Pfizer to discontinue twice-daily weight loss pill due to high rates of adverse side effects

Biotech
Friday, December 1st, 2023 4:44 pm EDT

Key Points

  • Pfizer Halts Development of Twice-Daily Weight Loss Pill: Pfizer announced the discontinuation of the twice-daily version of its experimental weight loss pill due to significant tolerability issues observed in a mid-stage clinical study. Despite patients experiencing substantial weight loss, the high rates of adverse side effects, mainly mild and gastrointestinal, led to a significant portion of patients ceasing the use of the drug.
  • Impact on Pfizer’s Market Aspirations and Investor Sentiment: The decision dealt a blow to Pfizer’s aspirations in the booming $10 billion weight loss drug market. The setback led to a more than 6% decline in Pfizer’s stock, reflecting investor concerns. This development compounds previous skepticism, as Pfizer had earlier scrapped a different once-daily pill in favor of the less appealing danuglipron, putting the company behind leading players Eli Lilly and Novo Nordisk in the competitive weight loss drug market.
  • Future Plans and Challenges for Pfizer: While the twice-daily formulation will not advance to Phase 3 studies, Pfizer still plans to release data on a once-a-day version in the first half of 2024. The company aims to assess this data before deciding on a potential phase three study for the once-daily pill, perceived as a more competitive form of treatment. The hope is that a once-daily version could address tolerability issues, particularly gastrointestinal side effects. However, skepticism remains among analysts, with doubts about the once-daily version significantly improving tolerability. The weight loss achieved by the twice-daily danuglipron fell short of analyst expectations, raising questions about Pfizer’s competitiveness in the weight loss drug market.

Pfizer announced on Friday that it would halt the development of the twice-daily version of its experimental weight loss pill due to high rates of adverse side effects observed in a mid-stage clinical study. Although obese patients taking the drug experienced significant weight loss, the pharmaceutical company found that many had difficulty tolerating the medication. The adverse events, primarily mild and gastrointestinal in nature, led to a notable percentage of patients discontinuing the pill. Pfizer aimed to provide a more convenient alternative to popular weight loss injections with this formulation.

The decision means that the twice-daily danuglipron formulation will not progress to Phase 3 studies. However, Pfizer still intends to release data on a once-a-day version of the drug in the first half of 2024. This data will shape the company’s decision on whether to initiate a phase three study for the once-daily pill, which is considered a more competitive form of the treatment.

Pfizer’s stock experienced a more than 6% decline following the announcement of the trial results. The setback represents a blow to Pfizer’s aspirations to secure a significant share of the lucrative $10 billion weight loss drug market. The company had been counting on a successful weight loss pill to offset declining demand for its COVID-19 products and a substantial share price drop.

Investor pessimism had already set in after Pfizer abandoned a different once-daily pill in June, opting for the less appealing danuglipron. With Friday’s data, Pfizer finds itself trailing behind leading players in the weight loss drug market, Eli Lilly and Novo Nordisk, both racing to develop pill versions of their blockbuster weight loss and diabetes injections.

The phase two trial involved around 600 obese adults without Type 2 diabetes, evaluating the drug’s impact on weight loss over 26 or 32 weeks at various dosage levels. Pfizer’s pill, like Novo Nordisk’s Wegovy and Ozempic, mimics a gut hormone called GLP-1, signaling fullness to the brain. While the trial demonstrated statistically significant reductions in body weight, high rates of adverse events, particularly gastrointestinal issues, were observed.

Patients taking the twice-daily pill experienced weight loss ranging from 6.9% to 11.7% at 32 weeks and 4.8% to 9.4% at 26 weeks. Comparatively, the placebo group gained 1.4% at 32 weeks and 0.17% at 26 weeks. Adjusting for the placebo’s weight gain, the twice-daily pill caused 8% to 13% weight loss on average at 32 weeks and 5% to 9.5% at 26 weeks.

The adverse events led to over 50% of patients across all doses discontinuing the pill, compared to about 40% in the placebo group. Notably, no new safety issues were observed, and danuglipron did not elevate liver enzymes, unlike Pfizer’s previous discontinued weight loss pill.

Analysts had predicted the tolerability issues, with concerns about the higher discontinuation rate for Pfizer’s twice-daily danuglipron compared to Eli Lilly’s once-daily pill. Pfizer’s total daily dose was significantly higher, potentially causing more adverse effects. Additionally, the phase-two trial did not allow for dose reduction over time, unlike Eli Lilly’s trial.

Despite the setback, there is hope that patients may better tolerate the once-daily version of danuglipron. Pfizer believes that a once-daily formulation could reduce gastrointestinal side effects, providing a more acceptable option for patients. However, skepticism remains, with some analysts expressing doubt that a once-daily version will significantly improve tolerability.

The weight loss achieved by twice-daily danuglipron fell short of analysts’ expectations, who were looking for a more competitive 14% to 15% weight loss. Pfizer faces tough competition from Eli Lilly and Novo Nordisk, whose pills have shown superior results, with Eli Lilly’s once-a-day pill leading the pack.

In conclusion, Pfizer’s decision to halt the twice-daily version of its weight loss pill due to tolerability issues and adverse events poses a setback to the company’s aspirations in the weight loss drug market. The focus now turns to the release of data on the once-a-day version, slated for the first half of 2024, as Pfizer seeks to navigate challenges and competition in this lucrative sector.

For the full original article on CNBC, please click here: https://www.cnbc.com/2023/12/01/pfizer-to-discontinue-twice-daily-version-of-weight-loss-pill.html