Control-IQ – when?

It’s a question many Australians are asking:

“When will we get Control-IQ?”

And it seems a fair enough question. Many people have been looking forward to the Tandem t:slim X2 pump having a hybrid closed-loop implementation (using Dexcom G6 CGM).

Stepping through the years

Some of the details are buried in my Australian Insulin Pump Choices article. But it might be educational to spell the history out in a bit of a timeline here.

August 2018 The t:slim X2 is introduced to Australia. Initially as in-warranty replacement for the discontinued Animas Vibe. Thus some people’s t:slim warranties have been expiring 4 years from when they got their Vibes (not when they got their t:slim).

Part of the marketing of the t:slim has always been that software updates are included (at least while in warranty).

The initial pump firmware uses the Dexcom G5 CGM for alarms and for bolus advice.

late 2018 Basal-IQ firmware for the t:slim is launched in the USA.
This removed support for G5, making the t:slim a G6-only pump. Basal-IQ is a low-glucose-suspend system, suspending insulin delivery if the CGM shows the BG is heading towards hypo, and resuming as you start to head up again.
late 2019 Control-IQ firmware for the t:slim is launched in the USA.

Control-IQ is a hybrid closed-loop system, reducing insulin delivery as you start to head down, and increasing it as you head up. It works to keep you in range, protecting you from highs as well as lows.

mid 2020 Basal-IQ is introduced in Australia.

People could choose the G5 version or upgrade to Basal-IQ. But going to Basal-IQ forces a change from Dexcom G5 to G6.

November 2020 The t:slim-with-Control-IQ was added to the Prostheses List (which specifies what insurance companies will pay for).
November 2020 t:slim X2 was suspended by the TGA due to safety concerns that had not been addressed by Tandem/AMSL.

No supply of new pumps allowed, but existing users could continue to be supported. In fact warranty support for users that would have expired while the pump was “in limbo” seems to have been extended during the suspension.

early 2021 AMSL conducted Control-IQ training for DEs/endos/etc in preparation for a roll-out of Control-IQ once the suspension was resolved.

This was taken as a positive sign by most people, setting the expectation that Control-IQ should follow soon after the suspension was lifted.

April 2021 The TGA suspension was lifted. The t:slim X2 was again available for sale.

Tandem had updated the Basal-IQ firmware to v6.4.1 (apparently to address the TGA concerns). They did not update the older G5 firmware.

Quite importantly, the TGA registration was modified to impose several restrictions:

  1. The hardware must have a manufacturing date of 1st August 2020 or later.
  2. The software must be Basal-IQ 6.4.1 or above.
  3. The registration is under extra scrutiny for adverse events for 12 months from the 30th of March 2021.

AMSL have reported that Tandem will be doing a 6-12 month review and then reporting back to the TGA.

These restrictions have complicated things.

Removal of G5 support

When Basal-IQ was introduced, people getting their CGM via the NDSS CGM Subsidy (e.g. everyone under 21) had to wait until a special exemption was made and Dexcom G6 was added to the subsidy scheme (only for Basal-IQ users even today). But today there is no choice to get a G5-compatible Tandem.

Any new Tandem users who have been paying for their Dexcom G5 CGM (i.e. are not eligible for the NDSS CGM Subsidy, and remember that most people with T1D are not eligible) have to instead start paying for Dexcom G6. Some people have managed to build up reasonable supplies of G5 sensors, which they suddenly have little use for.

Note that for many people Dexcom G6 is more expensive than G5.

Yes AMSL sell a “monthly” G6 box of sensors for $330, and a G5 box for $370. The G6 box has three “10-day” sensors for $110 each, but the G5 box has four “7-day” sensors for $92.50 each. But many people’s G5 sensors have been lasting a lot longer than the warranted 7 days, and their cost per day has been within reach whereas the G6 has inflated their costs significantly in real-world use. That simple example does ignore the cost of transmitters (and the option to commit to a 12-month G6 subscription) but the bottom line has still been more expensive.

G6 does have a bunch of technical advantages, but it also has some drawbacks and for many people it has not been cheaper.

The same situation will happen to anyone who’s G5-compatible pump has to get replaced under warranty. AMSL is only allowed to supply Basal-IQ pumps. For example if the screen of the pump gets damaged, the user suddenly has to budget for a new CGM to replace the one they’ve already got.

Of course, it’s always been clear that Basal-IQ and Control-IQ will require G6. It’s people happy to run without those who have suddenly had the G6 requirement imposed.

Basal-IQ only

That restriction of “Basal-IQ 6.4.1 or later” could be read as not permitting the supply of Control-IQ.

Unless a new version of Control-IQ is classified as “later than Basal-IQ 6.4.1” in which case there might be a loophole.

Otherwise the supply of Control-IQ in Australia will depend on getting the restrictions changed on the t:slim’s registration in the TGA’s Australian Register of Therapeutic Devices (ARTG).

Scrutiny for 12 months

Does this mean that the pump will be restricted to Basal-IQ until the end of March 2022? Or is there a chance that Tandem will get TGA approval for an updated version of Control-IQ in the pump before that?

My crystal ball gets a bit hazy there, but I won’t be surprised if things take a long time to resolve.

Some people have been reporting things online like “my [DE/endo] said probably August for Control-IQ” but I don’t put much stock in that. I gather that the last update most DEs had was the Control-IQ training earlier this year, and that anything after that is purely guesswork.

The start of October 2021 is 6 months after the restrictions came into effect, while 12 months takes us to April 2022.

In fact AMSL Diabetes has actually written on Facebook (in a comment on this post):

[…] as part of the t:slim X2 insulin pump’s listing conditions, Tandem Diabetes Care must conduct post-marketing surveillance detailing Basal-IQ technology performance within Australia. This review could last between 6-12 months. Following this, AMSL Diabetes and Tandem Diabetes Care will look to launch the Control-IQ technology update as soon as possible […]

That seems reasonably definitive (although the bold highlighting is mine). No sooner than October, and probably closer to April.

Dreaming of looping?

Without Control-IQ (which many t:slim owners feel they were promised) people hoping for closed-loop pumping do have a few options:

Medtronic’s 770G pump system uses its own Guardian 3 CGM and implements a hybrid closed loop. A different one to Control-IQ though.

It may be that the eventual Medtronic 780G pump (which will be apparently also available as a firmware update to the 770G) leapfrogs the current Control-IQ in features/performance, but only time will tell.

Opensource, “DIY” closed-looping, with phone-based controllers people build to connect their CGMs (often Dexcom G5 or G6: there’s a lot of flexibility) with their pumps.
But t:slims are not capable of connecting with these systems. The pumps being used for this by most people include old Paradigms, the DANA RS, and the Combo. At the moment, of those the Accu-Chek Combo is the only pump that can be purchased new. There is of course a starting point for people looking for info on building their own closed-loop systems (via the “Closed-loop pumps” link in the site’s top menu).

Most t:slim owners will be locked into their pump for at least 4 years by their insurer (depending on when it was purchased) although some people may be in a position to buy other pumps outright, and some people’s warranty periods will be rolling over.

Of course, when Control-IQ finally does arrive, many people will be keen to give it a go (based on the mountains of feedback from users in the US and Europe). Which they’ll be able to do, as long as they have a t:slim pump that’s in warranty at the time.

What now?

At the moment the Tandem users are essentially being told to wait, and to use Basal-IQ in the meantime. I guess we will see what they do over the coming months.

5 thoughts on “Control-IQ – when?”

  1. It’s worth a look at what people in the UK are achieving with 780G – looks impressive.

    I must also admit, I’ve been left disappointed by the time in range that control iq offers on average. FDA approvals and research all indicate less than the 670G algorithm.

    No doubt looping offers best results, but I am excited for the future of technology.

  2. Dylan Sutton

    Hi David,
    I have a few problems with some of the interpretations made from the limited statements AMSL have made in writing.
    Firstly, the AMSL facebook comment which you suggest is ‘reasonably definitive’ is anything but. Regulatory bodies such as TGA are not permitted to apply arbitrary or undefined restrictions in trade. I can’t see any circumstance under which TGA could impose a review period of “6-12 months” – the period could be 6 months or could be 12 months, but would always be explicitly defined, e.g. 12 months data commencing on date x to be submitted for consideration at TGA meeting on date y, following which a decision will be made within z business days.
    Secondly, regarding the suggestion that it could be a ‘loophole’ that a Control-IQ version is considered a later version than Basal-IQ 6.4.1, I would more think that whether it is ‘later’ or not is solely determined by the version number (if they follow the same numbering) or release date (if they don’t), and that the name attached to the front is the ‘loophole’ scenario. The pump software version isn’t actually named “Basal IQ 6.4.1” anyway, the pump reports the name as “Carlsbad 6.4.1” from memory. Nobody in their right mind would talk about SQL server 2008 “SP2” being a later version than SQL Server 2016 “SP1”, for instance.
    Lastly, and I believe most importantly, AMSL management have not said either verbally to me or in writing to others (insofar as that has been shared) that release of Control-IQ is contingent upon the outcome of the post-marketing surveillance of Basal-IQ, only that the surveillance was a requirement of being allowed to resume supply of the pump. While the details of the nature of the surveillance required have not been released, the simplest explanation is that it is no more than what is stated by TGA in their release that it is heightened surveillance for adverse events (which in fact is no more than a removal of the standard exemption of reporting requirements for certain classes of events). AMSL have indeed said to me verbally that the restriction in supply of Control-IQ was _not coming from TGA_, but rather from Tandem USA refusing to supply it to AMSL.

    1. David Burren

      When the pump’s registration was suspended in November, that suspension would have become a deletion if things weren’t resolved by May (6 months). But somehow many people got into their heads that it would be fixed *in* 6 months. People’s interpretations of timeframes are sometimes a bit weird.

      In this case I wouldn’t be surprised if there was a 12-month timeframe imposed by the TGA (or rather, by the legislation they work within) and Tandem is planning to get stuff to them after gathering data (and possibly updating code) later this year so that it can be resolved before the 12 months are up. AMSL saying “6-12 months” may be a translation of that into a simpler form for mass consumption without having to explain all the moving parts.

  3. Dylan Sutton

    Further to my previous comment regarding whether Control IQ software would fall under the TGA requirement for the pump to only be sold with “software version Basal-IQ 6.4.1 or above” (actually reported by the pump as “Carlsbad 6.4.1”), the “T:slim X2 with Control IQ User Guide” gives the Control-IQ software version as “Moonlight 7.4”. I hesitate to speculate on whether “Moonlight” trumps “Carlsbad”, but in software versioning we all know that 7.4 is “above” 6.4.1…


    1. David Burren

      7.4 may be “higher” than 6.4.1 (and BTW I do believe it’s appropriate to refer to it as “Basal-IQ 6.4.1” – I thought “Carlsbad” was just an internal development name). But it’s not necessarily later.
      We’ll just have to wait and see what happens from here.

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