Pfizer’s Oxbryta Was Transformational For My Sickle Cell Warriors. Bring it Back

Mapillar Dahn, founder, MTS Sickle Cell Foundation
Following Pfizer’s voluntary withdrawal of Oxbryta from the global market, a mother of three daughters battling sickle cell disease shares why patients need it as a therapeutic option.
The headline rocked our family to the core.
At 5 pm ET, Sept. 25, 2024, the statement read: “Pfizer Voluntarily Withdraws All Lots of Sickle Cell Disease Treatment OXBRYTA® (voxelotor) From Worldwide Markets.”
This pulled the rug out from under the global sickle cell disease community. We did not see it coming. We weren’t ready for the chaos that ensued.
Oxbryta was the only disease modifying therapy for sickle cell disease that actually worked for my oldest daughter Tully. She’s a college student, and the drug offered her hope for a bright future, free of pain crises. Breaking the news to her, that she could no longer have access to Oxbryta, was one of the hardest things I’ve had to do as a mother.
The day started out beautifully. I had just landed at home in Atlanta after joining other patient advocates in Washington for the Sickle Cell Disease Summit. It was a first-of-its-kind event organized by the US Department of Health and Human Services to highlight progress in research, care, and cures. I was on an emotional high, more hopeful and optimistic than ever about the future of my daughters and all people living with this dreadful disease.
The swing from high to low sent a shock through my system that I still haven’t recovered from nearly four months later. It is a numb sensation that continues to permeate my body.
At first, I was stunned, broken, and saddened. There was no time to process feelings of shock and grief. Instantly, a barrage of messages started coming in from other caregivers, patients, and community members.
“How is this even happening?”
“Are you OK?”
“Do we just stop taking the drug?”
Great questions. I did not have the answers. Pfizer’s announcement was vague, leaving room for a host of interpretations. No guidance was provided on how to go about stopping the therapy. Those questions went to doctors and community leaders.
No one knew what to do.
This loss felt personal.
Prior to the FDA approving Oxbryta in November 2019, hydroxyurea was the only drug on the market for sickle cell disease. It offers a marginal benefit for some but provides no real clinical benefit for almost half of patients. As a mother of three daughters who all suffer from sickle cell disease, I was painfully aware that one medication on the market is nowhere near enough. Millions of patients around the world are suffering and need more treatment options. Patients have long been neglected, and that’s a great injustice.
So, when Oxbryta came along, I fought for it. It wouldn’t have mattered if it worked for my daughters or not. This was a fight of principle. I fought for the right of my children and all patients to have therapeutic options. I fought knowing that, like all medications, Oxbryta will work for some and wouldn’t work for others.
I painted the picture of three sisters — ages 15, 14, and 10 at the time — being hammered by an unpredictable disease that has no boundaries of the types of havoc it wreaks. I shared our challenges with pain crises, a stroke, too many hospitalizations to count, over 10 surgeries, stigma, acute chest syndrome, monthly blood transfusions, jaundice, and so much more.
Before my oldest daughter Tully started taking Oxbryta, she suffered from chronic fatigue, hemoglobin that tethered between mid-6 to low-7 grams per deciliter of blood (normal is 11.5-15 g/dl). Her immune system develops antibodies against the donor blood she’s given, making it difficult and dangerous for her to be transfused.
Oxbryta raised her hemoglobin level, making it less likely for her to need a transfusion. Now, if her hemoglobin drops suddenly, or she needs a higher level for a procedure requiring anesthesia, she will not have Oxbryta to help her. She will instead get daily injections of erythropoietin to try to stimulate her already overworked bone marrow to make more red cells, a painful treatment that is far less safe and effective than Oxbryta. About one in five people with sickle cell disease are hard to transfuse safely and are in the same situation as Tully.
My daughter’s life was shaken by the withdrawal of Oxbryta. She went to the emergency room for a pain crisis three or four times a year when she was on the drug. When the drug was taken away, in the first month, she had to go to the ER every single week.
There is never a good time to need emergency care; however what breaks my heart even more is that this happened during a time when hospitals were out of IV fluids. When the hospitals were forced to ration what little supplies they had, sickle cell patients were unable to get access to these vital fluids. Sickle cell patients like my daughter who were seeking emergency care because of pain were only receiving strong opioids.
Tully missed a lot of school and lost a lot of weight. She is back to being chronically fatigued, jaundiced, with low hemoglobin.
She and many patients who relied on Oxbryta are back to living life without any disease modifying therapy that works for them. In fact, they are back to being defenseless against a monstrous disease that is systematically damaging their organs.
That is not OK.
When Pfizer acquired Global Blood Therapeutics (GBT), the company that developed Oxbryta, we all had concerns about what this meant for the future of sickle cell drug development. Pfizer, the world’s second largest pharmaceutical company, bought out a company that existed unapologetically for the advancement of sickle cell disease. We knew that GBT had other sickle cell compounds in the pipeline and were afraid that they might become a lower priority for development at a big company like Pfizer.
After all, Pfizer had left our community high and dry before, when it was unsuccessful in developing rivipansel to treat acute pain in sickle cell.
Even so, with all of our reservations, while we hated to see GBT go, we prayed that with Pfizer’s global reach, Oxbryta and the other therapies would reach parts of the world that are being hit the hardest by sickle cell disease, like sub-Saharan Africa, where 50-80% of children born with the disease die before their 5th birthday and upwards of 90% die before their 18th birthday.
Unfortunately, rather than making Oxbryta available to more individuals, Pfizer has taken it away from everyone. The reasons for this drastic decision have not been fully explained but appear to be related to risk in malaria endemic areas.
As a member of the sickle cell community, I am speaking for many when I say that we need this medication. We have only the small hope that on careful review with the FDA, Pfizer will do the right thing and reverse their voluntary withdrawal of Oxbryta.