Xarelto Study Red Flags Ignored: Why were medical research professionals ignored when red flags were raised over the viability of the Xarelto Rocket AF and Einstein DVT study results? Now the clinical trials for both are considered flawed, and the two most recent studies, the “Commander HF” and “Mariner,” failed to produce clear evidence that Xarelto is able to reduce the rate of blood clots in certain high-risk patients or after an acute decline in their condition.
By Mark A. York (October 23, 2018)
(MASS TORT NEXUS MEDIA) Xarelto (rivaroxaban) is a prescription blood thinner created by Bayer and Janssen Pharmaceuticals that was approved by the Food and Drug Administration (FDA) in 2011. This drug is an anticoagulant for preventing blood from clotting, often used to treat deep vein thrombosis, atrial fibrillation, pulmonary embolism, stroke, and other conditions.
More than one study has shown Xarelto can cause a higher rate of internal bleeding, than other anticoagulant drugs and until very recently, there was no available “antidote” for stopping internal bleeding in patients taking Xarelto. With warfarin, vitamin K has been shown to stop bleeding but there is no vitamin K “parallel” for people taking Xarelto. For Xarelto, it can take 24 hours for a dose to get out of the body. That means that if internal bleeding starts, the patient may simply have to wait it out and hope it stops on its own.
What The Medical Studies Say About Xarelto?
The FDA has received thousands of adverse event reports regarding Xarelto and medical studies have examined the safety of this drug:
- New England Journal of Medicine (2011): Published the ROCKET-AF study, which compared Xarelto to Warfarin in patients suffering from atrial fibrillation. This was the biggest clinical trial of this medication and it compared the effects of Xarelto to the effects of a similar drug known as Warfarin in over 14,000 patients. The study concluded that “there was not significant between-group difference in the risk of major bleeding.”
- Archives of Internal Medicine (2012): The study discussed the risk of uncontrollable bleeding outweighing the benefits for several different blood thinners including Xarelto. The researchers in this study found that there was a tripled risk of bleeding among the patients, who were given the drug, and no improvement in overall survival rates.
- Institute for Safe Medication Practices (2012): Issued a report based on FDA data from the first quarter of 2012. During this period, the FDA received 356 adverse event reports of Xarelto side effects including “serious, disabling, or fatal injury.” Additionally, 158 reports indicated blood clots were the serious side effect.
- New England Journal of Medicine (2013): Published the results of the MAGELLAN study, which found that Xarelto may carry an increased risk of bleeding.
- Medscape (2013): Xarelto is associated with a higher risk of bleeding in certain patients. It caused a nearly 3-fold increase of the risk of bleeding in “acutely ill patients” and 4-fold increased risk of major bleeding in patients that had “Acute Coronary Syndrome” (ACS).
Drug Makers Failed To Disclose Faulty Device In Xarelto Trials
Rivaroxaban and the ROCKET AF trial issue chronicles: A closer look at benefit risk profile of the drug.
- BMJ2016; 354 doi: https://doi.org/10.1136/bmj.i5131 (Published 28 September 2016)Cite this as: BMJ 2016;354:i5131
- Study Analysis: There has been a lot of hue and cry over the recent question raised about the ROCKET AF trial for rivaroxaban which was the only trial used by the company for drug approval from USFDA. This is indeed a very important concern as it directly impacts the well-being of the patients who are at the receiving end of this very highly prescribed anticoagulant drug in 2014. The main concern with this whole confusion surrounding the ROCKET AF trial is that the device used for measuring the INR in trial arm of warfarin patient was faulty and gave lower INR values than it should have, leading to over dosing of warfarin and thereby increasing bleeding problems with the same, compared to the trial arm of rivaroxaban. However, there has been a reanalysis done by the ROCKET AF researchers, which again reinforced the prior result database of the trial and which was accepted by FDA as well. In the reanalysis, the US FDA clearly mentioned that the effect of the faulty device results in causing bleeding episodes, both minor and major, was minimal.
- However, following this reanalysis, not everyone who raised the question in the first place was convinced and there was a demand that the data of the complete ROCKET AF trial should be made public for everyone to assess and understand the risks. But since the trial was done and results released before the principles on responsible clinical trial data sharing came into effect, the parent pharmaceutical company for rivaroxaban refused to share the patient level details, citing concerns on privacy and transparency policy .
- In spite of everything said and written for and against this issue, a simple question arises, regarding the amount of belief, honesty and hard work that goes without questioning when you bring a new chemical entity to the research stage, get it approved and then bring it to market. For this to happen, there have to be maintained a very fine balance between pharmaceutical companies, drug regulatory authorities and marketing people. In this case, after initial suspicions, the drug regulatory authorities have cleared and supported the approval of rivaroxaban after reanalysis and that should have a say, in case we want to continue trust with this process of drug entry into the market.
- Rivaroxaban has shown its efficacy and safety both in patients who required adequate anticoagulation e.g. those who had atrial fibrillation and underwent cardioversion. There are few other trials where rivaroxaban has performed better or equally good than warfarin in terms of both efficacy and safety . These results lead us to believe that all was not wrong with the ROCKET AF trial results. All these, combined with personal experiences of those physicians who had been using the drug rivaroxaban for the last couple of years with a hugely favorable result clearly imply that the drug rivaroxaban is holding its side strongly in the midst of all the controversies surrounding its approval and efficacy and it is here to stay. Adding a last word to all this discussion is that rivaroxaban will always hold an upper hand compared to warfarin when prescribed because of its very favorable and easy to use once daily dosing. We cannot discard all the positive reports and positive experiences associated with this drug, based on real time data, only because of the question raised by some, and considering the fact that the question had been satisficatorily answered with a re analysis with no change in the result.
What Did Or Didn’t The FDA Do About Xarelto?
- In July, 2011, the U.S Food and Drug Administration (FDA) initially approved the medicine for sale on the market for a limited group of people. This included people who had knee or hip replacement surgery because they were considered to be at a higher risk of blood clotting. Read the FDA News Release here.
- In November, 2011, Xarelto was approved for a larger group of people, including people with an abnormal heart rhythm, and was used to prevent stroke. Read further.
- In June, 2012, an FDA advisory panel voted against approving this medicine for the treatment of acute coronary syndrome.
- In November, 2012, Xarelto was later approved for general treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE) after a fast track regulatory review by the FDA. Read more.
- October 22, 2014, the FDA issued a recall for approximately 13,500 bottles of Xarelto after receiving a customer complaint about contamination in a sales sample.
- January 12, 2015 – An antidote may have been discovered by Portola Pharmaceuticals for Xarelto. A late-stage clinical trial of the intravenous medication, andexanet alfa, met its goal of “immediately and significantly” reversing Xarelto.
The approval history for Xarelto was actually pretty controversial. FDA reviewers originally said that they recommended against approval, then there was an FDA advisory committee (independent group of key opinion leaders) and they voted in favor, so the FDA approved the drug. Their concern was with how the Phase III trials were run and whether Xarelto had really proved its efficacy. The tests compared patients on warfarin to patients on Xarelto, but the patients on the warfarin run had poor TTR. That means the patients weren’t well controlled on warfarin to begin with, which skews the data in favor of Xarelto.
During the approval process, Xarelto actually wanted a superiority label, which would say that the drug was better than warfarin and other blood thinners. Because of the concerns with the Phase III data, the FDA only gave them a non-inferior label, which says they’re essentially the same in terms of effectiveness.
The INRatio device was the subject of two FDA warning letters about inaccurate readings just as the trial was starting in 2005 and 2006. In 2014, the device was recalled. The use of the INRatio device may have skewed the results with inaccurate readings, making Xarelto look better in comparison with warfarin.
In a 2017 annual report issued by the Institute for Safe Medication Practices (ISMP), it was stated that oral anticoagulant drugs, including Xarelto (rivaroxaban), showed “unacceptably high risks,” according to two government data sources, the FAERS adverse events reports for 2016 and a new systematic study by the Centers for Disease Control and Prevention (CDC).
Overall, the CDC found in its systematic study that the FDA’s FAERS voluntary reporting underestimates anticoagulant drug-related injuries. The CDC discovered that approximately 228,600 emergency department visits occur each year due to the use of blood thinner drugs, including Xarelto, which is 10 times more than the FAERS total number of voluntary reports.
Xarelto Clinical Trial Red Flags
Controversy Surrounding ROCKET-AF: A Call for Transparency, But Should We Be Changing Practice?
Arrhythm Electrophysiol Rev. 2016 May; 5(1): 12–13.
Prior to the emergence of novel oral anticoagulants (NOACS), nearly all patients were prescribed vitamin K antagonists for thromboembolic prophylaxis in non-valvular atrial fibrillation (AF). Rivaroxaban (Xarelto, Bayer/Johnson & Johnson), an oral factor Xa inhibitor, is now one of the most frequently prescribed NOACs used for this indication.1,2
ROCKET-AF (Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation), published in the New England Journal of Medicine in 2011, demonstrated the non-inferiority of rivaroxaban compared with warfarin for the primary prevention of stroke or systemic embolism in patients with AF. This double-blinded randomised trial, which included 14,264 patients across 45 countries, also showed no significant difference in the risk of major bleeding between these two groups.3
Rivaroxaban use in AF has become widespread since the publication of this trial and US Food and Drug Administration (FDA) approval. Two additional Factor Xa inhibitors, apixaban and edoxaban, have also been evaluated in similar randomised trials and have demonstrated non-inferiority to warfarin for stroke or systemic embolism prophylaxis in patients with non-valvular AF with no significant difference in major bleeding.4,5
In recent months, the results of ROCKET-AF have come into question after the FDA issued a recall notice for the device used to obtain International Normalised Ratio (INR) measurements in the warfarin control group. The FDA found that lower INR values were seen with the ‘point-of-care’ INRatio Monitor System (Alere) compared with a plasma-based laboratory in patients with certain medical conditions.2 These conditions included abnormal haemoglobin levels, abnormal bleeding and abnormal fibrinogen levels.6Since the FDA recall of this device, there has been widespread concern that falsely low INR readings in ROCKET-AF may have led to warfarin overdosing. Inappropriately high warfarin dosing could have increased bleeding rates in the control group and therefore made the rivaroxaban arm appear falsely favourable.7 This point-of-care device recall also highlighted a lack of transparency of the specifics of devices used in large clinical trials.
In response, the authors from ROCKET-AF released a correspondence in February 2016, citing the FDA recall. They also provided a post hoc analysis of patients who may have been affected by the recall. They found that major bleeding was greater in patients with conditions affected by the recall, but, reassuringly, the bleeding risk was greater in those who were on rivaroxaban and not warfarin.6
Despite this post hoc analysis, concern has arisen regarding the generalisability of ROCKET-AF given the faulty point-of-care INR readings. There has been a call for complete transparency of the data from this trial and a better explanation of the mechanism of the incorrect INR measurements.7
Once published, the data supporting an FDA-approved treatment should be available for independent analysis. One issue is that rivaroxaban was approved in the US prior to 1 January 2014, before a new transparency policy on clinical trial data sharing was approved by the European Federation of Pharmaceutical Industries and Associations (EFPIA) and the Pharmaceutical Research and Manufacturers of America (PhRMA).2 Drug companies are refusing to share any data on pharmaceuticals approved before 2014.
A device malfunction in a large clinical trial also should raise concern, especially when that trial has altered clinical practice for millions of patients. On review of Patel et al’s correspondence regarding the point-of-care malfunction, there is inadequate explanation of the mechanism of these faulty readings. Why are they only seen only in patients with abnormal haemoglobin and fibrinogen levels? How inaccurate could the readings be – within 0.1 or 1.0 of a gold standard value? Most alarming is the revelation that the manufacturer had evidence of faulty readings in similar models dating back to 2002.2
Despite legitimate concerns regarding the absence of data transparency and the faulty point-of-care device, rivaroxaban need not be removed from clinical practice for AF patients. In ROCKET-AF, the drug demonstrated non-inferiority to warfarin in preventing thromboembolic events. In addition, data has shown that patients potentially affected by the faulty point-of-care device actually bled more on rivaroxaban than warfarin.6 Therefore, the original risk–benefit ratio presented in ROCKET-AF remains true.
There are other, albeit smaller, randomised trials with shorter follow-up times that compare rivaroxaban and warfarin for thromboembolic prophylaxis.8,9 For example, Cappato et al in 2014, randomised 1,504 patients to show that oral rivaroxaban was non-inferior to warfarin in preventing a composite endpoint of stroke, transient ischaemic attack, peripheral embolism, myocardial infarction and cardiovascular death in patients with AF undergoing cardioversion. Major bleeding rates in the rivaroxaban and warfarin arms were similar (0.6 % versus 0.8 % respectively).8
The prospective observational trial XANTUS (Xarelto for Prevention of Stroke in Patients with Atrial Fibrillation) followed 6.784 patients on rivaroxaban for AF during a mean time of 329 days at 311 different hospitals. Major bleeding occurred in 128 patients (2.1 events/100 patient years) and 43 patients (0.7 events/100 patient years) suffered a stroke. These numbers are more reassuring than those seen in ROCKET-AF, though the patient population had a lower risk profile, with an average CHADS2 score of 2.0 compared with 3.5 in ROCKET-AF.10
To further mitigate concern regarding inaccuracies of bleeding rates in the ROCKET-AF control group, it is helpful to compare bleeding rates in the warfarin arms of the other major NOAC trials. The RE-LY (Randomised Evaluation of Long-Term Anticoagulation Therapy) trial, had a warfarin-arm major bleeding rate of 3.4%/year.11 The ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial, had a warfarin-arm major bleeding rate of 3.1%/year.4 The ENGAGE AF-TIMI 48 (Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) trial, had a warfarin-arm major bleeding rate of 3.4 %/year.5The warfarin arm of ROCKET-AF had a 3.4 %/year major bleeding rate, comparable to the other studies. Furthermore, the ROCKET-AF patients are known to be at higher risk for stroke and bleeding; their average CHADS2 score was highest among these studies (3.5 compared with 2.1–2.8).3 In addition, ROCKET-AF had a very high percentage of patients with a HAS-BLED score ≥3 (62 %) compared with the other studies (23 % in ARISTOTLE and 51 % in ENGAGE AF-TIMI 48).12–14
Several large randomised trials have compared the safety and efficacy of rivaroxaban versus warfarin for venous thromboembolic disease. The warfarin arm of the EINSTEIN-PE trial (Oral Direct Factor Xa Inhibitor Rivaroxaban in Patients with Acute Symptomatic Pulmonary Embolism), which randomised patients with pulmonary embolism to warfarin or rivaroxaban, had a major bleeding rate of 2.2 %. The bleeding rate was lower in the rivaroxaban arm (1.1 %) and notably patients received a higher loading dose of rivaroxaban for the first 3 weeks (15 mg twice daily) compared with the daily 20 mg daily in ROCKET-AF.15
The recent uncertainties surrounding ROCKET-AF demonstrate the need for widespread data transparency for major trials with the capability of so greatly affecting patients’ lives. These are complicated issues both for the companies’ manufacturing products and the clinical trial organisations who carry out these studies and analyse the data. Ultimately the goal of full transparency to allow increased confidence in trial results should be sought. In this instance there is no compelling evidence of imminent danger of excessive bleeding with rivaroxaban. We should take notice of the recent findings, but there is no need to change practice.
What Are Xarelto Side Effects?
The most dangerous Xarelto side effect is uncontrollable bleeding. Blood thinning drugs have also been associated with bleeding complications. Other side effects include:
- Blood clots
- Gastrointestinal bleeding
- Spinal bleeding
- Intracranial bleeding
- Epidural bleeding
- Cerebral bleeding
- Difficulty breathing
For Information on Xarelto and other mass torts see:
Michael Brady Lunch will speak on the Xarelto litigation as well as the status of Pradaxa litigation and related issues at the upcoming Mass Tort Nexus “CLE Immersion Course”
November 9 -12, 2018 at The Riverside Hotel in Fort Lauderdale , FL.
For class attendance information please contact Jenny Levine at 954.520.4494 or Jenny@masstortnexus.com.
- For the most up to date information on all MDL dockets and related mass torts visit masstortnexus.com and review our mass tort briefcases and professional site MDL briefcases.
- To obtain our free newsletters that contain real time mass tort updates, visit masstortnexus.com/news and sign up for free access.
REFERNCES CITED IN STUDIES SHOWN ABOVE
Rivaroxaban and the ROCKET AF trial issue chronicles: A closer look at benefit risk profile of the drug. References:
BMJ 2016; 354 doi: https://doi.org/10.1136/bmj.i5131 (Published 28 September 2016)Cite this as: BMJ 2016;354:i5131
- Patel MR, Mahaffey KW, Garg J, et al. Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med 2011; 365:883-891. Article
2. Top 50 pharmaceutical products by global sales. PMLiVE, Available here.
3. FDA analyses conclude that Xarelto clinical trial results were not affected by faulty monitoring device.https://www.fda.gov/Drugs/DrugSafety/ucm524678.htm
4. ROCKET AF Reanalysis Reviews.http://www.accessdata.fda.gov/drugsatfda_docs/nda/2011/202439Orig1s000Ro…
5. Joint EFPIA-PhRMA Principles for Responsible Clinical Trial Data Sharing Become Effective.http://www.efpia.eu/mediaroom/132/43/Joint-EFPIA-PhRMA-Principles-for-Re…
6. Cappato R, Ezekowitz MD, Klein AL, et al. Rivaroxaban vs vitamin K antagonists for cardioversion in atrial fibrillation. Eur Heart J 2014; 35:3346-3355.
Controversy Surrounding ROCKET-AF: A Call for Transparency, But Should We Be Changing Practice? References
Jason D Matos1 and Peter J Zimetbaum1,,2 Arrhythm Electrophysiol Rev. 2016 May; 5(1): 12–13.; doi: [10.15420/aer.2016.24.2]
- Kubitza D, Becka M, Wensing G, et al. Safety, pharmacodynamics, and pharmacokinetics of BAY 59-7939 – an oral, direct Factor Xa inhibitor – after multiple dosing in healthy male subjects. Eur J Clin Pharmacol. 2005;61:873–80. PMID: 16328318. [PubMed]
- Cohen D. Rivaroxaban: can we trust the evidence? BMJ. 2016;352:i575. DOI: 10.1136/bmj.i575; PMID: 26843102. [PubMed]
- Patel MR, Mahaffey KW, Garg J, et al. Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med. 2011;365:883–91. DOI: 10.1056/NEJMoa1009638; PMID: 21830957. [PubMed]
- Granger CB, Alexander JH, McMurray JJ, et al. Apixaban versus warfarin in patients with atrial fibrillation. N Engl J Med. 2011;365:981–92. DOI: 10.1056/NEJMoa1107039; PMID: 21870978.[PubMed]
- Giugliano RP, Ruff CT, Braunwald E, et al. Edoxaban versus warfarin in patients with atrial fibrillation. N Engl J Med. 2013;369:2093–104. DOI: 10.1056/NEJMoa1310907; PMID: 24251359. [PubMed]
- Patel MR, Hellkamp AS, Fox KA, et al. Point-of-care warfarin monitoring in the ROCKET AF Trial. N Engl J Med. 2016;374:785–8. DOI: 10.1056/NEJMc1515842; PMID: 26839968. [PubMed]
- Mandrola J. Rivaroxaban: It’s not time to cut the rope, yet. Medscape. 9 February 2016. Available at: www.medscape.com/viewarticle/858648. (accessed 6 May 2016.
- Cappato R, Ezekowitz MD, Klein AL, et al. Rivaroxaban vs. vitamin K antagonists for cardioversion in atrial fibrillation. Eur Heart J. 2014;35:3346–55. DOI: 10.1093/eurheartj/ehu367; PMID: 25182247.[PubMed]
- Cappato R, Marchlinski FE, Hohnloser SH, et al. Uninterrupted rivaroxaban vs. uninterrupted vitamin K antagonists for catheter ablation in non-valvular atrial fibrillation. Eur Heart J. 2015;36:1805–11. DOI: 10.1093/eurheartj/ehv177; PMID: 25975659. [PMC free article] [PubMed]
- Camm AJ, Amarenco P, Haas S, et al. XANTUS: a real-world, prospective, observational study of patients treated with rivaroxaban for stroke prevention in atrial fibrillation. Eur Heart J. 2016;37:1145–53.DOI: 10.1093/eurheartj/ehv466; PMID: 26330425. [PMC free article] [PubMed]
- Connolly SJ, Ezekowitz MD, Yusuf S, et al. Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med. 2009;361:1139–51. DOI: 10.1056/NEJMoa0905561; PMID: 19717844.[PubMed]
- Sherwood MW, Nessel CC, Hellkamp AS, et al. Gastrointestinal bleeding in patients with atrial fibrillation treated With rivaroxaban or warfarin: ROCKET AF trial. J Am Coll Cardiol. 2015;66:2271–81.DOI: 10.1016/j.jacc.2015.09.024; PMID: 26610874. [PubMed]
- Lopes RD, Al-Khatib SM, Wallentin L, et al. Efficacy and safety of apixaban compared with warfarin according to patient risk of stroke and of bleeding in atrial fibrillation: a secondary analysis of a randomised controlled trial. Lancet. 2012;380:1749–58. DOI: 10.1016/S0140-6736(12)60986-6; PMID: 23036896. [PubMed]
- Eisen A, Giugliano RP, Ruff CT, et al. Edoxaban vs warfarin in patients with nonvalvular atrial fibrillation in the US Food and Drug Administration approval population: An analysis from the Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48 (ENGAGE AF-TIMI 48) trial. Am Heart J. 2016;172:144–51. DOI: 10.1016/j.ahj.2015.11.004; PMID: 26856226. [PubMed]
- EINSTEIN-PE Investigators, Buller HR, Prins MH, et al. Oral rivaroxaban for the treatment of symptomatic pulmonary embolism. N Engl J Med. 2012;366:1287–97. DOI: 10.1056/ NEJMoa1113572. PMID: 22449293. [PubMed]