In 2021, hepatitis B virus (HBV) is still a virus that cannot be completely cured all over the world. At present, there are no drugs that can completely cure HBV, but there are drugs that can inhibit HBV replication, which can help slow down the progress of chronic hepatitis B. It can be said that inhibition of HBV remains the priority among priorities for chronic hepatitis B treatment.
Both TDF and ETV have side effects
Tenofovir fumarate diester (TDF) and entecavir (ETV) have been the main drugs for treatment in the past decade; However, they all have their own side effects: TDF can damage renal function and cause osteotoxicity; ETV has potential viral resistance, especially in patients resistant to lamivudine. In 2019, a new HBV virus inhibitor was approved – propofol tenofovir (TAF).
TAF has little side effects
TAF is a new prodrug of tenofovir. It has a strong inhibitory effect on HBV replication at low dose. The intracellular concentration is high, and the systemic drug concentration is more than 90% lower than TDF. In two randomized, double-blind, multinational, phase 3 trials, the non inferiority test of hepatitis B e antigen (HBeAg) positive and negative patients, the ALT normalization rate of TAF once a day was higher than that of TDF at 48 weeks, and there were no adverse renal and bone events during the long follow-up period of 96 weeks.
A small prospective clinical trial was conducted in 75 patients with chronic hepatitis B who underwent TDF treatment and HBV DNA<21 IU/mL in the past. TDF was converted to TAF. After 24 weeks of follow-up, bone and renal tubule markers were improved.
Recently, an article published in Hepatology, the top journal of Hepatology, published a long-term follow-up data on TDF for TAF. Let’s see how the curative effect and adverse reactions are after dressing change!
834 patients with chronic hepatitis B treated with TDF for more than 12 months were studied and analyzed. These patients were treated with TAF to observe the changes of virus (HBV DNA < 20 IU / ml) and biochemical (ALT < 35 / 25 U / L, male / female) response. Glomerular filtration rate (an important index of renal function) was evaluated until 96 weeks after dressing change.
The results showed that the virus inhibition rate and liver function normalization rate increased significantly after conversion, and the complete response rate (ptrend = 0.004) showed an upward trend. The trend of eGFR or average eGFR (adjusted by age, gender, baseline eGFR and diabetes) remained stable. It can be seen from the data that after switching from TDF to TAF, the virological response continued to improve, ALT normalized, and EGFR did not change significantly. In other words, when TDF is replaced by TAF, the virus volume continues to decrease or remain negative, the liver function is easier to return to normal, but the function of kidney has not been improved.
Therefore, it is suggested that if the renal function is abnormal after TDF for a period of time, it is better to change the dressing to entecavir rather than TAF, because the renal function is not improved after TAF. Of course, whether to change or stop the medicine and how to change it should follow the doctor’s advice!