Thanks, Paul, and thank you, Todd, for the earlier introduction. As Todd mentioned, I'll be touching on a few of our pipeline programs, namely Zelsuvmi, Filspari, ensifentrine and V116. But first, I'd like to just make a few comments on today's Agenus announcement. .
Regarding Agenus' BOT/BAL, this is an exciting program, and in my view, the potential impact on colorectal cancer is very promising. Approximately 900 patients have been treated with BOT/BAL in clinical trials across 9 different difficult-to-treat solid tumor cancers. The novel therapeutic regimen has demonstrated the potential to be combined with chemotherapy and other standard of care therapies and as an immunotherapy only combo in colon rectal cancer, one of the most prevalent solid tumors globally.
In April 2023, Agenus was granted Fast Track Designation from the FDA, for the investigation of the BOT/BAL combination in patients with metastatic relapsed/refractory microsatellite stable, CRC with non-liver metastases. Botensilimab is an investigational, multifunctional, anti-CTLA-4 immune activator designed to boost both innate and adaptive antitumor immune responses.
Its novel design potentially leverages mechanisms of action to extend immunotherapy benefits to cold tumors, which generally respond poorly to standard of care or are refractory to conventional PD-1 CTLA-4 therapies and other investigational therapies. Botensilimab potentially augments immune responses across a wide range of tumor types by priming and activating T-cells, down-regulating intratumor regulatory T-cells, activating myeloid cells and inducing long-term memory responses.
Okay. Let me move on to the next slide and focus now on Zelsuvmi. Zelsuvmi approved by the FDA, January 5, 2024, and is a first-in-class nitric oxide releasing product for the treatment of molluscum contagiosum, a highly contagious viral skin infection, predominantly affecting children with no other approved at-home treatment.
Molluscum is a poxvirus causing chronic dome-shaped skin papules with a central indentation and can appear multiple lesions anywhere on the body, lasting from 6 to 8 months and even up to 5 years. Zelsuvmi is approved for pediatric patients, 1 year of age and older and adults. Molluscum affects an estimated 6 million children and up to 5% of the general population in the U.S.
This FDA-approved treatment can be applied by patients, parents or caregivers at home outside of the physician's office. One of the challenges of treating molluscum has been the available destructive therapies such as cryotherapy and [ caratage ] have major drawbacks, especially for children, such as pain and potential for scarring. So Zelsuvmi is a much more patient-friendly treatment. Even though molluscum can affect quality of life, cause social distress and persist for many months or years, approximately 70% of children go untreated.
Therefore, the at-home treatment is a distinct advantage for both treatment and compliance. Zelsuvmi's ease of use as well as being available for children as young as 1, will hopefully open the doors for more treatment, for this disfiguring contagious viral illness. As recently disclosed in our press releases, we have created a new stand-alone company called Pelthos Therapeutics that will commercialize Zelsuvmi. This company creation effort is very similar to our prior efforts related to Viking Therapeutics and Primrose Bio.
Pelthos will be operated fully independent of Ligand, although we expect to own a significant equity stake in the business at inception. We are excited to have attracted the talented leadership of Scott Plesha, and our 2 highly experienced independent directors, Peter Greenleaf and Matt Pauls.
Let's turn to ensifentrine with an FDA PDUFA date of June 26. Verona Pharma is developing and commercializing ensifentrine, a novel, selective, dual inhibitor of phosphodiesterase, PD-3 and PD-4 for maintenance treatment of COPD by inhalation therapy. Both Phase III efficacy and safety trials, ENHANCE-1 and 2 met the primary bronchodilation FEV1 endpoint. Improvement of symptoms was shown across trials and the rate and risk of exacerbation were reduced in a clinically meaningful and consistent manner in the trial.
Many COPD patients remain symptomatic even on multiple therapies. Ensifentrine can be used in combination with other approved products and potential competitors. And there is no need to take into consideration smoking status or eosinophilia. Verona estimates there are over 8 million COPD patients currently receiving chronic treatment in the U.S. alone. Over half of whom are dissatisfied with their current treatment regimens.
If approved, ensifentrine could offer an effective add-on or alternative treatment with a good safety profile to address both symptoms and exacerbations. Verona is currently building its commercial infrastructure to prepare for launch, following potential approval in June. Ligand will earn a milestone of approximately $5 million upon approval and $14 million upon launch of ensifentrine. Ligand benefits from a low single-digit royalty on ensifentrine and we believe the program could be another of our key growth drivers.
Moving on to Filspari. The FDA granted an accelerated approval in February 2023, as the first and only non-immunosuppressive therapy for primary IgA nephropathy in patients with a urinary protein-to-creatinine ratio equal to or greater than 1.5 gram, per gram.
And Travere filed an supplemental NDA for full approval March 11, 2024 here in the U.S. In the EU, Filspari received the European Commission approval for a conditional marketing authorization for the treatment of adults with primary IgAN with the urine -- sorry, with the urine protein excretion equal to or greater than 1.0 grams per day, or urine protein-to-creatinine ratio equal or greater to 0.75 gram per gram.
Filspari is a once-daily, oral medication that directly targets glomerular injury in the kidney, by blocking 2 critical pathways of IgAN disease progression, endothelin-1 and angiotensin II, with potential to be a mainstay for those who don't respond to single-agent ACE or ARB. Just yesterday, Travere announced that the FDA granted priority review of their sNDA to convert Filspari from accelerated approval to full approval for the treatment of IgAN in the U.S.
The FDA assigned PDUFA target action date is September 5, 2024. Filspari is one of our key growth drivers. Travere reported Q1 revenue numbers yesterday afternoon, and the quarter came in nicely with sales of $19.8 million. Travere also continued to disclose the momentum on new patient recruitment. Travere had 511 new patient forms submitted in Q1, bringing the total, since launch, to 1,963.
The continued steady addition of potential new patients provides good evidence of future revenue potential. Filspari appears to be on track to meet consensus estimates for 2024, which are at approximately $110 million of revenue for the year.
In Europe, CSL Vifor, expects to launch Filspari in the second half of 2024. We earn a 9% royalty on net sales, and we expect that this will be a significant driver of long-term growth for our royalties. Moving on to Merck's V116. V116 is a 21-valent pneumococcal vaccine for the prevention of invasive pneumococcal disease in pneumococcal pneumonia. It is potentially the first pneumococcal conjugate vaccine specifically designed for adults, including 8 unique serotypes not at any currently approved vaccine.
According to Merck, V116 is specifically designed to prevent adult invasive pneumococcal disease and the serotypes covered account for approximately 83% and of pneumococcal disease in adults 65 and older for CDC data from 2018 to '21. Immune responses were seen to all 21 serotypes and a diversity of adult patients, regardless of immune status or previous vaccine status and higher than comparators in immune response for the serotypes unique to V116.
The FDA granted V116 priority review, and we await the fast approaching PDUFA date June 17. We will earn a low single-digit royalty on V116. We would earn a $2 million milestone upon the approval of V116. And with that, I will turn it over to Matt for more comments on the portfolio.