Implantable Neurostimulators Under FDA PMA: Approval Pathways and Indication Expansion for SCS, DBS, and Sacral Neuromodulation

Implantable neurostimulators under FDA PMA: how SCS, DBS and sacral neuromodulation indications were approved and expanded

Spinal cord stimulation (SCS), deep brain stimulation (DBS) and sacral neuromodulation (SNM) systems are Class III devices that reach the US market through premarket approval (PMA). The three therapy areas have taken different routes to broader labeling. SCS and DBS sponsors have mostly added new indications through supplements to long-lived original PMAs. SNM's main new clinical indication, chronic fecal incontinence, arrived through separate original PMAs. Most of the thousands of supplements in these files cover hardware, software, manufacturing and MR Conditional labeling, not new indications.

How the PMA files are organized

Each therapy area sits under its own FDA product codes, and a single PMA can span more than one code when its indications cross therapy categories.

The base files are large. In the indexed PMA records, Medtronic's SCS PMA P840001 has more than 600 distinct supplement numbers. Its first supplements, for the Itrel totally implantable spinal cord stimulation system, date to February 1985 ³²⁰⁶. The Medtronic DBS file P960009 has roughly 500 ³, and the InterStim urinary file P970004 has more than 440 ⁹⁴². These counts reflect supplement records in FDA's PMA database and include manufacturing and administrative changes.

Spinal cord stimulation

Original approvals

Most major SCS original PMAs share a narrow core indication: chronic intractable pain of the trunk and/or limbs associated with failed back surgery syndrome, intractable low back pain and leg pain. Biotronik's Prospera (P210037) is the exception; its original indication already used a 12-item etiology list.

Dorsal root ganglion (DRG) stimulation received its own original PMA. Abbott's Axium system (P150004) was approved on 2016-02-11 for moderate to severe chronic intractable lower-limb pain in adults with CRPS types I and II ³⁸. The pivotal ACCURATE study randomized 152 subjects 1:1 to DRG stimulation or a legally marketed SCS control ^41504151. Its primary endpoint was a composite of at least 50% VAS pain relief with no stimulation-induced neurological deficit, assessed for noninferiority or superiority ⁴¹⁵². FDA reported no stimulation-induced neurological deficits in either arm. Serious adverse event rates were similar (10.5% Axium vs 14.5% control), but procedure-related events were more frequent with Axium (46.1% vs 26.3%) ^41534154.

Phase 1: etiology-list expansions (2000 to 2017)

Medtronic was first to widen the label beyond FBSS through supplements:

• P840001/S045 (2000-06-13) expanded the indications for the Itrel, Itrel II, Itrel III and Synergy devices to a list of etiologies that began with failed back syndrome and radicular pain syndrome ⁴⁵⁹.
• P840001/S047 (2001-02-21) set out the full list: radiculopathies secondary to failed back syndrome or herniated disc, post-laminectomy pain, multiple back operations, unsuccessful disc surgery, refractory DDD/herniated disc pain, peripheral causalgia, epidural fibrosis, arachnoiditis, and CRPS/RSD/causalgia ²⁶.
• P840001/S052 (2001-08-03) changed "trunk or limbs" to "trunk and/or limbs" ⁴⁶⁰.

Later Medtronic platforms, including Restore (S074, 2005) and the SureScan MRI system (S219, 2013), carried a 10-item etiology list ³⁰³⁶³.

Boston Scientific matched this scope 13 years after its original approval. P030017/S275 (2017-08-11) added CRPS types I and II, radicular pain syndrome, radiculopathies, epidural fibrosis, DDD, arachnoiditis and multiple back surgeries ³⁴⁹². Biotronik's Prospera entered the market in 2023 with the broad etiology list already in its original indication ²².

Phase 2: new disease populations (2021 to 2024)

From 2021, several sponsors added two populations within about three years: painful diabetic peripheral neuropathy (DPN) and back pain in patients without prior surgery.

Indications are tied to a waveform. In SCS, the indication often depends on the stimulation paradigm used in the supporting study, not only on the hardware. Nevro's DPN and non-surgical back pain indications apply only when the system is programmed to include 10 kHz ^33363333. Abbott's split tonic and BurstDR modes ³⁷⁹⁷, and Boston Scientific's DPN claim is limited to paresthesia-based stimulation ³⁴¹⁰. Sponsors adding waveforms to a platform should expect FDA to consider indication scope separately for each waveform.

Clinical-data updates can also go through supplements that do not change indications. Nevro added 24-month Senza-PDN results to its Clinical Summary manual to support long-term safety and effectiveness of 10 kHz therapy for painful diabetic neuropathy ⁴¹³⁹. Medtronic's P840001/S480 (2021) added post-market RCT data to its SCS Clinical Summary manual and stated that indications were unchanged ³¹⁰².

The most recent Nevro platform supplement, P130022/S069 (2026-08-18), approved the HFX Dynamis system with a "Bolus 10kHz" therapy. It restated all three indications (FBSS/back and leg pain, diabetic neuropathy at 10 kHz, and non-surgical refractory back pain at 10 kHz). FDA also reviewed and approved a predetermined change control plan (PCCP) covering two future firmware modifications ³³⁰⁸.

Deep brain stimulation

Medtronic Activa/Percept (P960009): one PMA, five indication families

Medtronic's DBS file shows the full range of supplement-based indication expansion:

1. Original, 1997-07-31: the Activa Tremor Control System for unilateral thalamic stimulation to suppress upper-extremity tremor in essential tremor or parkinsonian tremor not adequately controlled by medication ³.
2. P960009/S007, 2002-01-14: Activa Parkinson's Control Therapy for bilateral GPi or STN stimulation as adjunctive therapy for advanced, levodopa-responsive Parkinson's disease (PD) not adequately controlled with medication ³⁹⁷⁴. Later platform supplements such as Activa PC (S052, 2009) carried both the PD and tremor indications ⁵.
3. P960009/S229, 2015-11-17: modified the PD indication from "advanced" disease to levodopa-responsive PD of at least 4 years' duration not adequately controlled with medication ⁹. The indexed order statement does not describe the supporting clinical data.
4. P960009/S219, 2018-04-27 (with a related S318 on 2018-10-12): added epilepsy. The indication is bilateral anterior nucleus of the thalamus (ANT) stimulation as adjunctive therapy in adults 18 and older with partial-onset seizures refractory to three or more antiepileptic drugs. The label states that effectiveness was shown in patients averaging six or more seizures per month and that the device has not been evaluated in patients with less frequent seizures ^7362132.
5. P960009/S482, 2025-11-22: added primary dystonia (bilateral GPi). This covers generalized, segmental head/neck and cervical dystonia in adults, and generalized dystonia in pediatric patients 12 years and older ⁵³⁶. The indexed records do not describe the evidence for this supplement or confirm the earlier dystonia pathway ^40854093.

Two other recent supplements changed the label without adding a disease:

• P960009/S474 (2024-07-01) removed the contraindication against implantation in patients whose test stimulation is unsuccessful. It replaced it with a precaution that allows full implantation after successful test stimulation or after imaging confirms the lead is at the target. The same action updated MRI labeling and cross-referenced parallel supplements to HDE files H020007 and H050003 ¹⁹⁸³.
• P960009/S478 (2025-02-20) approved adaptive DBS (aDBS) as an optional programming feature. The PD indication was restated to include motor complications of recent onset (4 months to 3 years) or of longer-standing duration ¹⁰.

Abbott (P140009) and Boston Scientific (P150031): converging on the same three targets

Later DBS entrants started with narrower target sets and closed the gap with Medtronic through supplements.

By 2024 all three DBS sponsors had STN, GPi and VIM targets on label. Each sponsor added a new anatomical target through a separate PMA supplement.

Sacral neuromodulation

Urinary indications: refined within the original file

Medtronic InterStim's urinary PMA (P970004) has records starting 1997-10-31 ⁹⁴². Its indication was broadened through early supplements:

• S002 (1998-07-08): InterStim Model 3023 IPG for urinary urge incontinence in patients who failed or could not tolerate more conservative treatments ⁹⁴⁶.
• S004 (1999-04-15): InterStim System for Urinary Control for urinary urge incontinence, urinary retention, and significant symptoms of urgency/frequency ¹⁸⁰⁹.
• S021 (2002-02-15): revised the indication to the current overactive bladder (OAB) wording: urinary retention and the symptoms of OAB, including urge incontinence and significant urgency-frequency alone or in combination ¹⁷⁹⁴.

Competing systems have since used that 2002 wording as their original indication. These include Axonics (P180046, 2019-11-13, now held by Boston Scientific) ¹⁸¹⁴ and Virtis (P170001, 2023-01-11, Cirtec Medical) ¹⁰⁴⁶. The newest entrant, Neuspera (P240031, 2025-06-17), was approved for urinary urge incontinence only, not retention or urgency-frequency ¹⁰⁴⁹.

Fecal incontinence: a separate original PMA, not a supplement

SNM differs from SCS and DBS here. Fecal incontinence was added through stand-alone original PMAs under a separate product code (QON), not through a supplement to the urinary file:

• Medtronic P080025 (2011-03-14): InterStim for chronic fecal incontinence in patients who failed or could not tolerate more conservative treatments ¹⁰³⁹. The pivotal study (G010206) was a prospective, multicenter, single-arm, unblinded study in which patients served as their own controls ⁴⁰⁷⁹. Of 285 enrolled patients, 120 were implanted ⁴⁰⁸⁰. The primary endpoint was the proportion of implanted patients with at least 50% reduction in weekly incontinent episodes at 12 months ^40814082. At 12 months, 73% (88/120) met the endpoint in the intent-to-treat modified worst-case analysis, and mean weekly episodes fell from 9.4 to 3.1 ^40834084.
• Axonics P190006 (2019-09-06): chronic fecal incontinence, filed separately from its urinary PMA P180046 ^10421814.

As a result, Axonics has parallel supplements in both files. One example is the MRI labeling expansions for abandoned lead fragments, broken leads, and Medtronic lead fragments ^{187318581853260625912586}.

Labeling expansions that are not new indications

For all three therapy areas, the largest group of "expansion" supplements covers MR Conditional labeling. Examples:

• Medtronic's SureScan MRI SCS system (P840001/S219, 2013) ⁶³ and expanded DBS MRI conditions (P960009/S211, 2015) ²²¹⁵.
• Boston Scientific's extension of Precision Montage MRI conditional labeling to existing leads (P030017/S269, 2017) ³⁴⁹⁸.
• Nuvectra's whole-body 1.5T MRI labeling for Algovita (P130028/S025, 2019) ³²⁸³.
• Abbott's expanded conditions for the Octrode lead with Proclaim XR (P010032/S176, 2021) ³⁸¹², and prone positioning for Eterna/Proclaim SCS and Proclaim DRG (2026) ^37523015.

Contraindications have also been converted into warnings by supplement. Abbott's P010032/S063 (2013) replaced the contraindication for patients with demand-type cardiac pacemakers with a warning recommending interaction testing and avoidance of unipolar programming ³⁹¹⁹. Medtronic's 2024 DBS test-stimulation change is a second example ¹⁹⁸³.

Takeaways for regulatory strategy

• Expected pathway for a new indication. For SCS and DBS, new disease populations (DPN, non-surgical back pain, epilepsy, dystonia) and new anatomical targets (GPi, VIM) have all been added through PMA supplements to the existing file ^{157333673653625114009}.
• Separate PMA under a different product code. SNM fecal incontinence shows that when a new indication maps to a different product code, sponsors have used a separate original PMA instead ^10391042.
• Waveform defines indication scope in SCS. Recent SCS indications are tied to specific programming (10 kHz, tonic, BurstDR, paresthesia-based) ^333637973410. Clinical evidence for one waveform does not automatically carry over to another on the same IPG.
• Followers close the gap by supplement. Later entrants typically launch with the narrow legacy indication and then add the incumbents' broader etiologies or targets ^{163492840444009}.
• PCCPs are appearing in neuromodulation supplements. Nevro's 2026 HFX Dynamis approval included an FDA-reviewed PCCP for future firmware changes ³³⁰⁸.