Early testing for actionable genomic alterations is now recommended for metastatic pancreatic cancer patients who progress on therapy or experience intolerable toxicity and who are potential candidates for additional treatment after first-line therapy, according to an American Society of Clinical Oncology guideline update.
Both germline and somatic testing, including for microsatellite instability/mismatch repair deficiency, BRCA mutations with known significance, and NTRK gene fusions, are recommended in this population, reported Davendra P.S. Sohal, MD, MPH, of the University of Cincinnati, and colleagues on ASCO’s expert panel. The update was published online Aug. 5 in the Journal of Clinical Oncology.
The ASCO guideline on clinical decision making for patients with metastatic pancreatic cancer was first published in 2016 to address initial assessment and first- and second-line treatment options, supportive care, and follow-up and was updated in 2018.
The phase 3 POLO trial, for example, showed significantly improved progression-free survival with the poly (ADP-ribose) polymerase (PARP) inhibitor olaparib for maintenance therapy after first-line treatment in patients with a germline BRCA1 or BRCA2 mutation and metastatic pancreatic cancer that had not progressed during first-line platinum-based chemotherapy. An integrated analysis of three studies showed that entrectinib, a potent inhibitor of tropomyosin receptor kinase (TRK) A, B, and C, safely induced durable and clinically meaningful responses in patients with NTRK fusion-positive solid tumors, and a phase 1-2 study showed that the highly selective TRK inhibitor larotrectinib had marked and durable antitumor activity in both children and adults with TRK fusion-positive solid tumors.
With respect to the new recommendation endorsing early testing for actionable genomic alterations (Recommendation 1.5), the authors noted that the results of testing can lead to treatment with PARP inhibitors, programmed death-1 (PD-1) checkpoint inhibitor therapy, TRK fusion inhibitors, and clinical trials of targeted therapies.
“Genomic testing is recommended as part of an initial assessment to ensure that the results of testing are available at the time of treatment decision where applicable after first-line therapy,” the new recommendation states.
A “qualifying statement” further notes that the decision to test should “involve a discussion between the patient and physician regarding the frequency of actionable findings, treatment implications of testing results, and genetic counseling related to germline testing.”
Recommendation 1.5 is rated by the panel as “strong” and is based on informal consensus.
The panel also added two recommendations on treatment options after first-line therapy:
- Recommendation 3.1 calls for treatment with larotrectinib or entrectinib in patient with tumors harboring NTRK fusions.
- Recommendation 3.3 states that patients with a germline BRCA1 or BCA2 mutation who have received first-line platinum-based chemotherapy without disease progression for at least 16 weeks can receive chemotherapy or PARP inhibition with olaparib.
The relevant evidence for these two recommendations is of low quality, but shows that the benefits outweigh the harms; the strength of both recommendations is “moderate.”
A qualifying statement for the latter notes that “the decision to continue treatment with chemotherapy or proceed to maintenance therapy with olaparib should be based on a discussion between the patient and the oncologist, including consideration of whether a maximum response and plateau in response to chemotherapy have been achieved, the level of cumulative toxicities associated with chemotherapy treatment, patient preference, convenience, toxicity, goals of care, cost, and clinical evidence, including a lack of overall survival benefit demonstrated in the POLO randomized controlled trial.”
This focused update includes minor modifications to three existing recommendations:
- In addition to capecitabine or erlotinib, nab-paclitaxel is now included in Recommendation 2.3 as another possible add-on to gemcitabine alone for patients with either an Eastern Cooperative Oncology Group (ECOG) performance score of 2 or a comorbidity profile that precludes more aggressive regimens. The recommendation was also updated to encourage proactive dose and schedule adjustments to minimize toxicities.
- Recommendation 3.5 now includes patients treated previously with a gemcitabine-based regimen in the criteria for the preferred second-line treatment combination of fluorouracil plus nanoliposomal irinotecan or fluorouracil plus irinotecan “where the former is unavailable.”
- Recommendation 3.7 now includes nab-paclitaxel as an add-on option to gemcitabine, and nanoliposomal irinotecan as an add-on option to fluorouracil for second-line therapy – with proactive dose and schedule adjustments to minimize toxicities – in patients with ECOG performance score of 2 or a comorbidity profile that precludes more aggressive regimens.
These three minor modifications reflect new evidence in the first-line treatment setting, including from the FRAGRANCE trial, and are based on expert panel consensus. All other recommendations in the 2018 update are endorsed for the current update, which is available at the ASCO website.
Dr. Sohal reported honoraria from Foundation Medicine, and consulting or advisory roles with Perthera, Ability Pharma, and PierianDx. He reported research funding to his institution from Novartis, Celgene, OncoMed, Bayer, Genentech, Bristol Myers Squibb, Agios, Incyte, Loxo, and Rafael Pharmaceuticals.
SOURCE: Sohal D et al. J Clin Oncol. 2020 Aug 5. doi: 10.1200/JCO.20.01364.