Wearable on-body injectors and handheld autoinjectors are now common delivery platforms for biologics, and each fails in its own ways. Regulatory, human-factors and postmarket teams working on combination products need to know which device problems and patient outcomes FDA actually receives in medical device reports. Those reports feed design verification priorities, use-related risk analyses, labeling and instructions for use, and complaint-trending thresholds.
The analysis below codes the MAUDE reports identified for on-body injectors and for autoinjectors used with biologics (29 and 14 reports). It is not a census of either database. Each identified report was coded by device problem and patient outcome. The analysis looks at which manufacturers and products the reports involve, and compares the failure modes and clinical consequences of the two device types. For context it also draws on reports for high-volume small-molecule and peptide autoinjector families and on a FAERS cross-check.
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On-body injector vs autoinjector complaints in FDA MAUDE: device problems and adverse events for biologic delivery
In the Neulasta Onpro MAUDE reports reviewed here, on-body injector (OBI) failures cluster in the wear period: error lights and alarms, detachment from the skin, leakage, and doses that were never delivered. Autoinjector reports for biologics look different. Most describe a needle that would not deploy or retract, a device that jammed at the moment of injection, or, less often, needle-safety events such as a broken needle tip left in the skin. In both device types the usual consequence is a missed or partial dose rather than direct physical injury. The clinical and human-factors profile of each failure still differs in ways that matter for design verification, labeling and postmarket surveillance.
This analysis covers 29 unique OBI medical device reports (MDRs) and 14 MDRs for autoinjectors used with biologics (etanercept, evolocumab, darbepoetin alfa and vedolizumab). Each report was read and coded for device problem and patient outcome. It also draws on MAUDE reports for two high-volume small-molecule and peptide autoinjector families, and on a FAERS cross-check.
The OBI evidence base is concentrated in one product
Every OBI report identified in this MAUDE search involved the pegfilgrastim on-body injector (Neulasta Onpro kit). The reports list Amgen as manufacturer, sometimes alongside Insulet Corporation or Flextronics as co-manufacturer 79879748273. Event dates run from 2015 to 2026 4832936. Of the 29 reports, 27 are coded as malfunctions and 2 as injuries 732429. The two injury-coded reports describe a burning, itching skin reaction around the patch with a wet adhesive and an empty reservoir before the scheduled dose time 7314685, and a device that fell off at home 242914680.
The biologic autoinjector reports cover Amgen's SureClick platform (Enbrel, Repatha and Aranesp), the Enbrel Mini autoinjector, and Takeda's Entyvio autoinjector 975236549111423. Of these 14 reports, 10 are malfunctions, 3 are injuries and 1 is coded "Other" 9749112336.
Most common OBI device problems
| Coded problem or outcome (reports can carry more than one code) | OBI, n=29 | Biologic autoinjector, n=14 |
|---|---|---|
| Incomplete or missed dose | 18 (62%) | 8 (57%) |
| Error light, alarm or beeping | 13 (45%) | 0 |
| Adhesion failure or detachment from skin | 9 (31%) | 0 |
| Activation or start failure | 6 (21%) | 4 (29%) |
| Leakage | 5 (17%) | 4 (29%) |
| Premature or unintended activation | 4 (14%) | 0 |
| Needle or cannula failed to deploy or retract | 3 (10%) | 7 (50%) |
| Needle-safety event (protruding or retained needle) | 0 | 3 (21%) |
| Injection-site pain or reaction | 1 (3%) | 2 (14%) |
| Broken or damaged device | 1 (3%) | 1 (7%) |
Missed or incomplete dose
The most frequent outcome in OBI reports is a dose that was not delivered, or not delivered in full. Several reports describe a device whose chamber still looked full the day after placement, often together with a flashing red light 146781471614712. Others describe a device that started and then stopped. In one case only about one-third of the dose was dispensed before a red-light error, and the patient needed an injection to complete the dose 14708. In another, the device showed an error with loud beeping as soon as it activated, and the full dose stayed in the reservoir 14713. A returned device was confirmed to be still full 14710.
Error indicators and alarms
A red light or audible alarm appears in 45% of OBI reports. That is the most distinctive OBI signal, and nothing comparable appears among the autoinjector reports. Alarms were often noticed after the patient had left the clinic. One report describes a flashing red light and continuous beeping within 60 minutes of leaving the infusion center 14704. Another describes an alarm about one hour before the scheduled dose 14707. Some alarm events are ambiguous. In one report the device flashed red instead of green after the medication had apparently been fully delivered 14719.
Adhesion failure and detachment
Nine reports (31%) involve an adhesive that failed or a device that came off. Reported scenarios include:
- the device falling off overnight while the patient slept 14690
- the device coming off when clothing was removed 14687
- the device detaching while the patient sat on a couch, then beeping beside them 14698
- the device being knocked loose against a refrigerator door, so no dose was delivered 14699
One report describes a device that would not adhere at all. Its catheter lay against the skin without perforating it, and the clear plastic component around the catheter was dislodged 14696.
Leakage
Leakage reports usually describe drug soaking the patient's arm or sleeve, with the delivered dose left uncertain 1470514697. One patient reported that 2 of 3 injectors leaked, with tape near the status light lifting 14684. A single health-professional report aggregated eight Onpro devices that failed to deploy, fell off or leaked, and noted delayed treatment 14688.
Timing and premature activation
Four OBI reports involve activation outside the intended sequence, a failure mode specific to the delayed-delivery OBI design. In one, cannula insertion was triggered during the fill step, before the permitted application window 14683. In another, the dose was delivered at 26 hours instead of the expected 27 hours 14718; because the label describes delivery at approximately 27 hours, that report may reflect normal timing variation rather than a true premature activation.
Most common biologic autoinjector device problems
Needle deployment and retraction failures
Half of the biologic autoinjector reports involve a needle that would not come down, would not retract, or both. Reports describe a Repatha SureClick needle that stayed stuck and made the device unusable 14700. Another describes a SureClick injector that did not give its second click, leaving the needle protruding about 1/4 inch so the patient had to pull it out manually 14689. Enbrel SureClick reports describe a needle entering the skin with no medication delivered and no retraction afterward, leading to two missed doses 14720, and a needle that did not deploy at all 14706.
Jamming and activation failure
Mechanical lockout at the moment of use is the second main pattern. In one report, pharmacists received returned Enbrel SureClick injectors from three patients on the same lot that had locked and failed to discharge; the pharmacists confirmed the patients knew how to use the device 14691. An Aranesp SureClick would not activate under normal pressure 14693. An Enbrel Mini cartridge stuck inside the reusable autoinjector 14702. A Repatha SureClick did not release drug after several attempts and then spilled medication when tapped 14714.
Needle-safety events and physical injury
The most serious physical harms in the biologic dataset involve autoinjectors, not OBIs. In one Entyvio autoinjector report, the needle tip broke and stayed embedded about 6 mm in the patient's skin. The patient went to the emergency room, a retained fragment was found on a second ultrasound, and the fragment was left in place after discussion with a physician. Pain and burning lasted about 24 hours and swelling about a week 14681. A second Entyvio report describes most of the dose leaking from the needle after the pen was removed, persistent injection-site pain, and concern about a retained needle fragment 14679.
How the two device classes differ
When the failure shows up. Autoinjector failures happen at the moment of injection and are seen straight away: the needle won't deploy, the device won't fire, or drug spills 147001469114714. OBI failures often show up hours later or the next day, once the patient is away from the clinic. They are signaled by alarms, a full reservoir or a wet adhesive 147041467814685.
Failure modes unique to the platform. Error indicators, adhesion loss and premature activation account for a large share of OBI reports and do not appear in the autoinjector reports reviewed 1469814683. Needle retraction failure and retained needle fragments occur only in the autoinjector reports 1468914681.
Clinical consequence. In OBI reports, a failed pegfilgrastim dose was usually made up with a manual subcutaneous injection at the clinic, sometimes the next day 146901471214709. One report links a questionable OBI injection in the first chemotherapy cycle to a later admission for sepsis and dose reductions in subsequent cycles. The report does not specify the failure mode 14703. Autoinjector reports more often describe missed doses managed at home 1472014692, plus the needle-injury events above.
Who reports. Most OBI reports in this set came from health professionals, which fits clinic-applied devices whose failures bring the patient back for a replacement dose 97441468614701. Most biologic autoinjector reports were voluntary patient or consumer submissions 146891471714720. The two Entyvio reports were manufacturer-filed 1467914681.
Broader autoinjector context: non-biologic platforms
The autoinjectors with the most MAUDE reports are not biologic products, but they show the same mechanical failure modes. For the WhisperJect autoinjector, used mainly with glatiramer acetate, reports describe failure to inject or incomplete delivery, mechanical jamming or sticking, and breakage or component deformation 14729147301473514746. Local injection-site reactions such as welts, redness and pain are also reported 147361473814743. For the Adrenaclick/Twinject epinephrine autoinjectors, the reports reviewed centered on needle, sheath or cap deployment problems. They also included accidental needlesticks to the person giving the injection and delayed treatment of allergic reactions 147221472414726. Manufacturer investigations often could not confirm a defect, and several pointed to incomplete sheath removal or handling factors 1472514727.
FAERS cross-check for the OBI
Combination-product device complaints are also coded in FAERS. A sample of 25 Neulasta FAERS reports from 2023 to 2024 that mention OBI device terms showed a similar pattern, with adhesion stronger than in MAUDE. It is a coding check, not a census, so its counts are not FAERS frequencies. Device adhesion issue appeared in about 20 reports, device leakage in about 11, device placement issue in about 8, and incorrect dose administered by device in about 7 14767147691477914781. All 25 were classified as non-serious. Febrile neutropenia appeared only as the indication, not as an outcome 14771.
Interpreting these data
MAUDE counts are passive-surveillance signals. They are not incidence rates, and the report counts here are small (29 OBI and 14 biologic autoinjector MDRs). Because FDA regulates these devices as drug-device combination products, many device complaints are coded in FAERS instead of MAUDE, so a MAUDE-only count understates complaint volume 14767. Absolute numbers in either database therefore understate the true complaint volume. The OBI picture rests on a single product, so it may not carry over to newer large-volume wearable injectors. For sponsors developing OBIs, the reports point to alarm handling after the patient leaves the clinic, adhesive durability, and verification that a dose was delivered as the areas to address in human factors validation and in instructions for use.