Prospective cohort study of Kaposi sarcoma treated under real-world conditions in Malawi.

Abstract

11569 Background: Kaposi sarcoma (KS) is the leading cancer in Malawi (34% of cancers). Outside of clinical trials, prospective KS studies from sub-Saharan Africa (SSA) are few and limited by loss to follow up. We conducted a prospective KS cohort study of standard of care bleomycin/vincristine (BV) at Lighthouse HIV clinic, in Lilongwe, Malawi. Methods: We enrolled pathologically confirmed, newly diagnosed, HIV+ KS patients from Feb 2017 to Jun 2019. We collected clinical and treatment characteristics, toxicity, and outcomes of KS with follow-up censored Jun 2020. Patients were treated with bleomycin (25 mg/m2) and vincristine (0.4 mg/m2) every 14 days for a planned maximum of 16 cycles. STATA v13.0 was used to calculate descriptive statistics and Kaplan Meier survival analysis. Toxicity was graded using NCI CTCAE v5.0. Results: We enrolled 138 participants, median age 36 (IQR 32-44) and 110 (80%) male. By ACTG staging, 107 (78%) were T1 (tumour severity), 46 (33%) were S1 (illness severity) and 46 (33%) had Karnofsky performance status ≤70. Presenting symptoms included edema in 69 (53%), visceral disease in 9 (7%), and oral involvement in 43 (33%). Prior to KS diagnosis, 70 (51%) participants were aware of being HIV+ for median 17 months (IQR 6-60) and had been on ART for median 16 months (IQR 6-60). Median CD4 count was 197 (IQR 99-339), median HIV-viral load was 2.6 log copies/mL (IQR 1.6 – 4.8) and 57% were HIV-suppressed ( < 1000 HIV copies/ml). The median number of cycles was 16 (IQR 7-16). 62 (45%) participants missed at least one dose due to stock out. Amongst patients with missed doses, the median number was 3 (IQR 2-4) for bleomycin and 2 (IQR 1-3) for vincristine. 14 (10%) participants experienced at least one reduced dose due to toxicity. 5 (4%) participants suffered grade ≥3 anaemia, 13 (9%) grade ≥3 neutropenia, and one participant had grade 4 bleomycin-induced dermatitis. There was no reported grade ≥3 bleomycin lung toxicity or vincristine-induced neuropathy. Of 115 evaluable participants, responses at the end of therapy were: complete response in 52 (45%), partial response in 27 (23%) stable disease in 5 (4%), and progressive disease in 31 (28%). Median duration of follow-up was 20 months. At censoring, 69 (50%) were alive, 36 (26%) dead, and 33 (24%) lost to follow-up. Overall survival is shown Table as crude and worst-case scenario; worst-case assumes all participants lost to follow up died. Conclusions: Here, we present one of the most complete characterizations of KS presentation and treatment from SSA. As in other studies from the region, the majority of patients presented with advanced disease, chemotherapy stock-outs and loss to follow up were common, and mortality was high. Studies are planned to understand the virologic characteristics, improve therapies, and better implement existing therapies.[Table: see text]