DUBLIN--(BUSINESS WIRE)--The "Disease Analysis: HIV Pre-Exposure Prophylaxis (HIV PrEP)" report has been added to ResearchAndMarkets.com's offering.
Since its initial US and EU approvals for HIV pre-exposure prophylaxis (PrEP) in 2012 and 2016, respectively, Truvada's PrEP-specific sales have steadily risen to blockbuster levels, with estimated 2019 PrEP sales of $2,279m in the US and five major European markets.
Truvada's strong performance has been driven by its status as the only approved therapy for PrEP until Descovy's US approval in October 2019, the favorable recommendations for its use in US CDC and WHO guidelines, and reimbursement by the healthcare systems of four of the five major European markets in either national or pilot programs.
However, PrEP remains underutilized due to poor awareness and lack of/limited reimbursement in some European countries, though uptake is increasing due to recent favorable reimbursement decisions in Germany, Spain, England, Wales, and Northern Ireland, as well as Gilead's marketing efforts.
The US has the highest rate of uptake (estimated at 22.6% of at-risk individuals in 2020) and generates the majority of global PrEP revenues, though the October 2020 launch of generic versions of Truvada has triggered a steep decline in the drug's sales. Within the EU and UK, Truvada is the only approved agent for PrEP but generates minimal sales due to generic competition since July 2017. PrEP uptake is also estimated to be much lower in the five major European markets (5.3% in 2020), due partially to a historical lack of reimbursement in some countries and continued lack of reimbursement in Italy.
In order to protect PrEP revenues from generic versions of Truvada, since October 2019 Gilead has been promoting swapping to Descovy, which has displayed non-inferior efficacy and marginal improvements in bone and renal safety.
Despite the COVID-19 pandemic reducing interaction between physicians and their patients, Gilead has successfully converted approximately half of patients to Descovy (46% market share versus 54% for Truvada as of the end of Q3 2020), due largely to Descovy being priced at parity to Truvada. However, in October 2020, Teva launched the first generic version of Truvada, which will severely limit further swapping to Descovy as widespread use of Descovy in patients with no pre-existing renal or bone risk factors is unlikely to be deemed as cost effective compared to lower-cost generic Truvada.
Descovy does have a potential growth opportunity in the planned HIV Women's Prevention Study, which is expected to begin in mid-2021 and will support its US approval in adolescents and adult women (the FDA refused to approve Descovy for women as the sole pivotal DISCOVER trial only included men who have sex with men [MSM] and transgender women).
However, if trial timelines are comparable to the DISCOVER trial, supplementary approval for use in women is unlikely to occur until late 2024, leaving Descovy little time to capitalize on the new indication before its anticipated patent expiry in June 2025. It also seems likely that Gilead will shift its PrEP development focus to its six-monthly subcutaneously administered lenacapavir, which would be more competitive against longer-acting pipeline rivals and was added to the HIV Women's Prevention Study in December 2020.
There are currently six agents in clinical development for pharmacological PrEP, comprising five antiretrovirals and a single broadly neutralizing antibody. All of the pipeline agents aim to offer less frequent dosing schedules in order to address the issue of suboptimal adherence to once-daily Truvada/Descovy, which can result in impaired effectiveness in real-world practice. Notable threats to Truvada/Descovy include ViiV Healthcare's Vocabria, which is dosed intramuscularly every two months (eight weeks) and has already demonstrated superior efficacy compared to Truvada in the HPTN 083 (cisgender men and transgender women) and HPTN 084 (cisgender women) trials.
Vocabria's bimonthly administration could be very attractive to patients who struggle to adhere to daily pills, though its injectable nature and requirement for physician administration will deter some patients, meaning Descovy will still be able to maintain some market share following Vocabria's anticipated US launch in late 2021/early 2022. Merck & Co's oral once-monthly islatravir is another major threat, as a once-monthly option should greatly improve adherence while avoiding the need for physician administration, though no in-human proof-of-concept efficacy data are currently available for islatravir in the PrEP setting.
The overall likelihood of approval of a Phase I antiviral asset is 13.1%, and the average probability a drug advances from Phase III is 68.3%. Antiviral assets, on average, take 8.5 years from Phase I to approval, which is slightly less than the average of 9.0 years for the overall infectious disease space.
Key Topics Covered:
OVERVIEW
- Latest key takeaways
DISEASE BACKGROUND
PHARMACOLOGICAL PREVENTION
EPIDEMIOLOGY
MARKETED DRUGS
PIPELINE DRUGS
KEY REGULATORY EVENTS
- First PrEP In China: Gilead Faces Changing Market For Truvada
PROBABILITY OF SUCCESS
CLINICAL TRIAL LANDSCAPE
DRUG ASSESSMENT MODEL
- Truvada
- Descovy
- Vocabria
- Islatravir
MARKET DYNAMICS
FUTURE TRENDS
- Uptake of PrEP is expected to continue following positive European reimbursement decisions in recent years, in addition to the launches of additional options with more convenient dosing
- Dominance of generic Truvada has limited growth of the European market, but Vocabria's potential to improve adherence and effectiveness will drive growth
- Vocabria is expected to become the top-selling therapy through 2026
- Descovy will fail to fully preserve Gilead's US PrEP revenues because of competition from Vocabria, islatravir, and generic Truvada
- Oral once-monthly islatravir is expected to become the new standard of care from 2025 if improved adherence translates into superior effectiveness compared to Truvada/Descovy
CONSENSUS FORECASTS
RECENT EVENTS AND ANALYST OPINION
- Vocabria for HIV Prevention (November 9, 2020)
- Vocabria for HIV Prevention (May 18, 2020)
- Descovy for HIV Prevention (August 7, 2019)
- Descovy for HIV Prevention (August 5, 2019)
KEY UPCOMING EVENTS
UNMET NEEDS
- Greater awareness and access to PrEP
- Longer-acting agents with less frequent dosing regimens, particularly in women
BIBLIOGRAPHY
APPENDIX
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