Data regarding protection against mortality and severe complications after Omicron BA.2 infection with CoronaVac and BNT162b2 vaccines remains limited. We conducted a case–control study to evaluate the risk of severe complications and mortality following 1–3 doses of CoronaVac and BNT162b2 using electronic health records database. Cases were adults with their first COVID-19-related mortality or severe complications between 1 January and 31 March 2022, matched with up-to 10 controls by age, sex, index date, and Charlson Comorbidity Index. Vaccine effectiveness against COVID-19-related mortality and severe complications by type and number of doses was estimated using conditional logistic regression adjusted for comorbidities and medications. Vaccine effectiveness (95% CI) against COVID-19-related mortality after two doses of BNT162b2 and CoronaVac were 90.7% (88.6–92.3) and 74.8% (72.5–76.9) in those aged ≥65, 87.6% (81.4–91.8) and 80.7% (72.8–86.3) in those aged 50–64, 86.6% (71.0–93.8) and 82.7% (56.5–93.1) in those aged 18–50. Vaccine effectiveness against severe complications after two doses of BNT162b2 and CoronaVac were 82.1% (74.6–87.3) and 58.9% (50.3–66.1) in those aged ≥65, 83.0% (69.6–90.5) and 67.1% (47.1–79.6) in those aged 50–64, 78.3% (60.8–88.0) and 77.8% (49.6–90.2) in those aged 18–50. Further risk reduction with the third dose was observed especially in those aged ≥65 years, with vaccine effectiveness of 98.0% (96.5–98.9) for BNT162b2 and 95.5% (93.7–96.8) for CoronaVac against mortality, 90.8% (83.4–94.9) and 88.0% (80.8–92.5) against severe complications. Both CoronaVac and BNT162b2 vaccination were effective against COVID-19-related mortality and severe complications amidst the Omicron BA.2 pandemic, and risks decreased further with the third dose.

Objectives: Myeloma relapse remains challenging. Daratumumab (dara) with immunomodulatory agents (IMiD) and dexamethasone (dex) was proven highly effective in relapsed or refractory multiple myeloma (RRMM) in randomized controlled trials. The recommended schedule of dara is weekly for eight doses, followed by 2-weekly for eight doses, and then every 4-weekly thereafter. However, the cost of daratumumab is daunting, precluding widespread and prolonged use in some countries. In this study, we aimed to evaluate the efficacy of using a 3-weekly daratumumab regimen in RRMM. Methods: Thirteen RRMM patients were treated with dara-IMiD-dex till maximal response, followed by single-agent IMiD maintenance until disease progression. Dara (every 6 weekly) would be added upon significant biochemical disease progression. Results: After a median of four daratumumab infusions (range: 3-10), the best responses included complete response (CR) in seven patients (53.8%), very good partial response (VGPR) in four patients (30.8%), and partial response (PR) in two patients (15.4%). The median time to VGPR was four weeks. At 10 months, the overall survival was 90%, and progression-free survival was 54.7%. Two of three patients tested achieved MRD-ve CR. Another patient, who had PET-CT reassessment, showed PET-ve CR. Discussion: Despite less frequent daratumumab use, we reported rapid responses with a median time to VGPR of only four weeks, and a response rate of 100% including CR rate of 54%. Despite less frequent daratumumab use, grade ¾ neutropenia remained common with a frequency comparable to that observed in Pollux. Conclusion: This 3-weekly dara-IMiD-dex regimen preserves a high efficacy with rapid, deep responses including MRD-ve and PET-ve CR, hence a cost-effective regimen.

e19521 Background: Daratumumab (dara) with immunomodulatory agents (IMiD) and dexamethasone (dex) is highly effective in relapsed multiple myeloma (MM). The recommended schedule of dara is weekly for 8 doses, followed by 2-weekly for 8 doses, and then every 4-weekly thereafter. Given the high cost and the long half-life as an antibody, a 3-weekly dosing of dara was used together with IMiD/dexamethasone. Methods: Dara at 16mg/kg was used every 3-weekly with lenalidomide or pomalidomide. Patient achieving best response received single agent IMiD maintenance until disease progression. Results: Fourteen relapsed MM patients were enrolled. One had received weekly dara from a private oncologist, hence was excluded from analysis. Thirteen patients at a median age of 63 years (range: 50-84 years) were studied. The median number of previous therapies was 2 (range: 1-5), with nine patients (69.2%) having undergone autologous stem cell transplantation. Three patients (23.1%) were refractory to bortezomib, seven patients (53.8%) to lenalidomide, and eight patients (61.5%) to last treatment. At relapse, two (15.4%) had high LDH, eight (61.5%) impaired renal function, and three (23.1%) extramedullary disease. Treatment was dara-lenalidomide-dex in six (46.2%), and dara-pomalidomide-dex in seven (53.8%). Responses after four cycles included CR in 5 patients (38.5%), VGPR in five patients (38.5%), and PR in three patients (23.1%). After a median of four dara infusions (range: 3-10), the best responses included CR in seven patients (53.8%), nCR in two patients (15.4%), VGPR in two patients (15.4%), and PR in two patients (15.4%). Median time to VGPR was one month. At 10 months, the OS was 90%, and PFS 54.7%. Three patients progressed, one of whom died of ruptured hepatic plasmacytoma. The most frequent toxicity was haematological especially neutropenia (all grades: 92.3%, Grade ¾: 76.9%), infusion reaction (38.5%, all grade ½), neuropathy (38.5%, all grade ½), gastrointestinal (all grades: 38.5%, grade ¾: 7.7%), and sepsis (all grades: 30.8%; grade ¾: 23.1%). Neutropenia was effectively prevented with prophylactic G-CSF. Conclusions: In conclusion , a 3-weekly dara-IMiD-dex regimen is highly efficacious, inducing deep and rapid responses, hence cost-effective for less affluent countries. In view of prevalent grade 3/4 neutropenia despite less frequent dara, 3-weekly dara might be more suitable for Asian patients.

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Background Acute kidney injury (AKI) may complicate up to 10% of primary lower-extremity total joint arthroplasties. However, none of these previous studies evaluated the duration and reversibility of AKI. Moreover, none specifically evaluated the impact of perioperative celecoxib on the incidence and severity of AKI, especially for patients with preexisting renal impairment. The aim of this study was to retrospectively review the incidence, severity and duration of AKI with short term perioperative celecoxib. We also aimed to evaluate the impact of perioperative celecoxib on the incidence and severity of AKI in patients with and without preexisting renal impairment. Methods We retrospectively reviewed 1077 patients at Queen Mary Hospital, Hong Kong, from January 2018 to December 2021. Data were retrieved from the computerized medical records system. Results One hundred of 1077 patients (9.3%) had postoperative AKI. Eight hundred eighty-eight patients (82.5%) were prescribed perioperative celecoxib, while 189 patients (17.5%) were not. The overall incidence of AKI in those taking perioperative celecoxib was 9.2%, while it was 9.5% in those not taking perioperative celecoxib. There was no statistically significant difference. There was no association between perioperative celecoxib and postoperative AKI. Among those who received perioperative celecoxib, the overall incidence of postoperative AKI in those with and without preexisting renal impairment was 9.3% and 9.2%, respectively. This was not statistically significant. The duration of AKI was 4 days for both groups. In both groups, most AKI cases were stage 1. Conclusions Short term perioperative celecoxib probably had no additional AKI risk even in patients with preexisting renal impairment. Trial Registration ClinicalTrials.gov registration number NCT05595694. Trial Registration ClinicalTrials.gov registration number NCT05595694