed every-three days till the achievement of desired haematocrit. Complete blood count was performed before and after each procedure and iron studies were done at the time of enrolment and after the achievement of desired haematocrit. Post-procedure symptomatic relief was assessed by a 10-point visual analogue scale (VAS). RESULTS: Of the 29 patients enrolled in the study, 3 patients were lost to follow up and data of 26 patients was analyzed. Mean Hb declined from 17.84 ± 1.88 gdL-1 to 14.67 ± 1.14 gdL-1 (p < 0.001) and mean haematocrit decreased from a baseline of 57.11 ± 5.47% to 46.27 ± 3.763% (p < 0.001) upon achievement of desired haematocrit. There was a significant decline in serum iron from the baseline of 132.85 ± 94.136 µg dL-1 to 69.41 ± 58.643 µg dL-1 at desired haematocrit. A significant change in VAS score of almost all clinical parameters was observed. Post phlebotomy hematocrit correlated negatively with the number of procedures (p = 0.015). CONCLUSION: Our protocol yielded rapid and marked improvement in patients of primary and secondary polycythemia with minimal adverse events and significant amelioration of clinical parameters.

Evaluating Antivenom Efficacy against Echis carinatus Venoms-Screening for In Vitro Alternatives.

In India, polyvalent antivenom is the mainstay treatment for snakebite envenoming. Due to batch-to-batch variation in antivenom production, manufacturers have to estimate its efficacy at each stage of IgG purification using the median effective dose which involves 100-120 mice for each batch. There is an urgent need to replace the excessive use of animals in snake antivenom production using in vitro alternatives. We tested the efficacy of a single batch of polyvalent antivenom from VINS bioproducts limited on Echis carinatus venom collected from three different locations-Tamil Nadu (ECVTN), Goa (ECVGO) and Rajasthan (ECVRAJ)-using different in vitro assays. Firstly, size-exclusion chromatography (SEC-HPLC) was used to quantify antivenom-venom complexes to assess the binding efficiency of the antivenom. Secondly, clotting, proteolytic and PLA2 activity assays were performed to quantify the ability of the antivenom to neutralize venom effects. The use of both binding and functional assays allowed us to measure the efficacy of the antivenom, as they represent multiple impacts of snake envenomation. The response from the assays was recorded for different antivenom-venom ratios and the dose-response curves were plotted. Based on the parameters that explained the curves, the efficacy scores (ES) of antivenom were computed. The binding assay revealed that ECVTN had more antivenom-venom complexes formed compared to the other venoms. The capacity of antivenom to neutralize proteolytic and PLA2 effects was lowest against ECVRAJ. The mean efficacy score of antivenom against ECVTN was the greatest, which was expected, as ECVTN is mainly used by antivenom manufacturers. These findings pave a way for the development of in vitro alternatives in antivenom efficacy assessment.

Pharmacokinetics, Safety and Efficacy of Intravenous Vedolizumab in Paediatric Patients with Ulcerative Colitis or Crohn's Disease: Results from the Phase 2 HUBBLE Study.

BACKGROUND AND AIMS: To date, there are no systematic pharmacokinetic [PK] data on vedolizumab in paediatric inflammatory bowel disease [IBD]. We report results from HUBBLE, a dose-ranging, phase 2 trial evaluating the PK, safety and efficacy of intravenous vedolizumab for paediatric IBD. METHODS: Enrolled patients [aged 2-17 years] with moderate to severe ulcerative colitis [UC] or Crohn's disease [CD] and body weight ≥10 kg were randomized by weight to receive low- or high-dose vedolizumab [≥30 kg, 150 or 300 mg; <30 kg, 100 or 200 mg] on Day 1 and Weeks 2, 6 and 14. Week 14 assessments included PK, clinical response and exposure-response relationship. Safety and immunogenicity were assessed. RESULTS: Randomized patients weighing ≥30 kg [UC, n = 25; CD, n = 24] and <30 kg [UC, n = 19; CD, n = 21] had a baseline mean [standard deviation] age of 13.5 [2.5] and 7.6 [3.2] years, respectively. In almost all indication and weight groups, area under the concentration curve and average concentration increased ~2-fold from low to high dose; the trough concentration was higher in each high-dose arm compared with the low-dose arms. At Week 14, clinical response occurred in 40.0-69.2% of patients with UC and 33.3-63.6% with CD in both weight groups. Clinical responders with UC generally had higher trough concentration vs non-responders, while this trend was not observed in CD. Fourteen per cent [12/88] of patients had treatment-related adverse events and 6.8% [6/88] had anti-drug antibodies. CONCLUSIONS: Vedolizumab exposure increased in an approximate dose-proportional manner. No clear dose-response relationship was observed in this limited cohort. No new safety signals were identified.

Evaluation of safety and pharmacokinetics of bismuth-containing quadruple therapy with either vonoprazan or lansoprazole for Helicobacter pylori eradication.

AIMS: Helicobacter pylori (Hp) eradication plays a key role in the treatment and prevention of peptic ulcer diseases. Increasing clarithromycin resistance in Hp necessitates more effective treatments for eradication, such as bismuth-containing quadruple therapy. We aimed to compare the safety and pharmacokinetics (PK) of bismuth between vonoprazan- and lansoprazole-containing quadruple therapy in Hp-positive subjects. METHODS: In this randomised, double-blind, parallel-group study, Hp-positive subjects were randomised to receive vonoprazan- or lansoprazole-containing quadruple therapy. Each subject received vonoprazan 20 mg or lansoprazole 30 mg combined with bismuth 220 mg, clarithromycin 500 mg and amoxicillin 1000 mg twice daily for 14 days. Blood sampling and urine collection for bismuth PK were conducted predose and up to 12 hours postdose at steady-state. The PK parameters of bismuth were derived using a noncompartmental method and compared between treatments. An exploratory breath test for Hp was conducted at screening and at the follow-up visit on day 42. Safety was assessed by adverse event monitoring, physical examinations, vital signs, 12-lead electrocardiograms and clinical laboratory tests. RESULTS: A total of 30 subjects were randomised and 26 subjects completed the study (12 in the vonoprazan group and 14 in the lansoprazole group). The systemic exposure of bismuth in the 2 treatments was comparable (~5% difference). All subjects turned negative for Hp at the follow-up visit. No significant difference in safety profiles was noted between the 2 treatments. CONCLUSION: The systemic exposure of bismuth was similar between vonoprazan- and lansoprazole-containing quadruple therapy. Vonoprazan-containing quadruple therapy was safe and well tolerated.

Efficacy and Safety of Subcutaneous Vedolizumab in Patients With Moderately to Severely Active Crohn's Disease: Results From the VISIBLE 2 Randomised Trial.

BACKGROUND AND AIMS: To report results from VISIBLE 2, a randomised, double-blind, placebo-controlled, phase 3 trial evaluating a new subcutaneous [SC] vedolizumab formulation as maintenance treatment in adults with moderately to severely active Crohn's disease [CD]. METHODS: Following open-label vedolizumab 300 mg intravenous induction therapy at Weeks 0 and 2, Week 6 clinical responders (≥70-point decrease in CD Activity Index [CDAI] score from baseline) were randomised 2:1 to receive double-blind maintenance vedolizumab 108 mg SC or placebo every 2 weeks until Week 50. Assessments at Week 52 included clinical remission [primary endpoint; CDAI ≤150], enhanced clinical response [≥100-point decrease in CDAI from baseline], corticosteroid-free clinical remission among patients using a corticosteroid at baseline, clinical remission in anti-tumour necrosis factor [anti-TNF]-naïve patients, and safety. RESULTS: Following vedolizumab intravenous induction, 275 patients were randomised to vedolizumab SC and 135 to placebo maintenance. At Week 52, 48.0% of patients receiving vedolizumab SC versus 34.3% receiving placebo were in clinical remission [p = 0.008]. Enhanced clinical response at Week 52 was achieved by 52.0% versus 44.8% of patients receiving vedolizumab SC versus placebo, respectively [p = 0.167]. At Week 52, 45.3% and 18.2% of patients receiving vedolizumab SC and placebo, respectively, were in corticosteroid-free clinical remission, and 48.6% of anti-TNF-naïve patients receiving vedolizumab SC and 42.9% receiving placebo were in clinical remission. Injection site reaction was the only new safety finding observed for vedolizumab SC [2.9%]. CONCLUSIONS: Vedolizumab SC is an effective and safe maintenance therapy in patients with CD who responded to two infusions of vedolizumab intravenous induction therapy.

Immunorecognition capacity of Indian polyvalent antivenom against venom toxins from two populations of Echis carinatus.

Clinicians report low efficacy of Indian polyvalent antivenom (PAV), with >20 vials required for treatment of a snakebite envenoming. We hypothesize that the antivenom efficacy could be reduced due to insufficient antibodies against some venom toxins. To test this, we used third-generation antivenomics to reveal bound and unbound venom toxins of Echis carinatus venom from Goa (ECVGO) and Tamil Nadu (ECVTN). We used 60, 120, 180, 240, 300, and 360 µg of venom and passed through mini-columns containing ~5 mg Antivenom bound to CNBr beads. The non-retained (unbound) and retained (bound) toxins were identified using reverse-phase HPLC and tandem mass spectrometry. Low molecular weight toxins - Short disintegrins (5.3 kDa) and DIS domain of P-II SVMP from ECVGO and ECVTN showed poor binding with antivenom. The immunorecognition sites of antivenom saturated at the lower antivenom-venom ratio for ECVGO than for ECVTN. The immunoretained capacity of antivenom against ECVTN was 140.6 µg and ECVGO was 125.1 µg. The amount of immunoretained toxins quantified can further be used to estimate the efficacy of antivenom by correlating it with in-vivo studies. The unbound toxins identified from this study could be targeted to improve the effectiveness of antivenom.

Comparative proteomics of geographically distinct saw-scaled viper (Echis carinatus) venoms from India.

Snakebite is a socio-economic problem in tropical countries and it is exacerbated by geographical venom variation of snakes. We investigated on venom variation in geographically distinct populations of Echis carinatus from three ecologically distinct regions: Tamil Nadu (ECVTN), Goa (ECVGO), and Rajasthan (ECVRAJ). Venom was fractionated by RP-HPLC, combined with SDS-PAGE, and subjected to tandem mass spectrometry. Toxins were identified, and their relative abundance was estimated. Using NCBI database of Echis genus, we queried the MS/MS spectra, and found 69, 38 and 38 proteins in ECVTN, ECVGO and ECVRAJ respectively, belonging to 8-10 different toxin families. The differences in the venom profiles were due to change in the relative composition of the toxin families. Snake venom metalloproteinase (svMP), Snaclecs and Phospholipase A2 (PLA2) were the major venom components in all the venoms. Heteromeric Disintegrins were found in ECVTN and absent in other venoms. ECVRAJ showed higher abundance of low-molecular-weight (>30 kDa) proteins than ECVTN and ECVGO. Cysteine-rich venom protein (CRISP) was highest in ECVRAJ (7.34%), followed by ECVTN (0.01%) and in ECVGO, it was not detected. These findings highlight the need for evaluating the efficacy of the polyvalent anti-venom to neutralize the toxins from geographically distinct venoms of E. carinatus.

Efficacy and Safety of Vedolizumab Subcutaneous Formulation in a Randomized Trial of Patients With Ulcerative Colitis.

BACKGROUND & AIMS: Maintenance treatment with vedolizumab, a monoclonal antibody that inhibits the gut-selective α4ß7 integrin, is administered intravenously. Some patients might prefer a subcutaneous formulation of vedolizumab for maintenance treatment. Subcutaneous vedolizumab was investigated as maintenance treatment in patients with moderately to severely active ulcerative colitis. METHODS: We performed a phase 3, double-blind, double-dummy trial at 141 sites in 29 countries from December 18, 2015 through August 21, 2018. Patients with moderately to severely active ulcerative colitis received open-label treatment with intravenous vedolizumab 300 mg at weeks 0 and 2. At week 6, patients with clinical response were randomly assigned maintenance treatment with subcutaneous vedolizumab 108 mg every 2 weeks, intravenous vedolizumab 300 mg every 8 weeks, or placebo. The primary end point was clinical remission at week 52, which was defined as a total Mayo score of ≤2 and no subscore >1. RESULTS: Among the randomized 216 patients, clinical remission at week 52 was achieved by 46.2%, 42.6%, and 14.3% of patients in the subcutaneous vedolizumab, intravenous vedolizumab, and placebo groups, respectively (subcutaneous vedolizumab vs placebo: Δ32.3%; 95% confidence interval, 19.7%-45.0%; P < .001). The subcutaneous vedolizumab group also had greater endoscopic improvement and durable clinical response at week 52 compared with placebo (both P < .001). The incidence of injection-site reactions was more frequent in patients given subcutaneous vedolizumab (10.4%) than intravenous vedolizumab (1.9%) or placebo (0%); these were not treatment limiting, most were mild, and none resulted in discontinuation. Subcutaneous and intravenous vedolizumab safety profiles were otherwise similar. CONCLUSIONS: Subcutaneous vedolizumab is effective as maintenance therapy in patients with moderately to severely active ulcerative colitis who had a clinical response to intravenous vedolizumab induction therapy. It has a favorable safety and tolerability profile. ClinicalTrials.gov ID: NCT02611830; EudraCT 2015-000480-14.