Episode Overview
Title: Inside Tandem's Latest: catching up with VP of Product Management Marisa Fienup
Podcast: Diabetes Connections | Type 1 Diabetes
Host: Stacey Simms
Guest: Marisa Fienup, VP of Product Management, Tandem Diabetes
Date: November 11, 2025
This episode provides a comprehensive update on the latest offerings, progress, and future plans from Tandem Diabetes, including new device integrations (notably Libre 3), insulin options, upcoming innovations such as Mobi Tubeless and Steady Set infusion sets, and software developments. Stacey Simms asks insightful, community-sourced questions to Marisa Fienup, garnering clarity on timelines, feature requests, and the broader vision of the company.
Key Discussion Points & Insights
1. Tandem's Product Management Philosophy
- Marisa Fienup’s Role: As VP of Product Management, Marisa bridges global patient, doctor, and industry needs with Tandem’s product pipeline.
- Focus on Choice: Tandem prioritizes varied options—“diabetes is not one size fits all.”
“I get to understand what patients, doctors and payers are looking for … then I get to help shape our pipeline to meet those needs.” — Marisa Fienup [06:19]
2. Libre 3 CGM Integration with T Slim X2
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Major News: The T Slim X2 insulin pump with Control IQ is now compatible with Abbott’s Freestyle Libre 3 CGM (US), giving users more sensor choice.
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User Experience: Selection of sensors (G6, G7, or Libre 3) is done with a toggle in the pump software.
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Data Handling: Even though Libre 3 offers 1-minute glucose readings, Control IQ processes data every five minutes, maintaining consistency across sensors.
“The experience that a user will have with the algorithm itself will be the same regardless of what sensor they choose.” — Marisa [09:16]
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Mobi Compatibility: Libre 3 integration for the Mobi pump is “top priority” now that T Slim X2 integration is launched. No firm timeline yet, but work is actively underway.
“We will be moving as quickly as possible to offer it on Mobi as soon as possible and we'll make sure to keep you and your listeners updated.” — Marisa [09:51]
3. International Expansion
- Early Access & Scaling: Plans for international early access programs before the end of 2025 and broader scaling in 2026.
“We do have plans for early access programs internationally before the end of the year and we'll be scaling fully internationally in 2026.” — Marisa [10:33]
4. Lumev (Ultra-Rapid Insulin) Approval
- Now Available: Lumev is approved for use in the T Slim X2 in the US and Europe for U100 insulin.
- Current Status: Only available for X2, not Mobi yet.
- Clinical Results: High satisfaction and quality of life benefits demonstrated in clinical trials.
- No U200 Support: No Tandem product (nor any insulin pump currently) is cleared for U200.
“As far as I know … all insulin pumps on the market use U100 insulins exclusively.” — Marisa [11:50]
5. Mobi Pump Launch and User Feedback
- Market Differentiator: First screenless, phone-controlled, tubed pump from Tandem.
- User Segment: Particularly appeals to tech-comfortable patients preferring minimal device size.
- No Major Surprises: Tandem is happy with positive feedback; users appreciate flexibility.
- Teaser for Tubeless: Mobi Tubeless (patch pump mode) to expand platform even further.
6. Infusion Set Innovations: Steady Set and Mobi Tubeless
Steady Set Infusion Set
- FDA Cleared: Extended wear infusion set with a 7-day wear time.
- Technology: Features a tiny coil that renders the cannula kink-resistant, improving reliability and duration.
- Two-Step Insertion:
- Peel the adhesive and stick to skin
- Squeeze sides for insertion—“boom, insertion’s done.” [17:29]
Mobi Tubeless
- Not Just a New Pump: It’s a new infusion set (“sled”) option for Mobi users to wear their pump tubeless/patch-style.
- Easy Swap: Users can switch between tubed and tubeless by changing the infusion set.
- Insurance/Supply Chain: Details with payers/insurers/logistics still being worked out.
- Timeline: Targeting a 2026 launch for Mobi Tubeless, which will use Steady Set technology.
“Mobi Tubeless … will utilize the steady flow technology, making it a patch wear option that is also kink resistant and extended wear … truly transformational.” — Marisa [15:04]
Order of Launch
- Mobi Tubeless First: Tandem is prioritizing Mobi Tubeless before the broader commercial release of Steady Set.
- Steady Set Compatibility: Will be available for both Mobi and T Slim X2.
“We totally recognize the urgency to improve the infusion set experience for our patients.” — Marisa [22:53]
7. Listener Questions & Requested Features
- 5-inch Tubing: Will be offered on all new platforms going forward [23:45].
- App Updates/Feature Requests:
- Extended bolus via app, improved alarms, and timers for features like Exercise Mode are all in the pipeline, with focus on achieving feature parity between T Slim and Mobi.
- “We are really focused on making sure that we get to a place where the features on Mobi are at parity with T Slim.” — Marisa [25:17]
- Caregiver/Parent Follow App:
- A new Caregiver follow app based on SugarMate is coming “very, very soon,” initially for Dexcom/Libre users; real-time monitoring to expand in 2026.
"It will be built off of the original Sugar Mate platform that we acquired … very, very soon.” — Marisa [26:08]
- Real-Time Data Clarification: Stated upload process is not real-time; plans to improve monitoring capabilities are underway [26:52].
8. Algorithm Advances & Mealtime Management
- Rocket AP (Artificial Pancreas):
- Tandem is prioritizing fully closed loop insulin delivery.
- Collaboration with University of Virginia to expedite next-generation algorithm research and clinical application.
- Goal: Allow users to personalize mealtime management—fully automated or with user input.
- No specific timeline for new algorithm rollouts yet—pivotal trial planning ongoing.
“Our vision … is intended to ensure that patients can personalize how they manage mealtime … with fully closed loop, they can have no engagement at all.” — Marisa [28:24]
9. Shortage and New Product Pipeline
- 5-inch Tubing Shortage: Temporary manufacturing hiccup with the unique 5-inch sets will be resolved soon [30:00].
- SIGI Patch Pump:
- Still in development, but focus is on Mobi Tubeless for near future.
- SIGI is a pure-play, patch-only pump—development ongoing but no new details or timelines.
“Mobi Tubeless is our near term focus … SIGI, again, is the patch only design … we're continuing to refine that technology platform.” — Marisa [31:15]
10. Additional CGM Integrations
- Eversense & Others: Open to more CGM integrations but nothing specific to announce; iCGM designation is first hurdle [33:00].
11. Personal Reflections & Passion
- Work at Tandem:
- Marisa genuinely enjoys shaping products that respond to direct patient needs and sees Tandem as an impactful, mission-driven company.
“The work that I get to do at Tandem Diabetes is probably some of the most amazing work that I’ve gotten to do ... It's just really, really exciting.” — Marisa [33:46]
Notable Quotes & Memorable Moments
- “Diabetes is not one size fits all.” — Marisa Fienup [06:28]
- “Now that we've launched Libre 3 with T Slim, we will be moving as quickly as possible to offer it on MOBI as soon as possible ...” — Marisa [09:32]
- “You will … line it up, squeeze on both sides, and boom, insertion’s done.” — Marisa (on Steady Set) [17:29]
- “We are really focused on making sure that we get to a place where the features on Mobi are at parity with T Slim.” — Marisa [25:17]
- “Tandem has made it a top priority in our algorithm pipeline to fully close the loop.” — Marisa [28:09]
Timestamps of Key Segments
- 06:00 — Marisa describes her role and background
- 07:14 — Libre 3 integration discussion
- 09:30 — Mobi and Libre 3 integration outlook
- 10:33 — International expansion plans
- 11:13 — Lumev insulin approval and compatibility
- 12:19 — Mobi pump launch feedback
- 14:01 — Steady Set (extended wear) infusion set approval
- 15:04 — Mobi Tubeless details and strategic focus
- 20:11 — Switching Mobi between tubed and tubeless
- 21:45 — Prioritization of Mobi Tubeless over Steady Set
- 23:45 — 5-inch tubing plans and new platforms
- 24:09 — App updates, feature requests
- 26:08 — Caregiver follow app coming soon
- 28:02 — Rocket AP/algorithm pipeline
- 30:00 — 5-inch tubing shortage update
- 30:54 — SIGI patch pump development status
- 33:00 — Additional CGM integrations (Eversense)
- 33:46 — Marisa on her passion for the work at Tandem
Tone and Style
The conversation is engaging, user-focused, and transparent, with Stacey balancing tough, specific questions (often sourced directly from her active listener community) and Marisa responding openly—sometimes with precise details and sometimes candidly noting where answers are not yet available.
Overall Summary
This episode delivers an in-depth, user-oriented look into Tandem Diabetes’ latest developments and roadmap. Highlights include the major new Libre 3 integration, affirmation of Tandem’s commitment to options and user flexibility, new infusion set technologies, and clear answers to community-submitted queries about timelines, algorithms, and insurance logistics. The tone is both optimistic and realistic, with the host and guest showing clear investment and excitement for how these innovations will impact people living with type 1 diabetes.