Pfizer Withdraws Sickle Cell Disease Treatment

By Kashish Tandon and Christy Santhosh
(Reuters) – Pfizer (NYSE:PFE) announced on Wednesday its decision to withdraw its sickle cell disease treatment due to associated death risks, which analysts believe may expedite trials for new competing therapies.

Oxbryta Overview

Oxbryta is among at least six treatments available for sickle cell disease, primarily used by patients with mild-to-moderate symptoms. This drug received accelerated approval in the U.S. in 2019, pending further trials to validate its benefits.

Regulatory Concerns

The European Medicines Agency raised alarms in July regarding deaths in two Oxbryta trials. Following a Thursday meeting, the agency expressed serious safety concerns and recommended an immediate suspension of the drug’s authorization.

The U.S. Food and Drug Administration (FDA) is also reviewing safety data from post-marketing clinical reports and will assess real-world registry studies, planning to communicate additional findings as required.

Impact on Competitors

Wall Street analysts from at least three brokerages noted that the withdrawal might drive an urgent need to accelerate trials for alternative treatments, including Agios Pharmaceuticals’ mitapivat and Fulcrum Therapeutics’ pociredir. Analysts from Leerink pointed out that enrollment in Fulcrum’s early-stage trial has been challenging.

For Agios, the withdrawal could heighten pressure on regulators for an expedited review. Piper Sandler analysts indicated that if mitapivat proves effective in alleviating painful episodes associated with sickle cell disease, this could simplify regulatory review under current circumstances.

Agios shares increased by 4% before losing ground, while Fulcrum shares surged over 17% on Thursday.

Gene Therapies

Two recent gene therapies, Bluebird Bio’s Lyfgenia and Vertex Pharmaceuticals (NASDAQ:VRTX) partnered with CRISPR Therapeutics’ Casgevy, target severe forms of sickle cell disease.

The cessation of Oxbryta likely forces most patients with mild-moderate symptoms to resort to hydroxyurea, a chemotherapy drug, according to Stifel analyst Dae Gon Ha.

Sickle cell disease affects around 100,000 individuals in the U.S., predominantly impacted are Black patients.

Broader Implications for Pfizer

This withdrawal adds to ongoing challenges for Pfizer and its CEO Albert Bourla, as the company faces declining sales for its COVID vaccines and drugs, a weaker-than-anticipated launch for its respiratory syncytial virus (RSV) vaccine, and unsatisfactory clinical outcomes for an obesity treatment.

Consequently, Pfizer’s shares saw a modest decline on Thursday, now trading at about half their pandemic highs.

Oxbryta played a pivotal role in Pfizer’s $5.4 billion acquisition of Global Blood Therapeutics (NASDAQ:GBT) in 2022, which was part of a series of investments made possible by pandemic profits. The company also acquired two other experimental sickle cell treatments still under clinical trials.

In sickle cell disease patients, red blood cells morph into a sickle or crescent shape, leading to strokes, organ damage, premature death, and extreme pain crises.