Late-breaker on clinical trials: less is more, but not always.

This years’ late-breaker session on clinical trials at ECCMID had 8 presentations; 3 on shortening duration of treatment; 2 compared antibiotics; 2 phase PK/PD studies and 1 PK/PD study in kids. The room was packed (and not that big anyway), so you may be interested to read what I thought I heard (and saw).

Dafna Yahav presented 7 vs 14 days for GNB BSI (community- and hospital-acquitred), an open-label non-inferiority RCT in 3 centers (2 in Israel and 1 in Italy). They adopted a non-inferiority margin of 10%, and pursued a sample size of 2×300 patients. Patients with GNB BSI that were afebrile and haemodynamically stable before day 5, could be randomzied. The priary outcome was a composite of all cause mortality, clinical failure and readmission/extended stay at day 90. They had 306 patients in the 7 days group and 298 in 14 days, with a balanced baseline table; 25% of infections was hospital-acquired; 70% had UTI, 65% were E. coli. The primary endpoint was reached in 141/306 and 149/298 patients yielding an absolute Risk Difference (aRD) of -3.9% (95% CI -11.9-4%), with non-inferiority demonstrated. 7 days was associated with less antibiotic use and earlier recovery. Conclusion: safe to stop at day 7 in non-neutropenic, HD stable patients not having an uncontrolled source infection that had a GNB BSI.

Duncan Cranendonk presented the DANCE trial comparing 6 days to 12 days of antibiotic treatment for severe cellulitis; all started with flucloxacillin (Dutch study, no MRSA) and were randomized at day 5-6 to placebo or continuation of antibiotics. The primary endpoint was clinical cure at  day 14. In all, 151 patients were randomized; 74 to 6 days 77 to 12 days, and 69 and 71 were evaluable in the modified Intention To Treat (mITT). The groups were well balanced, and the clinical cure rate was about 50% in both groups, with and aRD of 1.4% (95% CI 14.8-17.5%). So, the the non-inferiority margin of 10% was crossed. Moreover, relapses occurred more frequently in the 6-day group. Thus: non-inferiority not demonstrated (which may have resulted from not reaching the pursued enrollment) and more relapses….. So, keep on finalzing your 12-day course of antibiotics, is their message.

Aurelien Dinh presented the effectivenes of 3 days (vs 8 days) of beta-lactam antibiotics for hospitalized community-acquired pneumonia (CAP): a randomized non-inferiority double-blind trial. Fresh from the press, with last data from last Friday. The study domain included patients with “non-ICU CAP” treated with either amoxi-clav or 3rd generation cephalosporin and clinically stable at day 3. Dual therapy was not allowed (only 1 dose of macrolide or quinolone was). Randomization occurred at day 3, to placebo or oral amoxi clav. The primary endpoint was clinial cure (absence of fever, absence/improvement of clinica symptims, no new antibiotics ater day 3) at day 15. In the ITT they had 152 (8 days) and 156 patients (3 days), well balanced, median PSI 81-84, 4% had bacteremia, and 5% had a positive urinary pneumococcal antigen test. The primary endpoint was reached in 69.9% of patients in the 3-day group and in 61.2% in the 8-day group, yielding a 95% CI ranging from -1.09% to 20.55%, clearly demonstrating non-inferiority. One attendee in the audience not suffering from the oxygen-deficit had calculated that on average each participating hospital had included 3 patients per year, and whatt that meant for generalizibility.

Patrick Harris presented the MERINO trial in which piperacillin-tazobactam was compared to meropenem for definite treatment of BSI caused by 3rdG-Ceph-non-susceptible GNB (mainly E. coli). The primary endpoint was day-30 mortality. Patients needed to be enrolled within 72 hours after the index blood culture and had to receive at least 5 days of antibiotics. In all 391 patients were randomized and 378 evaluable; 85% of infections caused by E. coli, 45% community-were acquired. The study was suspened ath 3rd preplanned interim-analysis as it was highly unlikely that non-inferiority could be demonstrated, For day-30 mortality the aRD was 8.6% (95% CI 3.4-14.5), yielding a number needed to harm of 12! All secondary endpoinits favored meropenem. So, what started as a trial to reduce carbapenem use, provided undisputable evidence to do the opposite.

Finally, Angela Huttner presented a study from the AIDA project, which aimed to preserve old antibiotics for the future. in this open-label/analyst-blinded RCT, non-pregnant women aged ≥18 years with symptoms of lower UTI, a positive urine dipstick and no known colonization or previous infection with uropathogens resistant to the study antibiotics were included in Switzerland, Poland, and Israel. Women were randomized to either nitrofurantoine (5 days) (n=255) or a single-dose of fosfomycin (3 gram) (n=258). The primary outcome was clinical response at 28 days after therapy completion, defined as cure (complete resolution of symptoms and signs of UTI), failure (need for additional or change in antibiotic treatment due to UTI, or discontinuation due to lack of efficacy), or indeterminate (persistence of symptoms without objective evidence of infection). Both clinical and microbiological cure at day 28 was achieved more frequently in patients receiving nitrofurantoin (70% vs 58%; p=0.016; 74% vs 63%; p=0.037), as was hypothesized by the investigators. For those patients with E. coli infection the difference was even larger (aRD of 28%). So, the old drug (fosfo when used as a single-dose treatment) was worse than what is currently used in most countries for this indication. The study was published online in JAMA during the late-breaker session.

Five excellent investigator-initiated studies, that may all change our treatment guidelines. Unfortunately, short, old and less broad-spectrum is not always the better choice. Hope that many young scientists get inspired and will not be stopped by upcoming new EU regulations for clinical trials, see.

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The antibiotic resistance crisis resolved by bateriophages (part 4)

Yesterday at ECCMID was the long-awaited presentation of the Phagoburn trial: A randomized controlled trial of bacteriophages against Pseudomonas aeruginosa infections in burn wound patients. Bacteriophages have regained considerable attention recently. Proposed as an answer to the rising problems in treating bacterial infections by some, others have remained sceptic due to the absence of evidence of effectiveness coming from well-designed studies, see parts 1, 2 & 3. The Phagoburn trial, though, would the first to deliver high-quality data. So what was presented? Continue reading

Preventing S. aureus SSI: Who does what? (part 2)

A month ago I blogged on the practices of pre-operative (or better peri-operative) treatment of nasal S. aureus carriage to prevent S. aureus surgical site infection (SSI) in orthopaedic or cardiothoracic surgery patients. The issue brought forward was that a “treat-all” (thus “screen none”) strategy is more feasible, more effective and cheaper than the “screen & treat” strategy. The latter strategy, is associated with less mupirocin exposure and thus less selective pressure for mupirocin-resistance genes. There was a poll with 2 questions. What is your current practice for patients undergoing orthopaedic or cardiothoracic surgery and what do you think the strategy should be, with 3 options for each question; “do nothing”, “screen & treat”, or “treat all”. Today the results. Continue reading

The antibiotic resistance crisis resolved by bacteriophages (part 3)

Last October Dutch people were “informed” about the potential of bacteriophages. In short, “bacteriophages work where antibiotics fail because of resistance in critically ill patients, something that is already known for 100 years, and that is neglected by modern medicine”. Some questions were raised, see here and here, but curretly Dutch physicians receive many/daily requests from patients on phage therapy and the most desperate patients pay thousands of euros to seek help abroad, without reimbursement from health insurance. Last week, we had invited the most experienced clinical experts and scientists acting at the cutting edge of preclinical bacteriophage research. Here is my impression of the clinical part. Continue reading

Preventing S. aureus SSI: Who does what?

Pre-operative (or better peri-operative) treatment of nasal S. aureus carriage is one of the most – if not the most – effective infection prevention measure. A large double-blind randomized controlled trial convincingly confirmed the meta-analysis results of previously performed smaller studies: 5 days of nasal mupirocin ointment together with chlorhexidine showering reduced the incidence of deep-seated S. aureus surgicial site infection (SSI) with 80% among S. aureus carriers undergoing orthopaedic or cardiothoracic surgery. Eight years after publication of these findings I (and others) still have the feeling that many hospitals have not implemented this measure. Continue reading

All models are wrong…..

Yesterday, our study on antibiotic cycling strategies in ICUs was published. Thanks to Joppe van Duijn, involved in all study phases, we could report that in 8 ICUs in 5 countries with 8,776 patients the unit-wide prevalence of antibiotic resistance was similar when cycling antibiotics every 6 weeks or when cycling antibiotics for every next patient treated (mixing). The study was motivated by prior mathematical models, of which most predicted that cycling would do better. So, now all can raise their voices: (1) “all models are wrong, but some are useful”; (2) “most studies are wrong, but some are useful”; or (3) “if model predictions are not confirmed, where did the study go wrong?”

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Test-negative design: the best study design ever?

To kick off the 2018 Journal Club our PhD students discussed a bewildering new trial design* to determine vaccine effectiveness (VE) published in Lancet ID, from which Meri Varkila reports.  The classical approach to quantify VE was to spend the best 5 years of your life to find 2,000 general practitioners, to invite 600,000 elderly to randomize 85.000 and to find 139 primary endpoints in 57 hospitals while all involved remain blinded. This new approach, called the test-negative design (TND) study would give you that number in a year, by just studying a few hundred patients with community-acquired pneumonia. A true Quality-of-Life enhancer for many…., if reliable. Continue reading