Second lenacapavir PrEP study shows 99.9% efficacy in the PURPOSE 2 trial: ACT UP London challenge pricing

26 September 2024. Related: HIV prevention and transmission.

Simon Collins, HIV i-Base

On 12 September 2024, Gilead issued a press release with results from a planned interim analysis from the large international placebo-controlled PURPOSE 2 study. [1]

PURPOSE 2 is being run in Argentina, Brazil, Mexico, Peru, South Africa, Thailand and the US, in cisgender men and trans and non-binary people, all who have sex with men. [2]

The only efficacy data reported were the top-line results that there were two cases of incident HIV in 2180 participants receiving lenacapavir, showing 99.9% efficacy.

Lenacapavir, given as a 6-monthly subcutaneous injection after a short oral lead-in, was also significantly more effective in PURPOSE 2 than the control arm using daily oral TDF/FTC.

These results led the study DSMB to recommend stopping the randomised phase of the study early in order to offer all participants open-label lenacapavir.

This news was keenly awaited after results from the similarly-designed PURPOSE 1 in cisgender women in Southern Africa were presented at the IAS conference in Munich. [3]

Follow-up will continue in all participants.

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Such astonishing efficacy results carry the ethical responsibility for Gilead to ensure effective and fair global access. This includes the challenge to set a price that is affordable to health settings in high, low and middle-income countries. [4, 5]

Although Gilead have said they are committed to pricing that will enable broad access, and that this will be very different to the current annual US list price of $44,000 for MDR treatment, the company has not engaged with the Medicines Patent Pool, for example, to transfer licences and technology that would enable involvement of generic manufacturers.

ACT UP protest outside Gilead Sciences HQ in London

This was the focus of a protest outside Gilead’s offices on Tuesday 24 September by ACT UP London. The group also handed in a letter demanding affordable pricing in all countries and the importance of including generic manufacturers to meet global demand. [6]

Once lenacapavir receives regulatory approval for a PrEP indication, global demand is likely to be immediate and extensive, and will likely need multiple manufacturers.

A timeline for proposed regulatory submissions has also not yet been released, but profile of lenacapavir for PrEP warrants WHO prequalification and inclusion on the list of essential medicines, both of which would help with fast-track regulatory approval in individual countries.

This report was first published on 15 September 2024 and updated on 26 September to refer to the London protest.

References

1. Gilead press release. Gilead’s twice-yearly lenacapavir for HIV prevention reduced HIV infections by 96% and demonstrated superiority to daily Truvada in second pivotal phase 3 trial. (12 September 2024).
   https://www.gilead.com/news-and-press/press-room/press-releases/2024/9/gileads-twiceyearly-lenacapavir-for-hiv-prevention-reduced-hiv-infections-by-96-and-demonstrated-superiority-to-daily-truvada-in-second-pivotal-ph
2. clinicaltrials.gov. Study of lenacapavir for HIV pre-exposure prophylaxis in people who are at risk for HIV infection (PURPOSE 2).
   https://clinicaltrials.gov/study/NCT04925752
3. i-Base. AIDS 2024: Lenacapavir as PrEP is “beyond wonderful” but PURPOSE 1 study tells us so much more. (HTB July 2024).
   https://i-base.info/htb/48260
4. UNITAID. Unitaid renews call for clear access strategy after positive results from Gilead’s PURPOSE 2 lenacapavir trial. (13 September 2024).
   https://unitaid.org/news-blog/unitaid-renews-call-for-clear-access-strategy-after-positive-results-from-gileads-purpose-2-lenacapavir-trial/#en
5. UNITAID. Unitaid calls for accelerated global access to long-acting HIV prevention drug lenacapavir after positive trial results. (21 June 2024).
   https://unitaid.org/news-blog/unitaid-renews-call-for-clear-access-strategy-after-positive-results-from-gileads-purpose-2-lenacapavir-trial/#en
   
6. ACT-UP London. Activists demand global access to miricle HIV prevention drug. (24 September 2024).
   https://actuplondon.wordpress.com/2024/09/24/for-immediate-release-gileads-greed-kills-activists-demand-global-access-to-miracle-hiv-prevention-drug/