Paul Edick
Analyst · Mizuho Group
Thanks, Allison. Good morning to everyone who's listening. We appreciate your interest in Xeris and our discussion this morning. Xeris had a very strong second quarter, especially with Gvoke following a strong first quarter and maintaining momentum with our -- with what is clearly our #1 priority. We've shown steady and consistent progress in all leading indicators for the core business. We also announced a major move in the process of transitioning our business to a commercially focused rare disease and specialty pharma company as well as a number of other key achievements.
I'll start with a few highlights. The major highlight of the second quarter was the continued strong demand for Gvoke, driven by the HypoPen sales, as evidenced by impressive increases in several key metrics that I'll share with you shortly. Equally important was the announcement of the proposed acquisition of Strongbridge Biopharma, a major step to becoming a more commercially focused, rare disease and specialty pharma company, which we'll discuss in more detail as well in my follow-on remarks.
We also found in Tetris Pharma a great U.K. and EU partner to prioritize the commercialization of Ogluo in that territory. We received FDA approval during the quarter for an extended shelf life of the Gvoke 1 milligram HypoPen and prefilled syringe, moving from 24 months to 30 months at room temperature. We renegotiated our Oxford-SVB venture debt facility to extend our cash runway. And based on feedback -- FDA feedback, we determined it was best to terminate the mini-dose post-bariatric hypoglycemia prevention program and advance our micro-dose, exercise-induced hypoglycemia prevention program with an interim Phase II study in a broader diabetes population, which we'll talk further about as well.
Let me start with Gvoke. Since the launch of Gvoke HypoPen, a strong foundation has been built and our growth is beginning to accelerate. Although overall market growth is not yet back to pre-pandemic growth of 20% to 30% that we have seen, the market showed modest growth of 5% in the second quarter. However, our market share in the second quarter improved by 18% from the first quarter and is now approaching 16% of the new prescription market at the end of June, significantly outpacing the overall glucagon market.
We do see modest signs of acceleration, driven by the innovative ready-to-use brands like Gvoke. Compared to the first quarter, Gvoke prescription volume was up 32% in the second quarter. Gvoke unit sales to wholesalers and direct customers were up 36% in the second quarter, and net sales were up 10% in the same quarter. We've also increased the number of unique prescribers of Gvoke by 30% in the quarter.
The end result was a very strong performance at the gross sales level not fully reflected in our net sales number, only mostly to our gross to net being negatively impacted by: one, continuation of the $0 co-pay, which we think is extremely important; and two, wholesaler and indirect returns of the PFS product that was sold prior to June 2020. We don't see returns as a recurring event, especially for the 1-milligram HypoPen, which, as I mentioned, now has 30-month dating from manufacture.
With our expanded sales force with approximately 135 customer-facing people, including our inside sales group, we are now able to target approximately 20,000 endocrinologists, pediatric endocrinologists and top decile primary care physicians. We're seeing momentum in our effort to expand ready-to-use glucagon prescribing to the 6 million-plus insulin-taking people with diabetes who currently don't carry glucagon. We've developed and are currently launching an integrated campaign to pediatric endocrinologists during the fast approaching critical back-to-school season. These physicians drive the natural periodic third quarter spike in glucagon prescriptions.
Of course, this is assuming we have a more normal back-to-school this year. As we see COVID resurging again due to the Delta variant around the country, we're closely monitoring the nature of in-person school reopenings around the country, and we'll be anxiously awaiting children returning to school. We'll see what looks like.
Turning to Ogluo in our European glucagon brand. I want to remind everyone of our approach and process with Ogluo in the U.K. and the EU. We originally viewed this ex-U.S. territory as having very limited potential based on reimbursed pricing of the legacy Novo kits. In fact, we had analyzed and reported that we'll be losing proposition to launch anywhere in the region and then reimbursed prices -- after then, reimbursed prices of the legacy kits. Therefore, our going-in assumption was the only viable strategy would be to launch in a select few countries for the self-pay market only. We were thus not looking for a commercial partner, but rather contracted distributors in select markets.
What changed in early 2021 was the successful -- the success of the Lilly launch and the levels at which they're getting reimbursed pricing in many countries as well as the higher-than-expected prices people are paying out of pocket in countries where Lilly is not yet even reimbursed. As a result, and since Ogluo's approval in the EU in February of 2021 and in the U.K. at the end of April of 2021, we had several inbound inquiries and also started our own outbound partnering outreach.
Speaking with several potential partners. Our priority was getting a partner who would prioritize Ogluo and put the kind of time and attention necessary into making it a success in the territory. Essentially, for Ogluo to get the attention it deserves, it needed to be in the hands of a company for whom success of Ogluo would be -- Ogluo, that is a hard name to pronounce -- for whom success would be absolutely critical to their overall success as a company. And as you know, a few weeks ago, we announced that we had found, in Tetris, a great partner. Tetris is a U.K.-based company founded by a leadership team of complementary and highly experienced individuals from U.K. and international pharmaceutical companies. They're scaling up in the U.K. for launch, and they're expanding across the EU. We're also very excited by their entrepreneurial approach to their organization.
Starting in 2022 and over several subsequent years, Tetris could potentially receive up to $71 million in payments tied to the first commercial sale and other time launch and sales-related milestones as well as collecting a mid-single-digit royalty on net sales. Tetris anticipates that Ogluo will be available in the U.K. later this year and launched subsequently in additional countries as individual country pricing and reimbursement is secured.
Now let me provide an update on our mini- and micro-dose, ready-to-use glucagon programs. As we've reported, we've spent the past several months in dialogue with the FDA trying to find a reasonable clinical pathway in order to advance our ready-to-use mini- and micro-dose glucagon programs.
As you recall, that is prevention of post-bariatric hypoglycemia and prevention of the exercise-induced hypoglycemia, both into Phase III. We've gotten all the feedback we need and have made decisions on both programs. In short, the new FDA requirements for these programs to enter full Phase III development are far too costly and complex for us to contemplate any Phase III work at this point on either program. For PBH, we have discontinued further clinical development. For EIH, based on FDA feedback and specific underlying data requirements, we will develop and execute an additional Phase II study in prevention of exercise-induced hypoglycemia to examine the efficacy and safety of long-term use in a broader range of type 1 and type 2 patients. That -- patients that exercise at least twice a week. We will anticipate initiating the study in early 2022.
Now on to the rest of the pipeline. With our intensified focus on the commercial business, especially with the anticipated close of the Strongbridge Biopharma acquisition, we are reprioritizing our approach to our pipeline, and we'll focus our development efforts going forward, solely on products for our own potential commercialization.
Now what do I mean by that? First, like our liquid stable diazepam and pramlintide-insulin combination, we're never intended towards Xeris development beyond Phase II. The intent was to develop these products to, first, prove that our XeriSol technology was applicable beyond glucagon; and second, to out-license them for further development to other companies. We've clearly, with these products, proven the technology is broadly applicable.
However, the competitive landscape has changed rather rapidly making out-licensing more difficult. That said, we will continue to look for development and commercialization partners to advance both of our XeriSol pramlintide-insulin co-formulation program and our diazepam program. Our goal is to find suitable partners. However, we will otherwise not spend additional resources on advancing these assets.
We will continue to advance our 2 undisclosed programs in endocrinology and gastroenterology as they have high potential for development and commercialization in our primary area of current commercial focus and an adjacent therapy area in which we have a development program underway. We will also continue to look for partners and/or out-license our unique technologies to companies for whom our formulation science may create a competitive advantage. We currently have 3 such programs that continue to advance in proof-of-concept, and all in the top 10 pharma companies, and we're in discussions on additional potential projects as we speak.
Now I'd like to spend some time discussing the Strongbridge Biopharma acquisition and revisiting why this is the perfect combination in our mind for Xeris. First, by bringing Xeris and Strongbridge together, we're creating a scalable and diversified biopharmaceutical company increasingly oriented towards more specialty and rare disease products. We will have a stronger revenue base with 2 rapidly growing assets, Gvoke and KEVEYIS. We will also have the opportunity for a near-term launch of RECORLEV. And subject to FDA approval, we will be well positioned to leverage Xeris' experienced, endocrinology-focused commercial infrastructure to bring RECORLEV to market.
Our commercial footprint in endocrinology is larger than Strongbridge had envisioned for the launch of RECORLEV, enabling a greater potential reach at launch. We will also have an overall more robust rare disease and endocrinology-focused commercial infrastructure into which we can add additional products benefit in a broader range of patients.
We also expect that new products will be brought forward in these therapeutic areas using our unique formulation technology platforms to put into our larger and scalable infrastructure for continued development of specialist-oriented and rare disease products from XeriSol and XeriJect. Furthermore, with a stronger financial and strategic foundation, we see the potential opportunity to participate in the consolidation of commercial and late-stage products and companies focused on endocrinology, neurology, gastroenterology and rare diseases. We also have the potential to realize significant synergies and substantial cost avoidance. And importantly, we believe this combination will provide significant benefits to all of our stakeholders and will position us to drive enhanced value for shareholders.
Now transitioning to our finance specifics of our quarter, I want to talk just briefly about the change in our CFO. In April of 2018, we were readying for our IPO. It was important that we have a finance leader who could build the team we would need as a new public company and guide our financing debt and reporting efforts as a development-stage company. Barry Deutsch stepped into that role and has built a superb team that stewarded our finances for the last 3 years, culminating in the pending close of the Strongbridge acquisition. Barry and I believe the next stage for Xeris as an increasingly commercially focused, larger and more complicated company needs the appropriate leader out -- of our finance team for that stage.
Barry has been mentoring Steve Pieper for several years, and Steve has a significant background in commercial finance. We believe Steve is what Xeris needs for the next stage of our development. And as such, has recently been tapped to succeed Barry as our CFO. I want to thank Barry for everything he's done for the company. And I want to welcome Steve to the role. And now I'll turn it over to Steve to review the highlights of our financial performance.